DYNAGEN INC
10-Q, 1997-11-14
IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES
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                                    FORM 10-Q

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549



[X]      QUARTERLY  REPORT  PURSUANT  TO SECTION  13 OR 15(d) OF THE  SECURITIES
         EXCHANGE ACT OF 1934 FOR THE  QUARTERLY  PERIOD  ENDED:  SEPTEMBER  30,
         1997; or

[ ]      TRANSITION  REPORT  PURSUANT  TO SECTION 13 OR 15(d) OF THE  SECURITIES
         EXCHANGE ACT OF 1934

         For the transition period from ________________ to ____________________


Commission File Number 1-11352



                                    DynaGen, Inc.
- --------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)

             Delaware                                04-3029787
  --------------------------------          -------------------------------

  (State or other jurisdiction of          (IRS Employer Identification No.)
   incorporation or organization)

                               840 Memorial Drive
                               Cambridge, MA 02139
           -----------------------------------------------------------
          (Address of principal executive offices, including zip code)

                                 (617) 491-2527
              ---------------------------------------------------
             (Registrant's telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days.

Yes    X          No
    -------          -----


As of November  12, 1997,  there were  outstanding  33,685,664  shares of common
stock, $.01 par value per share.








                                  DYNAGEN, INC.

                                    FORM 10-Q

                                QUARTERLY REPORT

                                   ----------

                                TABLE OF CONTENTS



Facing Page                                                                  1

Table of Contents                                                            2

PART I.  FINANCIAL INFORMATION (*)

         Item 1.  Financial Statements:
                   Condensed Consolidated Balance Sheets                     3
                   Condensed Consolidated Statements of Loss                 5
                   Condensed Consolidated Statements of Changes
                    in Stockholders' Equity                                  7
                   Condensed Consolidated Statements of Cash Flows           9
                   Notes to Unaudited Consolidated Financial Statements     11

         Item 2.  Management's Discussion and Analysis                      16
                  of Financial Condition and Results of Operations

PART II.  OTHER INFORMATION

         Item 2.  Changes in Securities                                     18
         Item 5.  Other Information                                         20
         Item 6.  Exhibits and Reports on Form 8-K                          20

SIGNATURES                                                                  22






(*)      The  financial  information  at December 31, 1996 has been derived from
         the  audited  financial  statements  at that date and should be read in
         conjunction therewith. All other financial statements are unaudited.


                                       2









                          PART I. FINANCIAL INFORMATION

Item 1.  Financial Statements

                                  DYNAGEN, INC.

                      CONDENSED CONSOLIDATED BALANCE SHEETS
                                   (Unaudited)

<TABLE>
<CAPTION>
                                     ASSETS

                                                                              September 30,    December 31,
                                                                                  1997            1996
                                                                                  ----            ----
<S>                                                                           <C>             <C>
Current assets:
         Cash and cash equivalents
          (including interest-bearing
          deposits of $1,835,000 at December 31, 1996)                         $    32,145      $ 2,112,300
         Investment securities available for sale at fair value                       --          3,004,700
         Accounts receivable, net of allowance for
          doubtful accounts of $71,429 at September 30, 1997                     3,207,355          261,932
         Rebates                                                                   627,180             --
         Inventory (Note 3)                                                      8,201,045          451,883
         Notes receivable                                                          185,000          185,000
         Prepaid expenses and other current assets                                 215,290          295,613
                                                                               -----------      -----------

            Total current assets                                                12,468,015        6,311,428
                                                                               -----------      -----------

Property and equipment, net of accumulated depreciation
and amortization of $488,640 and $337,813                                        1,676,506          673,969
                                                                               -----------      -----------

Other assets:
         Goodwill, net of accumulated amortization of $277,949                  14,016,585             --
         Patents and trademarks, net of accumulated amortization
         of $83,907 and $65,639                                                    247,572          265,840
         Deferred debt financing costs, net of accumulated
         amortization of $81,046 and $119,039                                      411,439          119,039
         Deposits                                                                  292,873           92,873
                                                                               -----------      -----------

            Total other assets                                                  14,968,469          477,752
                                                                               -----------      -----------

                                                                               $29,112,990      $ 7,463,149
                                                                               ===========      ===========


</TABLE>


     See accompanying notes to unaudited consolidated financial statements.



                                       3





                                  DYNAGEN, INC.

                CONDENSED CONSOLIDATED BALANCE SHEETS (Continued)
                                   (Unaudited)

                      LIABILITIES AND STOCKHOLDERS' EQUITY

<TABLE>
<CAPTION>
 

                                                                               September 30,    December 31,
                                                                                    1997            1996
                                                                                    ----            ----
<S>                                                                              <C>              <C>       

Current liabilities: 
  Bank overdraft                                                                 $   844,509      $        -
  Current maturities of long term debt                                             2,701,669               -
  Loan payable - bank                                                              5,270,890               -
  Accounts payable                                                                 3,929,707             712,239
  Accrued payroll and payroll taxes                                                  349,389              96,894
                                                                                 -----------      --------------

                  Total current liabilities                                       13,096,164             809,133

Warrant put liability                                                                725,821               -
Long term debt                                                                     5,245,627           1,600,000
                                                                                 -----------      --------------

                  Total liabilities                                               19,067,612          2,409,133
                                                                                ------------      --------------

Stockholders' equity:
  Preferred  stock,  $.01 par  value,  10,000,000  shares  authorized:
   Series A  convertible, 50,000 shares authorized, 45,150 shares
      issued and outstanding, (liquidation value - $4,515,000)                           452                  -
    Series B convertible, 7,500 shares authorized, issued
      and outstanding, (liquidation value - $747,750)                                     75                  -
     Series C convertible, 7,500 shares authorized, issued
      and outstanding, (liquidation value - $750,000)                                     75                  -
   Series D convertible, 60,000 shares authorized, none issued and
     outstanding                                                                          -                   -
   Common stock, $.01 par value, 75,000,000 shares authorized,
      33,510,114 and 29,106,231 shares issued and outstanding                        335,101             291,062
  Additional paid-in capital                                                      41,637,570          29,076,838
  Accumulated deficit                                                            (31,927,895)        (24,315,191)
                                                                                  ----------       -------------
                                                                                  10,045,378           5,052,709
  Unrealized gain on investment securities                                                -                1,307
                                                                                  ----------       -------------

                  Total stockholders' equity                                      10,045,378           5,054,016
                                                                                 -----------       -------------

                                                                                $ 29,112,990        $  7,463,149
                                                                                ============        ============

</TABLE>





     See accompanying notes to unaudited consolidated financial statements.


                                       4





                                  DYNAGEN, INC.

                    CONDENSED CONSOLIDATED STATEMENTS OF LOSS
                                   (Unaudited)


<TABLE>
<CAPTION>

                                                                             Three Months Ended
                                                                             ------------------
                                                                         September 30,    September 30,
                                                                             1997              1996
                                                                          -----------      -----------
<S>                                                                      <C>              <C>         

Revenues:
         Product sales                                                   $  5,571,779     $     58,693
         Fees and royalties                                                    38,086             --
                                                                         ------------     ------------

          Total revenues                                                    5,609,865           58,693
                                                                         ------------     ------------

Costs and expenses:
         Cost of sales                                                      4,644,546           25,313
         Research and development                                             723,143          760,062
         Selling, general and administrative                                2,546,360        1,072,573
                                                                         ------------     ------------

          Total costs and expenses                                          7,914,049        1,857,948
                                                                         ------------     ------------

          Operating loss                                                   (2,304,184)      (1,799,255)
                                                                         ------------     ------------

Other income (expense):
         Investment income, net                                                 3,136           95,547
         Interest expense                                                    (488,359)         (40,000)
         Amortization of debt financing costs                                 (28,995)         (34,338)
                                                                         ------------     ------------

          Other income (expense), net                                        (514,218)          21,209
                                                                         ------------     ------------

          Net loss                                                       $ (2,818,402)    $ (1,778,046)
                                                                         ============     ============

Net loss per share                                                       $       (.09)    $       (.06)
                                                                         ============     ============

Weighted average shares outstanding (Note 2)                               32,463,119       28,616,450
                                                                         ============     ============

</TABLE>




     See accompanying notes to unaudited consolidated financial statements.


                                       5






                                  DYNAGEN, INC.

                    CONDENSED CONSOLIDATED STATEMENTS OF LOSS
                                   (Unaudited)



<TABLE>
<CAPTION>

                                                                        Nine Months Ended
                                                                        -----------------
                                                                 September 30,      September 30,
                                                                      1997              1996
                                                                -----------------    -----------
<S>                                                              <C>                <C>         

Revenues:
         Product sales                                           $  7,355,636       $    221,583
         Fees and royalties                                            88,744             60,000
                                                                 ------------       ------------

          Total revenues                                            7,444,380            281,583
                                                                 ------------       ------------

Costs and expenses:
         Cost of sales                                              7,352,213             93,155
         Research and development                                   2,369,821          2,841,586
         Selling, general and administrative                        4,795,008          2,568,665
                                                                 ------------       ------------

          Total costs and expenses                                 14,517,042          5,503,406
                                                                 ------------       ------------

          Operating loss                                           (7,072,662)        (5,221,823)
                                                                 ------------       ------------

Other income (expense):
         Investment income, net                                       112,170            351,741
         Interest expense                                            (604,846)          (103,999)
         Amortization of debt financing costs                         (47,366)           (91,568)
                                                                 ------------       ------------

          Other income (expense), net                                (540,042)           156,174
                                                                 ------------       ------------

          Net loss                                               $ (7,612,704)      $ (5,065,649)
                                                                 ============       ============

Net loss per share                                               $       (.25)      $       (.19)
                                                                 ============       ============

Weighted average shares outstanding (Note 2)                       30,959,820         27,364,110
                                                                 ============       ============
</TABLE>





     See accompanying notes to unaudited consolidated financial statements.


                                       6








                                  DYNAGEN, INC.

      CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY
                      Nine Months Ended September 30, 1997
                                   (Unaudited)


<TABLE>
<CAPTION>


                                                                                                     
                                                           Convertible Preferred Stock               
                                                   ---------------------------------------------
                               Common Stock          Series A          Series B         Series C     
                               ------------         --------          --------          --------     
                                                                                                     
                            Shares     Amount     Shares   Amount   Shares   Amount  Shares   Amount 
                            ------     ------     ------   ------   ------   ------  ------   ------ 

Balance at
<S>                       <C>          <C>         <C>    <C>       <C>      <C>      <C>    <C>
 December 31, 1996         29,106,231  $291,062      -     $  -         -     $   -      -     $ -   
Decrease in unrealized
 gain on investment
 securities                    -            -        -        -         -         -      -       -   
Shares issued in private
 placements                 1,475,000    14,750   45,950     460       7,500      75   7,500    75   
Stock issued for Superior
 acquisition                1,666,667    16,667      -        -         -         -      -       -   
Exercise of stock options       1,500        15      -        -         -         -      -       -   
Issuance of common stock
 purchase warrants                -         -        -        -         -         -      -       -   
Stock options and warrants
issued for services               -         -        -        -         -         -      -       -   
Stock issued for
 interest obligation          38,633        386      -        -         -         -      -       -   
Conversion of note  
 payable                     989,594      9,896      -        -         -         -      -       -   
Conversion of
 Preferred stock
 and stock dividend          232,489      2,325     (800)     (8)       -         -      -        -  
Net loss                          -          -       -        -         -         -      -        -  
                          ----------   --------   ------    ----      -----      ---    ----      ---
Balance at
 September 30, 1997       33,510,114   $335,101   45,150    $452      7,500      $75    7,500     $75
                          ==========   ========   ======    ====      =====      ===    ====      ===

</TABLE>


                                                                  
<TABLE>
<CAPTION>
                                                                  
                                                                  
                                                         Unrealized                
                             Additional                   Gain on                   
                             Paid-in      Accumulated   Investment                 
                             Capital      Deficit       Securities   Total        
                             ----------- -------------  ----------   -----        
                                                                  
                                                                  
<S>                         <C>            <C>           <C>      <C>                       
 Balance at                 $29,076,838    $(24,315,191) $ 1,307  $5,054,016                
  December 31, 1996                                                                         
 Decrease in unrealized                                                                     
  gain on investment              -               -       (1,307)     (1,307)               
  securities                                                                                
 Shares issued in private     5,825,390           -          -      5,840,750               
  placements                                                                                
 Stock issued for Superior    4,983,333           -          -      5,000,000               
  acquisition                     1,110           -          -          1,125               
 Exercise of stock options                                                                  
 Issuance of common stock           450           -          -            450               
  purchase warrants                                                                         
 Stock options and warrants     728,145           -          -        728,145               
 issued for services                                                                        
 Stock issued for                48,752           -          -         49,138               
  interest obligation                                                                       
 Conversion of note             975,869           -          -        985,765               
  payable                                                                                   
 Conversion of                                                                              
  Preferred stock                (2,317)          -          -           -                  
  and stock dividend              -               -          -           - 
Net loss                          -         (7,612,704)      -     (7,612,704)                                   
                           ----------          --------    ------ ----------- 
Balance at                 $41,637,570     $(31,927,895)  $  -    $10,045,378               
  September 30, 1997       ===========     ============    ====== ===========               
                                                                        
 
</TABLE>










     See accompanying notes to unaudited consolidated financial statements.

                                       7






                                  DYNAGEN, INC.

      CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY
                      Nine Months Ended September 30, 1996
                                   (Unaudited)




<TABLE>
<CAPTION>
                                                          Convertible                                                  
                                                        Preferred Stock                                
                                                       ----------------                                      Unrealized        
                                   Common Stock            Series A           Additional                     Gain on
                                -------------------    ------------------     Paid-in      Accumulated       Investment
                                Shares      Amount     Shares     Amount      Capital      Deficit           Securities   Total
                                ------      ------     ------     ------      ----------- --------------     ----------   -----

<S>                           <C>          <C>        <C>        <C>         <C>           <C>              <C>        <C>       
Balance at December 31, 1995  25,196,963   $251,970      -        $   -       $23,094,903   $(16,721,448)    $   1,142  $6,626,567
Increase in unrealized
 gain on investment
 securities                      -            -          -            -            -              -              1,287       1,287
Shares issued in private
 placements                    1,520,686     15,207   1,178,264     3,461,150   1,376,204         -               -      4,852,561
Conversion of preferred
 stock                         1,612,834     16,128  (1,178,264)   (3,461,150)  3,445,022         -               -           -
Costs related to exercise of
 public warrants                 -            -          -            -            (3,756)        -               -         (3,756)
Exercise of stock options        176,672      1,767      -            -            19,558         -               -         21,325
Employee stock and stock
 option grants                   117,250      1,172      -            -           557,685         -               -        558,857
Stock options issued for
 services                        -            -          -            -            78,875         -               -         78,875
Stock issued for 
 interest obligation              37,057        370      -            -            76,963         -               -         77,333
Net loss                         -            -          -            -            -          (5,065,649)         -     (5,065,649)
                              ----------   --------     -------      ---       ------------   ------------     ------    ----------
Balance at September 30,
 1996                         28,661,412   $286,614      -         $  -      $ 28,645,454   $(21,787,097)       $2,429  $7,147,400
                              ==========   ========     =======      ===       ============   ============        ======  ==========


</TABLE>


     See accompanying notes to unaudited consolidated financial statements.


                                       8






                                  DYNAGEN, INC.
                 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                                   (Unaudited)


<TABLE>
<CAPTION>

                                                                                  Nine Months Ended
                                                                                  -----------------
                                                                          September 30,         September 30,
                                                                              1997                   1996
                                                                       --------------------      -------------
<S>                                                                        <C>                     <C>          

Cash flows from operating activities:
  Net loss                                                                 $ (7,612,704)           $ (5,065,649)
  Adjustments to reconcile net loss to net cash used for
  operating activities:
         Stock option and warrants issued for services                          728,145                  23,650
         Employee stock and stock option grants                                    --                   558,857
         Depreciation and amortization                                          494,411                 147,263
         Amortization and accretion of (discounts) premiums
         on investment securities                                               (10,152)               (134,196)
         Amortization and accretion of loan discount and
           Warrant put liability                                                 54,784                    --
         Stock issued for interest obligation                                    49,138                  77,333
           Write-off of patent costs                                               --                    41,852
  (Increase) decrease in operating assets:
         Accounts receivable                                                   (390,132)                 24,974
         Prepaid expenses and other current assets                              112,982                (502,496)
         Inventory                                                             (358,105)                (66,818)
         Rebates                                                               (128,876)                   --
  Increase (decrease) in operating liabilities:
          Accounts payable and accrued expenses                               2,315,208                 399,100
          Deferred revenue                                                         --                   (68,228)
                                                                           ------------            ------------

                  Net cash used for operating activities                     (4,745,301)             (4,564,358)
                                                                           ------------            ------------

Cash flows from investing activities:
  Acquisition of Superior                                                    (6,878,463)                   --
  Acquisition of Able                                                              --                  (700,000)
  Purchase of investment securities                                          (1,186,455)            (26,543,490)
  Proceeds from sales and maturities of investment securities                 4,200,000              24,175,257
  Purchase of property and equipment                                           (783,268)                (37,420)
  Patent and trademark costs                                                       --                   (39,744)
  Increase in deposits                                                         (200,000)                (65,895)
  Increase in notes receivable                                                     --                   (75,000)
                                                                           ------------            ------------
                  Net cash used for investing activities                     (4,848,186)             (3,286,292)
                                                                           ------------            ------------
Cash flows from financing activities:
         Net proceeds from exercise of
          stock warrants and options                                              1,125                  17,569
         Net proceeds from issuance of common
          stock and warrants                                                    854,250               4,852,561
         Net proceeds from preferred stock                                    5,790,052               1,725,295
         Net proceeds from private debt placement                             2,696,898                    --
         Increase in deferred financing costs                                  (419,002)                   --
         Net repayments, notes payable-bank                                  (1,837,833)                   --
         Repayments of long-term debt                                          (416,667)                   --
         Bank overdraft                                                         844,509                    --
                                                                           ------------            ------------
                  Net cash provided by financing activities                   7,513,332               6,595,425
                                                                           ------------            ------------
</TABLE>


     See accompanying notes to unaudited consolidated financial statements.



                                       9






                                  DYNAGEN, INC.

           CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Continued)
                                   (Unaudited)

<TABLE>
<CAPTION>

                                                                                             Nine Months Ended
                                                                                             -----------------
                                                                                         September 30,   September 30,
                                                                                             1997             1996
                                                                                       ---------------   ------------



<S>                                                                                        <C>              <C>        
Net change in cash and cash equivalents                                                    (2,080,155)      (1,255,225)
Cash and cash equivalents at beginning of year                                              2,112,300        1,765,604
                                                                                        -------------    -------------

Cash and cash equivalents, end of period                                               $       32,145    $     510,379
                                                                                       ==============    =============

Supplemental cash flow information:  
         Conversion of preferred stock to common stock                                 $        2,325    $  3,461,150
         Conversion of convertible notes into common stock                             $    1,065,000    $       -
         Interest paid                                                                 $      549,527    $     77,332
Schedule of non cash investing and financing  activities:  On June 18, 1997, the
Company  purchased all of the common stock of Superior  Pharmaceutical  Company,
Inc. for  $16,250,000.  In connection with the  acquisition,  non cash financing
activities, liabilities assumed and goodwill were as follows:
         Fair value of assets acquired                                                   $10,913,834
         Cash paid for common stock                                                       (6,250,000)
         Fair value of common stock issued                                                (5,000,000)
         Note payable issued                                                              (5,000,000)
         Liabilities assumed                                                              (8,263,478)
                                                                                         -----------
         Goodwill (exclusive of other acquisition costs
         of $694,890)                                                                    $13,599,644
                                                                                         ===========




</TABLE>


     See accompanying notes to unaudited consolidated financial statements.




                                       10






                                  DYNAGEN, INC.

              NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS
                               September 30, 1997



1.       BASIS OF PRESENTATION

         The accompanying  unaudited  consolidated  financial  statements of the
Company have been  prepared in accordance  with  generally  accepted  accounting
principles  for  interim  financial  information  and  in  accordance  with  the
instructions  to Form 10-Q and Rule  10-01 of  Regulation  S-X and  include  the
accounts  of  DynaGen,   Inc.  and  its  wholly-owned   subsidiaries,   Superior
Pharmaceutical  Company and Able  Laboratories,  Inc.  Accordingly,  they do not
include all information and footnotes required by generally accepted  accounting
principles   for  complete   financial   statement   presentation.   Significant
intercompany balances and transactions have been eliminated in consolidation.

         As of December 31, 1996, the Company  changed from a fiscal year ending
June 30 to a fiscal year ending December 31.

         The results of  operations  for the interim  periods  reported  are not
necessarily  indicative of expected results for any future interim period or for
a full fiscal year. In the opinion of management, all adjustments have been made
(consisting only of normal recurring adjustments) which are necessary for a fair
presentation of operating results for the interim periods presented.

         The financial  information included in this report has been prepared in
conformity with the accounting  policies  reflected in the financial  statements
included in the Company's Transition Report on Form 10-K as of December 31, 1996
filed with the Securities and Exchange Commission.

2.       NET LOSS PER SHARE

         Net loss per common share has been computed by dividing the net loss by
the weighted  average  number of shares of common stock  outstanding  during the
periods indicated. The effect of all common stock equivalents have been excluded
from the calculation of the weighted average number of common shares outstanding
since their inclusion would be anti-dilutive.

3.       INVENTORY

Inventory at September 30, 1997 consists of the following:

         Raw material               $  412,126
         Work in-process               221,059
         Finished goods              7,567,860
                                    ----------
                                    $8,201,045








                                       11





                                  DYNAGEN, INC.

              NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS
                               September 30, 1997

                                   (Continued)


4.       BUSINESS ACQUISITIONS

         On  August  19,  1996,  the  Company  acquired  certain  assets of Able
Laboratories,  Inc.  ("Able").  The purchase price consisted of $550,000 in cash
and acquisition  costs of $150,000.  The acquisition has been accounted for as a
purchase.  The results of  operations  related to Able have been  included  with
those of the Company since August 19, 1996.

         On June 18, 1997, the Company acquired all of the outstanding  stock of
Superior   Pharmaceutical   Company  ("Superior"),   a  distributor  of  generic
pharmaceutical   products.   The  Company  paid  the  shareholders  of  Superior
$6,250,000  in cash,  $5,000,000  in three  year notes and  1,666,667  shares of
DynaGen's  common  stock  with a  guaranteed  value of  $5,000,000.  DynaGen  is
obligated to issue to the  shareholders up to an additional  1,666,667 shares of
its common  stock after  twelve  months if its common stock is not trading at an
average  of at least  $3.00 per  share  for 10  consecutive  trading  days.  If,
immediately following the issuance of the additional 1,666,667 shares, DynaGen's
common stock is not trading for at least $1.50 per share,  DynaGen  shall pay to
the shareholders the difference between $1.50 and the then current trading price
of its common stock for each of the  3,333,334  shares.  DynaGen is obligated to
register the shares within eleven months after the closing of the acquisition.

         The former shareholders of Superior, who remain as senior management at
Superior,  may also  receive  certain  incentive  payments  based on  Superior's
performance  during  the three  years  following  the close of the  acquisition.
Immediately  following  the  closing  of the  acquisition,  DynaGen  contributed
additional capital of $1,750,000 to Superior.

         The  Superior  acquisition  has  been  accounted  for  as  a  purchase.
Accordingly,  the results of  operations  of Superior  have been included in the
Company's consolidated  financial statements since the date of acquisition.  The
preliminary  purchase price allocation was based on the estimated fair values at
the date of  acquisition  which resulted in an excess of purchase price over net
assets  acquired of  $14,294,534,  which is being  amortized on a  straight-line
basis over 15 years. The preliminary  allocation is subject to change because of
the  incentive  payments that may be made to certain  shareholders  and deferred
income  taxes.  The  Company  capitalized  costs  of  $694,890  related  to  the
acquisition.

         Unaudited  proforma  consolidated  operating  results for the  Company,
assuming the acquisitions of Able and Superior had been made as of the beginning
of the fiscal year for each of the periods presented, are as follows:

                     Nine Months Ended             Three Months Ended
                       September 30,                  September 30,
                   1997             1996           1997            1996
                  ------          --------        --------       ---------    

Revenues       $ 19,557,291     $ 24,825,713   $  5,609,865     $ 8,280,819
Net loss       $ (8,517,250)    $ (5,698,709)  $ (2,818,402)    $(1,682,102)
Net loss
  per share    $       (.25)    $       (.19)  $       (.09)    $      (.05)

The unaudited proforma  information is not necessarily  indicative either of the
actual  results of operations  that would have  occurred had the purchases  been
made as of the  beginning of each of the fiscal  periods  presented or of future
results of operations of the combined companies.



                                       12





                                  DYNAGEN, INC.

              NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS
                               September 30, 1997

                                   (Continued)

5.       NOTES PAYABLE - SUPERIOR ACQUISITION

         In connection  with the  acquisition  of Superior,  the Company  issued
$5,000,000 in notes payable to the former Superior  stockholders.  The notes are
payable in quarterly  installments of principal and interest over three years at
an interest rate of 9.5% and are secured by a pledge of Superior Common Stock.

         As of September  30, 1997,  amounts  payable on the notes over the next
three fiscal years are as follows:

                       Year Ended
                       December 31,                Amount
                       ------------                ------

                           1997                $   833,333
                           1998                  1,666,667
                           1999                  1,666,667
                           2000                    416,666
                                               ------------
                                                $4,583,333
                                               ============

6.       FINANCING OF SUPERIOR ACQUISITION

         The  following  debt and equity  financings  were  arranged to fund the
acquisition of Superior:

         (A) DynaGen obtained senior  subordinated  debt financing of $3,000,000
from two  private  investors  bearing  interest  at  13.5%  payable  in  monthly
installments.  The principal is paid upon maturity at the end of five years. The
loan is secured by a first-lien  security  interest on the assets of DynaGen,  a
second-lien  security  interest  on the  assets of  Superior  and a  second-lien
interest  in the  pledge  of the  Superior  stock.  DynaGen  also  issued to the
investors  warrants to purchase  400,000 shares of Common Stock of DynaGen at an
exercise  price per share of $.01  exercisable  for five  years.  Under  certain
circumstances, the two investors may exchange the warrants to buy DynaGen common
stock for  warrants to purchase  15% of  Superior's  common stock at an exercise
price per share of $.01. In addition, these warrants are subject to put features
under certain circumstances.

         Proceeds of $702,000 from this  financing were allocated to the DynaGen
stock warrants, based on their estimated fair value. This amount is reflected in
the  accompanying  financial  statements as a warrant put liability  because the
warrants  are  subject  to a put which  gives the  holders  the choice of a cash
settlement  under  certain  conditions.  The  put  allows  the  holders  to sell
two-thirds of the warrants to the company  after three years for  $667,000,  and
all of the warrants after five years for $1,500,000,  unless the market value of
the shares issuable  pursuant to the warrant is equal to or greater than the put
value.

         The remaining proceeds from this offering  $2,298,000 were allocated to
the subordinated  debt. The debt discount of $702,000 is being amortized,  using
the interest method, over the term of the debt.

         (B) DynaGen  obtained  debt  financing  in the form of a bridge loan of
$500,000,  from a private  investor at an interest  rate of 7% per annum and due
September 30, 1997, to be used for the maintenance of net worth requirements for
Superior's  credit  facility,  working capital for operations of DynaGen and the
acquisition.  This loan is a non-recourse obligation of DynaGen. Two founders of
DynaGen have pledged 1 million shares of DynaGen's Common Stock in order



                                       13




                                  DYNAGEN, INC.

              NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS
                               September 30, 1997

                                   (Continued)

to secure the  obligations  represented by this bridge loan. In connection  with
this bridge  loan,  the Company has issued  150,000  shares of its  unregistered
Common  Stock to the  investor.  On October  10,  1997,  the bridge loan and all
accrued  interest was converted into 5,015 shares of Series B Preferred Stock in
full satisfaction of the debt. An additional  150,000 shares of common stock was
issued to the investor in connection with the conversion.

         Proceeds of $150,000  from the debt  financing  were  allocated  to the
common stock based on the fair value of the common  stock at June 18, 1997.  The
balance of the proceeds was  allocated to the bridge loan.  The debt discount of
$150,000 on the bridge loan was fully amortized through September 30, 1997.

         (C) The  Company  sold 41,000  shares of Series A  Preferred  Stock and
warrants to purchase 328,000 shares of Common Stock for $4,100,000. The Series A
Preferred Stock has a stated  dividend of $5.00 per share per annum.  DynaGen is
obligated to register the shares of Common Stock issuable upon conversion of the
Series A Preferred  Stock and exercise of the warrants  within 90 days after the
closing of the  Acquisition.  The exercise price of the warrants will be 120% of
the average  closing bid price of  DynaGen's  Common  Stock for the five trading
days  immediately  preceding  the date on which the  registration  statement  is
declared effective.  The holders of Series A Preferred Stock have certain rights
of first refusal on future equity financings.

         The Series A preferred  stock may be  converted  into common stock at a
conversion  price equal to the lesser of 120% of the average  closing bid price,
as defined  (the  Series A Effective  Price) or  discounted  percentages  of the
Series A Effective  Price  decreasing  from 80% to 74% over time.  In  September
1997,  800 shares of Series A Preferred  Stock with  accumulated  dividends  was
converted into 232,489  shares of common stock.  Any  outstanding  shares of the
Series A Preferred  Stock will be  automatically  converted  to common stock two
years from the issue date.

         (D) The  Company  sold  7,500  shares of Series B  Preferred  Stock and
225,000 shares of Common Stock for $750,000 to a private investor.  The Series B
Preferred  Stock  has a stated  dividend  of $7.00 per  share  per  annum.  Upon
liquidation, the Series B Preferred Stock ranks junior to the Series A Preferred
Stock.  DynaGen is  obligated  to register  the 225,000  shares of Common  Stock
issued and the shares of Common Stock  issuable upon  conversion of the Series B
Preferred Stock within 150 days after the closing of the acquisition.

         The Series B preferred  stock may be  converted  into Common Stock at a
conversion  price equal to the lesser of 125% of the average  closing bid price,
as defined (the "Series B Effective  Price") or  discounted  percentages  of the
Series B Effective  Price  decreasing from 80% to 75% over time. Any outstanding
shares of the Series B Preferred Stock will be automatically converted to common
stock two years from the issue date.

7.       NOTES PAYABLE - BANK

         Superior  obtained  a  secured  revolving  line  of  credit  of  up  to
$9,000,000 from a bank to provide  working  capital for its general  operations.
Advances under the line of credit are subject to a borrowing base  consisting of
the sum of (1) 80% of Superior's eligible accounts  receivable,  plus (2) 60% of
Superior's eligible inventory.



                                       14







                                  DYNAGEN, INC.

              NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS
                               September 30, 1997

                                   (Continued)


         The  advances  under  the line are  secured  by a  first-lien  security
interest  in all of the  assets  of  Superior  and are  guaranteed  by  DynaGen.
Superior  may draw on the line of credit  until  April 5, 1998.  Interest on the
line of credit is based on the lower of the prime  lending rate or LIBOR plus 2%
(7.66% at September 30, 1997).

8.       LONG-TERM DEBT

Long-term debt consists of the following:
         Notes payable - Superior acquisition        $4,583,333
         Senior subordinated debt                     2,328,963
         Bridge loan                                    500,000
         Convertible note payable                       535,000
                                                        -------
                                                      7,947,296
Less: current maturities                             (2,701,669)
                                                     ---------- 
Long-term debt                                       $5,245,627
                                                     ==========


9.       RECENT FINANCING ACTIVITIES

         On August 7,  August 15 and  August 22,  1997,  the  Company  issued an
aggregate  of 4,950  shares of its Series A Preferred  Stock,  .01 par value per
share and Common Stock  Purchase  Warrants to purchase  39,600  shares of Common
Stock for a purchase price of $495,000.

         On August 21, 1997,  DynaGen  issued 7,500 shares of Series C Preferred
Stock and a Common  Stock  Purchase  Warrant to purchase  250,000  shares of its
Common Stock to a private investor for a purchase price of $750,000.

         On August 21 and  September  11,  1997,  the Company  issued  1,100,000
shares of its common stock to investment bankers as consideration for investment
banking and placement agent services  rendered to the Company in connection with
its debt and equity financings.

         On August 28, 1997, the Company issued a warrant to purchase  1,000,000
shares of Common Stock at an exercise price of $0.15 per share as  consideration
of investment  banking services rendered to the Company by an investment banker.
The Company recognized  compensation expense of $452,000 in the third quarter of
Fiscal 1997 based on the fair value of the warrant.

         Additional information on financing activities is presented in Part II,
Item 2c, Changes in Securities.


                                       15







                                  DYNAGEN, INC.

            Item 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                       CONDITION AND RESULTS OF OPERATIONS

              ----------------------------------------------------------

         The Private  Securities  Litigation  Reform Act of 1995  contains  safe
harbor provisions regarding  forward-looking  statements.  Except for historical
information contained herein, the matters discussed in the Liquidity and Capital
Resources  section below contain potential risks and  uncertainties,  including,
without limitation,  risks related to the Company's ability to raise capital for
future operations and  commercialization of its products;  successfully develop,
test, produce and market its proposed products; obtain governmental approvals in
a timely manner;  identify and attract marketing  partners to help commercialize
the Company's  products;  attract and retain key  employees;  obtain  meaningful
patent  protection  or  otherwise  over the  Company's  proprietary  technology;
protect  itself  from  product  liability  risks or  limitations  imposed due to
potential  health care reform;  integrate the products and personnel the Company
acquired  in the  acquisition  of Able  Laboratories,  Inc.  ("Able"),  Superior
Pharmaceutical   Company   ("Superior")   and  any  future   acquisitions;   and
successfully respond to technological changes in the marketplace.  Specifically,
regulatory approvals of the Company's products are subject to factors beyond the
Company's control, and there can be no assurance that such approvals will not be
delayed  or  ultimately  denied.  The  Company  will need to  attract  marketing
partners in order to exploit its  products,  and there can be no assurance  that
the  Company  will  be  successful  in  attracting  such  partners.   Additional
information  on potential  factors  which could affect the  Company's  financial
results are included in the Company's  public  filings with the  Securities  and
Exchange Commission,  including without limitation its transition report on Form
10-K for the period ended December 31, 1996.

                              RESULTS OF OPERATIONS

RECENT AND PROPOSED ACQUISITIONS

         On August 19,  1996,  the  Company  acquired  the tablet  manufacturing
business of Able, a generic pharmaceutical product subsidiary of ALPHARMA,  Inc.
On June  18,  1997,  the  Company  acquired  all of the  outstanding  shares  of
Superior, a distributor of generic pharmaceutical  products.  These acquisitions
have been accounted for using the "purchase" method of accounting.  As a result,
the results of operations  for the three and nine month periods ended  September
30, 1997 reflect a full three and nine months of operations,  respectively,  for
Able, and for Superior,  reflect a full three months of operations for the three
months ended  September 30, 1997 and three and one-half months of operations for
the nine months ended  September  30, 1997.  The results of  operations  for the
three and nine months ended  September 30, 1996 do not reflect any operations of
Superior and includes 42 days of operations for Able.

         On September 18, 1997, the Company signed a letter of intent to acquire
assets and liabilities of Generic  Distributors Limited Partnership ("GDI"). GDI
distributes  generic  pharmaceutical  products  primarily in  Louisiana  and the
southern  United  States.  In 1996,  GDI  reported  revenues of $6.0 million and
earnings  before taxes of  $325,000.  The  proposed  acquisition  price of $2.25
million  consists  of $1.2  million  in cash and $1.05  million  in  convertible
preferred  stock.  The preferred stock would not be convertible for at least one
year from the closing of the  transaction.  The  Company  intends to finance the
cash portion of the purchase price through bank debt.

         Finalization  of the GDI  acquisition by the Company will depend on the
Company's  ability  to  obtain  adequate  financing  and  the  negotiation  of a
definitive  acquisition  agreement.  There  can be no  assurance  that  the  GDI
acquisition  will occur and if the  acquisition  does occur that any anticipated
benefits from this acquisition will be realized.

                   THREE-MONTH PERIOD ENDED SEPTEMBER 30, 1997
        AS COMPARED WITH THE THREE-MONTH PERIOD ENDED SEPTEMBER 30, 1996

         Revenues  for the third  quarter of the year ending  December  31, 1997
("Fiscal 1997") were $5,610,000 versus $59,000 for the third quarter of the year
ended  December  31,  1996  ("Fiscal  1996").  This  increase of  $5,551,000  is
primarily  the result of generic  pharmaceutical  product sales by the Company's
wholly-owned subsidiaries, Able and Superior.


                                       16







                                  DYNAGEN, INC.
            Item 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                       CONDITION AND RESULTS OF OPERATIONS

         Cost of product sales was 83% of product sales for the third quarter of
Fiscal  1997 as  compared  to 43% for the same  period as Fiscal  1996.  This is
primarily due to low  production  and sales levels at Able which did not support
the fixed  manufacturing  costs at the Able  facility.  Gross  profit on product
sales  increased from $33,000 in the third quarter of Fiscal 1996 to $927,000 in
the third quarter of Fiscal 1997  primarily due to Superior's  product sales and
gross profit.

         Research and development  expenses for the third quarter of Fiscal 1997
were $723,000  versus $760,000 for the same period as Fiscal 1996, a decrease of
$37,000.  Research  and  development  expenses  primarily  decreased  due to the
completion of  NicErase-SL  Phase 3 clinical  trials and  discontinuance  of the
NicErase-SL  development  program.  This was  partially  offset by research  and
development expenses for the Company's breast biopsy and ImmuDynTM technologies,
both in early stages of development. In addition, the Company is also conducting
research and  development on generic  pharmaceuticals  and expects  research and
development  expenses to increase in the future.  Continuance  of the  Company's
research  and  development  programs  is  dependent  upon its  ability to obtain
sufficient capital. See Liquidity and Capital Resources.

         Selling,  general and administrative  expenses for the third quarter of
Fiscal  1997 were  $2,546,000  versus  $1,072,000  for the same period as Fiscal
1996,  an increase of  $1,474,000.  This increase is primarily  attributable  to
operating expenses of the Company's generic pharmaceutical  business at Superior
and Able and compensation  expense recognized from the issuance of stock options
and warrants.

         Investment  income  decreased by $92,000 from $96,000 to $3,000 for the
third  quarter of Fiscal 1997 as compared to the third  quarter of Fiscal  1996,
respectively,  as the Company had less funds available for  investment.  For the
third quarter of Fiscal 1997, the increase in interest  expense is primarily due
to private debt financing for the Superior acquisition.

                   NINE-MONTH PERIOD ENDED SEPTEMBER 30, 1997
         AS COMPARED WITH THE NINE-MONTH PERIOD ENDED SEPTEMBER 30, 1996

         Revenues  for the nine  months of Fiscal  1997 were  $7,444,000  versus
$281,000  for the nine months of Fiscal 1996.  This  increase of  $7,193,000  is
primarily  the result of product  sales by the  Company's  wholly-owned  generic
pharmaceutical subsidiaries, Able and Superior.

         Cost of product sales was  approximately  100% of product sales for the
nine months of Fiscal 1997 due to low  production and sales levels at Able which
did not  support  the  fixed  manufacturing  costs  of the  Able  facility.  The
Company's  management  recently  initiated  cost  reduction  measures at Able to
eliminate  or reduce  costs,  including  staff  reductions  and  elimination  of
discretionary spending.

         Research  and  development  expenses for the nine months of Fiscal 1997
were $2,370,000 versus $2,842,000 for the same period as Fiscal 1996, a decrease
of  $472,000.  This  decrease  is  primarily  the  result of the  completion  of
NicErase-SL  Phase 3 clinical trials and the  discontinuance  of the NicErase-SL
development  program.  The Company is continuing its development  efforts on the
breast biopsy and ImmuDynTM,  technologies, both in early stages of development.
The   Company  is  also   developing   several   generic   versions  of  branded
pharmaceuticals to support its generic drug business.

         Selling,  general and  administrative  expenses  for the nine months of
Fiscal  1997 were  $4,795,000  versus  $2,569,000  for the same period as Fiscal
1996,  an increase of  $2,226,000.  This increase is primarily  attributable  to
acquisition and business development costs, and compensation expense of $728,000
recognized  from the issuance of stock options and warrants,  and the inclusion,
in Fiscal 1997, of selling, general and administrative expenses of the Company's
subsidiary operations at Able and Superior.

         Investment  income  decreased by $240,000 from $352,000 to $112,000 for
the nine months of Fiscal  1997 as  compared to the same period as Fiscal  1996,
respectively,  as the Company had less funds available for investment.  Interest
expense and  amortized  debt  financing  costs relate  primarily to private debt
financing for the Superior acquisition.


                                       17




                                  DYNAGEN, INC.

            Item 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                       CONDITION AND RESULTS OF OPERATIONS

            ----------------------------------------------------------

                         LIQUIDITY AND CAPITAL RESOURCES

         As of September 30, 1997, the Company had a deficit  working capital of
$628,000  versus  working  capital of $5,502,000 at December 31, 1996.  Cash and
investment  securities  were  $32,000  at  September  30,  1997 as  compared  to
$5,117,000 at December 31, 1996. Working capital was used primarily for research
and development and to fund Able and its operations during Fiscal 1997.

         The  Company's  current  working  capital is  insufficient  to fund its
current level of operations.  In addition,  the Company has incurred significant
losses since inception. To date, the Company has financed current operations and
acquisitions  primarily through private and public sale of equity as well as the
private sale of debt.  In the third quarter of Fiscal 1997,  the Company  raised
gross proceeds of $1,245,000  through the private sale of its equity.  In August
1997,  the Company  negotiated the sale to a third party of between $2.4 million
and $4.8  million of its  equity  subject  to  certain  restrictions  based upon
trading  volume,  share price and other factors.  If the Company is able to draw
upon this financing,  management  anticipates that the available working capital
will be sufficient to fund the current level of  operations,  including the Able
and Superior businesses,  through June 1998. There can be no assurance, however,
that the Company  will be able to draw upon this  financing.  The  Company  also
intends  to spin off its  breast  biopsy  and  ImmuDynTM  technologies  into two
separate majority-owned  operating entities and to pursue separate financing for
each.  There can be no  assurance,  however,  that the  Company  will be able to
secure this  financing.  The survival of the Company is dependent on its ability
to obtain additional  financing and to generate revenue and profits from sale of
its  products.  If the  Company is unable to obtain  additional  financing,  the
Company will be unable to maintain its current level of  operations  and will be
required to reduce or eliminate its expenditures relating to its business.

         While the acquisition of Able has increased the Company's revenues, the
acquisition has also increased costs and expenses,  capital expenditures and net
cash used for operating activities.  In recent months, the Company has initiated
certain  cost  reduction  programs  to reduce the net cash  required  to support
Able's operation. The Company intends to fund Able's operations until it becomes
self-supporting.  The Company continues to pursue additional  sources of capital
in order to fund the growth and operations of the Able generic drug business and
its product development efforts. There can be no assurance that the Company will
be able to secure  additional  financing  for the Able business or its continued
product  development  efforts or that  financing  will be available on favorable
terms.  If the  Company  is unable  to obtain  such  additional  financing,  the
Company's  ability  to  maintain  its  current  level  of  operations  would  be
materially and adversely  affected and the Company will be required to reduce or
eliminate certain expenditures,  including its research and development activity
with respect to certain proposed products.

         Superior's  operations  are funded from its  internally  generated cash
flow and  financed  with a line of credit to fund short term cash  requirements.
The  Company  believes  that  Superior  will  fund  its own  operations  for the
foreseeable future.


PART II.  OTHER INFORMATION
Item 2.  Changes in Securities
         a.       Not applicable.
         b.       Not applicable.
         c.       On August 7, August 15 and August 22, 1997, the Company issued
                  an aggregate of 4,950 shares of its Series A Preferred  Stock,
                  $.01 par value per share,  and Common Stock Purchase  Warrants
                  to purchase an aggregate  of 39,600  shares of Common Stock to
                  ten  accredited  investors for an aggregate  purchase price of
                  $495,000.  The  Company is  obligated  to  register  under the
                  Securities  Act the  shares  of  Common  Stock  issuable  upon
                  conversion of the Series A Preferred Stock and exercise of the
                  warrants  within  90 days  after  the date of the sale of such
                  Series A Preferred Stock and warrants.  The Series A Preferred
                  Stock is  convertible  into Common  Stock at the lesser of (i)
                  120% of the average


                                       18


                                  DYNAGEN, INC.

                           PART II. OTHER INFORMATION

                  closing bid price of the Company's Common Stock as reported by
                  the Nasdaq  SmallCap  Market (or such other  exchange on which
                  the Common  Stock is then  traded) for the five  trading  days
                  immediately  preceding  the date on which the  Securities  and
                  Exchange Commission (the "Commission")  declares effective the
                  registration  statement to be filed  registering the shares of
                  Common  Stock  issuable  upon   conversion  of  the  Series  A
                  Preferred  Stock  and  exercise  of  the  warrants  or  (ii) a
                  discount  on the average  closing  bid price of the  Company's
                  Common  Stock as  reported by the Nasdaq  SmallCap  market (or
                  such other  exchange on which the Common Stock is then traded)
                  for the five trading days  immediately  preceding  the date on
                  which the Series A Preferred Stock is converted.  The exercise
                  price of the warrants will be 120% of the average  closing bid
                  price of the Company's  Common Stock as reported by the Nasdaq
                  SmallCap  Market (or such other  exchange  on which the Common
                  Stock is then traded) for the five  trading  days  immediately
                  preceding the date on which the Commission  declares effective
                  the registration  statement to be filed registering the shares
                  of Common  Stock  issuable  upon  conversion  of the  Series A
                  Preferred Stock and exercise of the warrants. The warrants are
                  exercisable  for two years.  The Series A Preferred  Stock and
                  warrants  were  issued  pursuant  to  Regulation  D under  the
                  Securities Act of 1933, as amended (the "Securities Act").

                  On August 21,  1997,  the Company  issued  7,500 shares of its
                  Series C  Preferred  Stock,  $.01 par value per  share,  and a
                  Common Stock  Purchase  Warrant to purchase  250,000 shares of
                  its  Common  Stock  to  Endeavour  Capital  Fund  S.A.  for an
                  aggregate purchase price of $750,000. The Company is obligated
                  to  register  under the  Securities  Act the  shares of Common
                  Stock issuable upon conversion of the Series C Preferred Stock
                  and  exercise of the warrant  within 90 days after the date of
                  the sale of such Series C  Preferred  Stock and  warrant.  The
                  Series C Preferred  Stock is convertible  into Common Stock at
                  the lesser of (i) 125% of the average closing bid price of the
                  Company's  Common  Stock as  reported  by the Nasdaq  SmallCap
                  Market (or such other  exchange  on which the Common  Stock is
                  then traded) for the five trading days  immediately  preceding
                  August 21, 1997 or (ii) a discount on the average  closing bid
                  price of the Company's  Common Stock as reported by the Nasdaq
                  SmallCap  Market (or such other  exchange  on which the Common
                  Stock is then traded) for the five  trading  days  immediately
                  preceding  the date on which the Series C  Preferred  Stock is
                  converted.  The exercise  price of the warrants is 125% of the
                  average  closing bid price of the  Company's  Common  Stock as
                  reported by the Nasdaq SmallCap Market (or such other exchange
                  on which the Common  Stock is then  traded) for the 10 trading
                  days  immediately  preceding  August 21, 1997.  The warrant is
                  exercisable  for three years.  In connection  with the sale of
                  the Series C Preferred Stock and the warrant, the Company also
                  entered into a binding obligation to sell to Endeavour Capital
                  Fund S.A. no less than 24,000  shares and up to 48,000  shares
                  of its Series D Preferred  Stock,  at a purchase price of $100
                  per share,  in a series of tranches of between 2,000 and 4,000
                  shares not less than 30 days  apart.  The  Series C  Preferred
                  Stock and the warrant  were issued  pursuant to  Regulation  D
                  under the Securities Act.

                  On August 21, 1997,  the Company  issued 100,000 shares of its
                  Common Stock to Jesup & Lamont as consideration for investment
                  banking and placement agent services  rendered to the Company.
                  The  shares  of  Common   Stock  were   issued  in  a  private
                  transaction  not  involving  a public  offering,  pursuant  to
                  Section 4(2) of the Securities Act.

                  On August 28, 1997,  the Company  issued to H.J.  Myers & Co.,
                  Inc. a warrant to purchase 1,000,000 shares of Common Stock at
                  an exercise  price of $0.15 per share,  as  consideration  for
                  investment  banking  services  rendered  to the  Company.  The
                  warrant was  immediately  exercisable  on the date of issuance
                  with respect to 700,000 of the shares of Common Stock  subject
                  thereto,   and  the  remaining  300,000  shares  shall  become
                  exercisable,  in such  installments  as shall be determined by
                  the Board of Directors of the Company,  upon the  satisfactory
                  performance  by H.J.  Meyers  & Co.,  Inc.  of the  investment
                  banking  services.   The  warrant  was  issued  in  a  private
                  transaction  not  involving  a public  offering,  pursuant  to
                  Section 4(2) of the Securities Act.



                                       19





                                  DYNAGEN, INC.

                           PART II. OTHER INFORMATION

                  On August 1, 1997,  the Company  issued  13,481  shares of its
                  Common  Stock to GFL  Performance  Fund  Limited in payment of
                  $10,700 in  interest  due on the  Company's  Convertible  Note
                  dated  February  7, 1996.  The shares were issued in a private
                  transaction  not  involving  a public  offering,  pursuant  to
                  Section 4(2) of the Securities Act.

                  On September 11, 1997, the Company issued  1,000,000 shares of
                  its Common Stock to Curzon Management Limited as consideration
                  for investment  banking and placement agent services  rendered
                  to the  Company.  The shares of Common  Stock were issued in a
                  private transaction not involving a public offering,  pursuant
                  to Section 4(2) of the Securities Act.

Item 5.           Other Information.

                  On  August  29,  1997,  the  Company  issued  a press  release
                  regarding  its  decision  to  discontinue   its   NicErase7-SL
                  (sublingual  tablet)  program as a result of  clinical  trials
                  which did not show  statistically  significant  efficacy  with
                  respect  to this  technology.  The press  release  is filed as
                  Exhibit 99a to this report.

                  Under   applicable  law,  the  Company's   current  or  future
                  licensees  will not be  permitted to sell  NicErase,  and thus
                  generate  any  revenue  from their  development  of  NicErase,
                  unless they obtain the necessary regulatory approvals from the
                  U.S.  Food  and  Drug   Administration  (the  "FDA")  for  the
                  commercial  sale of that  product.  To obtain such  regulatory
                  approvals,  the  Company's  current or future  licensees  must
                  demonstrate   to  the   satisfaction   of  the  FDA,   through
                  preclinical studies and clinical trials, that NicErase is safe
                  and effective.  In light of the Company's  recently  completed
                  pivotal Phase 3 clinical trial of  NicErase-SL,  which did not
                  show statistically significant efficacy, the Company is unable
                  to predict  whether  delivery  formulations  of lobeline other
                  than  sublingual  will  demonstrate   acceptable   safety  and
                  efficacy  to obtain FDA  approval.  There can be no  assurance
                  that the Company's current or future licensees will be able to
                  successfully formulate new delivery systems for lobeline, that
                  such licensees will have sufficient technological or financial
                  resources  to initiate  and  complete  the  required  clinical
                  trials, or that such trials will demonstrate sufficient safety
                  and  efficacy to obtain the required  regulatory  approvals or
                  develop  marketable  products.  A number of  companies  in the
                  pharmaceutical  industry have suffered significant setbacks in
                  advanced  clinical  trials,  even after  promising  results in
                  earlier  trials.  If any  future  clinical  trials do not show
                  NicErase to be safe and effective in any alternative  delivery
                  format,  and if the  Company's  licensees  are thus  unable to
                  commercialize  NicErase,  the  Company  will not  realize  any
                  revenues from the NicErase product.

Item 6.           Exhibits and Reports on Form 8-K

                  (a)      List of Exhibits:

                  The  following  exhibits,  required by Item 601 of  Regulation
                  S-K, are filed as part of this Quarterly  Report on Form 10-Q.
                  Exhibit  numbers,   where  applicable,   in  the  left  column
                  correspond to those of Item 601 of Regulation S-K.



                                       20





                                  DYNAGEN, INC.

                           PART II. OTHER INFORMATION





Exhibit
  No.                          Description of Exhibit
  ---                           ----------------------

3a       Certificate  of  Designations,  Preferences  and  Rights  of  Series  A
         Preferred  Stock of the Company (filed as Exhibit 4.13 to the Company's
         Current Report on Form 8-K dated June 18, 1997).

3b       Certificate  of  Designations,  Preferences  and  Rights  of  Series  C
         Preferred Stock of the Company (filed herewith).

3c       Certificate  of  Designations,  Preferences  and  Rights  of  Series  D
         Preferred Stock of the Company (filed herewith).

4a       Form  of  Securities  Purchase  Agreement  among  the  Company  and the
         purchasers of Series A Preferred Stock (filed herewith).

4b       Master  Registration  Rights  Agreement  dated August 6, 1997 among the
         Company  and  the  purchasers  of  Series  A  Preferred   Stock  (filed
         herewith).

4c       Form of Common  Stock  Purchase  Warrant  issued by the  Company to the
         purchasers  of Series A Preferred  Stock  (filed as Exhibit 4.16 to the
         Company's Current Report on Form 8-K dated June 18, 1997).

4d       Stock Purchase  Agreement dated August 21, 1997 between the Company and
         Endeavour Capital Fund S.A. (filed herewith).

4e       Registration Rights Agreement dated August 21, 1997 between the Company
         and Endeavour Capital Fund S.A. (filed herewith).

4f       Common  Stock  Purchase  Warrant  dated  August 21,  1997 issued by the
         Company to Endeavour Capital Fund S.A. (filed herewith).

4g       Common  Stock  Purchase  Warrant  dated  August 28,  1997 issued by the
         Company to H.J. Meyers & Co., Inc. (filed herewith).

10a      Indenture of Lease dated July 1, 1997 between Rivertech  Associates LLC
         and the Company (filed herewith).

27       Financial Data Schedule (filed herewith in electronic format only).

99a      Press Release of the Company dated August 29, 1997 (filed herewith).

         (b) Reports on Form 8-K:

         During the quarter ended  September 30, 1997, the Company filed on July
         3, 1997 a Current  Report on Form 8-K dated June 18, 1997 reporting the
         Company's   acquisition   of  the   outstanding   stock   of   Superior
         Pharmaceutical  Company.  On July 11 and August 29,  1997,  the Company
         filed Current Reports on Form 8-K/A amending the Current Report on Form
         8-K dated June 18, 1997.



                                       21




                                   SIGNATURES



         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
the  Registrant  has duly  caused  this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                    DYNAGEN, INC.



                           By:       /s/ Indu A. Muni
                              ------------------------------------------
                                    Indu A. Muni, Ph.D.
                                    President, Chief Executive Officer, and
                                    Treasurer (Principal Executive, Financial,
                                    and Accounting Officer)








Date: November 14, 1997


  
                                     22





                                                                      Exhibit 3b



                                  DYNAGEN, INC.

                    CERTIFICATE OF DESIGNATIONS, PREFERENCES

                     AND RIGHTS OF SERIES C PREFERRED STOCK



         The undersigned officer of DynaGen,  Inc., a corporation  organized and
existing under the General Corporation Law of the State of Delaware, does hereby
certify  that,   pursuant  to  authority   conferred  by  the   Certificate   of
Incorporation, as amended to date, and pursuant to the provisions of Section 151
of the General Corporation Law of the State of Delaware,  the Board of Directors
of DynaGen, Inc., on August 13, 1997, adopted a resolution providing for certain
powers, designations, preferences and relative, participating, optional or other
rights, and the qualifications,  limitations or restrictions thereof, of certain
shares of Series C Preferred Stock,  $.01 par value, of the  Corporation,  which
resolution is as follows:

         RESOLVED:  That,  pursuant  to the  authority  vested  in the  Board of
Directors of the Corporation and in accordance with the General  Corporation Law
of the State of Delaware and the provisions of the Corporation's  Certificate of
Incorporation,  a series of 7,500  shares of the class of  authorized  Preferred
Stock,  par value $.01 per share,  of the  Corporation  is hereby created as the
Series C Preferred  Stock, and that the designation and number of shares thereof
and the voting powers,  preferences  and relative,  participating,  optional and
other  special  rights of the  shares of such  series,  and the  qualifications,
limitations  and  restrictions  thereof,  are as set forth on Exhibit A attached
hereto.

         EXECUTED as of this 14th day of August, 1997.

                             DYNAGEN, INC.


                             By:      /s/ Indu A. Muni
                                -------------------------------
                                Indu A. Muni
                                President













                                    EXHIBIT A
                                    ---------



A.       DESCRIPTION AND DESIGNATION OF SERIES C PREFERRED STOCK

         1.       DESIGNATION AND DEFINITIONS.

                  (A) DESIGNATION.  A total of 7,500 shares of the Corporation's
previously  undesignated Preferred Stock, $.01 par value, shall be designated as
the "Series C Preferred Stock." The original issue price per share of the Series
C Preferred Stock shall be $100.00 (the "ORIGINAL ISSUE PRICE").

                  (B) CERTAIN DEFINITIONS.  As used herein, the following terms,
unless the context otherwise requires, have the following respective meanings:

                           (i) "AVERAGE  QUOTED  PRICE" means the average of the
closing  bid price of the Common  Stock of the  Corporation  as  reported by the
Nasdaq SmallCap Market or Nasdaq National Market or, if the Corporation's Common
Stock is no longer traded on a Nasdaq  market,  such other exchange on which the
Corporation's  Common  Stock  is then  traded,  for the five  (5)  Trading  Days
immediately  preceding any holder's  Conversion  Date, the Mandatory  Conversion
Date (as  defined  in Section  5(c)  below) or the date of the  consummation  or
closing of a Fundamental Change, as the case may be.

                           (ii) "COMMON STOCK" means the common stock, par value
$.01 per share, of the
Corporation.

                           (iii)  "CONVERSION DATE" means each date on which the
Corporation receives by
telecopy  written notice in accordance with Section 5(i) hereof from a holder of
Series C Preferred Stock that such holder elects to convert shares of its Series
C Preferred Stock.

                           (iv) "FUNDAMENTAL CHANGE" means: (i) any sale, lease,
exchange  or other  transfer  of all or  substantially  all of the assets of the
Corporation;  or (ii) any merger or  consolidation to which the Corporation is a
party.  Notwithstanding the foregoing,  the following shall not be a Fundamental
Change: A merger or  consolidation  (a) to which the Corporation is a party; (b)
in  which  it  is  the   surviving   corporation   and  there  is  no  resulting
reclassification of the outstanding Common Stock; and (c) after giving effect to
which, persons who were,  immediately before the consummation or closing of such
merger or consolidation,  holders of outstanding Common Stock will be the direct
or indirect  owners of  securities  of the  Corporation  possessing,  on a fully
diluted basis,  at least  seventy-five  percent (75%) of the voting power of all
voting  securities  of  the  Corporation   (excluding,   for  purposes  of  such
computation,   any  such   person  who  also  is  a  party  to  such  merger  or
consolidation).

                           (v) "ISSUE DATE" means, with respect to each share of
Series C Preferred  Stock held by any holder,  the date on which the Corporation
originally  issued such share to such holder  (regardless of the number of times
transfer of such share is made on the stock transfer books  maintained by or for
the  Corporation,  and  regardless  of the number of 










                                      -2-



certificates which may be issued to evidence such share, and irrespective of any
subsequent transfer or other disposition of such share to any other holder).

                           (vi) "TRADING DAY" means a day on which the principal
national  securities exchange on which the Common Stock is listed or admitted to
trading is open for the transaction of business;  or, if the Common Stock is not
listed or admitted to trading on any national  securities exchange but is listed
on the Nasdaq system (or such other  trading  system then in use by the National
Association of Securities Dealers, Inc.), a day on which such system is open for
the transaction of business;  or, if the foregoing does not apply,  any Business
Day.

         2.       DIVIDENDS.

                  (A)  PREFERRED  DIVIDEND - CASH  AND/OR  IN-KIND.  When and as
declared by the Board of  Directors  and to the extent  permitted by the General
Corporation Law of the State of Delaware, the Corporation shall pay preferential
dividends  to the  holders of the Series C  Preferred  Stock as provided in this
Section 2(a).

                           (I) PREFERRED DIVIDEND.  Except as otherwise provided
herein,  dividends  on each  share of Series C  Preferred  Stock  shall  accrue,
cumulatively,  at the rate of seven  percent  (7.0%)  per annum of the  Original
Issue Price,  from and  including  the Issue Date of such share to and including
the date on which the  Liquidation  Value of such share is paid or such share is
converted in accordance with the provisions  hereof (the "PREFERRED  DIVIDEND").
Such  Preferred  Dividend  will accrue  whether or not it has been  declared and
whether  or not there are  profits,  surplus or other  funds of the  Corporation
legally available for its payment.

                           (II)  SEMI-ANNUAL  PAYMENTS.  Commencing  on July 31,
1998,  the  Preferred  Dividend  shall be  payable in cash  (subject  to Section
2(a)(v)  below)  semi-annually,  for the actual number of days elapsed,  on each
July 31 and January 31, to the holders of record of shares of Series C Preferred
Stock as of the tenth  (10th)  trading day  preceding  the  applicable  dividend
payment date.

                           (III)  NO  INTEREST.  Accrued  but  unpaid  Preferred
Dividends shall not bear interest. Preferred Dividends paid in cash in an amount
less than the total  amount of such  dividends  at the time  accrued and payable
shall be  allocated  on a  share-by-share  basis  among  all  shares of Series C
Preferred Stock at the time outstanding.

                           (IV)  PAYMENT UPON  CONVERSION.  On the date on which
any holder's  shares of Series C Preferred Stock are converted into Common Stock
pursuant to Section 5 hereof, the accrued Preferred Dividend with respect to the
shares  so  converted  shall  be paid  to such  holder.  All  accrued  Preferred
Dividends also shall be payable upon the liquidation,  dissolution or winding up
of the Corporation.

                           (V) PAYMENT IN COMMON STOCK. The Corporation,  at its
sole discretion,  may pay the Preferred Dividends in cash or in shares of Common
Stock at the then fair market  value per share of Common Stock as of the date on
which the Preferred  Dividend is payable.  For purposes of this Section 2(a)(v),
fair  market  value  shall be the average of the closing bid price of the Common
Stock of the  Corporation  as reported by the Nasdaq  SmallCap 








                                      -3-



Market or Nasdaq  National  Market or, if the  Corporation's  Common Stock is no
longer traded on a Nasdaq market, such other exchange on which the Corporation's
Common Stock is then traded, for the ten (10) Trading Days immediately preceding
the date on which the Preferred Dividend is payable.

                           (VI)  FRACTIONAL  SHARES.   Notwithstanding  anything
herein to the contrary,  no fractional  shares shall be issued  pursuant to this
Section 2, and the number of shares of Common  Stock  issued upon the payment of
the Preferred Dividend shall be rounded up or down to the nearest whole share.

                  (B)  DECLARED  DIVIDENDS  ON  COMMON  STOCK.  If the  Board of
Directors shall declare a cash dividend payable upon the then outstanding shares
of Common  Stock (other than a stock  dividend on the Common  Stock  distributed
solely in the form of  additional  shares of Common  Stock),  the holders of the
Series C Preferred  Stock shall be  entitled to the amount of  dividends  on the
Series C Preferred  Stock as would be declared  payable on the largest number of
whole shares of Common  Stock into which the shares of Series C Preferred  Stock
held by each holder  thereof  could be converted  pursuant to the  provisions of
Section  5  hereof,  such  number  determined  as of the  record  date  for  the
determination of holders of Common Stock entitled to receive such dividend. Such
determination  of "whole  shares"  shall be based upon the  aggregate  number of
shares of Series C Preferred Stock held by each holder,  and not upon each share
of Series C Preferred Stock so held by the holder.

                  (C)  DIVIDENDS ON OTHER  SECURITIES.  Subject to the foregoing
provisions  of this  Section  2, the  Board of  Directors  may  declare  and the
Corporation may pay or set apart for payment, or cause the accrual of, stated or
cumulative  dividends and other distributions on the Series A Preferred Stock or
the  Series B  Preferred  Stock  of the  Corporation,  or any  other  series  of
preferred stock hereafter  designated,  and may purchase or otherwise redeem any
of the same (or any warrants,  rights,  options or other securities  exercisable
therefor or convertible or exchangeable thereinto),  and the holders of Series C
Preferred Stock shall not be entitled to share therein.

         3.       LIQUIDATION, DISSOLUTION OR WINDING UP.

                  (A) TREATMENT AT  LIQUIDATION,  DISSOLUTION  OR WINDING UP. In
the event of any  liquidation,  dissolution  or winding  up of the  Corporation,
whether voluntary or involuntary, or in the event of its insolvency,  before any
distribution  or  payment is made to any  holders  of Common  Stock or any other
class or series of capital stock of the  Corporation  designated to be junior to
the  Series C  Preferred  Stock,  and  subject  to the  liquidation  rights  and
preferences of any class or series of Preferred Stock designated by the Board of
Directors  in the  future  to be  senior  to or on a parity  with  the  Series C
Preferred  Stock with  respect to  liquidation  preferences,  the holder of each
share of Series C Preferred  Stock shall be entitled to be paid first out of the
assets  of  the  Corporation  available  for  distribution  to  holders  of  the
Corporation's  capital  stock of all  classes,  whether such assets are capital,
surplus or earnings,  an amount  equal to the Original  Issue Price per share of
Series  C  Preferred  Stock  held by any  holder,  plus the  Preferred  Dividend
accruing  to the  Series C  Preferred  Stock  pursuant  to  Section 2 above (the
"LIQUIDATION  VALUE"). 









                                      -4-



For  purposes  hereof,  the Series C Preferred  Stock shall rank on  liquidation
junior to the Series A Preferred Stock and on parity with the Series B Preferred
Stock.

                  If,  upon  liquidation,  dissolution  or  winding  up  of  the
Corporation,  the assets of the  Corporation  available for  distribution to its
stockholders  shall be insufficient to pay the holders of the Series C Preferred
Stock the full amount to which they otherwise would be entitled,  the holders of
Series C Preferred  Stock shall share ratably in any  distribution  of available
assets pro rata in proportion to the respective  liquidation  preference amounts
which  would  otherwise  be  payable  upon   liquidation  with  respect  to  the
outstanding shares of the Series C Preferred Stock if all liquidation preference
amounts with respect to such shares were paid in full,  based upon the aggregate
Liquidation  Value  payable  upon all  shares of Series C  Preferred  Stock then
outstanding.

                  After such payment shall have been made in full to the holders
of the Series C Preferred  Stock, or funds necessary for such payment shall have
been set aside by the  Corporation  in trust for the  account  of holders of the
Series C Preferred  Stock so as to be available for such payment,  the remaining
assets available for distribution shall be distributed ratably among the holders
of the Common Stock and any class or series of capital  stock  designated  to be
junior to the Series C  Preferred  Stock (if any) in right of  payment  upon any
liquidation, dissolution or winding up of the Corporation.

                  The  amounts  set forth  above  shall be subject to  equitable
adjustment  by the  Board  of  Directors  whenever  there  shall  occur  a stock
dividend,   stock   split,   combination,   reorganization,    recapitalization,
reclassification  or other  similar  event  involving  a change  in the  capital
structure of the Series C Preferred Stock.

                  (B) DISTRIBUTIONS  OTHER THAN CASH. Whenever the distributions
provided for in this Section shall be payable in property  other than cash,  the
value of such  distribution  shall be the fair market value of such  property as
determined in good faith by the Board of Directors. All distributions (including
distributions  other  than cash)  made  hereunder  shall be made pro rata to the
holders of Series C Preferred Stock.

                  (C)  EVENTS NOT DEEMED A  LIQUIDATION.  Neither  the merger or
consolidation of the Corporation into or with any other corporation(s),  nor the
sale or transfer by the  Corporation  of all or any part of its assets,  nor the
reduction  of the  capital  stock of the  Corporation,  will be  deemed  to be a
liquidation, dissolution or winding up of the Corporation under this Section 3.

         4.       VOTING POWER.

                  (A) GENERAL.  Except as otherwise  expressly  provided in this
Section 4 or as otherwise  required by the General  Corporation Law of the State
of Delaware,  each holder of Series C Preferred  Stock shall be entitled to vote
on all  matters  and shall be  entitled  to that  number  of votes  equal to the
largest  number of whole shares of Common Stock into which such holder's  shares
of Series C Preferred  Stock could be converted,  pursuant to the  provisions of
Section 5 hereof,  at the  record  date for the  determination  of  stockholders
entitled to vote on any 









                                      -5-


matter or, if no such record date is established, at the date such vote is taken
or any  written  consent  of  stockholders  is  solicited.  Except as  otherwise
expressly  required by law,  the holders of shares of Series A Preferred  Stock,
Series B Preferred  Stock,  Series C Preferred Stock and Common Stock shall vote
together (or render written consents in lieu of a vote) as a single class on all
matters submitted to the stockholders of the Corporation.

                  Such  determination  of "whole shares" shall be based upon the
aggregate number of shares of Series C Preferred Stock held by each holder,  and
not upon each share of Series C Preferred Stock so held by the holder.

                  (B) AMENDMENTS TO CHARTER. For so long as there are any shares
of Series C Preferred Stock  outstanding,  the  Corporation  shall not amend its
Certificate of  Incorporation  or this  Certificate  of Designation  without the
approval,  by vote or written consent,  of the holders of at least a majority of
the then outstanding  shares of Series C Preferred  Stock,  voting together as a
class, each share of Series C Preferred Stock to be entitled to one vote in each
instance,  if such amendment would adversely affect the rights of the holders of
Series C Preferred Stock. Without limiting the generality of the foregoing,  the
creation, or increase in the authorized number of shares, of any class or series
of stock  ranking  prior to or on a parity  with the  Series C  Preferred  Stock
either as to dividends or upon  liquidation  shall be deemed to adversely affect
the  rights of the  holders of Series C  Preferred  Stock for  purposes  of this
Section 4(b).

         5.       CONVERSION RIGHTS.

                  (A) CONVERSION AT THE OPTION OF HOLDERS. Each holder of Series
C Preferred Stock shall have the right, at such holder's  option,  to convert at
any time any of the shares of Series C Preferred  Stock held by such holder into
such number of fully paid and  nonassessable  shares of Common Stock as shall be
determined by multiplying the number of shares of Series C Preferred Stock to be
converted by a fraction, the numerator of which is the Original Issue Price, and
the denominator of which is the applicable Conversion Price (as defined below).

                  (B)  CONVERSION  PRICE.  The  conversion  price per share (the
"CONVERSION  PRICE")  shall be equal to the lesser of  subsections  (i) and (ii)
below.

                           (i) One  hundred  twenty-five  percent  (125%) of the
average of the  closing  bid price of the  Common  Stock of the  Corporation  as
reported  by the Nasdaq  SmallCap  Market or Nasdaq  National  Market or, if the
Corporation's  Common Stock is no longer traded on a Nasdaq  market,  such other
exchange on which the  Corporation's  Common Stock is then traded,  for the five
(5) Trading Days immediately preceding the Issue Date.

                           (ii) (A)  Beginning  on the 60th day  after the Issue
Date and ending on the 150th day after the Issue Date,  eighty  percent (80%) of
the Average Quoted Price;

                                (B)  Beginning  on the 151st day after the Issue
Date and  ending on the 210th day after the Issue  Date,  seventy-eight  percent
(78%) of the Average Quoted Price;






                                      -6-

                                (C)  Beginning  on the 211th day after the Issue
Date and ending on the 365th day after the Issue Date, seventy-six percent (76%)
of the Average Quoted Price; and

                                (D)  Beginning  on the 366th day after the Issue
Date, seventy-four (74%) of the Average Quoted Price.

                  (C) CONVERSION AT OPTION OF CORPORATION. At any time after the
close of  business  on the one (1)  year  anniversary  of the date on which  the
Securities and Exchange Commission declares effective the registration statement
registering  the shares of Common Stock issuable upon conversion of the Series C
Preferred  Stock,  all of the  shares  of  Series  C  Preferred  Stock  shall be
convertible,  at the option of the  Corporation,  into such number of fully paid
and  nonassessable  shares of Common Stock as shall be determined by multiplying
the number of shares of Series C Preferred  Stock  outstanding  on the Mandatory
Conversion Date (as defined below) by a fraction,  the numerator of which is the
Original Issue Price, and the denominator of which is the applicable  Conversion
Price.

                  The  Corporation  shall give  notice of its  exercise  of such
conversion  option to all holders of Series C Preferred Stock no later than five
(5) Trading Days before the date as of which the Corporation has elected to make
such conversion effective (such effective date of the conversion, the "MANDATORY
CONVERSION  Date").  Each holder of Series C Preferred Stock as of the Mandatory
Conversion Date shall, promptly after such date, surrender for conversion to the
Corporation  at its principal  office or to any transfer  agent for the Series C
Preferred Stock or the Common Stock all certificates  representing all shares of
Series C Preferred  Stock held by such holder,  accompanied  by a written notice
specifying the name or names in which such holder wishes the  certificate(s) for
shares of Common Stock to be issued.

                  Effective  as of  the  close  of  business  on  the  Mandatory
Conversion Date, each share of Series C Preferred Stock then  outstanding  shall
be (and be deemed to have been)  converted  automatically,  without  any further
action by the holders  thereof,  into shares of Common  Stock.  Such  conversion
shall be deemed to have occurred  whether or not the  certificates  representing
such shares are surrendered to the Corporation or its transfer agent.

                  (D)   LIMITATION   ON   NUMBER   OF   SHARES.    Additionally,
notwithstanding  anything  set forth in this  Section 5 to the  contrary,  in no
event shall any holder of Series C Preferred Stock, prior to earlier to occur of
the Mandatory  Conversion  Date or the date of the  consummation or closing of a
Fundamental  Change, be entitled to convert Series C Preferred Stock into shares
of Common Stock to the extent that (x) the number of shares of the Corporation's
Common Stock  beneficially  owned by such holder and its affiliates  (other than
shares  of Common  Stock  which may be deemed  beneficially  owned  through  the
ownership of the  unconverted  portion of the shares of Series C Preferred Stock
held by such holder) plus (y) the number of shares of Common Stock issuable upon
such  conversion  would  result in  beneficial  ownership  by the holder and its
affiliates of more than 4.9% of the shares of Common Stock then outstanding. For
purposes of this Section  5(d),  beneficial  ownership  shall be  determined  in
accordance  with  Section  13(d) of the  Securities  Exchange  Act of  1934,  as
amended, and Regulation 13D and 13G promulgated thereunder,  except as otherwise
provided in clause (x) of








                                      -7-

this Section 5(d).  Each holder  shall,  upon  delivering  to the  Corporation a
notice of election to convert  shares of Series C Preferred  Stock in accordance
with  Section  5(i)  hereof,  be  required  to provide  the  Corporation  with a
certification in form and substance reasonably  satisfactory to the Corporation,
that the  conversion of the Series C Preferred  Stock being  converted  will not
result in such holder and its  affiliates  beneficially  holding more than 4.9%,
determined as heretofore provided,  of the outstanding shares of Common Stock on
such Conversion Date. If the holder cannot make such  certification,  the shares
of  Series  C  Preferred  Stock  to  be  converted  shall  not  be  convertible.
Notwithstanding  the foregoing,  upon the Mandatory  Conversion Date or upon the
consummation  or closing of a  Fundamental  Change,  all such shares of Series C
Preferred  Stock  then  outstanding  shall be  converted  into  Common  Stock in
accordance with Section 5(c) or 5(g), as applicable.

                  (E) DIVIDENDS OTHER THAN COMMON STOCK DIVIDENDS.  In the event
the  Corporation  shall  make or  issue,  or  shall  fix a  record  date for the
determination of holders of Common Stock entitled to receive a dividend or other
distribution  (other than a distribution  in  liquidation or other  distribution
otherwise  provided for herein) with respect to the Common Stock  payable in (i)
securities of the  Corporation  other than shares of Common Stock, or (ii) other
assets (excluding cash dividends or distributions),  then and in each such event
provision  shall be made so that the  holders  of the Series C  Preferred  Stock
shall  receive  upon  conversion  thereof in addition to the number of shares of
Common Stock receivable thereupon, the number of securities or such other assets
of the  Corporation  which they would have received had their Series C Preferred
Stock been  converted  into Common  Stock on the date of such event and had they
thereafter,  during the period from the date of such event to and  including the
Conversion  Date,  retained such  securities or such other assets  receivable by
them during such period,  giving application to all other adjustments called for
during  such  period  under  this  Section 5 with  respect  to the rights of the
holders of the Series C Preferred Stock.

                  (F) CAPITAL REORGANIZATION OR RECLASSIFICATION.  If the Common
Stock  issuable  upon the  conversion  of the Series C Preferred  Stock shall be
changed into the same or  different  number of shares of any class or classes of
capital   stock,   whether   by   capital   reorganization,    recapitalization,
reclassification or otherwise (other than a subdivision or combination of shares
or stock  dividend  provided for elsewhere in this Section 5, or the sale of all
or substantially all of the  Corporation's  capital stock or assets to any other
person),  then and in each such event the  holders of Series C  Preferred  Stock
shall have the right  thereafter to convert such shares into the kind and amount
of shares of capital stock and other  securities  and property  receivable  upon
such reorganization,  recapitalization,  reclassification or other change by the
holders of the number of shares of Common Stock into which such shares of Series
C  Preferred  Stock  might  have  been  converted   immediately  prior  to  such
reorganization,  recapitalization,  reclassification  or change,  all subject to
further adjustment as provided herein.

                  (G)  MANDATORY   CONVERSION  -  FUNDAMENTAL   CHANGE.  If  any
Fundamental  Change  shall  occur,  then each share of Series C Preferred  Stock
outstanding as of the date of the  consummation or closing thereof shall be (and
be deemed to have been) converted  automatically,  without any further action by
the holders thereof,  into such number of fully paid and nonassessable shares of
Common  Stock as shall be  determined  by  multiplying  the  number of 








                                      -8-

shares  of  Series  C  Preferred  Stock  outstanding  on the on the date of such
consummation  or  closing  date by a  fraction,  the  numerator  of which is the
Original Issue Price, and the denominator of which is the applicable  Conversion
Price.  Such  conversion  shall be deemed to have  occurred  whether  or not the
certificates  representing such shares are surrendered to the Corporation or its
transfer agent.

                  The Corporation shall give notice of a proposed or anticipated
Fundamental Change to all holders of the Series C Preferred Stock not later than
thirty (30) days before the expected closing or consummation of such Fundamental
Change,  provided that at all times during such thirty-day period a registration
statement  shall be in effect to permit the  registration  of the  Common  Stock
issuable upon  conversion of the Series C Preferred  Stock under the  Securities
Act of 1933, as amended.  The  Corporation  also shall give prompt notice of the
closing or consummation of such  Fundamental  Change to all holders of record of
the Series C  Preferred  Stock as of the date of such  closing or  consummation.
Each holder of Series C Preferred Stock shall thereupon  promptly  surrender for
conversion,  to the Corporation at its principal office or to any transfer agent
for  the  Series  C  Preferred  Stock  or the  Common  Stock,  all  certificates
representing  all  shares  of  Series C  Preferred  Stock  held by such  holder,
accompanied  by a  written  notice  specifying  the name or names in which  such
holder wishes the certificate(s) for shares of Common Stock to be issued.

                  (H) CERTIFICATE AS TO ADJUSTMENTS;  NOTICE BY CORPORATION.  In
each case of an  adjustment or  readjustment  of the Original  Issue Price,  the
Corporation at its expense will furnish each holder of Series C Preferred  Stock
so  affected  with a  certificate  prepared  by an officer  of the  Corporation,
showing such  adjustment or  readjustment,  and stating in detail the facts upon
which such adjustment or readjustment is based.

                  (I)  EXERCISE  OF  CONVERSION   PRIVILEGE.   To  exercise  its
conversion  privilege,  a holder of Series C Preferred  Stock shall give written
notice by telecopy to the  Corporation at its principal  office that such holder
elects to convert  shares of its Series C Preferred  Stock and shall  thereafter
surrender the original certificate(s) representing the shares being converted to
the  Corporation at its principal  office  together with an originally  executed
copy of such  notice.  Such notice  shall also state the name or names (with its
address or  addresses,  as well as the  address(es)  for  delivery) in which the
certificate(s) for shares of Common Stock issuable upon such conversion shall be
issued.   The  certificate(s)  for  the  shares  of  Series  C  Preferred  Stock
surrendered for conversion shall be accompanied by proper assignment  thereof to
the  Corporation or in blank.  As promptly as practicable  after the Corporation
receives the original  certificate(s) for the shares of Series C Preferred Stock
surrendered for conversion,  the proper assignment thereof to the Corporation or
in blank and the original  notice of  conversion  (collectively,  the  "ORIGINAL
DOCUMENTATION"),  but in no event  more than  three (3)  Trading  Days after the
Corporation's receipt of the Original Documentation, the Corporation shall issue
and shall deliver to the holder of the shares of Series C Preferred  Stock being
converted,   at  the   addresses  set  forth   therefor  by  the  holder,   such
certificate(s)  as it may request for the number of whole shares of Common Stock
issuable  upon the  conversion  of such  shares of Series C  Preferred  Stock in
accordance  with the  provisions  of this  Section 5, and cash,  as  provided in
Section  5(j),  in respect of any fraction of a share of Common  Stock  issuable
upon such  conversion.  Such  conversion  shall be deemed to have been  effected
immediately  prior to the








                                      -9-


close of business  on the  Conversion  Date,  and at such time the rights of the
holder as holder of the converted shares of Series C Preferred Stock shall cease
and the person(s) in whose name(s) any certificate(s) for shares of Common Stock
shall be  issuable  upon such  conversion  shall be deemed  to have  become  the
holder(s) of record of the shares of Common Stock  represented  thereby.  If the
Corporation  fails to issue and deliver to such holder such  certificate(s)  for
shares of Common Stock  within  three (3) Trading  Days after the  Corporation's
receipt of the Original Documentation,  the Corporation shall pay the liquidated
damages set forth in the Stock Purchase  Agreement  between the  Corporation and
the initial purchasers of the Series C Preferred Stock.

                  (J) CASH IN LIEU OF FRACTIONAL SHARES. No fractional shares of
Common Stock or scrip  representing  fractional  shares shall be issued upon the
conversion  of shares of Series C  Preferred  Stock.  Instead of any  fractional
shares of Common  Stock that would  otherwise  be issuable  upon  conversion  of
Series C Preferred Stock, the Corporation  shall pay to the holder of the shares
of Series C Preferred Stock being converted a cash adjustment in respect of such
fractional  shares in an amount  equal to the same  fraction of the market price
per share of the Common Stock (as determined in a reasonable  manner  prescribed
by the Board of Directors) at the close of business on the Conversion  Date. The
determination  as to whether or not any fractional  shares are issuable shall be
based upon the  aggregate  number of shares of Series C  Preferred  Stock  being
converted at any one time by any holder thereof, not upon each share of Series C
Preferred Stock being converted.

                  (K) PARTIAL  CONVERSION.  In the event some but not all of the
shares of Series C Preferred Stock  represented by a certificate(s)  surrendered
by a holder are converted,  the  Corporation  shall execute and deliver to or on
the order of the holder,  at the expense of the  Corporation,  a new certificate
representing  the number of shares of Series C  Preferred  Stock  which were not
converted.  Such new  certificate  shall be so delivered on or prior to the date
set forth in Section 5(i) for the delivery of certificates  for shares of Common
Stock.

                  (L) RESERVATION OF COMMON STOCK. The Corporation  shall at all
times reserve and keep available out of its  authorized  but unissued  shares of
Common Stock,  solely for the purpose of effecting the  conversion of the shares
of the Series C Preferred  Stock,  such number of its shares of Common  Stock as
shall  from  time  to  time  be  sufficient  to  effect  the  conversion  of all
outstanding  shares of the Series C  Preferred  Stock  (including  any shares of
Series C Preferred Stock represented by any warrants,  options,  subscription or
purchase rights for the Series C Preferred Stock), and if at any time the number
of  authorized  but unissued  shares of Common Stock shall not be  sufficient to
effect the conversion of all then  outstanding  shares of the Series C Preferred
Stock  (including  any shares of Series C  Preferred  Stock  represented  by any
warrants,  options,  subscriptions or purchase rights for the Series C Preferred
Stock),  then the Corporation shall be deemed to be in breach and default of its
obligations hereunder,  and in addition to all charges, claims and rights at law
or in equity that each holder  shall be entitled to, the  Corporation  shall use
all means  reasonably  available to it, and promptly take any and all actions as
may be necessary, to increase its authorized but unissued shares of Common Stock
to such number of shares as shall be sufficient for such purpose.










                                      -10-

         6.  REDEMPTION AND REPURCHASE  RIGHTS.  The  Corporation  shall have no
right to redeem, and holders of shares of Series C Preferred Stock shall have no
right to cause the Corporation to redeem,  any or all of the outstanding  shares
of Series C Preferred Stock.

         7. NOTICES OF RECORD DATE. In the event of any:

                  (A) taking by the  Corporation  of a record of the  holders of
any class of securities for the purpose of determining  the holders  thereof who
are  entitled to receive any  dividend  or other  distribution,  or any right to
subscribe for,  purchase or otherwise acquire any shares of capital stock of any
class or any other securities or property, or to receive any other right, or

                  (B)   capital   reorganization   of   the   Corporation,   any
reclassification  or  recapitalization  of the capital stock of the Corporation,
any  merger or  consolidation  of the  Corporation,  or any  transfer  of all or
substantially all of the assets of the Corporation to any other Corporation,  or
any other entity or person, or

                  (C)  voluntary  or  involuntary  dissolution,  liquidation  or
winding up of the Corporation,

then and in each such event the  Corporation  shall telecopy and thereafter mail
or cause to be  mailed  to each  holder  of  Series C  Preferred  Stock a notice
specifying  (i) the date on which any such record is to be taken for the purpose
of such  dividend,  distribution  or right and a description  of such  dividend,
distribution  or  right,  (ii)  the  date  on  which  any  such  reorganization,
reclassification,    recapitalization,    transfer,    consolidation,    merger,
dissolution,  liquidation  or winding up is  expected to become  effective,  and
(iii) the time, if any, that is to be fixed, as to when the holders of record of
Common Stock (or other securities) shall be entitled to exchange their shares of
Common Stock (or other securities) for securities or other property  deliverable
upon  such   reorganization,   reclassification,   recapitalization,   transfer,
consolidation, merger, dissolution, liquidation or winding up. Such notice shall
be telecopied and thereafter mailed by first class mail, postage prepaid,  or by
express  overnight  courier  service,  at least ten (10) days  prior to the date
specified in such notice on which such action is to be taken.

         8.       GENERAL.

                  (a)  REPLACEMENT  OF  CERTIFICATES.   Upon  the  Corporation's
receipt,  from the  holder  of any  certificate  evidencing  shares  of Series C
Preferred  Stock,  of evidence  reasonably  satisfactory  to the Corporation (an
affidavit of such holder will be  satisfactory)  of the  ownership and the loss,
theft,  destruction  or mutilation of such  certificate,  and in the case of any
such  loss,  theft  or  destruction,   upon  receipt  of  indemnity   reasonably
satisfactory to the Corporation,  and in the case of any such  mutilation,  upon
surrender of such  certificate,  the  Corporation (at its expense) shall execute
and deliver to such holder, in lieu of such certificate,  a new certificate that
represents the number of shares  represented by, is dated the date of, is issued
in the name of the holder of, and is  substantially  identical  in form of, such
lost, stolen, destroyed or mutilated certificate.








                                      -11-


                  (B)  PAYMENT  OF TAXES.  The  Corporation  shall pay all taxes
(other than taxes based upon income) and other governmental  charges that may be
imposed in  connection  with the  issuance  or  delivery of any shares of Common
Stock (or  other of the  Corporation's  securities)  that  results  from (i) the
conversion of shares of Series C Preferred Stock pursuant to this Certificate of
Designations or (ii) the application of Section 2(a)(v) hereof.  Notwithstanding
the  foregoing,  if the  Corporation,  pursuant to a notice from a holder of any
shares of Series C  Preferred  Stock,  effects  the  issuance or delivery of any
shares of Common Stock (or other of the Corporation's securities) in any name(s)
other than such holder's name, then such holder shall deliver to the Corporation
with the aforesaid notice (A) all transfer taxes and other governmental  charges
payable upon the issuance or delivery of securities in such other name(s) or (B)
evidence  satisfactory to the Corporation  that such taxes and charges have been
or shall be paid in full.

                  (C) STATUS OF REDEEMED OR CONVERTED SHARES. Shares of Series C
Preferred  Stock that are  redeemed,  converted  or  otherwise  acquired  by the
Corporation in any manner  (including by purchase or exchange) shall be canceled
and upon  cancellation  (i) shall no longer  be deemed to be  outstanding,  (ii)
shall become  authorized but unissued shares of preferred stock  undesignated as
to series  and (iii) may be  reissued  as part of  another  series of  preferred
stock.




 

                                                                      Exhibit 3c


                                  DYNAGEN, INC.

                    CERTIFICATE OF DESIGNATIONS, PREFERENCES

                     AND RIGHTS OF SERIES D PREFERRED STOCK



         The undersigned officer of DynaGen,  Inc., a corporation  organized and
existing under the General Corporation Law of the State of Delaware, does hereby
certify  that,   pursuant  to  authority   conferred  by  the   Certificate   of
Incorporation, as amended to date, and pursuant to the provisions of Section 151
of the General Corporation Law of the State of Delaware,  the Board of Directors
of DynaGen, Inc., on August 13, 1997, adopted a resolution providing for certain
powers, designations, preferences and relative, participating, optional or other
rights, and the qualifications,  limitations or restrictions thereof, of certain
shares of Series D Preferred Stock,  $.01 par value, of the  Corporation,  which
resolution is as follows:

         RESOLVED:  That,  pursuant  to the  authority  vested  in the  Board of
Directors of the Corporation and in accordance with the General  Corporation Law
of the State of Delaware and the provisions of the Corporation's  Certificate of
Incorporation,  a series of 60,000 shares of the class of  authorized  Preferred
Stock,  par value $.01 per share,  of the  Corporation  is hereby created as the
Series D Preferred  Stock, and that the designation and number of shares thereof
and the voting powers,  preferences  and relative,  participating,  optional and
other  special  rights of the  shares of such  series,  and the  qualifications,
limitations  and  restrictions  thereof,  are as set forth on Exhibit A attached
hereto.

         EXECUTED as of this 14th day of August, 1997.

                                            DYNAGEN, INC.


                                            By:    /s/ Indu A. Muni
                                               ----------------------------
                                              Indu A. Muni
                                              President








                                    EXHIBIT A



A.       DESCRIPTION AND DESIGNATION OF SERIES D PREFERRED STOCK

         1.       DESIGNATION AND DEFINITIONS.

                  (A) DESIGNATION. A total of 60,000 shares of the Corporation's
previously  undesignated Preferred Stock, $.01 par value, shall be designated as
the "Series D Preferred Stock." The original issue price per share of the Series
D Preferred Stock shall be $100.00 (the "ORIGINAL ISSUE PRICE").

                  (B) CERTAIN DEFINITIONS.  As used herein, the following terms,
unless the context otherwise requires, have the following respective meanings:

                  "CLOSING  DATE" means the original  issue date of the Series C
Preferred  Stock  pursuant to a certain  Stock  Purchase  Agreement in which the
Corporation  agreed  to  issue,  and the  purchasers  named  therein  agreed  to
purchase, shares of Series C Preferred Stock and Series D Preferred Stock.

                  "COMMON  STOCK"  means the  common  stock,  par value $.01 per
share, of the Corporation.

                  "CONVERSION  DATE"  means  each date on which the  Corporation
receives by telecopy  written notice in accordance with Section 4(i) hereof from
a holder of Series D Preferred  Stock that such holder elects to convert  shares
of its Series D Preferred Stock.

                  "EFFECTIVE DATE" means the date as of which the Securities and
Exchange Commission has issued a declaration or order of effectiveness  relating
to a  registration  statement  filed,  in compliance  with the Securities Act of
1933,  as amended,  and Rule 415  thereunder,  with  respect to shares of Common
Stock issued or issuable on conversion of the Series D Preferred  Stock pursuant
to Section 4 below.

                  "FUNDAMENTAL  CHANGE" means: (i) any sale, lease,  exchange or
other transfer of all or substantially all of the assets or capital stock of the
Corporation;  or (ii) any merger or  consolidation to which the Corporation is a
party.  Notwithstanding the foregoing,  the following shall not be a Fundamental
Change:  A merger or  consolidation  to which the  Corporation is a party and in
which it is the surviving corporation and there is no resulting reclassification
of the outstanding  Common Stock; and after giving effect to which,  persons who
were,  immediately  before  the  consummation  or  closing  of  such  merger  or
consolidation,  holders  of  outstanding  Common  Stock  will be the  direct  or
indirect owners of securities of the Corporation possessing,  on a fully diluted
basis,  at least  seventy-five  percent  (75%) of the voting power of all voting
securities of the Corporation (excluding, for purposes of such computation,  any
such person who also is a party to such merger or consolidation).

                                      -2-







                 "ISSUE  DATE"  means,  with  respect to each share of Series D
Preferred Stock held by any holder, the date on which the Corporation originally
issued such share to such holder  (regardless of the number of times transfer of
such  share  is  made  on the  stock  transfer  books  maintained  by or for the
Corporation, and regardless of the number of certificates which may be issued to
evidence  such  share,  and  irrespective  of any  subsequent  transfer or other
disposition of such share to any other holder),  pursuant to a periodic issuance
of the Series D Preferred Stock (not less than thirty (30) days apart) under the
Stock  Purchase  Agreement in which the  Corporation  has the right to request a
purchase of the Series D Preferred Stock during any thirty-day period.

                  "MARKET  PRICE"  means the average of the closing bid price of
the Common Stock of the Corporation as reported by the Nasdaq SmallCap Market or
Nasdaq National Market or, if the Corporation's Common Stock is no longer traded
on a Nasdaq market, such other exchange on which the Corporation's  Common Stock
is then  traded,  for the five (5)  Trading  Days  prior  to the  Closing  Date,
Effective  Date,  any Issue  Date,  or any date of  conversion  of the  series D
Preferred Stock..

                  "TRADING  DAY"  means a day on which  the  principal  national
securities  exchange on which the Common  Stock is listed or admitted to trading
is open for the  transaction of business;  or, if the Common Stock is not listed
or admitted to trading on any national  securities exchange but is listed on the
Nasdaq  system  (or  such  other  trading  system  then  in use by the  National
Association of Securities Dealers, Inc.), a day on which such system is open for
the transaction of business;  or, if the foregoing does not apply,  any business
day.

                  2.       LIQUIDATION, DISSOLUTION OR WINDING UP.

                  (A) TREATMENT AT  LIQUIDATION,  DISSOLUTION  OR WINDING UP. In
the event of any  liquidation,  dissolution  or winding  up of the  Corporation,
whether voluntary or involuntary, or in the event of its insolvency,  before any
distribution  or  payment is made to any  holders  of Common  Stock or any other
class or series of capital stock of the  Corporation  designated to be junior to
the  Series D  Preferred  Stock,  and  subject  to the  liquidation  rights  and
preferences of any class or series of Preferred Stock designated by the Board of
Directors  in the  future  to be  senior  to or on a parity  with  the  Series D
Preferred  Stock with  respect to  liquidation  preferences,  the holder of each
share of Series D Preferred  Stock shall be entitled to be paid first out of the
assets  of  the  Corporation  available  for  distribution  to  holders  of  the
Corporation's  capital  stock of all  classes,  whether such assets are capital,
surplus or earnings,  an amount  equal to the Original  Issue Price per share of
Series D  Preferred  Stock held by any holder  (the  "LIQUIDATION  VALUE").  For
purposes hereof,  the Series D Preferred Stock shall rank on liquidation  junior
to the Series A Preferred Stock, Series B Preferred Stock and Series C Preferred
Stock.

                  If,  upon  liquidation,  dissolution  or  winding  up  of  the
Corporation,  the assets of the  Corporation  available for  distribution to its
stockholders  shall be insufficient to pay the holders of the Series D Preferred
Stock the full amount to which they otherwise would be entitled,  the holders of
Series D Preferred  Stock shall share ratably in any  distribution  of available
assets pro rata in proportion to the respective  liquidation  preference amounts
which  would  otherwise  be  payable  upon   liquidation  with  respect  to  the
outstanding shares of the Series D Preferred Stock if








                                      -3-


all  liquidation  preference  amounts  with  respect to such shares were paid in
full,  based upon the  aggregate  Liquidation  Value  payable upon all shares of
Series D Preferred Stock then outstanding.

                  After such payment shall have been made in full to the holders
of the Series D Preferred  Stock, or funds necessary for such payment shall have
been set aside by the  Corporation  in trust for the  account  of holders of the
Series D Preferred  Stock so as to be available for such payment,  the remaining
assets available for distribution shall be distributed ratably among the holders
of the Common Stock and any class or series of capital  stock  designated  to be
junior to the Series D  Preferred  Stock (if any) in right of  payment  upon any
liquidation, dissolution or winding up of the Corporation.

                  The  amounts  set forth  above  shall be subject to  equitable
adjustment  by the  Board  of  Directors  whenever  there  shall  occur  a stock
dividend,   stock   split,   combination,   reorganization,    recapitalization,
reclassification  or other  similar  event  involving  a change  in the  capital
structure of the Series D Preferred Stock.

                  (B) DISTRIBUTIONS  OTHER THAN CASH. Whenever the distributions
provided for in this Section shall be payable in property  other than cash,  the
value of such  distribution  shall be the fair market value of such  property as
determined in good faith by the Board of Directors. All distributions (including
distributions  other  than cash)  made  hereunder  shall be made pro rata to the
holders of Series D Preferred Stock.

                  (C)  EVENTS NOT DEEMED A  LIQUIDATION.  Neither  the merger or
consolidation of the Corporation into or with any other corporation(s),  nor the
sale or transfer by the  Corporation  of all or any part of its assets,  nor the
reduction  of the  capital  stock of the  Corporation,  will be  deemed  to be a
liquidation, dissolution or winding up of the Corporation under this Section 2.

         3.       VOTING POWER.

                  (A) GENERAL.  Except as otherwise  expressly  provided in this
Section 3 or as otherwise  required by the General  Corporation Law of the State
of Delaware,  each holder of Series D Preferred  Stock shall be entitled to vote
on all  matters  and shall be  entitled  to that  number  of votes  equal to the
largest  number of whole shares of Common Stock into which such holder's  shares
of Series D Preferred  Stock could be converted,  pursuant to the  provisions of
Section 4 hereof,  at the  record  date for the  determination  of  stockholders
entitled to vote on any matter or, if no such record date is established, at the
date such vote is taken or any written  consent of  stockholders  is  solicited.
Except as otherwise expressly required by law, the holders of shares of Series A
Preferred Stock,  Series B Preferred Stock,  Series C Preferred Stock,  Series D
Preferred Stock and Common Stock shall vote together (or render written consents
in  lieu  of a  vote)  as a  single  class  on  all  matters  submitted  to  the
stockholders of the Corporation.

                  Such  determination  of "whole shares" shall be based upon the
aggregate number of shares of Series D Preferred Stock held by each holder,  and
not upon each share of Series D Preferred Stock so held by the holder.









                                      -4-

                  (B) AMENDMENTS TO CHARTER. For so long as there are any shares
of Series D Preferred Stock  outstanding,  the  Corporation  shall not amend its
Certificate of  Incorporation  or this  Certificate  of Designation  without the
approval,  by vote or written consent,  of the holders of at least a majority of
the then outstanding  shares of Series D Preferred  Stock,  voting together as a
class, each share of Series D Preferred Stock to be entitled to one vote in each
instance,  if such amendment would adversely affect the rights of the holders of
Series D Preferred Stock. Without limiting the generality of the foregoing,  the
creation, or increase in the authorized number of shares, of any class or series
of stock  ranking  prior to or on a parity  with the  Series D  Preferred  Stock
either as to dividends or upon  liquidation  shall be deemed to adversely affect
the  rights of the  holders of Series D  Preferred  Stock for  purposes  of this
Section 3(b).

         4.       CONVERSION RIGHTS.

                  (A) CONVERSION AT THE OPTION OF HOLDERS. Each holder of Series
D Preferred Stock shall have the right at any time, at such holder's option,  to
convert  the shares of Series D  Preferred  Stock held by such  holder into such
number  of fully  paid and  nonassessable  shares  of  Common  Stock as shall be
determined by multiplying the number of shares of Series D Preferred Stock to be
converted by a fraction, the numerator of which is the Original Issue Price, and
the denominator of which is the applicable Conversion Price (as defined below).

                  (B)  CONVERSION  PRICE.  The  conversion  price per share (the
"CONVERSION  PRICE")  shall be equal to the lesser of  subsections  (i) and (ii)
below:

                           (i)  Eighty-five  percent  (85%) of the Market  Price
prior to any conversion of the Series D Preferred Stock; or

                           (ii) one hundred  twenty-five  percent  (125%) of the
Market Price on the Closing Date.

                  (C) CONVERSION AT OPTION OF CORPORATION. At any time after the
close of business on the two-year  anniversary of the Effective Date, all of the
shares of Series D Preferred  Stock shall be  convertible,  at the option of the
Corporation,  into such number of fully paid and nonassessable  shares of Common
Stock as shall be  determined  by  multiplying  the number of shares of Series D
Preferred Stock outstanding on the Mandatory  Conversion Date (as defined below)
by a fraction,  the  numerator  of which is the Original  Issue  Price,  and the
denominator of which is the applicable Conversion Price.

                  The  Corporation  shall give  notice of its  exercise  of such
conversion  option to all holders of Series D Preferred Stock no later than five
(5) Trading Days before the date as of which the Corporation has elected to make
such conversion effective (such effective date of the conversion, the "MANDATORY
CONVERSION  Date").  Each holder of Series D Preferred Stock as of the Mandatory
Conversion Date shall, promptly after such date, surrender for conversion to the
Corporation  at its principal  office or to any transfer  agent for the Series D
Preferred Stock or the Common Stock all certificates  representing all shares of
Series D Preferred  Stock held by such holder,  accompanied  by a written notice
specifying the name or names in which such holder wishes the  certificate(s) for
shares of Common Stock to be issued.










                                      -5-

                  Effective  as of  the  close  of  business  on  the  Mandatory
Conversion Date, each share of Series D Preferred Stock then  outstanding  shall
be (and be deemed to have been)  converted  automatically,  without  any further
action by the holders  thereof,  into shares of Common  Stock.  Such  conversion
shall be deemed to have occurred  whether or not the  certificates  representing
such shares are surrendered to the Corporation or its transfer agent.

                  (D)   LIMITATION   ON   NUMBER   OF   SHARES.    Additionally,
notwithstanding  anything  set forth in this  Section 4 to the  contrary,  in no
event shall any holder of Series D Preferred Stock, prior to earlier to occur of
the Mandatory  Conversion  Date or the date of the  consummation or closing of a
Fundamental  Change, be entitled to convert Series D Preferred Stock into shares
of Common Stock to the extent that (x) the number of shares of the Corporation's
Common Stock  beneficially  owned by such holder and its affiliates  (other than
shares  of Common  Stock  which may be deemed  beneficially  owned  through  the
ownership of the  unconverted  portion of the shares of Series D Preferred Stock
held by such holder) plus (y) the number of shares of Common Stock issuable upon
such  conversion  would  result in  beneficial  ownership  by the holder and its
affiliates of more than 4.9% of the shares of Common Stock then outstanding. For
purposes of this Section  4(d),  beneficial  ownership  shall be  determined  in
accordance  with  Section  13(d) of the  Securities  Exchange  Act of  1934,  as
amended, and Regulation 13D and 13G promulgated thereunder,  except as otherwise
provided in clause (x) of this Section 4(d). Each holder shall,  upon delivering
to the  Corporation a notice of election to convert shares of Series D Preferred
Stock in  accordance  with  Section  4(i)  hereof,  be  required  to provide the
Corporation with a certification in form and substance  reasonably  satisfactory
to the  Corporation,  that the conversion of the Series D Preferred  Stock being
converted will not result in such holder and its affiliates beneficially holding
more than 4.9%,  determined as heretofore provided, of the outstanding shares of
Common  Stock  on  such  Conversion   Date.  If  the  holder  cannot  make  such
certification,  the shares of Series D Preferred Stock to be converted shall not
be convertible.  Notwithstanding  the foregoing,  upon the Mandatory  Conversion
Date or upon the  consummation  or closing  of a  Fundamental  Change,  all such
shares of Series D Preferred  Stock then  outstanding  shall be  converted  into
Common Stock in accordance with Section 4(c) or 4(g), as applicable.

                  (E) DIVIDENDS OTHER THAN COMMON STOCK DIVIDENDS.  In the event
the  Corporation  shall  make or  issue,  or  shall  fix a  record  date for the
determination of holders of Common Stock entitled to receive a dividend or other
distribution  (other than a distribution  in  liquidation or other  distribution
otherwise  provided for herein) with respect to the Common Stock  payable in (i)
securities of the  Corporation  other than shares of Common Stock, or (ii) other
assets (excluding cash dividends or distributions),  then and in each such event
provision  shall be made so that the  holders  of the Series D  Preferred  Stock
shall  receive  upon  conversion  thereof in addition to the number of shares of
Common Stock receivable thereupon, the number of securities or such other assets
of the  Corporation  which they would have received had their Series D Preferred
Stock been  converted  into Common  Stock on the date of such event and had they
thereafter,  during the period from the date of such event to and  including the
Conversion  Date,  retained such  securities or such other assets  receivable by
them during such period,  giving application to all other adjustments called for
during  such  period  under  this  Section 4 with  respect  to the rights of the
holders of the Series D Preferred Stock.







                                      -6-

                  (F) CAPITAL REORGANIZATION OR RECLASSIFICATION.  If the Common
Stock  issuable  upon the  conversion  of the Series D Preferred  Stock shall be
changed into the same or  different  number of shares of any class or classes of
capital   stock,   whether   by   capital   reorganization,    recapitalization,
reclassification or otherwise (other than a subdivision or combination of shares
or stock  dividend  provided for elsewhere in this Section 4, or the sale of all
or substantially all of the  Corporation's  capital stock or assets to any other
person),  then and in each such event the  holders of Series D  Preferred  Stock
shall have the right  thereafter to convert such shares into the kind and amount
of shares of capital stock and other  securities  and property  receivable  upon
such reorganization,  recapitalization,  reclassification or other change by the
holders of the number of shares of Common Stock into which such shares of Series
D  Preferred  Stock  might  have  been  converted   immediately  prior  to  such
reorganization,  recapitalization,  reclassification  or change,  all subject to
further adjustment as provided herein.

                  (G)  MANDATORY   CONVERSION  -  FUNDAMENTAL   CHANGE.  If  any
Fundamental  Change  shall  occur,  then each share of Series D Preferred  Stock
outstanding as of the date of the  consummation or closing thereof shall be (and
be deemed to have been) converted  automatically,  without any further action by
the holders thereof,  into such number of fully paid and nonassessable shares of
Common  Stock as shall be  determined  by  multiplying  the  number of shares of
Series D Preferred Stock  outstanding on the on the date of such consummation or
closing date by a fraction,  the numerator of which is the Original Issue Price,
and the denominator of which is the applicable Conversion Price. Such conversion
shall be deemed to have occurred  whether or not the  certificates  representing
such shares are surrendered to the Corporation or its transfer agent.

                  The Corporation shall give notice of a proposed or anticipated
Fundamental Change to all holders of the Series D Preferred Stock not later than
thirty (30) days before the expected closing or consummation of such Fundamental
Change,  provided that at all times during such thirty-day period a registration
statement  shall be in effect to permit the  registration  of the  Common  Stock
issuable upon  conversion of the Series D Preferred  Stock under the  Securities
Act of 1933, as amended.  The  Corporation  also shall give prompt notice of the
closing or consummation of such  Fundamental  Change to all holders of record of
the Series D  Preferred  Stock as of the date of such  closing or  consummation.
Each holder of Series D Preferred Stock shall thereupon  promptly  surrender for
conversion,  to the Corporation at its principal office or to any transfer agent
for  the  Series  D  Preferred  Stock  or the  Common  Stock,  all  certificates
representing  all  shares  of  Series D  Preferred  Stock  held by such  holder,
accompanied  by a  written  notice  specifying  the name or names in which  such
holder wishes the certificate(s) for shares of Common Stock to be issued.

                  (H) CERTIFICATE AS TO ADJUSTMENTS;  NOTICE BY CORPORATION.  In
each case of an  adjustment or  readjustment  of the Original  Issue Price,  the
Corporation at its expense will furnish each holder of Series D Preferred  Stock
so  affected  with a  certificate  prepared  by an officer  of the  Corporation,
showing such  adjustment or  readjustment,  and stating in detail the facts upon
which such adjustment or readjustment is based.

                  (I)  EXERCISE  OF  CONVERSION   PRIVILEGE.   To  exercise  its
conversion  privilege,  a holder of Series D Preferred  Stock shall give written
notice by telecopy to the  Corporation at its 










                                      -7-


principal  office  that such  holder  elects to  convert  shares of its Series D
Preferred  Stock and shall  thereafter  surrender  the  original  certificate(s)
representing  the shares being  converted to the  Corporation  at its  principal
office  together  with an originally  executed copy of such notice.  Such notice
shall also state the name or names  (with its address or  addresses,  as well as
the address(es) for delivery) in which the  certificate(s)  for shares of Common
Stock issuable upon such conversion shall be issued.  The certificate(s) for the
shares  of  Series  D  Preferred  Stock  surrendered  for  conversion  shall  be
accompanied by proper  assignment  thereof to the  Corporation  or in blank.  As
promptly  as   practicable   after  the   Corporation   receives   the  original
certificate(s)  for the  shares  of Series D  Preferred  Stock  surrendered  for
conversion, the proper assignment thereof to the Corporation or in blank and the
original notice of conversion (collectively, the "ORIGINAL DOCUMENTATION"),  but
in no event more than three (3) Trading Days after the Corporation's  receipt of
the Original Documentation, the Corporation shall issue and shall deliver to the
holder  of the  shares of  Series D  Preferred  Stock  being  converted,  at the
addresses  set forth  therefor  by the  holder,  such  certificate(s)  as it may
request  for the  number  of whole  shares  of Common  Stock  issuable  upon the
conversion  of such shares of Series D Preferred  Stock in  accordance  with the
provisions  of this Section 4, and cash, as provided in Section 4(j), in respect
of any fraction of a share of Common Stock issuable upon such  conversion.  Such
conversion shall be deemed to have been effected  immediately prior to the close
of business on the Conversion Date, and at such time the rights of the holder as
holder of the converted  shares of Series D Preferred  Stock shall cease and the
person(s) in whose name(s) any  certificate(s)  for shares of Common Stock shall
be issuable upon such conversion shall be deemed to have become the holder(s) of
record of the shares of Common Stock  represented  thereby.  If the  Corporation
fails to issue and  deliver to such  holder  such  certificate(s)  for shares of
Common Stock within  three (3) Trading Days after the  Corporation's  receipt of
the Original Documentation, the Corporation shall pay the liquidated damages set
forth in the Stock Purchase  Agreement  between the  Corporation and the initial
purchasers of the Series D Preferred Stock.

                  (J) CASH IN LIEU OF FRACTIONAL SHARES. No fractional shares of
Common Stock or scrip  representing  fractional  shares shall be issued upon the
conversion  of shares of Series D  Preferred  Stock.  Instead of any  fractional
shares of Common  Stock that would  otherwise  be issuable  upon  conversion  of
Series D Preferred Stock, the Corporation  shall pay to the holder of the shares
of Series D Preferred Stock being converted a cash adjustment in respect of such
fractional  shares in an amount  equal to the same  fraction of the market price
per share of the Common Stock (as determined in a reasonable  manner  prescribed
by the Board of Directors) at the close of business on the Conversion  Date. The
determination  as to whether or not any fractional  shares are issuable shall be
based upon the  aggregate  number of shares of Series D  Preferred  Stock  being
converted at any one time by any holder thereof, not upon each share of Series D
Preferred Stock being converted.

                  (K) PARTIAL  CONVERSION.  In the event some but not all of the
shares of Series D Preferred Stock  represented by a certificate(s)  surrendered
by a holder are converted,  the  Corporation  shall execute and deliver to or on
the order of the holder,  at the expense of the  Corporation,  a new certificate
representing  the number of shares of Series D  Preferred  Stock  which were not
converted.  Such new  certificate  shall be so delivered on or prior to the date
set forth in Section 4(i) for the delivery of certificates  for shares of Common
Stock.









                                      -8-

                  (L) RESERVATION OF COMMON STOCK. The Corporation  shall at all
times reserve and keep available out of its  authorized  but unissued  shares of
Common Stock,  solely for the purpose of effecting the  conversion of the shares
of the Series D Preferred  Stock,  such number of its shares of Common  Stock as
shall  from  time  to  time  be  sufficient  to  effect  the  conversion  of all
outstanding  shares of the Series D  Preferred  Stock  (including  any shares of
Series D Preferred Stock represented by any warrants,  options,  subscription or
purchase rights for the Series D Preferred Stock), and if at any time the number
of  authorized  but unissued  shares of Common Stock shall not be  sufficient to
effect the conversion of all then  outstanding  shares of the Series D Preferred
Stock  (including  any shares of Series D  Preferred  Stock  represented  by any
warrants,  options,  subscriptions or purchase rights for the Series D Preferred
Stock),  then the Corporation shall be deemed to be in breach and default of its
obligations hereunder,  and in addition to all charges, claims and rights at law
or in equity that each holder  shall be entitled to, the  Corporation  shall use
all means  reasonably  available to it, and promptly take any and all actions as
may be necessary, to increase its authorized but unissued shares of Common Stock
to such number of shares as shall be sufficient for such purpose.

         5.  REDEMPTION AND REPURCHASE  RIGHTS.  The  Corporation  shall have no
right to redeem, and holders of shares of Series D Preferred Stock shall have no
right to cause the Corporation to redeem,  any or all of the outstanding  shares
of Series D Preferred Stock.

         6. NOTICES OF RECORD DATE. In the event of any:

                  (A) taking by the  Corporation  of a record of the  holders of
any class of securities for the purpose of determining  the holders  thereof who
are  entitled to receive any  dividend  or other  distribution,  or any right to
subscribe for,  purchase or otherwise acquire any shares of capital stock of any
class or any other securities or property, or to receive any other right, or

                  (B)   capital   reorganization   of   the   Corporation,   any
reclassification  or  recapitalization  of the capital stock of the Corporation,
any  merger or  consolidation  of the  Corporation,  or any  transfer  of all or
substantially all of the assets of the Corporation to any other Corporation,  or
any other entity or person, or

                  (C)  voluntary  or  involuntary  dissolution,  liquidation  or
winding up of the Corporation,

then and in each such event the  Corporation  shall telecopy and thereafter mail
or cause to be  mailed  to each  holder  of  Series D  Preferred  Stock a notice
specifying  (i) the date on which any such record is to be taken for the purpose
of such  dividend,  distribution  or right and a description  of such  dividend,
distribution  or  right,  (ii)  the  date  on  which  any  such  reorganization,
reclassification,    recapitalization,    transfer,    consolidation,    merger,
dissolution,  liquidation  or winding up is  expected to become  effective,  and
(iii) the time, if any, that is to be fixed, as to when the holders of record of
Common Stock (or other securities) shall be entitled to exchange their shares of
Common Stock (or other securities) for securities or other property  deliverable
upon  such   reorganization,   reclassification,   recapitalization,   transfer,
consolidation, merger, dissolution, liquidation or winding up. Such notice shall
be telecopied and thereafter mailed by 









                                      -9-

first class mail, postage prepaid,  or by express overnight courier service,  at
least ten (10) days  prior to the date  specified  in such  notice on which such
action is to be taken.

         7.       GENERAL.

                  (A)  REPLACEMENT  OF  CERTIFICATES.   Upon  the  Corporation's
receipt,  from the  holder  of any  certificate  evidencing  shares  of Series D
Preferred  Stock,  of evidence  reasonably  satisfactory  to the Corporation (an
affidavit of such holder will be  satisfactory)  of the  ownership and the loss,
theft,  destruction  or mutilation of such  certificate,  and in the case of any
such  loss,  theft  or  destruction,   upon  receipt  of  indemnity   reasonably
satisfactory to the Corporation,  and in the case of any such  mutilation,  upon
surrender of such  certificate,  the  Corporation (at its expense) shall execute
and deliver to such holder, in lieu of such certificate,  a new certificate that
represents the number of shares  represented by, is dated the date of, is issued
in the name of the holder of, and is  substantially  identical  in form of, such
lost, stolen, destroyed or mutilated certificate.

                  (B)  PAYMENT  OF TAXES.  The  Corporation  shall pay all taxes
(other than taxes based upon income) and other governmental  charges that may be
imposed in  connection  with the  issuance  or  delivery of any shares of Common
Stock  (or  other  of  the  Corporation's  securities)  that  results  from  the
conversion of shares of Series D Preferred Stock pursuant to this Certificate of
Designations.  Notwithstanding the foregoing, if the Corporation,  pursuant to a
notice  from a holder of any shares of Series D  Preferred  Stock,  effects  the
issuance  or  delivery  of  any  shares  of  Common   Stock  (or  other  of  the
Corporation's  securities)  in any name(s) other than such holder's  name,  then
such holder shall deliver to the Corporation  with the aforesaid  notice (A) all
transfer  taxes and other  governmental  charges  payable  upon the  issuance or
delivery of securities in such other name(s) or (B) evidence satisfactory to the
Corporation that such taxes and charges have been or shall be paid in full.

                  (C) STATUS OF REDEEMED OR CONVERTED SHARES. Shares of Series D
Preferred  Stock that are  redeemed,  converted  or  otherwise  acquired  by the
Corporation in any manner  (including by purchase or exchange) shall be canceled
and upon  cancellation  (i) shall no longer  be deemed to be  outstanding,  (ii)
shall become  authorized but unissued shares of preferred stock  undesignated as
to series  and (iii) may be  reissued  as part of  another  series of  preferred
stock.







                                                                      Exhibit 4a
                          SECURITIES PURCHASE AGREEMENT

         This  Securities  Purchase  Agreement  (the  "AGREEMENT"),  dated as of
______________,  1997,  is entered  into by and between  the  parties  listed on
Schedule  I  hereto   (individually,   a  "PURCHASER"  and   collectively,   the
"PURCHASERS") and DYNAGEN, INC., a Delaware corporation (the "COMPANY").

         The parties hereto agree as follows:

         1. PURCHASE AND SALE OF PREFERRED  SHARES AND WARRANTS.  Upon the basis
of the representations  and warranties,  and subject to the terms and conditions
set forth in this  Agreement,  the Company  covenants and agrees to sell to each
Purchaser on the Closing Date (as hereinafter  defined) (i) the number of shares
(the "PREFERRED SHARES") of its Series A Preferred Stock (the "PREFERRED STOCK")
set forth opposite the name of such  Purchaser  under the heading "The Number of
Preferred  Shares to be  Purchased,"  each such Preferred  Share  convertible in
accordance  with the  terms  and  conditions  of the  Company's  Certificate  of
Designation  for the  Preferred  Stock  filed  with  the  Secretary  of State of
Delaware on June 16, 1997,  attached  hereto as EXHIBIT A (the  "CERTIFICATE  OF
DESIGNATION"),  on the dates set forth in the  Certificate of  Designation  (any
such date of  conversion,  the  "CONVERSION  DATE") into shares of the Company's
Common Stock (the "CONVERSION  SHARES") and (ii) a warrant in substantially  the
form of EXHIBIT B hereto (the "WARRANT") to purchase the number of shares of the
Company's  Common Stock (the  "WARRANT  SHARES") set forth  opposite the name of
such  Purchaser  under the heading  "Number of Warrant  Shares."  The  Preferred
Shares (together with the Warrant Shares, the "SHARES"),  and the Warrants shall
be purchased at the aggregate  purchase price (the  "PURCHASE  PRICE") set forth
opposite  the name of such  Purchaser  under  the  heading  "Aggregate  Purchase
Price." The Preferred Shares and Warrants are sometimes hereinafter collectively
referred to as the "SECURITIES."

         2.  CLOSING.  The  closing of the  purchase  and sale of the  Preferred
Shares and the  Warrants  pursuant  to Section 1 hereof  shall take place at the
offices of Morse,  Zelnick, Rose & Lander LLP, located at 450 Park Avenue, Suite
902, New York, New York 10022 on such date as the Purchasers and the Company may
agree  upon,  or at such other time at which the  Escrow  Agent (as  hereinafter
defined) shall have received all documents and  instructions  as it shall in its
sole judgment deem  necessary and  appropriate  to consummate  the  transactions
contemplated  hereby (such time and date for the closing,  the "CLOSING  DATE").
The certificates  representing the Preferred Shares and the executed Warrants to
be  purchased  by the  Purchasers  shall be  delivered  by, or on behalf of, the
Company  at the  closing  against  payment of the  Purchase  Price  therefor  in
immediately  available funds by, or on behalf of, the Purchasers to the attorney
trust account of Morse, Zelnick, Rose & Lander, LLP, (the "ESCROW AGENT") (Chase
Manhattan Bank, Account No. 967086639, ABA Routing Number 021000021). The Escrow
Agent shall receive from the Purchasers and the Company written  instructions of
the  Purchasers  and the Company in  substantially  the form of EXHIBIT C hereto
instructing  the  Escrow  Agent  with  respect  to the  closing  and  settlement
procedures,  subject,  however, to the terms and conditions of this 











Agreement on the date the  Purchasers  deliver the Purchase  Price to the Escrow
Agent.  Commencing on the fifth  business day after delivery to the Escrow Agent
of the Purchase  Price,  the  Purchasers,  if the purchase and sale  transaction
contemplated  hereby has not been  consummated  in accordance  with the terms of
this Agreement,  may terminate the proposed transaction by notice to the Company
and the Escrow Agent,  whereupon the Escrow Agent shall  promptly  redeliver the
Purchase Price to the Purchasers in accordance with the written  instructions of
the Purchasers.

         3.  REPRESENTATIONS,  WARRANTIES AND COVENANTS OF THE PURCHASERS.  Each
Purchaser  understands,  and  represents  and warrants to, and agrees with,  the
Company, that:

                  (a) The Preferred Shares (including the Conversion Shares) and
the Warrants (including the Warrant Shares) have not been and, unless registered
under  the  Securities  Act of 1933,  as  amended  (the  "SECURITIES  ACT"),  in
accordance with the Registration  Rights Agreement (as defined in Section 6(b)),
will not be  registered  under  the  Securities  Act,  or any  other  applicable
securities  law,  and,  accordingly,  may  not be  offered,  sold,  transferred,
pledged, hypothecated or otherwise disposed of ("TRANSFERRED") unless registered
under  the  Securities   Act  or  Transferred  in  a  transaction   exempt  from
registration  under the Securities Act and any other  applicable  securities law
(in which event, each Purchaser shall be required to provide the Company with an
opinion of counsel that  registration  is not  required,  in form and  substance
reasonably satisfactory to the Company and its counsel).

                  Each Purchaser  acknowledges  and agrees that the certificates
representing  the Preferred  Shares and the Warrants and, prior to the effective
date of the  registration  thereof  under the  Securities  Act  pursuant  to the
Registration  Rights  Agreement,  the Conversion  Shares and the Warrant Shares,
will bear a legend in substantially the following form:

          THE  SECURITIES   REPRESENTED  BY  THIS   CERTIFICATE  HAVE  NOT  BEEN
          REGISTERED  UNDER THE  SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"),
          OR ANY STATE SECURITIES LAWS AND MAY NOT BE OFFERED, SOLD OR OTHERWISE
          TRANSFERRED,  IN THE  ABSENCE  OF SUCH  REGISTRATION  OR AN  EXEMPTION
          THEREFROM UNDER SAID ACT AND ANY APPLICABLE  STATE SECURITIES LAWS OR,
          UNLESS, IN THE OPINION OF COUNSEL, IN FORM AND SUBSTANCE  SATISFACTORY
          TO  THE  ISSUER,   SUCH  OFFER,  SALE,  OR  TRANSFER  IS  EXEMPT  FROM
          REGISTRATION OR IS OTHERWISE IN COMPLIANCE WITH THE ACT AND SUCH LAWS.

                  (b) Each  Purchaser  is an  "accredited  investor"  within the
meaning of Rule 501(a)  under the  Securities  Act,  was not  organized  for the
specific  purpose of acquiring the Securities,  and is acquiring or will acquire
the  Securities  for its own  account.  The  Purchaser  has such  knowledge  and
experience  in financial  and business  matters that it is capable of evaluating
the merits and risks of an investment in the Securities.  The Purchaser is aware
that it may be 


                                      -2-







required to bear the economic  risk  (including  the possible loss of the entire
investment) of an investment in the Securities for an indefinite  period, and it
is able to bear such risk for an indefinite period.

                  (c) Each  Purchaser is acquiring or will acquire the Preferred
Shares and the Warrant for its own account for investment  purposes and not with
a view to, or for offer or sale in connection  with, any  distribution  thereof,
except in compliance  with  applicable  securities  laws  (including  exemptions
thereunder)  or  pursuant  to an  effective  registration  statement  under  the
Securities  Act.  Each  Purchaser   agrees  to  Transfer  the  Preferred  Shares
(including the Conversion Shares) and the Warrant (including the Warrant Shares)
only (i) in  accordance  with the terms of this  Agreement  and the Warrant,  as
applicable,  and (ii) pursuant to  registration  under the  Securities Act or an
exemption from  registration  under the Securities Act and any other  applicable
securities law.

                  (d)  The  Company  has  furnished  or made  available  to each
Purchaser  all  material  information  relating to the  business,  finances  and
operations  of the Company and  material  information  relating to the offer and
sale of the  Securities and which have been  requested by each  Purchaser.  Each
Purchaser  and/or its  advisors,  if any, in each case,  have been  afforded the
opportunity  to ask  questions  of the  Company and have  received  satisfactory
answers to any such inquiries. Without limiting the generality of the foregoing,
each Purchaser has had the opportunity to obtain and to review the Company's (1)
Transition Report on Form 10-K for the six-month period ended December 31, 1996,
as amended by Amendment No. 1 to Transition Report on Form 10-K/A, as filed with
the Securities and Exchange  Commission  (the "SEC"),  (2) Quarterly  Reports on
Form 10-Q for the fiscal  quarters  ended March 31, 1997 and June 30, 1997,  (3)
definitive Proxy Statement of the Company dated December 27, 1996 for its Annual
Meeting of Stockholders held on January 30, 1997, (4) Current Report on Form 8-K
filed with the SEC on July 3, 1997,  as  amended by  Amendment  No. 1 to Current
Report on Form 8-K/A filed with the SEC on July 11, 1997 and  Amendment No. 2 to
Current  Report on Form 8-K/A filed with the SEC on August 29, 1997, and (5) the
Company's  Registration  Statement  on Form S-3 filed with the SEC on August 11,
1997, as amended by Amendment No. 1 to Registration  Statement on Form S-3 filed
with the SEC on September 11, 1997  (collectively,  the "SEC DOCUMENTS"),  which
the Company has filed pursuant to the Securities Act or the Securities  Exchange
Act of  1934,  as  amended  (the  "EXCHANGE  ACT").  Each  Purchaser  has had an
opportunity to discuss in depth the Company's business, management and financial
affairs with the Company's management,  and has been provided access to material
contracts  and  other  documents  it has  requested  and  various  informational
brochures regarding the Company.

                  (e)  Each   Purchaser,   in  electing  to  subscribe  for  the
Securities  hereunder,  has relied upon an independent  investigation made by it
and its representative, if any. Each Purchaser has been given no oral or written
representations  or  assurances  from the Company or any  representative  of the
Company other than as set forth in this Agreement or in a document executed by a
duly  authorized   representative  of  the  Company  making  reference  to  this
Agreement.


                                      -3-










                  (f) Each Purchaser has no existing short position with respect
to the Common Stock.

                  (g)  Each  Purchaser   acknowledges   that,   except  for  the
historical  material  contained  herein  or in the SEC  Documents,  the  matters
disclosed  herein and therein are  forward-looking  statements under the federal
securities laws that involve risks and uncertainties, including, but not limited
to, the  Company's  ability  to obtain  future  financing,  the  management  and
integration of acquired  businesses and possible  future  acquisitions,  product
demand and market  acceptance  risks,  the effect of  economic  conditions,  the
impact   of   competitive    products   and   pricing,    product   development,
commercialization   and   technological   difficulties,   capacity   and  supply
constraints or difficulties,  the results of financing efforts, actual purchases
under  agreements,  and other risks  detailed in the  Company's  SEC  Documents.
Actual results could differ  materially  from those  estimated or anticipated in
these forward-looking statements.

                  (h) Each  Purchaser  is a resident of the state or country set
forth under its name on the signature page hereto.

                  (i) The foregoing  representations and warranties are true and
accurate as of the date hereof and unless  otherwise  informed in writing may be
relied upon by the Company as being true and correct as of the Closing  Date and
the date of each Purchaser's  purchase of the Securities  subscribed for herein,
and such representations and warranties shall survive such purchase.

         4.   REPRESENTATIONS  AND  WARRANTIES  OF  THE  COMPANY.   The  Company
represents  and warrants to, and agrees with,  the  Purchasers  that,  except as
disclosed in the Disclosure Schedule attached hereto:

                  (a) The  Company and each of its  subsidiaries  have been duly
incorporated  and are validly  existing as corporations  under the laws of their
respective  states of incorporation  and have the requisite  corporate powers to
own their properties and to carry on their businesses as now being conducted.

                  (b)  This  Agreement,  the  Certificate  of  Designation,  the
Warrants and the Registration Rights Agreement (as defined in Section 6(b)) have
been duly authorized, executed and delivered by the Company and constitute valid
and binding  agreements,  enforceable in accordance with their  respective terms
(except to the extent that enforceability  thereof may be limited by bankruptcy,
insolvency or other similar laws affecting creditors' rights generally), and the
Company has full  corporate  power and  authority  necessary  to enter into such
agreements and to perform its obligations thereunder.

                  (c) No consent, approval, authorization or order of any court,
governmental  agency or body or arbitrator having  jurisdiction over the Company
or any of its  affiliates  or of any third party or of the  stockholders  of the
Company is  required  for  execution  of this  Agreement,  the  Warrants  or the
Registration  Rights Agreement or the performance of its obligations  under such

                                      -4-









agreements,  including,  without  limitation,  the  issuance  and  sale  of  the
Preferred  Shares,  the Conversion  Shares,  the Warrants and the Warrant Shares
(except for the  registration of the Conversion  Shares and Warrant Shares under
the Securities Act pursuant to the Registration Rights Agreement, the listing of
the Conversion  Shares and the Warrant Shares on the NASDAQ  SmallCap Market and
any notices of sale  required to be filed with the SEC pursuant to  Regulation D
promulgated  under the  Securities  Act or any state  securities  law  authority
pursuant to applicable blue sky laws may be filed within the applicable  periods
therefor).

                  (d)  Neither  the sale of the  Preferred  Shares and  Warrants
pursuant to this Agreement,  nor the  performance of its obligations  under this
Agreement,  the  Certificate  of  Designation  (including  the  issuance  of the
Conversion  Shares  thereunder),  the  Warrants  (including  the issuance of the
Warrant Shares  thereunder) or the Registration  Rights Agreement by the Company
will:

                           (i) violate, conflict with, result in a breach of, or
constitute  a default  (or an event which with the giving of notice or the lapse
of time or both would be reasonably  likely to  constitute a default)  under (A)
the  Certificate  of  Incorporation  or By-laws of the Company,  (B) any decree,
judgment,  order, law, treaty, rule,  regulation or determination  applicable to
the Company of any court,  governmental  agency or body,  or  arbitrator  having
jurisdiction  over the Company or over the  properties or assets of the Company,
the  violation,  conflict,  breach or  default  of which  would  have a material
adverse effect on the Company and its  subsidiaries  considered as a whole,  (C)
the terms of any bond, debenture, or any other evidence of indebtedness,  or any
agreement, stock option or other similar plan, indenture,  lease, mortgage, deed
of trust or other  instrument  to which  the  Company  is a party,  by which the
Company is bound,  or to which any of the  properties of the Company is subject,
the  violation,  conflict,  breach or  default  of which  would  have a material
adverse effect on the Company and its subsidiaries considered as a whole, or (D)
the terms of any "lockup" or similar  provision of any  underwriting  or similar
agreement to which the Company is a party; or

                           (ii)  result in the  creation  or  imposition  of any
lien, claim or other encumbrance upon any of the assets of the Company.

                  (e) As of the Closing Date, the Preferred  Shares will be duly
and validly authorized and (i) will be free and clear of any security interests,
liens, claims or other encumbrances, (ii) will be duly and validly issued, (iii)
will be fully  paid  and  nonassessable,  (iv)  will  not be  issued  or sold in
violation  of any  preemptive  or other  similar  rights of the  holders  of any
securities  of the  Company,  and (v) will not subject  the  holders  thereof to
personal liability by reason of being such holders.  The Warrants have been duly
and validly  authorized and when issued and delivered pursuant to this Agreement
will have been duly executed,  issued and delivered and will constitute a legal,
valid,  binding and enforceable  obligation of the Company (except to the extent
that  enforceability  thereof may be limited by bankruptcy,  insolvency or other
similar laws affecting creditors' rights generally).

                                      -5-







                  (f) As of the Closing Date, the Conversion  Shares and Warrant
Shares will be duly and validly  authorized  and when issued in accordance  with
the  terms  of  this  Agreement,  the  Certificate  of  Designation  (as  to the
Conversion  Shares) and the Warrants (as to the Warrant Shares) (i) will be free
and clear of any security interests,  liens, claims or other encumbrances,  (ii)
will be duly and  validly  issued,  (iii) will be fully paid and  nonassessable,
(iv) will not have been issued or sold in violation of any  preemptive  or other
similar rights of the holders of any securities of the Company, and (v) will not
subject the holders thereof to personal liability solely by reason of being such
holders.

                  (g)  Except  as set  forth in the SEC  Documents,  there is no
pending or, to the best  knowledge  of the  Company,  threatened  action,  suit,
proceeding or investigation  before any court,  governmental  agency or body, or
arbitrator  having  jurisdiction  over the Company or any of its affiliates that
would  materially  adversely  affect the results of operations of the Company or
adversely affect the execution by the Company of, or materially adversely affect
the performance by the Company of its  obligations  under,  this Agreement,  the
Certificate of Designation,  the Warrants or the Registration  Rights Agreement,
or the transactions contemplated hereby or thereby.

                  (h) Neither the Company, nor any authorized  representative of
the Company,  has made any written or oral  communication in connection with the
offer or sale of the  securities  offered  hereby  which  contained  any  untrue
statement of a material fact or omitted to state any material fact  necessary in
order to make the statements, in the light of the circumstances under which they
were made, not misleading.

                  (i) None of the Company,  any affiliate of the Company, or any
person  acting on behalf of the Company or any such  affiliate  has engaged,  or
will engage, in any general  solicitation or general advertising with respect to
the Preferred Shares or the Warrants.

                  (j) The Company is duly  organized,  validly  existing  and in
good standing under the laws of the state of Delaware and is duly qualified as a
foreign  corporation  in all  jurisdictions  in which the  failure to so qualify
would have a material adverse effect on the Company and its  subsidiaries  taken
as a whole. The Company has registered its Common Stock pursuant to the Exchange
Act, and the Common Stock is listed and currently  trades on the NASDAQ SmallCap
Market.  The Company is not in violation  of the  applicable  listing  agreement
between the Company and any securities exchange or market on which the Company's
securities are listed. The Company has timely filed all materials required to be
filed pursuant to all reporting  obligations under either Section 13(a) or 15(d)
of the Exchange Act for at least twelve (12) months  immediately  preceding  the
date hereof, and has received no notice, either oral or written, with respect to
the  continued  eligibility  for such  listing.  The Company has timely made all
filings required under the Exchange Act during the twelve month period preceding
the date  hereof and is  eligible  to use Form S-3 to  register  the  Conversion
Shares  and  Warrant  Shares.  As  of  their  respective  dates,  the  financial
statements of the Company  included in the SEC Documents  complied as to form in
all material respects with applicable accounting  requirements and the published
rules and regulations of the SEC with respect thereto. Such financial statements
have


                                      -6-







been prepared in  accordance  with  generally  accepted  accounting  principles,
consistently applied during the periods involved (except (i) as may be otherwise
indicated in such financial statements or the notes thereto, or (ii) in the case
of unaudited interim statements, to the extent they may exclude footnotes or may
be condensed or summary  statements) and fairly present in all material respects
the financial position of the Company as of the dates thereof and the results of
its operations and cash flows for the periods then ended  (subject,  in the case
of unaudited  statements,  to normal year-end audit  adjustments).  Prior to the
date hereof, the Company has corrected all statements in the SEC Documents which
have  required  correction  and has filed all  necessary  amendments  to the SEC
Documents, in each case as required by applicable law.

                  (k) As of the date  hereof  and as of the  Closing  Date,  the
authorized  capital stock of the Company  consists of (i)  75,000,000  shares of
Common Stock $.01 par value per share, of which _____________  shares are issued
and outstanding,  and (ii) 10,000,000  shares of preferred stock, $.01 par value
per share,  of which (A) 50,000 shares have been  designated  Series A Preferred
Stock, of which __________  shares are issued and outstanding and ____ have been
converted into Common Stock,  (B) 12,515 shares have been designated as Series B
Preferred Stock, all of which are issued and outstanding,  (C) 7,500 shares have
been designated Series C Preferred Stock, $.01 par value per share, all of which
are issued and outstanding  and (D) 60,000 shares have been designated  Series D
Preferred  Stock,  $.01 par value per  share,  _______  of which are  issued and
outstanding,  and (iii) the  Company  has  reserved  for  issuance  no more than
_____________ shares of Common Stock with respect to the Derivative  Securities.
All  outstanding  shares of Common Stock,  Preferred  Stock,  Series B Preferred
Stock and Series C Preferred  Stock have been validly  issued and are fully paid
and  nonassessable.  No  shares  of  Common  Stock,  Preferred  Stock,  Series B
Preferred Stock or Series C Preferred Stock are subject to preemptive  rights or
any other similar rights or any liens or  encumbrances  suffered or permitted by
the  Company.  Except  as  disclosed  in the SEC  Documents,  (i)  there  are no
outstanding  options,   warrants,  scrip,  rights  to  subscribe  to,  calls  or
commitments  of any  character  whatsoever  relating to, or securities or rights
convertible into or exchangeable for, any shares of capital stock of the Company
or any of its  subsidiaries,  or arrangements by which the Company or any of its
subsidiaries is or may become bound to issue additional  shares of capital stock
of the  Company  or any of its  subsidiaries  (all such  securities  and  rights
contained in this  subsection (i) are  hereinafter  collectively  referred to as
"DERIVATIVE  SECURITIES"),  and (ii) there are no outstanding debt securities of
the Company.  The Company has made  available to the Purchaser  true and correct
copies of the Company's  Certificate of Incorporation,  as amended, as in effect
on the date hereof, and the Company's By-laws.

                  (l) The Company  undertakes  and agrees to make all  necessary
filings in connection with the sale of the securities offered hereby as required
by the  United  States  laws  and the  regulations  or any  domestic  securities
exchange or trading market.

                  (m) Except as set forth in the SEC  Documents,  since December
31,  1996,  there  has  been no  material  adverse  development  in the  assets,
liabilities, business properties,  operations, financial condition or results of
operations  of the Company  and its  subsidiaries  taken as a whole,  other than
continued losses.


                                      -7-








                  (n) None of the  filings  of the  Company  with the SEC  since
December 31, 1996 contained,  at the time they were filed,  any untrue statement
of a material  fact or omitted to state any material  fact required to be stated
therein  or  necessary  to  make  the  statements   therein,  in  light  of  the
circumstances under which they were made, not misleading.  The Company has since
December 31, 1996 timely filed all requisite forms, reports and exhibits thereto
with the SEC. As of their respective  dates,  the SEC Documents  complied in all
material  respects with the  requirements  of the Exchange Act and the rules and
regulations of the SEC promulgated  thereunder  applicable to the SEC Documents.
Prior to the date hereof,  the Company has corrected  all  statements in the SEC
Documents which have required correction and has filed all necessary  amendments
to the SEC Documents, in each case as required by applicable law.

                  (o)  Except  as set  forth in the SEC  Documents,  there is no
known  fact to the  Company  or any  subsidiary  (other  than  general  economic
conditions generally known to the public) that has not been disclosed in writing
to the  Purchasers  that (i) could  reasonably  be  expected  to have a material
adverse  effect on the  condition  (financial  or otherwise) or in the earnings,
business affairs, properties or assets of the Company or any subsidiary, or (ii)
could  reasonably be expected to adversely  affect the ability of the Company or
any  subsidiary  to perform  its  obligations  pursuant to this  Agreement,  the
Certificate of Designation, the Registration Rights Agreement or the Warrants.

                  (p) The Company  acknowledges  and agrees that  Purchasers are
acting solely in the capacity of an arm's length  purchaser with respect to this
Agreement  and  the   Registration   Rights   Agreement  and  the   transactions
contemplated  hereby  and  thereby.   The  Company  further   acknowledges  that
Purchasers are not acting as a financial advisor or fiduciary of the Company (or
in any similar  capacity)  with respect to this  Agreement and the  Registration
Rights  Agreement and the transactions  contemplated  hereby and thereby and any
advice  given by the  Purchasers  or any of its  representatives  or  agents  in
connection  with this  Agreement and the  transactions  contemplated  hereby and
thereby is merely incidental to the Purchasers' purchase of the Securities.  The
Company  further  represents to the  Purchasers  that the Company's  decision to
enter into this Agreement and the  Registration  Rights Agreement has been based
solely on the independent evaluation by the Company and its representatives.

                  (q)  Neither  the  Company,  nor any of its  affiliates,  has,
directly or indirectly,  made any offers or sales of any securities or solicited
any  offers  to  buy  any  security,  under  circumstances  that  would  require
registration of the Preferred Shares or the Warrants under the Securities Act.

                  (r) Except as set forth  within this  Agreement  or in the SEC
Documents, the Company and its subsidiaries own, have obtained or possess rights
to use the trademarks,  trade names,  service marks, service mark registrations,
patents, copyrights,  licenses,  approvals,  governmental authorizations,  trade
secrets and other rights necessary to conduct their respective businesses as now
conducted,  the Company does not have any knowledge of any material infringement
by the Company or its subsidiaries of any trademark,  trade name rights,  patent
rights, 

                                      -8-







copyrights,  licenses, service marks, service mark registrations,  trade secrets
or other similar rights of others,  and there is no claim being made against the
Company or its subsidiaries regarding trademark,  trade name, patent, copyright,
license,  service  marks,  service  mark  registrations,  trade  secret or other
infringement  which could have a material  adverse  effect on the  Company.  The
Company and its subsidiaries have taken reasonable  security measures to protect
the secrecy, confidentiality and value of all of their intellectual properties.

                  (s) The Company  understands and  acknowledges the potentially
dilutive effect to the Common Stock of the issuance of the Conversion Shares and
the Warrant Shares.

         5. COVENANTS OF THE COMPANY.  The Company covenants and agrees with the
Purchaser:

                  (a) To  comply  with  all  requirements  of  Section  4(2) and
Section 3(a)(9), as applicable,  and to the extent applicable Regulation D under
the  Securities  Act,  with  respect to the sale of the  Preferred  Shares,  the
Conversion Shares, the Warrants and the Warrant Shares, respectively.

                  (b) To notify the  Purchasers  promptly  if at any time during
the period  beginning  on the date of this  Agreement  and ending on the Closing
Date any event  shall  have  occurred  as a result of which any  written or oral
communication  made by the Company or any  authorized  person  representing  the
Company,  would include an untrue  statement of a material fact or omit to state
any material  fact  necessary in order to make the  statements  therein,  in the
light of the circumstances under which they were made, not misleading.

                  (c) To cause the  Conversion  Shares and Warrant Shares to be,
upon delivery,  fully paid,  nonassessable,  free of preemptive  rights and free
from all taxes, liens, charges, security interests or other encumbrances.

                  (d) To have at all times authorized and reserved for issuance,
free from  preemptive  rights,  a  sufficient  number of shares of Common  Stock
solely for the purpose of satisfying  the  conversion  rights of the  Purchasers
pursuant to the terms and conditions of the  Certificate of Designation  and the
Warrants  and to satisfy the  issuance of any other shares of Common Stock which
are reserved for issuance or which are issuable upon the  exercise,  conversion,
exchange or satisfaction of any outstanding  securities or obligations or rights
of the Company.  The Company shall not issue any shares of Common Stock,  or any
securities convertible into, or warrants,  options and the like exercisable for,
shares of Common Stock,  if as a result  thereof the Company may  reasonably not
have  sufficient  shares of authorized but unissued  Common Stock  sufficient to
satisfy in full the conversion  rights of the  Purchasers  pursuant to the terms
and conditions of the Certificate of Designation and the Warrants.

                  (e) Each party shall use its best efforts to take, or cause to
be taken,  all  action  and to do, or cause to be done,  all  things  necessary,
including without  limitation,  timely to satisfy


                                      -9-






the conditions to be satisfied as provided in Section 6 and 7 of this Agreement,
to consummate the transactions contemplated hereby.

                  (f) Until the  earlier of (i) the date which is one year after
the date as of which the Holders  (as that term is defined in Section  8(b)) may
sell all of the Conversion  Shares without  restriction  pursuant to Rule 144(k)
promulgated under the Securities Act (or successor  thereto) or (ii) the date on
which (a) the  Holders  shall have sold all the  Conversion  Shares and  Warrant
Shares and (b) none of the  Preferred  Shares or Warrants are  outstanding,  the
Company shall file all reports required to be filed with the SEC pursuant to the
Exchange  Act, and the Company shall not  voluntarily  terminate its status as a
Company required to file reports under the Exchange Act even if the Exchange Act
or the rules and regulations thereunder would permit such termination.

                  (g) The  Company  will use the  proceeds  from the sale of the
Securities for working capital and general corporate purposes.

                  (h) The  Company  shall  promptly  secure  the  listing of the
Conversion Shares and Warrant Shares upon each national  securities  exchange or
automated  quotation  system, if any, upon which shares of Common Stock are then
listed or quoted (subject to official notice of issuance) and shall maintain the
listing of all such  shares from time to time  issuable  under the terms of this
Agreement, the Certificate of Designation and the Registration Rights Agreement.
During  the  period  that the  Company  is  required  to  maintain  effective  a
registration  statement  covering the Conversion Shares and Warrant Shares,  the
Company  shall  maintain  the Common  Stock's  authorization  for listing on the
NASDAQ SmallCap Market and any such other national securities exchange.

         6. CONDITIONS PRECEDENT TO THE PURCHASER'S OBLIGATIONS. The obligations
of the Purchasers hereunder are subject to the performance by the Company of its
obligations  hereunder  and to the  satisfaction  of  the  following  additional
conditions precedent:

                  (a) The  representations and warranties made by the Company in
this Agreement  shall,  unless waived by the Purchasers,  be true and correct in
all material  respects as of the date hereof and at the Closing  Date,  with the
same  force and effect as if they had been made on and as of the  Closing  Date.
The  Company  shall have  performed,  satisfied  and  complied  in all  material
respects  with  the  covenants,  agreements  and  conditions  required  by  this
Agreement to be performed, satisfied or complied with by the Company at or prior
to the Closing Date.

                  (b) The Company and the Purchasers shall have entered into the
Master Registration Rights Agreement (the "REGISTRATION  RIGHTS AGREEMENT"),  in
substantially the form annexed hereto as EXHIBIT D.

                  (c) The Company will provide to the  Purchasers  an opinion or
opinions of counsel in substantially the form annexed hereto as EXHIBIT E.


                                      -10-






                  (d)  The  Company   shall  have  filed  the   Certificate   of
Designation with the Secretary of the State of Delaware.

                  (e) None of the following shall have occurred: (i) any general
suspension  of trading in, or  limitation on prices listed for, the Common Stock
on the NASDAQ,  (ii) a declaration of a banking  moratorium or any suspension of
payments in respect to banks in the United  States,  (iii) a  commencement  of a
war, armed  hostilities or other  international or national calamity directly or
indirectly  involving  the  United  States,  (iv) in the  case of the  foregoing
existing at the date of this  Agreement,  a material  acceleration  or worsening
thereof,  or (v) any  limitation  by the  federal  or state  authorities  on the
extension  of credit by  lending  institutions  that  materially  and  adversely
affects the Purchasers.

                  (f) The  Company  shall have  executed  and  delivered  to the
Escrow  Agent  the  certificates  representing  the  Preferred  Shares  and  the
Warrants.

                  (g) No action, suit,  investigation or proceeding before or by
any governmental  authority shall have been commenced or threatened  against the
Company or any of the officers,  directors or  affiliates of the Company,  which
seeks to restrain,  prevent or challenge the  transactions  contemplated by this
Agreement  or the  Registration  Rights  Agreement  or which  seeks  damages  in
connection with such transactions.

         7. CONDITIONS PRECEDENT TO THE COMPANY'S OBLIGATIONS.

                  (a) The  obligations  of the Company  hereunder are subject to
the  performance  by the  Purchasers of their  obligations  hereunder and to the
satisfaction of the condition  precedent that the representations and warranties
made by the Purchasers in this Agreement shall, unless waived by the Company, be
true and  correct  in all  material  respects  as of the date  hereof and at the
Closing Date,  with the same force and effect as if they had been made on and as
of the Closing Date.

                  (b) The Purchasers shall have delivered to the Escrow Agent by
wire transfer the Purchase Price for the Securities.

         8.       TRANSFER OF SECURITIES.

                  (a) Securities  Act Legend.  Each  certificate  evidencing the
Preferred  Shares and the  Warrants,  and,  prior to the  effective  date of the
registration  thereof  pursuant  to  the  Registration  Rights  Agreement,   the
Conversion  Shares and the  Warrant  Shares,  and any  certificates  issued upon
transfer or exchange of the  foregoing,  shall be stamped or imprinted  with the
legend  substantially  as set forth in  Section  3(a).  The  legend set forth in
Section 3(a) shall be removed and the Company shall issue a certificate  without
such legend to the holder of the Preferred Shares,  the Conversion  Shares,  the
Warrant  and the Warrant  Shares as  applicable  upon which it is  stamped,  if,
unless  otherwise  required by state  securities  laws,  (a) with respect to the
Conversion  Shares and the Warrant Shares,  the sale of the Conversion Shares or
the Warrant


                                      -11-




Shares,  as the case may be, is registered  under the Securities  Act, or (b) in
connection with a Transfer,  such holder provides the Company with an opinion of
counsel, in form,  substance and scope reasonably  acceptable to the Company, to
the effect that a Transfer  thereof may be made without  registration  under the
Securities  Act,  or (c)  such  holder  provides  the  Company  with  reasonable
assurances that the Preferred Shares, the Conversion Shares, the Warrant and the
Warrant  Shares,  as  applicable,  can be sold  pursuant  to Rule 144  under the
Securities Act (or a successor rule thereto). Notwithstanding the removal of any
such  legend,  each  Purchaser  agrees to Transfer  the  Preferred  Shares,  the
Conversion  Shares,  its  Warrant  and  the  Warrant  Shares,   including  those
represented  by  certificate(s)  from  which the  legend  has been  removed,  in
compliance  with all applicable  securities laws and, if, in connection with any
Transfer,  a legend would be appropriate under applicable  securities laws, each
Purchaser   shall,  in  connection  with  any  such  Transfer  ensure  that  the
certificates representing shares so Transferred shall bear the foregoing legend.

                  (b) Securities Act  Compliance.  Each holder (a "HOLDER") of a
certificate evidencing the Preferred Shares, the Conversion Shares, the Warrants
and the Warrant Shares which bears the  restrictive  legend set forth in Section
8(a) above (the  "RESTRICTED  SECURITIES"),  and who  proposes to  Transfer  any
Restricted  Securities  (other  than  pursuant  to  an  effective   registration
statement  under the Securities Act or pursuant to Rule 144 under the Securities
Act),  shall give written  notice to the Company of such  Holder's  intention to
effect  such   Transfer.   Each  such  notice  shall  describe  the  manner  and
circumstances of the proposed sale or other disposition in sufficient detail and
shall be accompanied by an opinion of legal counsel to the Holder. Promptly upon
receipt of such notice,  the Company shall present a copy thereof (together with
any  accompanying  opinion of legal counsel to the Holder) to its legal counsel,
and the following provisions shall apply:

                           (i) If,  in the  opinion  of  legal  counsel  to such
Holder,  reasonably  satisfactory  in form and  substance to the Company and its
legal  counsel,  or if such  notice was not  accompanied  by an opinion of legal
counsel to the Holder, then, if, in the opinion of legal counsel to the Company,
the proposed sale or other  disposition may be effected without  registering the
Restricted   Securities  involved  under  the  Securities  Act  or  under  state
securities  laws,  such Holder shall be entitled to so Transfer such  Restricted
Securities in accordance with the terms of such notice  delivered to the Company
pursuant to this paragraph (b). The Company will advise the Holder, within three
(3) business days after submission of such notice,  whether the Company believes
such Holder is entitled to so Transfer the  Restricted  Securities in accordance
with the  foregoing.  If the Holder is entitled to so Transfer,  he shall submit
the stock certificate or certificates evidencing the Restricted Securities to be
Transferred  to the  Company in proper  form for  Transfer  and  accompanied  by
appropriate  instruments  of Transfer and the Company shall  promptly  issue new
certificates  giving  effect  to  such  Transfer.  Certificates  for  Restricted
Securities  thus  Transferred  (and  each  of the  certificates  evidencing  any
untransferred  balance of the  Conversion  Shares or the  Warrant  Shares not so
transferred)  shall  bear the  restrictive  legend  set forth in  Section  8(a),
unless,  in the opinion of such Holder's legal  counsel,  which opinion shall be
reasonably  satisfactory  in form and  substance  to counsel for the Company (or
legal  counsel to 


                                      -12-









the Company if the Holder did not present an opinion of its legal counsel), such
legend is not required by the  applicable  provisions of the  Securities  Act or
state securities laws; and

                           (ii) If in the  reasonable  opinion of either of such
legal  counsel (or legal counsel to the Company if the Holder did not present an
opinion of its legal counsel),  the proposed Transfer cannot be effected without
registering the Restricted Securities involved under the Securities Act or state
securities  laws,  such Holder  shall not offer to  Transfer  or  Transfer  such
Restricted  Securities  unless and until such  Restricted  Securities  have been
registered under the Securities Act or state securities laws for such purpose or
an exemption from such registration becomes available.  Upon the consummation of
the transactions  contemplated by this Agreement,  the Company shall have agreed
to register the Conversion  Shares and the Warrant Shares  pursuant to the terms
of the Registration Rights Agreement.

                  (c) Subject to the restrictions set forth in Sections 8(a) and
(b) above,  upon the valid conversion of the Preferred Shares or exercise of the
Warrants,  the Company shall instruct its transfer agent to issue  certificates,
registered  in the name of each  Purchaser  or its nominee,  for the  Conversion
Shares and the Warrant  Shares in such amounts as specified from time to time by
the respective Purchasers to the Company. The Company shall provide instructions
and opinions of counsel to its transfer  agent in  accordance  the  Registration
Rights Agreement and this Section 8. Upon the  effectiveness of the registration
of the  Conversion  Shares and the Warrant Shares  pursuant to the  Registration
Rights  Agreement  and  thereafter,  any  Conversion  Shares or  Warrant  Shares
theretofore  issued bearing a restrictive legend of any kind may be submitted to
the Company for removal of such legend,  and within  three (3) business  days of
receipt thereof the Company shall cause to be issued and delivered to the Holder
submitting the certificates  for such shares new  certificates  representing the
same  number  of shares  that bear no  restrictive  legend  and that are  freely
transferable  on the books and records of the Company  and its  transfer  agent,
subject to such Holder's compliance with applicable  securities laws,  including
but not limited to such Holder's  obligation  pursuant to the  Securities Act to
provide a  prospectus  to buyers of such shares and further  subject to Sections
3(e) and 4(c) of the  Registration  Rights  Agreement.  Nothing in this  Section
shall affect in any way Purchasers' obligations and agreement to comply with all
applicable  securities laws upon resale of the Conversion Shares and the Warrant
Shares.

         9. FEES AND EXPENSES.  Each of the Purchasers and the Company agrees to
pay its  respective  expenses  incident to the  performance  of its  obligations
hereunder,  including,  but not limited to, the fees,  expenses,  due  diligence
costs and disbursements of such party's counsel.

         10. SURVIVAL OF THE  REPRESENTATIONS,  WARRANTIES,  ETC. The respective
agreements,  representations,  warranties, indemnities and other statements made
by or on behalf of the Company and the Purchaser, respectively, pursuant to this
Agreement,  shall  remain  in full  force and  effect  for a period of one year,
regardless of any investigation  made by or on behalf of the other party to this
Agreement or any  officer,  director or employee  of, or person  controlling  or
under common control with,  such party and will survive  delivery of any payment
for the Preferred Shares,  the Conversion  Shares,  the Warrants and the Warrant
Shares.

                                      -13-







         11. NOTICES. All notices,  requests and other communications  hereunder
must be in writing and  delivered to the parties at the  following  addresses or
facsimile numbers:

If to the Purchasers, to:

         The addresses listed on Schedule I attached hereto.

If to the Company, to:

         DynaGen, Inc.
         99 Erie Street
         Cambridge, MA  02139
         Attention:  President

         Telephone:        (617) 491-2527
         Telecopy:         (617) 354-3902

All such  notices,  requests  and  other  communications  will (i) if  delivered
personally  (including,  without  limitation,  by  reputable  overnight  courier
service)  to the  address as  provided  in this  Section,  be deemed  given upon
delivery, (ii) if delivered by facsimile transmission to the facsimile number as
provided in this Section,  be deemed given upon telecopy generated  confirmation
of receipt,  and (iii) if delivered by mail in the manner described above to the
address as provided in this Section,  be deemed given upon receipt (in each case
regardless of whether such notice, request or other communication is received by
any other  Person to whom a copy of such notice is to be  delivered  pursuant to
this  Section).  Any party from time to time may change its  address,  facsimile
number or other  information  for the purpose of notices to that party by giving
notice specifying such change to the other parties hereto.

         12. THIRD PARTY  BENEFICIARY.  Any permitted  transferee of any part of
the  principal  amount of the  Preferred  Shares,  the  Conversion  Shares,  the
Warrants  and the  Warrant  Shares  shall be a third  party  beneficiary  of the
Company's  obligations  under this Agreement,  the Warrants and the Registration
Rights  Agreement.  Such  person  shall  have all the  rights  of a third  party
beneficiary with respect to the enforcement against the Company of any provision
of this Agreement, the Warrants and the Registration Rights Agreement.

         13.      MISCELLANEOUS.

                  (a) This Agreement may be executed in one or more counterparts
and it is not  necessary  that  signatures  of all  parties  appear  on the same
counterpart,  but such  counterparts  together shall  constitute but one and the
same agreement.  This Agreement,  once executed by a party,  may be delivered to
the other party by facsimile  transmission  of a copy of this Agreement  bearing
the signature of the party so delivering this Agreement.

                                      -14-







                  (b)  This  Agreement  shall  inure  to the  benefit  of and be
binding upon the parties  hereto,  their  respective  successors  and  permitted
assigns.

                  (c) This  agreement  shall be governed  by, and  construed  in
accordance  with,  the laws of the State of Delaware  (without  giving effect to
conflicts of laws principles).  Each of the parties consents to the jurisdiction
of the federal courts whose districts encompass any part of the City of New York
or the state  courts of the State of New York sitting in the City of New York in
connection with any dispute  arising under this Agreement and hereby waives,  to
the maximum  extent  permitted by law, any  objection,  including  any objection
based on forum non  conveniens,  to the bringing of any such  proceeding in such
jurisdictions.

                  (d) The  headings of the sections of this  document  have been
inserted for  convenience of reference only and shall not be deemed to be a part
of this Agreement.

                  (e) The provisions of this Agreement are severable, and if any
clause or provision shall be held invalid,  illegal or unenforceable in whole or
in part in any  jurisdiction,  then such  invalidity or  unenforceability  shall
affect in that jurisdiction only such clause or provision,  or part thereof, and
shall  not  in  any  manner  affect  such  clause  or  provision  in  any  other
jurisdiction  or  any  other  clause  or  provision  of  this  Agreement  in any
jurisdiction.

                  (f) This  Agreement,  including  the  schedules  and  exhibits
hereto, constitutes the sole and entire agreement of the parties with respect to
the subject matter hereof.

                  (g) Each party shall do and  perform,  or cause to be done and
performed,  all such further acts and things,  and shall execute and deliver all
such other agreements, certificates, instruments and documents, as the party may
reasonably  request in order to carry out the intent and accomplish the purposes
of this Agreement and the consummation of the transactions contemplated hereby.

                  (h)  Notwithstanding any of the  representations,  warranties,
acknowledgments  or  agreements  made herein by the Company and  Purchaser,  the
Company and  Purchasers do not thereby or in any manner waive any rights granted
to it or him under U.S. Federal or state securities laws.

                  (i) The  provisions  of this  Agreement,  other than  Sections
5(i), 8, 10 and 12, shall terminate when all Preferred  Shares and Warrants have
been  converted into shares of the Company's  Common Stock that are  unlegended,
unrestricted and are freely transferable on the books and records of the Company
and its transfer  agent,  subject to each Holder's  compliance  with  applicable
securities laws,  including but not limited to such Holder's obligation pursuant
to the  Securities  Act to provide a prospectus  to buyers of such  shares,  and
further subject to Sections 3(e) and 4(c) of the Registration Rights Agreement.

         14. TIME OF ESSENCE. Time shall be of the essence in this Agreement.



                                      -15-







         15.      DELIVERY OF STOCK; DIVIDEND PAYMENTS.

                  (a) The Company  will permit each  Purchaser  to exercise  its
right to convert the Preferred Shares and exercise the Warrants by telecopying a
notice of  conversion in  accordance  with the  Certificate  of  Designation  (a
"NOTICE  OF  CONVERSION")  or  Form  of  Subscription  annexed  to the  Warrant,
respectively,  to the Company and delivering thereafter, as the case may be, (i)
the original  Notice of Conversion and  certificate  representing  the Preferred
Shares being converted, or (ii) (A) Form of Subscription,  (B) cash or certified
or official  bank check  payable to the Company and (C) Warrant  (the  "ORIGINAL
DOCUMENTATION"),  by express courier.  Each date on which a Notice of Conversion
or  Form of  Subscription  is  telecopied  to and  received  by the  Company  in
accordance  with the  provisions  hereof  shall be deemed a  Conversion  Date or
Exercise  Date, as the case may be. The Company will  transmit the  certificates
representing  the Conversion  Shares and the Warrant Shares and the newly issued
Preferred Stock  certificate  representing  the number of Preferred  Shares that
remain unconverted,  or the newly issued Warrant representing the portion of the
Warrant that remains  unexercised,  to such Purchaser via express courier within
three (3) trading days after the date on which the Company receives the Original
Documentation  or  make  such  securities  available  to such  Purchaser  at the
Company's transfer agent within such time period (the "DELIVERY DATE").

         (b) The Company and the  Purchasers  agree that the Company will comply
with its applicable federal or other tax withholding obligations.

         16. LIQUIDATED DAMAGES FOR FAILURE TO DELIVER.  The Company understands
that a delay beyond the deadline  for  delivery,  specified in Section 15, could
result in economic loss to the Purchaser.  As  compensation to the Purchaser for
such loss, the Company agrees to pay late payments to the Purchaser for the late
issuance of shares  issuable at conversion  or exercise in  accordance  with the
following  schedule (where "No.  Business Days Late" is defined as the number of
business  days beyond three  business  days after  receipt by the Company of the
Original Documentation):
                                           Late Payment for Each $5,000 of
           No. Business Days Late       Original Investment Being Converted
           ----------------------       -----------------------------------
                      2                             $     50.00
                      3                             $    100.00
                      4                             $    150.00
                      5                             $    200.00
                      6                             $    250.00
                      7                             $    300.00
                      8                             $    350.00
                      9                             $    400.00
                      9                 $400.00 + $100.00 for each Business
                                               Day Late Beyond 9 Days

         The Company  shall make any  payments  incurred  under this  Section in
immediately   available  funds  upon  demand.   Nothing  herein  shall  limit  a
Purchaser's  right to actual  damages  for the  Company's  failure  to issue and
deliver  the  Conversion  Shares  and  the  Warrant  Shares  to  the 


                                      -16-









Purchaser.  Furthermore,  in addition to any other remedy which may be available
to the  Purchaser,  in the event that the Company fails for any reason to effect
delivery of  Conversion  Shares or Warrant  Shares within five (5) business days
after the date on which the Company has received the Original Documentation, the
Purchaser  will be  entitled  to elect to be deemed to be  treated as not having
exercised the relevant  Notice of Conversion or Notice of Exercise by delivering
a notice to such effect to the Company  whereupon  the Company and the Purchaser
shall each be restored to their respective  positions  immediately prior to such
Notice of Conversion or Notice of Exercise; provided that no such election shall
constitute  waiver  of any right or remedy  Purchaser  may have and the  Company
shall still be  obligated  notwithstanding  any such  election  to make  penalty
payments hereunder and for any actual damages.

         17.  NON-DELIVERY  OF THE SHARES.  If, within ten (10) business days of
the date after receipt by the Company of the Original Documentation, the Company
shall fail to (i) issue the Conversion  Shares or the Warrant  Shares,  and (ii)
deliver to a Purchaser the  Conversion  Shares or the Warrant Shares as required
by the Warrant or Certificate of Designation, as the case may be, for any reason
other than failure by such Purchaser to comply with its  obligations  under this
Agreement, then the Company shall:

                  (a) hold such Purchaser  harmless  against any loss,  claim or
damage  arising from or as a result of such  failure by the Company  (including,
without limitation,  any such loss, claim or damage resulting from an obligation
to resell the Conversion Shares or the Warrant Shares); and

                  (b)  reimburse  the  Purchaser  for  all of its  out-of-pocket
expenses reasonably  incurred,  including fees and disbursements of its counsel,
incurred by the Purchaser in connection with this Agreement and the transactions
contemplated herein;  provided however,  that the Company shall not have further
liability to the Purchaser except as provided for in this Section 17.

         18. ESCROW  AGENT.  The Escrow Agent shall not be liable for any action
taken or  omitted  by it in good  faith  and its  liability  hereunder  shall be
limited to liability for gross negligence or willful misconduct on its part. The
Company and the  Purchasers  agree to save  harmless,  and the Company agrees to
indemnify and defend,  the Escrow Agent for,  from and against their  respective
share of any loss, damage, liability,  judgment, cost and expense whatsoever, by
reason of, or on account of, any  misrepresentation  made to it or its status or
activities  as Escrow Agent under this  Agreement  except for any loss,  damage,
liability,  judgment, cost or expense resulting from gross negligence or willful
misconduct on the part of the Escrow Agent.

                  The Escrow Agent shall not be  responsible  for any failure or
inability of any of the parties to perform or comply with the provisions of this
Agreement, or the agreements delivered in connection herewith.

                  In the performance of its duties  hereunder,  the Escrow Agent
shall be entitled to rely in good faith upon any document  (including  facsimile
transmitted copies of documents),



                                      -17-








instrument  or  signature  believed  by it in good faith to be genuine and to be
signed by any party hereto or an authorized officer or agent thereof,  and shall
not be required to investigate the truth or accuracy of any statement  contained
in any such  document or  instrument.  The Escrow Agent may assume in good faith
that any person  purporting to give any notice in accordance with the provisions
hereof has been duly authorized to do so.

                  Each party  hereto  acknowledges  that (a) the Escrow Agent is
not acting as legal counsel to such party in any manner or respect in connection
with the transactions  contemplated by this Agreement,  and (b) the Escrow Agent
is serving as an accommodation to the parties hereto.
                  It is  understood  and further  agreed  that the Escrow  Agent
shall:

                  (a) be under no duty to enforce  payment  of any  subscription
that is to be paid to and held by it hereunder;

                  (b)  promptly  notify the  Purchasers  and the  Company of any
discrepancy  between  the amounts set forth on any  statement  delivered  by the
Purchasers and/or the Company and the sum or sums delivered to it therewith;

                  (c) be  under  no duty to  accept  funds,  checks,  drafts  or
instruments  for the payment of money from anyone  other than the Company or the
Purchasers,  or to give  any  receipt  therefor  except  to the  Company  or the
Purchasers, with a copy in each case to the Company;

                  (d)  be  protected   in  acting  upon  any  notice,   request,
certificate,  approval,  consent or other paper reasonably  believed by it to be
genuine  and to be signed by the  proper  party or parties  (including,  but not
limited to, copies of documents transmitted by facsimile);

                  (e) be permitted  to consult  with counsel of its choice,  and
shall  not be  liable  for any  action  taken,  suffered,  or  omitted  by it in
accordance with the advice of such counsel;  provided,  however, that nothing in
this  subsection  (e), nor any action taken by the Escrow Agent,  or suffered or
omitted by it in  accordance  with the advice of any counsel,  shall relieve the
Escrow  Agent from  liability  for any claims that are  occasioned  by its gross
negligence or willful misconduct;

                  (f) not be bound by any modification,  amendment, termination,
cancellation,  or  rescission  of this  Agreement,  unless  the same shall be in
writing and signed by it;

                  (g) be entitled to refrain  from taking any action  other than
to keep all property held in escrow if it (i) shall be uncertain  concerning its
duties or rights  hereunder,  or (ii) shall have received claims or demands from
any party, or (iii) shall have received  instructions from the Purchasers and/or
the Company that, in the Escrow Agent's opinion, are in conflict with any of the
provisions of this Agreement, until it shall have received a final judgment by a
court of competent jurisdiction;

                                      -18-







                  (h) have no liability for following the instructions herein or
expressly provided for herein, or the written  instructions given jointly by the
Purchasers and/or the Company; and/or

                  (i) have the right, at any time, to resign hereunder by giving
written notice of its resignation to all other parties hereto at least three (3)
business days prior to the date  specified for such  resignation to take effect,
and upon the effective date of such  resignation all cash and other payments and
all other property then held by the Escrow Agent hereunder shall be delivered by
it to such person as may be designated in writing by the other parties executing
this Agreement,  whereupon the Escrow Agent's obligations  hereunder shall cease
and  terminate.  If no  such  person  has  been  designated  by such  date,  all
obligations  of the  Escrow  Agent  hereunder  shall,  nevertheless,  cease  and
terminate.  The Escrow Agent's sole  responsibility  thereafter shall be to keep
safely  all  property  then  held by it and to  deliver  the  same  to a  person
designated by the other parties  executing this Agreement or in accordance  with
the   directions  of  a  final  order  or  judgment  of  a  court  of  competent
jurisdiction.

                [REMAINDER OF PAGE IS INTENTIONALLY LEFT BLANK.]







                                      -19-






                                  DYNAGEN, INC.

                          SECURITIES PURCHASE AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                  Very truly yours,

                                  DYNAGEN, INC.

                                  By:______________________________________

                                  Title: __________________________________

















                                  DYNAGEN, INC.

                          SECURITIES PURCHASE AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                    Very truly yours,

                                    _______________________________________
                                   (exact name of Purchaser)


                                    By:____________________________________

                                    Print Name: ___________________________

                                    Title:_________________________________


                                    Address: ______________________________

                                    _______________________________________
 
                                    _______________________________________
  


                                                                      Exhibit 4b
                      MASTER REGISTRATION RIGHTS AGREEMENT

         MASTER REGISTRATION  RIGHTS AGREEMENT (this  "AGREEMENT"),  dated as of
August  6,  1997 by and  among  DYNAGEN,  INC.,  a  Delaware  corporation,  with
headquarters  located at 99 Erie  Street,  Cambridge,  Massachusetts  02139 (the
"COMPANY"),  and the undersigned parties who execute a counterpart  signature of
this Agreement (together with affiliates, the "INITIAL INVESTORS").

         WHEREAS:

         A. In connection  with the Securities  Purchase  Agreement of even date
herewith by and between the Company and the Initial  Investors (the  "SECURITIES
PURCHASE AGREEMENT"),  the Company has agreed, upon the terms and subject to the
conditions  contained therein, to issue and sell to the Initial Investors shares
of the  Company's  Series A Preferred  Stock (the  "PREFERRED  SHARES") that are
convertible into shares (collectively, the "CONVERSION SHARES") of the Company's
common  stock (the  "COMMON  STOCK")  and  Warrants  (the  "WARRANTS")  that are
exercisable  for shares of Common  Stock (the  "WARRANT  SHARES"),  all upon the
terms and subject to the limitations and conditions set forth in the Certificate
of Designation with respect to the Series A Preferred Stock or the Warrants,  as
applicable; and

         B.  To  induce  the  Initial  Investors  to  execute  and  deliver  the
Securities  Purchase  Agreement,  the  Company  has  agreed to  provide  certain
registration rights under the Securities Act of 1933, as amended,  and the rules
and regulations thereunder, or any similar successor statute (collectively,  the
"1933 ACT");

         NOW,  THEREFORE,  in  consideration  of the  premises  and  the  mutual
covenants  contained  herein  and other  good and  valuable  consideration,  the
receipt and  sufficiency of which are hereby  acknowledged,  the Company and the
Initial Investors hereby agree as follows:

         1.       DEFINITIONS.

                  (a) As used in this Agreement,  the following terms shall have
the following meanings:

                           (i) "CLOSING  DATE," with  respect to each  Investor,
means the date of the  consummation  of the  financing  in which  such  Investor
purchased debt or equity securities of the Company pursuant to which the Company
has granted registration rights.

                           (ii)  "INVESTORS"  means the Initial  Investors,  any
transferees  or assignees  who agree to become bound by the  provisions  of this
Agreement in accordance with Section 9 hereof and any party that becomes a party
to this Agreement in accordance with Section 10(b) hereof.

                           (iii) "REGISTER,"  "REGISTERED,"  and  "REGISTRATION"
refer  to a  registration  effected  by  preparing  and  filing  a  Registration
Statement or Statements in compliance with the





1933 Act and  pursuant  to Rule 415  under  the 1933 Act or any  successor  rule
providing for offering  securities on a continuous  basis ("RULE 415"),  and the
declaration or ordering of effectiveness of such  Registration  Statement by the
United States Securities and Exchange Commission (the "SEC").

                           (iv)  "POTENTIAL  MATERIAL  EVENT"  means  any of the
following:  (a) the possession by the Company of material  information  not ripe
for  disclosure  in a  registration  statement,  which  shall  be  evidenced  by
determinations  in good  faith by the Board of  Directors  of the  Company  that
disclosure  of  such  information  in  the   registration   statement  would  be
detrimental  to the  business  and affairs of the  Company;  or (b) any material
engagement  or  activity  by  the  Company  which  would,   in  the  good  faith
determination of the Board of Directors of the Company, be adversely affected by
disclosure in a registration  statement at such time, which  determination shall
be  accompanied by a good faith  determination  by the Board of Directors of the
Company that the registration  statement would be materially  misleading  absent
the inclusion of such information.

                           (v) "REGISTRABLE SECURITIES" means (i) the Conversion
Shares and the Warrant  Shares  issued or issuable,  (ii) shares of Common Stock
issued on a Closing  Date or  issuable  pursuant  to  securities  of the Company
issued on a Closing Date to an Investor that has signed a counterpart  signature
page to this Agreement  pursuant to Section 10(b) hereof and (iii) any shares of
capital  stock  issued  or  issuable  as a  dividend  on or in  exchange  for or
otherwise with respect to any of the foregoing.

                           (vi)  "REGISTRATION  STATEMENT"  means a registration
statement  of the  Company  under the 1933 Act or an  amendment  to an  existing
registration statement to add Registrable Securities.

                  (b)  Capitalized  terms used herein and not otherwise  defined
herein shall have the respective  meanings set forth in the Securities  Purchase
Agreement.

         2.       REGISTRATION.

                  (a)  Mandatory  Registration.  The Company  shall,  as soon as
practicable  after each Closing Date but in no event more than 45 days following
such Closing Date,  file with the SEC a Registration  Statement on Form S-3 (or,
if Form S-3 is not then available,  on such form of Registration Statement as is
then available to effect a registration of the Registrable  Securities,  subject
to the  consent of the  Investors  (as  determined  pursuant  to  Section  10(a)
hereof), which consent will not be unreasonably withheld conditioned or delayed)
covering  the resale of the  Registrable  Securities  issued or issuable to such
Investors  pursuant to  securities  of the Company  issued on each such  Closing
Date. The Registration Statement, to the extent allowable under the 1933 Act and
the Rules  promulgated  thereunder  (including Rule 416),  shall state that such
Registration  Statement  also covers  such  indeterminate  number of  additional
shares of Common Stock as may become  issuable upon  conversion of the Preferred
Shares and/or exercise of the Warrants to prevent dilution  resulting from stock
splits, stock dividends or similar transactions.  The Company shall use its best
efforts to cause such registration to become and remain effective


                                      -2-


(including  the taking of such steps as are  necessary  to obtain the removal of
any stop orders); provided, that the Investors shall furnish the Company, within
five (5) business days of the Company's  written request,  with such appropriate
information in connection  therewith  (whether  requested  prior to or after the
filing  of the  Registration  Statement  with  the  SEC)  as the  Company  shall
reasonably request in writing. The Registration Statement (and each amendment or
supplement thereto, and each request for acceleration of effectiveness  thereof)
shall be provided to (and subject to the approval  of) the  Investors  and their
counsel prior to its filing or other submission.  The number of shares of Common
Stock initially  included in such  Registration  Statement shall be no less than
one hundred  fifty  percent  (150%) of the shares of Common  Stock issued to the
Investors  on such Closing Date or issuable  pursuant to the  securities  of the
Company  issued to the Investors on such Closing Date  (assuming the  Conversion
Price set forth in Section  5(b)(ii)(A) of the Certificate of Designation).  The
Company  further  undertakes  to take  all  steps  necessary  to  ensure  that a
Registration  Statement is, or  Registration  Statements  are,  effective at all
times  during the  Registration  Period (as defined  below) with  respect to all
Registrable Securities and the resale thereof.

                  (b)  Eligibility  for Form S-3.  The  Company  represents  and
warrants that, as of the date hereof,  it meets the  requirements for the use of
Form  S-3 for  registration  of the  sale by the  Investors  of the  Registrable
Securities  and the Company  shall file all reports  required to be filed by the
Company with the SEC in a timely manner, and take any and all such other actions
as may be reasonably necessary or appropriate so as to maintain such eligibility
for the use of Form S-3.

         3.       OBLIGATIONS OF THE COMPANY.

         In connection with the registration of the Registrable Securities,  the
Company shall have the following obligations:

                  (a) The  Company  shall,  as soon as  practicable  after  each
Closing  Date but in no event more than 45 days  following  such  Closing  Date,
prepare and file promptly with the SEC a  Registration  Statement and thereafter
use its  Best  Efforts  (as  hereinafter  defined)  to cause  such  Registration
Statement relating to Registrable  Securities to promptly become effective,  but
in no event to become  effective  more than 90 days following such Closing Date,
and to keep the  Registration  Statement  effective  pursuant to Rule 415 at all
times  until  such  date as is the  earlier  of (i) the date on which all of the
Registrable  Securities  registered under such Registration  Statement have been
sold and no Preferred Shares, Warrants or other securities of the Company issued
on such  Closing  Date are  outstanding  or (ii)  the date on which  all of such
Registrable  Securities  (in the  opinion of counsel  to the  Investors)  may be
immediately  publicly  sold without  registration  and (iii) two years from such
Closing  Date  (the  "REGISTRATION   PERIOD"),   which  Registration   Statement
(including  any  amendments or supplements  thereto and  prospectuses  contained
therein and all documents  incorporated by reference  therein) shall not contain
any  untrue  statement  of a  material  fact or omit to  state a  material  fact
required to be stated therein,  or necessary to make the statements  therein not
misleading.  The Company  shall  furnish to the  Investors  copies of reasonably
complete drafts of all such documents proposed to be filed (including  exhibits,
if any),  and any such Investor  shall have the  opportunity  to object,  within


                                      -3-


three (3) business days, to any information  pertaining  solely to such Investor
that is contained  therein and the Company will make the corrections  reasonably
requested by such Investor with respect to such information  prior to filing any
such  Registration  Statement  or  amendment.  Any period of review and revision
resulting  from such review that extends  beyond five (5) business days shall be
added to the time in which  the  Registration  Statement  is to be filed  and no
penalty shall be assessed  with respect to such period.  If the Company fails to
cause such  Registration  Statement to become effective within 90 days following
the Closing Date due to a Corporation  Failure, as defined in the Certificate of
Designation, the Conversion Price, as defined in the Certificate of Designation,
shall  be  adjusted  as set  forth  in  paragraph  5(b)  of the  Certificate  of
Designation.  As used in Section 3(a), (b), (d), (f), (i) and (m) hereof,  "Best
Efforts"  shall  include  the  taking  of  any  and  all  actions  necessary  or
appropriate with respect thereto,  including timely response to all comments and
correspondence received (including from the SEC), the filing or providing of any
further drafts and other documents as may be required, and the like.

                  (b) The  Company  shall  prepare  and  file  with the SEC such
amendments  (including   post-effective   amendments)  and  supplements  to  the
Registration   Statement  and  the  prospectus   used  in  connection  with  the
Registration  Statement as may be necessary to keep the  Registration  Statement
effective at all times during the Registration  Period.  Without limiting any of
the  Company's  obligations  under  this  Agreement,  in the event the number of
shares available under a Registration Statement filed pursuant to this Agreement
is insufficient to cover all of the  Registrable  Securities  issued or issuable
upon  conversion of the Preferred  Shares and/or  exercise of the Warrants,  the
Company  shall  amend the  Registration  Statement,  or file a new  Registration
Statement (on the short form available therefore, if applicable), or both, so as
to  cover  all  of  the  Registrable  Securities,  in  each  case,  as  soon  as
practicable,  but in any  event  within  twenty  (20) days  after the  necessity
therefor  arises  (based  on the  market  price of the  Common  Stock  and other
relevant  factors on which the Company  reasonably  elects to rely). The Company
shall use its Best  Efforts to cause  such  amendment  and/or  new  Registration
Statement to become effective as soon as possible following the filing thereof.

                  (c)  The  Company  shall   furnish  to  each  Investor   whose
Registrable  Securities are included in the Registration Statement and its legal
counsel (i) promptly after the same is prepared and publicly distributed,  filed
with the SEC or received by the Company, one copy of the Registration  Statement
and any amendment thereto,  each preliminary  prospectus and prospectus and each
amendment or supplement thereto, and, in the case of the Registration  Statement
referred to in Section 2(a),  each letter written by or on behalf of the Company
to the SEC or the staff of the SEC,  and each  material  item of  correspondence
from the SEC or the staff of the SEC, in each case relating to such Registration
Statement  (other than any portion  thereof that contains  information for which
the Company has sought confidential  treatment),  and (ii) such number of copies
of a prospectus,  including a preliminary  prospectus,  and all  amendments  and
supplements  thereto and such other  documents as such  Investor may  reasonably
request in order to facilitate  the  disposition of the  Registrable  Securities
owned by such Investor.

                  (d) The Company shall use its Best Efforts to (i) register and
qualify the Registrable  Securities covered by the Registration  Statement under
such other  securities  or "blue sky" laws of such  jurisdictions  in the United
States as the  Investors  who hold a majority  in  interest


                                      -4-




of the Registrable Securities being offered reasonably request, (ii) prepare and
file  in  those   jurisdictions   such  amendments   (including   post-effective
amendments) and supplements to such  registrations and  qualifications as may be
necessary to maintain the effectiveness  thereof during the Registration Period,
(iii) take such other actions as may be necessary,  appropriate  or available to
maintain such registrations and qualifications in effect at all times during the
Registration  Period,  and (iv) take all other actions necessary or advisable to
qualify the  Registrable  Securities for sale in such  jurisdictions;  provided,
however,  that the Company shall not be required in connection therewith or as a
condition  thereto to (a) qualify to do business  in any  jurisdiction  where it
would not  otherwise  be  required  to qualify but for this  Section  3(d),  (b)
subject itself to general taxation in any such jurisdiction,  (c) file a general
consent  to  service  of  process  in any such  jurisdiction,  (d)  provide  any
undertakings  that cause the Company  undue  expense or burden,  or (e) make any
change in its charter or bylaws,  which in each case the Board of  Directors  of
the Company  determines to be contrary to the best  interests of the Company and
its  stockholders.  The Company  shall  promptly  notify each Investor who holds
Registrable  Securities of the receipt by the Company of any  notification  with
respect to the suspension of the  registration  or  qualification  of any of the
Registrable  Securities  for sale under the securities or "blue sky" laws of any
jurisdiction  in the  United  States  or its  receipt  of  actual  notice of the
initiation or threatening of any proceeding for such purpose.

                  (e) Notwithstanding the foregoing, if at any time or from time
to time  after the date of  effectiveness  of the  Registration  Statement,  the
Company  notifies  the  Investors  in writing of the  existence  of a  Potential
Material Event, the Investors shall not offer or sell any Registrable Shares, or
engage in any other transaction involving or relating to the Registrable Shares,
from the time of the giving of notice with respect to a Potential Material Event
until the  earlier  of (i) twenty  (20) days from the  receipt of notice of such
Potential Material Event, or (ii) such Investor receives written notice from the
Company that such  Potential  Material  Event  either has been  disclosed to the
public or no longer constitutes a Potential Material Event;  provided,  however,
that the Company shall use its best efforts to minimize any such  suspension and
under all circumstances the Company may not so suspend the right to such holders
of Registrable  Shares for more than two periods of twenty (20) days each in the
aggregate  during  any  12-month  period  during  the  period  the  Registration
Statement is required to be in effect; and provided,  further,  that there shall
be an interval of no less than 45 days between such two twenty (20) day periods.

                  (f) The  Company  shall use its Best  Efforts to  prevent  the
issuance  of  any  stop  order  or  other   suspension  of  effectiveness  of  a
Registration  Statement,  and,  if  such an  order  is  issued,  to  obtain  the
withdrawal  of such order at the  earliest  possible  moment and to notify  each
Investor  who holds  Registrable  Securities  being sold (or, in the event of an
underwritten  offering, the managing underwriters) of the issuance of such order
and the resolution thereof.

                  (g) For a period  of five (5)  business  days  prior to filing
with the SEC, the Company  shall permit a single firm of counsel  designated  by
the Investors  representing a majority of the Registrable Securities held by the
Investors (on an as converted and as exercised basis) to review the Registration
Statement and all amendments and supplements  thereto.  Any period of review and
revision  resulting  from any such review that extends  beyond five (5) business
days


                                      -5-



shall be added to the time in which  registration  is  required  to be filed and
effective, as appropriate, and no penalty shall be assessed with respect to such
period.

                  (h) The Company shall make available for inspection by (i) any
Investor, (ii) any underwriter  participating in any disposition pursuant to the
Registration Statement,  (iii) one firm of attorneys and one firm of accountants
or other  agents  retained  by the  Investors,  and  (iv) one firm of  attorneys
retained by all such underwriters (collectively, the "INSPECTORS") all pertinent
financial and other records, and pertinent corporate documents and properties of
the  Company  (collectively,  the  "RECORDS")  as  shall  be  reasonably  deemed
necessary  by each  Inspector  to enable  each  Inspector  to  exercise  its due
diligence  responsibility,  and  cause the  Company's  officers,  directors  and
employees to supply all information  which any Inspector may reasonably  request
for purposes of such due diligence; provided, however, that each Inspector shall
hold in  confidence  and shall not make any  disclosure  of any  Record or other
information which the Company  determines in good faith to be confidential,  and
of which determination the Inspectors are so notified, unless (a) the disclosure
of such Records is  determined  to be necessary by the Investors and the Company
to avoid or correct a misstatement  or omission in any  Registration  Statement,
(b) the release of such Records is ordered pursuant to a subpoena or other order
from  a  court  or  government  body  of  competent  jurisdiction,  or  (c)  the
information  in such  Records has been made  generally  available  to the public
other  than by  disclosure  in  violation  of this or any other  agreement.  The
Company shall not be required to disclose any  confidential  information in such
Records to any Inspector until and unless such Inspector shall have entered into
confidentiality  agreements (in form and substance  satisfactory to the Company)
with the Company with respect thereto, containing terms substantially similar to
those contained in this Section 3(i).  Each Investor agrees that it shall,  upon
learning  that  disclosure  of  such  Records  is  sought  in or by a  court  or
governmental body of competent  jurisdiction or through other means, give prompt
notice to the  Company  and allow the  Company,  at its  expense,  to  undertake
appropriate  action to prevent  disclosure  of, or to obtain a protective  order
for, the Records  deemed  confidential.  Nothing herein shall be deemed to limit
the  Investor's  ability to sell  Registrable  Securities  in a manner  which is
otherwise consistent with applicable laws and regulations.

                  (i) The  Company  shall  hold in  confidence  and not make any
disclosure of information  concerning an Investor provided to the Company unless
(i) disclosure of such  information is necessary to comply with federal or state
securities   laws,  or  other  applicable  law,  (ii)  the  disclosure  of  such
information is necessary to avoid or correct a  misstatement  or omission in any
Registration  Statement,  (iii)  the  release  of such  information  is  ordered
pursuant  to a  subpoena  or other  order from a court or  governmental  body of
competent  jurisdiction,  or (iv)  such  information  has  been  made  generally
available  to the public  other than by  disclosure  in violation of this or any
other agreement. The Company agrees that it shall, upon learning that disclosure
of such  information  concerning  an  Investor  is  sought  in or by a court  or
governmental body of competent  jurisdiction or through other means, give prompt
notice to such Investor prior to making such disclosure, and allow the Investor,
at its expense, to undertake  appropriate action to prevent disclosure of, or to
obtain a protective order for, such information.

                  (j) The  Company  shall use its Best  Efforts  to  secure  the
designation  and  quotation  of all the  Registrable  Securities  covered by the
Registration  Statement on the NASDAQ 


                                      -6-



SmallCap Market, if the listing of such Registrable Securities is then permitted
under the rules and regulations of such market.

                  (k) The Company shall provide a transfer  agent and registrar,
which may be a single  entity,  for the  Registrable  Securities  not later than
sixty (60) days from the Closing Date.

                  (l)  The  Company  shall   promptly   facilitate   the  timely
preparation and delivery of certificates  (not bearing any restrictive  legends)
representing  Registrable  Securities  to be sold  pursuant to the  Registration
Statement and enable such  certificates to be in such  denominations or amounts,
as the case may be, as the managing underwriter or underwriters,  if any, or the
Investors may  reasonably  request and  registered in such names as the managing
underwriter or underwriters, if any, or the Investors may request.

                  (m) The  Company  shall  use its Best  Efforts  to  cause  all
Registrable  Securities covered by such registration  statement to be registered
with or approved by such other  governmental  agencies or  authorities as may be
necessary to enable each holder thereof to consummate disposition of Registrable
Securities.

         4.       OBLIGATIONS OF THE INVESTORS.

         In connection with the registration of the Registrable Securities,  the
Investors shall have the following obligations:

                  (a) It shall be a condition  precedent to the  obligations  of
the Company to complete the registration pursuant to this Agreement with respect
to the Registrable  Securities of a particular Investor that such Investor shall
furnish to the Company,  within five (5) business days of the Company's  written
request, such information  regarding itself, the Registrable  Securities held by
it and the intended method of disposition of the Registrable  Securities held by
it  as  shall  be  reasonably  required  to  effect  the  registration  of  such
Registrable  Securities  and shall  execute  within  five (5)  business  days of
receipt by such Investor such documents in connection with such  registration as
the Company may reasonably request.

                  (b)  Each  Investor,  by  such  Investor's  acceptance  of the
Registrable  Securities,  agrees to  cooperate  with the  Company as  reasonably
requested by the Company in connection  with the  preparation  and filing of the
Registration Statement hereunder,  unless such Investor has notified the Company
in  writing  of such  Investor's  election  to  exclude  all of such  Investor's
Registrable Securities from the Registration Statement.

                  (c) Each Investor agrees that, upon receipt of any notice from
the  Company of the  happening  of a  Potential  Material  Event as set forth in
Section  3(e),  such  Investor  will  immediately   discontinue  disposition  of
Registrable  Securities  pursuant to the  Registration  Statement  covering such
Registrable Securities in accordance with Section 3(e).

                  (d) Without limiting an Investor's  rights under Section 2(a),
no Investor may participate in any  underwritten  distribution  hereunder unless
such Investor (i) agrees to sell such


                                      -7-



Investor's  Registrable  Securities  on the basis  provided in any  underwriting
arrangements  in usual and  customary  form entered  into by the  Company,  (ii)
completes  and executes  all  questionnaires,  powers of attorney,  indemnities,
underwriting  agreements and other documents reasonably required under the terms
of such underwriting arrangements, and (iii) agrees to pay its pro rata share of
all  underwriting  discounts and commissions and any expenses in excess of those
payable by the Company pursuant to Section 5 below.

                  (e) Each Investor whose Registrable Securities are included in
a Registration Statement understands that the 1933 Act may require delivery of a
prospectus relating thereto in connection with any sale thereof pursuant to such
Registration  Statement and each such  Investor  shall use its  reasonable  best
efforts to comply with the applicable  prospectus  delivery  requirements of the
1933 Act in connection with any such sale.

                  (f) Each Investor agrees to notify the Company  promptly,  but
in any  event  within  seventy-two  (72)  hours  after  the  date on  which  all
Registrable  Securities  owned by such Investor have been sold by such Investor,
so that the Company may comply with its obligation to terminate the Registration
Statement in accordance  with Item 512 of Regulation  S-K or Regulation  S-B, as
the case may be.

         5.       EXPENSES OF REGISTRATION.

         All  reasonable  expenses,   other  than  underwriting   discounts  and
commissions,   incurred   in   connection   with   registrations,   filings   or
qualifications pursuant to Sections 2 and 3, including all registration, listing
and  qualifications  fees,  printers  and  accounting  fees  and  the  fees  and
disbursements  of counsel for the Company,  shall be borne by the  Company.  All
fees and disbursements of counsel to the holders of Registrable Securities,  any
expenses incurred as a result of any investigation pursuant to Section 3(h), any
underwriting  discounts and  commissions  and all other expenses of such holders
not  contained  in the  previous  sentence  shall  be borne  by the  holders  of
Registrable Securities.

         6.       INDEMNIFICATION.

         In the event any Registrable  Securities are included in a Registration
Statement under this Agreement:

                  (a)  To  the  extent   permitted  by  law,  the  Company  will
indemnify,  hold  harmless  and  defend  (i) each  Investor  who is a seller  of
Registrable Securities under the Registration Statement, and (ii) the directors,
officers,  partners,  employees,  agents and each person who  controls  any such
Investor  within the meaning of the 1933 Act or the  Securities  Exchange Act of
1934, as amended (the "1934 ACT"),  if any,  (each,  an  "INDEMNIFIED  PERSON"),
against any joint or several losses,  claims,  damages,  liabilities or expenses
(collectively, together with actions, proceedings or inquiries by any regulatory
or  self-regulatory  organization,  whether commenced or threatened,  in respect
thereof,  "CLAIMS") to which any of them may become  subject under the 1933 Act,
the 1934 Act or  otherwise,  insofar as any such Claim arises out of or is based
upon: (i) any untrue statement or alleged untrue statement of a material fact in
a Registration  Statement or



                                      -8-


the omission or alleged omission to state therein a material fact required to be
stated or necessary to make the  statements  therein not  misleading or (ii) any
untrue statement or alleged untrue statement of a material fact contained in any
preliminary  prospectus if used prior to the effective date of such Registration
Statement, or contained in the final prospectus (as amended or supplemented,  if
the Company files any amendment  thereof or supplement  thereto with the SEC) or
the omission or alleged omission to state therein any material fact necessary to
make the statements made therein,  in light of the circumstances under which the
statements  therein were made,  not  misleading  (the  matters in the  foregoing
clauses  (i)  and  (ii)  being,  collectively,  "VIOLATIONS").  Subject  to  the
restrictions  set forth in  Section  6(c) with  respect  to the  number of legal
counsel,  the Company shall reimburse the Investors and each such underwriter or
controlling  person,  promptly as such  expenses  are  incurred  and are due and
payable,  for any reasonable legal fees or other reasonable expenses incurred by
them  in   connection   with   investigating   or  defending   any  such  Claim.
Notwithstanding  anything to the contrary contained herein, the  indemnification
agreement contained in this Section 6(a): (i) shall not apply to a Claim arising
out of or based upon a Violation which occurs in reliance upon and in conformity
with information  furnished in writing to the Company by any Indemnified  Person
expressly  for  use in  connection  with  the  preparation  of the  Registration
Statement,  preliminary prospectus or final prospectus, or any amendment thereof
or supplement thereto; (ii) shall not apply to amounts paid in settlement of any
Claim if such  settlement is effected  without the prior written  consent of the
Company,  which  consent  shall not be  unreasonably  withheld;  and (iii)  with
respect to any  preliminary  prospectus,  shall not inure to the  benefit of any
Indemnified  Person  if the  untrue  statement  or  omission  of  material  fact
contained in the  preliminary  prospectus was corrected on a timely basis in the
prospectus,  as then amended or supplemented,  if such corrected  prospectus was
timely made  available  by the Company  pursuant to Section  3(c)  hereof.  Such
indemnity shall remain in full force and effect  regardless of any investigation
made by or on behalf of the Indemnified Person and shall survive the transfer of
the   Registrable   Securities   by  the   Investors   pursuant  to  Section  9.
Notwithstanding  anything to the contrary  contained  herein,  any Investor that
does not fulfill its obligations under Sections 2(a), 3(a) or 4(a) hereof within
the period of time specified in such Sections shall not be an Indemnified Person
and shall not be entitled to indemnification pursuant to this Section 6.

                  (b) In connection with any Registration  Statement in which an
Investor is  participating,  each such Investor agrees severally and not jointly
to  indemnify,  hold  harmless  and  defend,  to the same extent and in the same
manner set forth in Section 6(a), the Company,  each of its  directors,  each of
its  officers who signs the  Registration  Statement,  each person,  if any, who
controls the Company within the meaning of the 1933 Act or the 1934 Act, and any
other stockholder selling securities  pursuant to the Registration  Statement or
any of its  directors  or officers or any person who controls  such  stockholder
within  the  meaning  of  the  1933  Act  or  the  1934  Act  (collectively,  an
"INDEMNIFIED PARTY"), against any Claim to which any of them may become subject,
under the 1933 Act, the 1934 Act or otherwise,  insofar as such Claim arises out
of or is based upon any  Violation,  in each case to the extent (and only to the
extent)  that such  Violation  occurs in reliance  upon and in  conformity  with
written information  furnished to the Company by such Investor expressly for use
in connection with such Registration Statement,  preliminary prospectus or final
prospectus,  or any amendment or supplement thereto; and subject to Section 6(c)
such  Investor  will  reimburse  any legal or other  expenses  (promptly as such



                                      -9-



expenses are incurred  and are due and payable)  reasonably  incurred by them in
connection with  investigating or defending any such Claim;  provided,  however,
that the indemnity  agreement  contained in this Section 6(b) shall not apply to
amounts paid in settlement of any Claim if such  settlement is effected  without
the  prior  written  consent  of  such  Investor,  which  consent  shall  not be
unreasonably withheld;  provided,  further,  however, that the Investor shall be
liable under this Agreement (including this Section 6(b) and Section 7) for only
that amount as does not exceed the net proceeds to such  Investor as a result of
the sale of Registrable Securities pursuant to such Registration Statement. Such
indemnity shall remain in full force and effect  regardless of any investigation
made by or on behalf of such Indemnified Party and shall survive the transfer of
the   Registrable   Securities   by  the   Investors   pursuant  to  Section  9.
Notwithstanding  anything to the contrary contained herein, the  indemnification
agreement  contained  in this  Section  6(b)  with  respect  to any  preliminary
prospectus shall not inure to the benefit of any Indemnified Party if the untrue
statement or omission of material fact contained in the  preliminary  prospectus
was  corrected  on a  timely  basis  in  the  prospectus,  as  then  amended  or
supplemented.

                  (c)  Promptly  after  receipt  by  an  Indemnified  Person  or
Indemnified  Party  under this  Section 6 of notice of the  commencement  of any
action  (including  any  governmental   action),   such  Indemnified  Person  or
Indemnified Party shall, if a Claim in respect thereof is to be made against any
indemnifying  party under this  Section 6, deliver to the  indemnifying  party a
written notice of the commencement  thereof,  and the  indemnifying  party shall
have the right to participate in, and, to the extent the  indemnifying  party so
desires,  jointly with any other indemnifying party similarly noticed, to assume
control  of the  defense  thereof  with  counsel  mutually  satisfactory  to the
indemnifying  party and the Indemnified  Person or the Indemnified Party, as the
case may be; provided,  however, that an Indemnified Person or Indemnified Party
shall have the right to retain its own counsel  with the fees and expenses to be
paid by the  indemnifying  party,  if,  in the  reasonable  opinion  of  counsel
retained by the indemnifying  party, the  representation  by such counsel of the
Indemnified  Person or  Indemnified  Party and the  indemnifying  party would be
inappropriate  due to actual  or  potential  differing  interests  between  such
Indemnified  Person or Indemnified Party and any other party represented by such
counsel  in such  proceeding.  The  indemnifying  party  shall  pay for only one
separate legal counsel for the Indemnified  Persons or the Indemnified  Parties,
as applicable,  and such legal counsel shall be selected by Investors  holding a
majority-in-interest  of the Registrable Securities included in the Registration
Statement  to  which  the  Claim  relates,  if the  Investors  are  entitled  to
indemnification  hereunder,  or the  Company,  if the  Company  is  entitled  to
indemnification  hereunder, as applicable. The failure to deliver written notice
to the  indemnifying  party within a reasonable time of the  commencement of any
such action shall not relieve such  indemnifying  party of any  liability to the
Indemnified  Person or  Indemnified  Party  under this  Section 6, except to the
extent  that the  indemnifying  party is actually  prejudiced  in its ability to
defend such action. The indemnification required by this Section 6 shall be made
by  periodic   payments  of  the  amount   thereof  during  the  course  of  the
investigation or defense, as such expense, loss, damage or liability is incurred
and is due and payable.

         7.       CONTRIBUTION.

         To  the  extent  any   indemnification  by  an  indemnifying  party  is
prohibited or limited by law, the indemnifying  party agrees to make the maximum
contribution  with respect to any amounts for


                                      -10-



which it would  otherwise  be  liable  under  Section  6 to the  fullest  extent
permitted by law;  provided,  however,  that (i) no  contribution  shall be made
under   circumstances   where  the  maker   would  not  have  been   liable  for
indemnification under the fault standards set forth in Section 6, (ii) no seller
of Registrable  Securities  guilty of fraudulent  misrepresentation  (within the
meaning of Section 11(f) of the 1933 Act) shall be entitled to contribution from
any person who was not guilty of such  fraudulent  misrepresentation,  and (iii)
contribution  (together with any indemnification or other obligations under this
Agreement) by any seller of Registrable Securities shall be limited in amount to
the amount of proceeds received by such seller from the sale of such Registrable
Securities.

         8.       REPORTS UNDER THE 1934 ACT.

         With a view to making  available to the  Investors the benefits of Rule
144  promulgated  under the 1933 Act or any other  similar rule or regulation of
the SEC that may at any time  permit the  Investors  to sell  securities  of the
Company to the public without registration ("RULE 144"), the Company agrees to:

                  (a) make and keep public information available, as those terms
are understood and defined in Rule 144;

                  (b) file with the SEC in a timely manner all reports and other
documents required of the Company under the 1933 Act and the 1934 Act so long as
the filing of such  reports and other  documents is required for the sale of the
Registrable Securities pursuant to Rule 144; and

                  (c)  furnish to each  Investor so long as such  Investor  owns
Registrable  Securities,  promptly upon request,  (i) a written statement by the
Company that it has complied  with the reporting  requirements  of Rule 144, the
1933 Act and the 1934 Act,  (ii) a copy of the most recent  annual or  quarterly
report of the  Company  and such other  reports  and  documents  so filed by the
Company,  and (iii) such other  information  as may be  reasonably  requested to
permit  the  Investors  to sell such  securities  pursuant  to Rule 144  without
registration.

         9.       ASSIGNMENT OF REGISTRATION RIGHTS.

         The rights of an Investor  hereunder,  including  the right to have the
Company register  Registrable  Securities  pursuant to this Agreement,  shall be
automatically  assignable by each Investor to any  transferee of at least 30% of
the Preferred Shares and/or Warrants, or Registrable Securities of such Investor
if (i) the Investor  agrees in writing with the transferee or assignee to assign
such rights,  and a copy of such  agreement is furnished to the Company within a
reasonable time after such assignment,  (ii) the Company is, within a reasonable
time after such transfer or assignment, furnished with written notice of (a) the
name and address of such  transferee or assignee,  and (b) the  securities  with
respect to which such  registration  rights are being  transferred  or assigned,
(iii)  following  such transfer or assignment,  the further  disposition of such
securities by the  transferee  or assignee is restricted  under the 1933 Act and
applicable  state  securities  laws,  (iv) at or  before  the time  the  Company
receives the written notice  contemplated  by clause (ii) of


                                      -11-


this sentence,  the transferee or assignee agrees in writing with the Company to
be bound by all of the provisions contained herein, (v) such transfer shall have
been made in  accordance  with the  applicable  requirements  of the  Securities
Purchase Agreement,  and (vi) such transferee shall be an "accredited  investor"
as that term defined in Rule 501 of Regulation D promulgated under the 1933 Act.

         10.      AMENDMENT OF REGISTRATION RIGHTS.

                  (a)  Provisions  of  this  Agreement  may be  amended  and the
observance  thereof may be waived (either generally or in a particular  instance
and either  retroactively  or  prospectively),  only with written consent of the
Company and Investors who hold at least 80% of the Registrable  Securities.  Any
amendment or waiver effected in accordance with this Section 10 shall be binding
upon each Investor and the Company.

                  (b)  Notwithstanding  the foregoing,  the Company may, without
the  consent of the  existing  Investors,  amend this  Agreement  at any time to
include  additional  parties so long as the Company and such additional  parties
execute a counterpart  signature page to this Agreement.  When this Agreement is
so amended,  such additional parties shall be "Investors" hereunder and shall be
entitled to all benefits and bound by all obligations hereunder.

         11.      MISCELLANEOUS.

                  (a) A person or entity is deemed to be a holder of Registrable
Securities  whenever  such  person or entity  owns of  record  such  Registrable
Securities.  If  the  Company  receives  conflicting  instructions,  notices  or
elections  from  two or more  persons  or  entities  with  respect  to the  same
Registrable  Securities,  the Company shall act upon the basis of  instructions,
notice  or  election  received  from the  registered  owner of such  Registrable
Securities.

                  (b) Notices  required or permitted to be given hereunder shall
be in  writing  and shall be deemed to be  sufficiently  given  when  personally
delivered (by hand, by courier,  by telephone  line  facsimile  transmission  or
other means) or sent by facsimile or overnight courier,

         If to the Company, to:

                  DynaGen, Inc.
                  99 Erie Street
                  Cambridge, MA  02139
                  Attention:  President

                  Telephone:        (617) 491-2527
                  Telecopy:         (617) 354-3902

if to the  Investors  as set forth in the  subscription  agreements  pursuant to
which the  Investors  purchased  securities  of the  Company,  or at such  other
address as each such party  furnishes  by 


                                      -12-


notice given in accordance with this Section 11(b), and shall be effective, when
personally  delivered,  upon receipt and, when so sent by facsimile or overnight
courier.

                  (c) Failure of any party to exercise any right or remedy under
this  Agreement or otherwise,  or delay by a party in  exercising  such right or
remedy, shall not operate as a waiver thereof

                  (d)  This  Agreement  shall  be  enforced,   governed  by  and
construed in  accordance  with the laws of the State of Delaware  applicable  to
agreements  made and to be performed  entirely  within such State.  In the event
that any  provision  of this  Agreement  is invalid or  unenforceable  under any
applicable  statute  or  rule  of law,  then  such  provision  shall  be  deemed
inoperative  to the extent that it may  conflict  therewith  and shall be deemed
modified to conform with such statute or rule of law. Any provision hereof which
may prove invalid or  unenforceable  under any law shall not affect the validity
or enforceability of any other provision hereof. Each of the parties consents to
the jurisdiction of the federal courts whose districts encompass any part of the
City of New York or the state  courts of the  State of New York  sitting  in the
City of New York in connection with any dispute arising under this Agreement and
hereby waives, to the maximum extent permitted by law, any objection,  including
any  objection  based on  forum  non  conveniens,  to the  bringing  of any such
proceeding in such jurisdictions.

                  (e) This Agreement and the subscription agreements pursuant to
which the Investors purchased securities of the Company (including all schedules
and exhibits  thereto)  constitute the entire agreement among the parties hereto
with  respect  to  the  subject   matter  hereof  and  thereof.   There  are  no
restrictions,  promises, warranties or undertakings,  other than those set forth
or  referred  to  herein  and  therein.  This  Agreement  and such  subscription
agreements  supersede all prior agreements and understandings  among the parties
hereto with respect to the subject matter hereof and thereof.

                  (f)  Subject to the  requirements  of  Section 9 hereof,  this
Agreement  shall inure to the benefit of and be binding upon the  successors and
assigns of each of the parties hereto.

                  (g) The  headings in this  Agreement  are for  convenience  of
reference only and shall not limit or otherwise affect the meaning hereof.

                  (h)  This   Agreement   may  be   executed   in  two  or  more
counterparts,  each of which shall be deemed an original  but all of which shall
constitute one and the same agreement. This Agreement, once executed by a party,
may be delivered to the other party hereto by facsimile  transmission  of a copy
of this  Agreement  bearing  the  signature  of the  party  so  delivering  this
Agreement.

                  (i) Each party shall do and  perform,  or cause to be done and
performed,  all such further acts and things,  and shall execute and deliver all
such other  agreements,  certificates,  instruments and documents,  as the other
party may reasonably request in order to carry out the intent and accomplish the
purposes of this Agreement and the consummation of the transactions contemplated
hereby.


                                      -13-



                  (j) All  consents and other  determinations  to be made by the
Investors  pursuant to this Agreement  shall be made by the Investors  holding a
majority of the Registrable  Securities  (determined as if all Preferred  Shares
and Warrants then  outstanding  had been  converted or exercised,  respectively,
into Registrable Securities).

                [REMAINDER OF PAGE IS INTENTIONALLY LEFT BLANK.]




                                      -14-





                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                     Very truly yours,

                                                     DYNAGEN, INC.

                                                     By:     /s/ Indu A. Muni
                                                        ------------------------
                                                     Title:  President
                                                           ---------------------






                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                              Very truly yours,

                                              Arab Commerce Bank, Ltd.
                                              ----------------------------------
                                              (print exact name of Investor)

                                              By:      [illegible]
                                                 -------------------------------

                                              Title:   Co. Secretary
                                                    ----------------------------





                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 Swedbank Luxembourg
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      [illegible]
                                                    ----------------------------

                                                 Title:   Senior Account Manager
                                                       -------------------------








                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 Paul Enquist
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      /s/ Paul Enquist
                                                    ----------------------------

                                                 Title:
                                                       -------------------------








                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                  Very truly yours,

                                                  Leo Genecco & Sons Inc.
                                                  ------------------------------
                                                  (print exact name of Investor)

                                                  By:      /s/ David L. Genecco
                                                     ---------------------------

                                                  Title:   President
                                                        ------------------------










                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 William S. Kissel
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      /s/ William S. Kissel
                                                    ----------------------------

                                                 Title:
                                                       -------------------------








                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 Irving Schotz
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      /s/ Irving Schotz
                                                    ----------------------------

                                                 Title:
                                                       -------------------------








                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 Dick Alaimo, Jr.
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      /s/ Dick Alaimo, Jr.
                                                    ----------------------------

                                                 Title:
                                                       -------------------------









                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                  Very truly yours,

                                                  Jon A. Travers
                                                  ------------------------------
                                                  (print exact name of Investor)

                                                  By:      /s/ Jon A. Travers
                                                     ---------------------------

                                                  Title:
                                                        ------------------------








                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                Very truly yours,

                                                C. Robert Cusick
                                                -------------------------------
                                                (print exact name of Investor)

                                                By:      /s/ C. Robert Cusick
                                                   -----------------------------

                                                Title:
                                                      --------------------------








                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                  Very truly yours,

                                                  Robert C. Cohen
                                                  ------------------------------
                                                  (print exact name of Investor)

                                                  By:      /s/ Robert C. Cohen
                                                     ---------------------------

                                                  Title:
                                                        ------------------------








                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 Christopher Grieco
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      /s/ Christopher Grieco
                                                    ----------------------------

                                                 Title:
                                                       -------------------------









                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 Richard and Ronda Tennis
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      /s/ Richard Tennis
                                                    ----------------------------

                                                 Title:
                                                       -------------------------







                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                Very truly yours,

                                                Robert D. Frankel
                                                --------------------------------
                                                (print exact name of Investor)

                                                By:      /s/ Robert D. Frankel
                                                   -----------------------------

                                                Title:
                                                      --------------------------







                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                             Very truly yours,

                                             A. Ronald Jacobstein
                                             -----------------------------------
                                             (print exact name of Investor)

                                             By:      /s/ A. Ronald Jacobstein
                                                 -------------------------------

                                             Title:
                                                   -----------------------------







                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                                 Very truly yours,

                                                 J. Michael Nixon
                                                 -------------------------------
                                                 (print exact name of Investor)

                                                 By:      /s/ J. Michael Nixon
                                                    ----------------------------

                                                 Title:
                                                       -------------------------






                                  DYNAGEN, INC.

                      MASTER REGISTRATION RIGHTS AGREEMENT

                           Counterpart Signature Page


         If you are in  agreement  with the  foregoing,  please sign the form of
acceptance on the enclosed  counterpart of this Agreement and return the same to
the Company,  whereupon,  this Agreement shall become a binding  Agreement among
us.

                                      Very truly yours,

                                      Guarantee & Trust Co. FBO J. Thomas Chess
                                      ------------------------------------------
                                      (print exact name of Investor)

                                      By:      /s/ J. Thomas Chess
                                         ---------------------------------------

                                      Title:
                                            ------------------------------------





                                                                      Exhibit 4d

                            STOCK PURCHASE AGREEMENT


         THIS STOCK PURCHASE  AGREEMENT,  dated as of the date of acceptance set
forth  below,  is  entered  into  by  and  between  DYNAGEN,  INC.,  a  Delaware
corporation,   with   headquarters   located  at  99  Erie  Street,   Cambridge,
Massachusetts 02139 (the "Company"), and the undersigned (the "Buyer").

                              W I T N E S S E T H:

         WHEREAS,  the Company and the Buyer are executing and  delivering  this
Agreement in reliance upon  exemptions  from  securities  registration  afforded
under  Regulation  D  ("Regulation  D")  as  promulgated  by the  United  States
Securities and Exchange Commission (the "SEC") under the Securities Act of 1933,
as amended (the "1933 Act") and/or Section 4(2) of the 1933 Act; and

         WHEREAS,  the Buyer wishes to  purchase,  upon the terms and subject to
the conditions of this Agreement, Series C Convertible Preferred Stock, $.01 par
value  per  share  and  Series D  Convertible  Preferred  Stock  $.01 par  value
(collectively the "Preferred  Stock"),  of the Company which will be convertible
into shares of Common Stock,  $.01 par value per share (the "Common Stock"),  of
the Company upon the terms and subject to the conditions of such Preferred Stock
(the  Common  Stock  and  Preferred  Stock  sometimes   referred  to  herein  as
"Securities"),  and a Warrant to purchase  250,000  shares of Common  Stock (the
"Warrant") and subject to acceptance of this Agreement by the Company;

         NOW  THEREFORE,  in  consideration  of  the  premises  and  the  mutual
covenants  contained  herein  and other  good and  valuable  consideration,  the
receipt and sufficiency of which are hereby  acknowledged,  the parties agree as
follows:

         1.       AGREEMENT TO PURCHASE; PURCHASE PRICE.

         A. PURCHASE. The undersigned hereby agrees to purchase from the Company
Series  C  Preferred  Stock  of the  Company,  in the  amount  set  forth on the
signature page of this Agreement,  and having the terms and conditions set forth
in the  Certificate  of  Designations  attached  hereto as ANNEX I. The purchase
price for the Series C Preferred  Stock  shall be as set forth on the  signature
page hereto and shall be payable in United States Dollars.

         B. FORM OF  PAYMENT.  The Buyer  shall pay the  purchase  price for the
Preferred Stock by delivering  immediately available good funds in United States
Dollars to the escrow agent (the "Escrow Agent")  identified in the Joint Escrow
Instructions  attached hereto as ANNEX II (the "Joint Escrow  Instructions")  as
set forth below.  Promptly following payment by the Buyer to the Escrow Agent of
the  purchase  price  of the  Preferred  Stock,  the  Company  shall  deliver  a
Certificate for the Preferred  Stock duly executed on behalf of the Company,  to
the Escrow  Agent.  By signing this  Agreement,  the Buyer and the Company,  and
subject to acceptance  by the Escrow Agent,  each agrees to all of the terms and
conditions of, and becomes a party to, the Joint Escrow









Instructions,  all of the  provisions of which are  incorporated  herein by this
reference as if set forth in full.

         C. METHOD OF PAYMENT. Payment into escrow of the purchase price for the
Preferred Stock shall be made by wire transfer of funds to:

                  Bank of New York
                  350 Fifth Avenue
                  New York, New York 10001

                  ABA# 021000018
                  For credit to the account of Krieger & Prager, Esqs.
                  Account No. 105

Not later  than 1:00  p.m.,  New York  time,  on the date  which is two (2) NASD
trading days after the Company shall have accepted this Agreement and returned a
signed counterpart of this Agreement to the Escrow Agent by facsimile, the Buyer
shall  deposit  with the  Escrow  Agent  the  aggregate  purchase  price for the
Preferred  Stock, in immediately  available  funds.  Time is of the essence with
respect to such  payment,  and failure by the Buyer to make such  payment  shall
allow the Company to cancel this Agreement.

         2. BUYER  REPRESENTATIONS,  WARRANTIES,  ETC.;  ACCESS TO  INFORMATION;
INDEPENDENT INVESTIGATION.

         The Buyer  represents  and warrants to, and  covenants and agrees with,
the Company as follows:

         a.  Without  limiting  its right to resell the Common  Stock  under the
Registration  Rights Agreement,  the Buyer is purchasing the Preferred Stock and
will be acquiring  the shares of Common Stock  issuable  upon  conversion of the
Preferred  Stock for its own  account  for  investment  only and not with a view
towards the resale,  public sale or distribution  thereof and not with a view to
or for sale in connection with any distribution thereof;

         b. The Buyer is (i) an "accredited investor" as that term is defined in
Rule 501 of the General  Rules and  Regulations  under the 1933 Act by reason of
Rule 501(a)(3),  (ii) experienced in making investments of the kind described in
this Agreement and the related documents,  (iii) able, by reason of the business
and  financial  experience  of its  officers  (if an  entity)  and  professional
advisors (who are not  affiliated  with or compensated in any way by the Company
or any of its  affiliates  or selling  agents),  to protect its own interests in
connection with the  transactions  described in this Agreement,  and the related
documents,  and (iv) able to afford the  entire  loss of its  investment  in the
Preferred Stock:

         c. All  subsequent  offers  and  sales of the  Preferred  Stock and the
shares of Common Stock  issuable upon  conversion of, or issued as dividends on,
the Preferred  Stock by the Buyer shall be made pursuant to  registration of the
Shares under the 1933 Act or with respect to the Preferred  Stock pursuant to an
exemption from registration;


                                      -2-





         d. The Buyer  understands that the Preferred Stock is being offered and
sold, and the Shares are being offered, to it in reliance on specific exemptions
from the registration requirements of United States federal and state securities
laws and that the Company is relying upon the truth and accuracy of, the and the
Buyer's   compliance   with,  the   representations,   warranties,   agreements,
acknowledgments  and  understandings  of the Buyer set forth  herein in order to
determine the  availability  of such exemptions and the eligibility of the Buyer
to acquire the Preferred Stock and to receive an offer of the Shares;

         e. The Buyer and its  advisors,  if any, have been  furnished  with all
materials  relating to the business,  finances and operations of the Company and
materials relating to the offer and sale of the Preferred Stock and the offer of
the Shares which have been requested by the Buyer, including ANNEX V hereto. The
Buyer and its  advisors,  if any,  have been  afforded  the  opportunity  to ask
questions of the Company and have received complete and satisfactory  answers to
any such inquiries.  Without limiting the generality of the foregoing, the Buyer
has also had the  opportunity  to obtain and to review the  Company's (1) Annual
Report on Form 10-K for the  fiscal  year ended June 30,  1996;  (2)  Transition
Report on Form 10-K for the  six-month  period from July 1, 1996 to December 31,
1996,  as amended;  (3) Quarterly  Reports on Form 10-Q for the fiscal  quarters
ended  September 30, 1996,  March 31, 1997 and June 30, 1997;  (4) The Company's
Proxy Statement for its Annual Meeting of Stockholders held on January 30, 1997;
(5) The  Company's  Current  Reports  on Form 8-K  filed  on  August  23,  1996,
September 23, 1996, January 15, 1997,  February 3, 1997, March 24, 1997 and July
3, 1997, as amended, and (6) The Company's Form S-3 Registration Statement filed
with the Securities and Exchange  Commission on August 11, 1997 (the  "Company's
SEC Documents").

         f. The Buyer understands that its investment in the Securities involves
a high degree of risk;

         g. The Buyer  understands that no United States federal or state agency
or any  other  government  or  governmental  agency  has  passed  on or made any
recommendation or endorsement of the Securities;

         h. This  Agreement has been duly and validly  authorized,  executed and
delivered  on behalf of the Buyer and is a valid and  binding  agreement  of the
Buyer enforceable in accordance with its terms,  subject as to enforceability to
general principles of equity and to bankruptcy, insolvency, moratorium and other
similar laws affecting the enforcement of creditors' rights generally.

         i.  Notwithstanding  the  provisions  hereof,  in no event (except with
respect to an Event of  Mandatory  Conversion)  shall the holder be  entitled to
convert any preferred  Stock in excess of that number of shares upon  conversion
of which the sum of (1) the number of shares of Common Stock  beneficially owned
by the Buyer and its affiliates  (other than shares of common Stock which may be
deemed  beneficially  owned through the ownership of the unconverted  portion of
the Preferred Stock), and (2) the number of shares of Common Stock issuable upon
the conversion of the Preferred Stock with respect to which the determination of
this proviso is being made,  would result in  beneficial  ownership by the Buyer
and its affiliates of more than 4.9% of the outstanding  shares of Common Stock.
For purposes of the proviso to the immediately  preceding 


                                      -3-









sentence,  beneficial  ownership  shall be determined in accordance with Section
13(d) of the Securities Exchange Act of 1934, as amended,  and Regulation 13 D-G
thereunder, except as otherwise provided in clause (1) of such proviso.

         3.       COMPANY REPRESENTATIONS, ETC.

         Except as disclosed in Annex V, delivered in writing to the Buyer,  the
Company represents and warrants to the Buyer that:

         A.  CONCERNING THE SHARES.  The Common Shares have been duly authorized
and, when issued upon  conversion  of, or as dividends on, the Preferred  Stock,
will be duly and  validly  issued,  fully paid and  non-assessable  and will not
subject the holder thereof to personal liability by reason of being such holder.
There are no preemptive rights except that the holders of the Company's Series A
Preferred  Stock have the right to acquire a portion of the Common  Shares which
rights have been waived or otherwise provided for.

         B.  REPORTING  COMPANY  STATUS.  The  Company  is  a  corporation  duly
organized,  validly existing and in good standing under the laws of the State of
Delaware and is duly qualified as a foreign  corporation in all jurisdictions in
which the  failure to so qualify  would  have a material  adverse  effect on the
Company and its  subsidiaries  taken as a whole.  The Company has registered its
Common Stock pursuant to Section 12 of the  Securities  Exchange Act of 1934, as
amended (the "Exchange  Act"),  and the Common Stock is listed and traded on the
NASDAQ/Small Cap Market.  The Company has timely filed all material  required to
be filed  pursuant to all reporting  obligations  under either  Section 13(a) or
15(d)  of  the  Exchange  Act  for a  period  of at  least  twelve  (12)  months
immediately preceding the offer or sale of the Preferred Stock, and has received
no notice,  either oral or written, with respect to the continued eligibility of
the Common Stock for such listing.

         C.  AUTHORIZED  SHARES.  The  Company  has  sufficient  authorized  and
unissued  Shares as may be reasonably  necessary to effect the conversion of the
Preferred  Stock.  The Common Shares have been duly  authorized and, when issued
upon  conversion  of, or as interest on, the Preferred  Stock,  will be duly and
validly issued,  fully paid and  non-assessable  and will not subject the holder
thereof to personal liability by reason of being such holder.

         D. STOCK PURCHASE  AGREEMENT;  REGISTRATION RIGHTS AGREEMENT AND STOCK.
This  Agreement  and the  Registration  Rights  Agreement,  the form of which is
attached hereto as ANNEX IV (the  "Registration  Rights  Agreement"),  have been
duly and  validly  authorized  by the  Company,  this  Agreement  has been  duly
executed  and  delivered  by  the  Company  and  this   Agreement  is,  and  the
Registration Rights Agreement,  when executed and delivered by the Company, will
be, valid and binding  agreements of the Company  enforceable in accordance with
their respective terms,  subject as to  enforceability to general  principles of
equity, the indemnification provisions of the Registration Rights Agreement, and
to  bankruptcy,  insolvency,  moratorium,  and other similar laws  affecting the
enforcement of creditors' rights generally; and the Preferred Stock will be duly
and validly issued,  fully paid and  non-assessable  when delivered on behalf of
the Company upon payment therefor in accordance with this Agreement,  subject to


                                      -4-







general principles of equity and to bankruptcy, insolvency, moratorium, or other
similar laws affecting the enforcement of creditors' rights generally.

         E. NON-CONTRAVENTION.  The execution and delivery of this Agreement and
the  Registration  Rights  Agreement  by  the  Company,   the  issuance  of  the
Securities,  and the  consummation  by the  Company  of the  other  transactions
contemplated by this  Agreement,  the  Registration  Rights  Agreement,  and the
Preferred  Stock do not and will not conflict  with or result in a breach by the
Company of any of the terms or provisions of, or constitute a default under, the
(i) certificate of incorporation or by-laws of the Company,  (ii) any indenture,
mortgage,  deed of trust, or other material agreement or instrument to which the
Company is a party or by which it or any of its  properties or assets are bound,
(iii)  any  material  existing  applicable  law,  rule,  or  regulation  or  any
applicable decree,  judgment,  or (iv) order of any court, United States federal
or state regulatory body,  administrative  agency,  or other  governmental  body
having jurisdiction over the Company or any of its properties or assets,  except
such conflict,  breach or default which would not have a material adverse effect
on the transactions contemplated herein.

         F.  APPROVALS.  No  authorization,  approval  or  consent of any court,
governmental body,  regulatory agency,  self-regulatory  organization,  or stock
exchange or market or the Stockholders of the Company is required to be obtained
by the  Company  for the  issuance  and sale of the  Securities  to the Buyer as
contemplated  by this  Agreement,  except  such  authorizations,  approvals  and
consents that have been obtained.

         G.  SEC  FILINGS.  None of the SEC  Filings  with  the  Securities  and
Exchange Commission at the time they were filed,  contained any untrue statement
of a material  fact or omitted to any state  material fact required to be stated
therein  or  necessary  to make the  statements  made  therein,  in light of the
circumstances under which they were made, not misleading. Except as set forth on
ANNEX V hereto,  the Company has timely filed all requisite  forms,  reports and
exhibits thereto with the Securities and Exchange Commission.

         H. ABSENCE OF CERTAIN CHANGES. Since January 1, 1997, there has been no
material  adverse  change and no material  adverse  development in the business,
properties,  operations,  financial  condition,  or results of operations of the
Company, except as disclosed in ANNEX V or in the Company's SEC Documents.

         I. FULL  DISCLOSURE.  There is no fact known to the Company (other than
general economic conditions known to the public generally), and other than facts
disclosed in the Company's SEC Documents, that has not been disclosed in writing
to the Buyer that (i) could  reasonably  be expected to have a material  adverse
effect on the condition  (financial or otherwise),  earnings,  business affairs,
properties  or assets of the  Company or (ii) could  reasonably  be  expected to
materially  and  adversely  affect  the  ability of the  Company to perform  its
obligations pursuant to this Agreement.

         J. ABSENCE OF LITIGATION. Except as set forth in ANNEX V hereto, and in
the Company's SEC Documents,  which the Buyer has reviewed,  there is no action,
suit, proceeding,  inquiry or investigation before or by any court, public board
or body pending or, to the knowledge of the Company or any of its  subsidiaries,
threatened against or affecting the Company 


                                      -5-







or any of its subsidiaries,  wherein an unfavorable decision,  ruling or finding
would have a material  adverse  effect on the  properties,  business,  condition
(financial or otherwise),  results of operations or prospects of the Company and
its  subsidiaries  taken as a whole  or the  transactions  contemplated  by this
Agreement or any of the documents  contemplated  hereby or which would adversely
affect the  validity or  enforceability  of, or the  authority or ability of the
Company to perform its  obligations  under,  this Agreement or any of such other
documents.

         K. ABSENCE OF EVENTS OR DEFAULT.  Except as set forth in ANNEX V hereto
and Section 3(e), no Event of Default, as defined in the respective agreement to
which the Company is a party,  and no event which,  with the giving of notice or
the passage of time or both,  would  become an Event of Default (as so defined),
has occurred and is  continuing,  which would have a material  adverse effect on
the Company's financial condition or results of operations.

         L. NO DEFAULT.  To its knowledge,  the Company is not in default in the
performance  or observance of any material  obligation,  agreement,  covenant or
condition contained in any indenture,  mortgage, deed of trust or other material
instrument or agreement to which it is a party or by which it or its property is
bound, and neither the execution of, nor the delivery by the Company of, nor the
performance  by the Company of its  obligations  under,  this  Agreement  or the
Preferred Stock, other than the conversion provision thereof, will conflict with
or result in the breach or  violation of any of the terms or  provisions  of, or
constitute  a default or result in the  creation  or  imposition  of any lien or
charge on any  assets or  properties  of the  Company  under,  (i) any  material
indenture,  mortgage deed of trust or other material agreement applicable to the
Company or  instrument  to which the Company is a party or by which it is bound,
(ii)  any  statute  applicable  to  the  Company  or  its  property,  (iii)  the
Certificate  of  Incorporation  or  By-Laws  of the  Company,  (iv) any  decree,
judgment,  order, rule or regulation of any court or governmental agency or body
having  jurisdiction  over the Company or its  properties,  or (v) the Company's
listing agreement for its Common Stock.

         M. PRIOR  ISSUES.  During the twelve  (12)  months  preceding  the date
hereof, the Company has not issued any securities other than (i) as reflected in
the Company's SEC Documents,  of which 44,700 shares of Series A Preferred Stock
and 7,500  shares of Series B  Preferred  Stock,  remain  unconverted,  and (ii)
options and warrants to purchase  shares of Common Stock which have been granted
to directors, employees, consultants and advisers of the Company, as further set
forth on Annex 3(m).

         4.       CERTAIN COVENANTS AND ACKNOWLEDGMENTS.

         A. TRANSFER  RESTRICTIONS.  The Buyer  acknowledges  that (1) Preferred
Stock has not been and is not being  registered under the provisions of the 1933
Act and, except as provided in the  Registration  Rights  Agreement,  the Shares
have not been and are not being  registered  under  the 1933 Act,  and may no be
transferred unless (A) subsequently registered thereunder or (B) the Buyer shall
have delivered to the Company an opinion of counsel,  reasonably satisfactory in
form,  scope and substance to the Company,  to the effect that the Securities to
be sold or transferred may be sold or transferred  pursuant to an exemption from
such  registration;  (2) any sale of the Securities made in reliance on Rule 144
promulgated  under the 1933 Act may be made only in accordance with the terms of
said  Rule and  further,  if said  Rule is not  applicable,  any  resale of



                                      -6-







such Securities under  circumstances in which the seller,  or the person through
whom the sale is made, may be deemed to be an underwriter,  as that term is used
in the 1933 Act, may require compliance with some other exemption under the 1933
Act or the rules and  regulations  of the SEC  thereunder;  and (3)  neither the
Company nor any other person is under any  obligation to register the Securities
(other than pursuant to the Registration Rights Agreement) under the 1933 Act or
to comply with the terms and conditions of any exemption thereunder.

         B.  RESTRICTIVE  LEGEND.  The Buyer  acknowledges  and agrees  that the
Preferred  Stock,  and, until such time as the Common Stock has been  registered
under the 1933 Act as contemplated by the Registration Rights Agreement and sold
in  accordance  with such  Registration  Statement,  the shares of Common  Stock
issued  to the  Buyer  upon  conversion  of the  Preferred  Stock  shall  bear a
restrictive  legend in  substantially  the following  form (and a  stop-transfer
order may be placed against  transfer of the Preferred  Stock and such shares of
Common Stock):

         THESE SECURITIES (THE  "SECURITIES")  HAVE NOT BEE REGISTERED UNDER THE
         SECURITIES  ACT OF 1933,  AS AMENDED  (THE  "SECURITIES  ACT"),  OR THE
         SECURITIES LAWS OF ANY STATE AND MAY NOT BE SOLD OR OFFERED FOR SALE IN
         THE ABSENCE OF AN EFFECTIVE  REGISTRATION  STATEMENT FOR THE SECURITIES
         OR  AN  OPINION  OF  COUNSEL  OR  OTHER  EVIDENCE   ACCEPTABLE  TO  THE
         CORPORATION THAT SUCH REGISTRATION IS NOT REQUIRED.

         C.  REGISTRATION  RIGHTS  AGREEMENT.  The parties hereto agree to enter
into the  Registration  Rights  Agreement,  in  substantially  the form attached
hereto as ANNEX IV, on or before the Closing Date (as defined in Section 7).

         D.  FILINGS.  The Company  undertakes  and agrees to make all necessary
filings in connection  with the sale of the  Preferred  Stock to the Buyer under
any United States laws and regulations,  or by any domestic  securities exchange
or trading  market,  and to provide a copy thereof to the Buyer  promptly  after
such filing.

         E. REPORTING STATUS. So long as the Buyer  beneficially owns any of the
Preferred  Stock,  the Company shall file all reports  required to be filed with
the SEC  pursuant to Section 13 or 15(d) of the  Exchange  Act,  and the Company
shall no terminate  its status as an issuer  required to file reports  under the
Exchange Act even if the Exchange  Act or the rules and  regulations  thereunder
would permit such termination.

         F. USE OF PROCEEDS.  The Company will use the proceeds from the sale of
the Preferred  Stock  (excluding  amounts paid by the Company for legal fees and
finder's fees in connection  with the sale of the Preferred  stock) for internal
working  capital  purposes,  and shall not,  directly  or  indirectly,  use such
proceeds for any loan to or  investment  in any other  corporation,  partnership
enterprise or other person.


                                      -7-






         G. CERTAIN  AGREEMENTS.  (i) Except as provided  herein with respect to
Acquisition  Financing  or in  4(g)(ii)(d)  hereof,  and the sale of up to 5,300
additional  shares of Series A Preferred Stock, the Company covenants and agrees
that it will not, without the prior written consent of the Buyer, enter into any
subsequent or further  offer or sale of Common Stock or  securities  convertible
into Common  Stock with any third party until the  expiration  of thirteen  (13)
months after the effective date of the  Registration  Statement (the  "Effective
Date").

                  (II)     SPECIAL PROVISION RELATING TO ACQUISITION FINANCING.

                           (a)  Following the issuance of the Series C Preferred
Stock to the Buyer,  and until the  expiration of the thirteen (13) month period
following  the  Expiration  Date,  the Company  shall provide the Buyer with the
following  rights to  participate in any private  placement  financing of equity
securities (or securities  convertible into Equity Securities of the Company) by
the Company (exempt from the registration  requirements of the Securities Act of
1993) where at least 90% of the  proceeds of such  financing  are intended to be
used by the Company to acquire the capital  stock or assets of another  business
enterprise  (including,  within the context of such Acquisition  Financing,  the
working  capital   requirements  of  the  acquired   entity)  (an   "Acquisition
Financing"). This right of first refusal is granted to the Buyer subject to, and
subordinate to, the prior rights of first refusal of the holders of the Series A
Preferred Stock with respect to private  placement of securities by the Company,
and is granted to Buyer  after the holders of Series A  Preferred  Stock  either
waive or decline to exercise their rights of first refusal, or if such rights of
first  refusal  of the  holders  of  Series  A  Preferred  Stock  are  otherwise
terminated.  If the Company  obtains  Acquisition  Financing  from a third party
during the  thirteen-month  period  following  the first  issuance  of shares of
Series D Preferred Stock, then the Buyer's  obligations under Section 4(i) below
to purchase  additional  tranches of Series D Preferred Stock shall be suspended
until the earlier of (x) such time that the Company provides written notice that
all equity securities  issued by the Company in such Acquisition  Financing have
been converted to Common Stock, or (y) the conclusion of the thirteen (13) month
period.

                           (b)  Notice  to  Participate.  Subject  to the  prior
exercise or waiver of the rights of the holders of the Series A Preferred Stock,
the Company shall, prior to any issuance by the Company of any of its securities
to be issued in an Acquisition  Financing,  offer to the Buyer by written notice
the right,  for a period of five (5)  business  days,  to  purchase  all of such
securities for cash at an amount equal to the price or other  consideration  for
which such securities proposed to be issued. The Company's written notice to the
Buyer shall  describe  the  securities  proposed to be issued by the Company and
specify the number,  price and payment  terms.  Except as may be necessary  with
respect to potential designees, the Buyer agrees to keep the terms and existence
of such securities issuance confidential. The Buyer, or its designee, may accept
the  company's  offer as to the full  number  of  securities  offered  to it, by
written notice thereof given by it to the Company prior to the expiration of the
aforesaid  five (5) day period,  in which event the Company shall  promptly sell
and such Buyer shall buy,  upon the terms  specified,  the number of  securities
agreed to be purchased by such Buyer, or its designee.  The rights  contained in
this Section are not transferable by the Buyer except as provided herein.



                                      -8-






                           (c)  Options  of Buyer.  Following  the  exercise  or
waiver of the rights of first refusal of the Series A Preferred Stock, the Buyer
shall  have the  following  rights:  (i) to  participate,  or have its  designee
participate,   or  decline  to  participate  in  the  Acquisition  Financing  by
delivering  notice (or fail to deliver notice) during the five-day period;  (ii)
continue to exercise its rights to purchase  shares of Series D Preferred  Stock
as provided in Section 4i; or (iii)  accelerate its right to purchase  shares of
Series D  Preferred  Stock up to an  aggregate  of  48,000  shares  of  Series D
Preferred Stock.

                           (d)  Exceptions  to Right to  Participate.  The first
refusal  rights  of the  Buyer  pursuant  to this  Section  shall  not  apply to
securities issued by the Company (i) upon conversion of any of the shares of any
series of Preferred  Stock or the exercise of Warrants to purchase Common Stock,
(ii) as a stock  dividend  or upon any  subdivision  of shares of Common  Stock,
provided  that  the  securities  issued  pursuant  to  such  stock  dividend  or
subdivision are limited to additional shares of Common Stock,  (iii) pursuant to
subscriptions,  warrants, options, convertible securities, or other rights which
are  outstanding on the date of this Agreement,  (iv) as non-cash  consideration
for the  acquisition  (whether by merger or  otherwise) by the Company or any of
its subsidiaries of all or substantially all of the stock or assets of any other
entity, (v) pursuant to exercise or warrants or options to purchase Common Stock
granted to  directors,  officers,  employees,  investment  bankers,  advisers or
consultants of the Company in connection with their service to the Company, (vi)
pursuant  to any  other  transaction  by the  Company  in  connection  with  the
financing of the acquisition of Superior  Pharmaceutical,  (vii) pursuant to the
licensing of technology  by the Company or from the Company,  or pursuant to any
corporate  partnership,  strategic alliance or joint venture entered into by the
Company,  and  (viii)  upon the  exercise  of any right  which was not itself in
violation of the terms of this Section.

                           (e)  Offering of  Securities  to Third  Parties.  The
Company shall be free at any time prior to sixty (60) days after the  expiration
of its  notice to offer to the  Buyer,  to offer and sell to any third  party or
parties the number of such  securities not agreed by the Buyer, or its designee,
to be purchased by it, at a price and on payment terms no less  favorable to the
Company than those specified in such notice of offer to the Buyer.  However,  if
such third  party sale or sales are not  consummated  within such sixty (60) day
period,  the  Company  shall  not sell  such  securities  as shall not have been
purchased  within such period  without again  complying  with this Section 5. No
Registration  Statement with respect to any Acquisition Financing with any third
party shall be made effective  until 45 days after the Effective Date as defined
above.

         H.  WARRANTS.  The Company agrees to issue to the Buyer at the Closing,
transferable  divisible  warrants (the  "Warrants") for 250,000 shares of Common
Stock.  Such Warrants  shall bear an exercise price per share of Common Stock as
follows: 125% of the Market Price, as defined in the Certificate of Designation,
on the Closing Date, and shall be exercisable immediately upon issuance, and for
a period  of three (3)  years  after  issuance,  in the form  annexed  hereto as
Exhibit  VI,  together  with   piggy-back   registration   rights,   and  demand
registration rights.

         I. SERIES D PREFERRED STOCK. The Buyer  irrevocably  agrees to purchase
up to  $4,800,000,  and the Company  irrevocably  agrees to sell the Buyer up to
$2,400,000  of Series D Preferred  Stock (the  "Series D Preferred  Stock") in a
series of tranches,  commencing thirty (30) 


                                      -9-







days after the Effective Date of the Registration  Statement contemplated by the
Registration  Rights  Agreement  attached  hereto  as ANNEX  IV (the  "Effective
Date").  Buyer's  obligation  to purchase  the Series D Preferred  Stock on each
Additional  Closing  Date (which shall occur not less than thirty (30 ) calendar
days  apart),  shall  be  contingent  upon  the  satisfaction  of the  following
conditions:

                   (a) The  Company  shall  give the Buyer  five (5) days  prior
written notice;

                  (b) The Series D Preferred  Stock issued in each tranche shall
be not less than $200,000 nor in excess of $400,000 principal amount;

                  (c)      On each Additional Closing Date;

                           (i) the Registration  Statement  required to be filed
under the Registration Rights Agreement, is effective;

                           (ii) The representations and warranties  contained in
Section 3 shall be true and
correct in all material respects;

                           (iii)  The  average  daily  trading  volume  for  the
previous thirty (30) trading days
must exceed $100,000;

                           (iv) The  average  daily  share  price of the  common
stock for the ten trading days
prior thereto, must exceed 60% of the price per share on the Closing Date of the
Series C Preferred  Stock, or on the immediately  preceding  Additional  Closing
Date as applicable; and

                  (d) In the event that (x) the Company  does not  exercise  its
option  to  require  the  Buyer to  purchase  at least  $2,400,000  of  Series D
Preferred  Stock,  or (y) the Buyer does not  purchase  at least  $2,400,000  of
Series D Preferred  Stock  because (A) the Buyer in its  discretion,  refuses to
purchase such amount  because of the failure to satisfy the conditions set forth
in  Paragraph  4i(c)(iii)  or  Paragraph  4i(c)(iv)  hereof,  or (B) the Buyer's
obligation to purchase is suspended under Paragraph 4g(i)(a),  the Company will,
not later than thirteen (13) months after the Effective  Date issue to the Buyer
an additional  300,000  Warrants upon the terms and conditions of Paragraph 4(h)
hereof.

                  (e) Notwithstanding anything to the contrary contained herein,
in the event the Buyer does not  purchase a tranche,  or at least  $200,000 of a
tranche,  of  Series D  Preferred  Stock  because  the  conditions  preceded  in
Paragraph  4(i)(c)(iii)  or (c)(iv)  have not been met, the Company may offer to
sell a tranche not  exceeding  $400,000  of such  Series D Preferred  Stock to a
third party, free of any other restrictions, provided however, that such refusal
by  Buyer  shall  not be  deemed  a waiver  of the  right  by Buyer to  purchase
subsequent tranches, or its entitlement to the Warrants in Paragraph 4(i)(d).

 

                                      -10-







        J. AVAILABLE SHARES. The Company shall have at all times authorized and
reserved  for  issuance,  free from  preemptive  rights,  shares of Common Stock
sufficient to yield the number of Common Stock  issuable at conversion as may be
required to satisfy the conversion rights of the Buyer pursuant to the terms and
conditions of the Preferred Stock.

         5.       TRANSFER AGENT INSTRUCTIONS.

         a.  Promptly  following  the  delivery  by the  Buyer of the  aggregate
purchase price for the Preferred  Stock in accordance  with Section 1(c) hereof,
the Company will  irrevocably  instruct its transfer agent to issue Common Stock
from time to time upon  conversion  of the  Preferred  Stock in such  amounts as
specified  from time to time by the Company to the transfer  agent,  bearing the
restrictive  legend  specified  in  Section  4(b) of  this  Agreement  prior  to
registration  of the Shares  under the 1933 Act,  registered  in the name of the
Buyer or its nominee and in such  denominations  to be specified by the Buyer in
connection with each  conversion of the Preferred  Stock.  The Company  warrants
that no instruction other than such instructions  referred to in this Section 5.
The Registration Rights Agreement, and stop transfer instructions to give effect
to Section  4(a) hereof prior to  registration  and sale of the Shares under the
1933 Act will be given by the Company to the transfer  agent and that the Shares
shall  otherwise be freely  transferable on the books and records of the Company
as to the extent provided in the Agreement,  the Registration  Rights Agreement,
and applicable law.  Nothing in this Section shall affect in any way the Buyer's
obligations  and agreement to comply with all  applicable  securities  laws upon
resale of the  Securities.  If the Buyer provides the Company with an opinion of
counsel reasonably  satisfactory to the Company that registration of a resale by
the Buyer of any of the  Securities in accordance  with clause (1)(B) of Section
4(a) of this  Agreement  is not required  under the 1933 Act, the Company  shall
(except as provided in clause (2) of Section 4(a) of this Agreement)  permit the
transfer of the Securities and, in the case of the Shares, promptly instruct the
Company's  transfer agent to issue one or more  certificates for Common Stock in
such name and in such denominations as specified by the Buyer.

         b. The Company  will permit the Buyer to exercise  its right to convert
the  Preferred  Stock and exercise the Warrants by  telecopying  an executed and
completed  Notice of  Conversion  or  Notice  of  Exercise  to the  Company  and
delivering  within  three  business  days  thereafter,  the  original  Notice of
Conversion or Notice of Exercise and the  certificate  for the  Preferred  Stock
representing the Shares or the Warrant to the Company by express  courier.  Each
date on which a Notice of  Conversion or Notice of Exercise is telecopied to and
received by the Company in accordance with the provisions hereof shall be deemed
a Conversion Date. The company will  immediately  confirm receipt of such notice
by telecopy  and  transmit the  certificates  representing  the Shares of Common
Stock  issuable  upon  conversion  of any  Preferred  Stock  (together  with the
Preferred  Stock  representing  the  Shares not so  converted)  to the Buyer via
express courier,  within three business days after receipt by the company of the
original  Notice of  Conversion  and the  certificate  for the  Preferred  Stock
representing the Shares to be converted (the "Delivery Date").

         c. The Company  understands  that a delay in the issuance of the Shares
of Common Stock beyond the  Delivery  Date could result in economic  loss to the
Buyer.  As  compensation  to the Buyer for such loss,  the Company agrees to pay
late  payments,  [not  exceeding  $200,000 per 


                                      -11-






tranche], to the Buyer for late issuance of Shares upon Conversion in accordance
with the following  schedule  (where "No.  Business Days Late" is defined as the
number of business days beyond three (3) business days from Delivery Date:

                                Late Payment for Each $10,000 of Preferred Stock
   No. Business Days Late                Principal Amount Being Converted

             1                                 $100
             2                                 $200
             3                                 $300
             4                                 $400
             5                                 $500
             6                                 $600
             7                                 $700
             8                                 $800
             9                                 $900
             10                                $1,000
             10                                $1,000 +$200 for each
                                               Business Day Late beyond
                                               10 days

The Company shall pay any payments  incurred  under this Section in  immediately
available  funds upon  demand.  Nothing  herein  shall limit a Buyer's  right to
pursue  actual  damages for the  Company's  failure to issue and deliver  Common
Stock to the Buyer. Furthermore,  in addition to any other remedies which may be
available  to the Buyer,  in the event that the Company  fails for any reason to
effect  delivery of such shares of Common Stock within five  business days after
the Delivery Date,  the Buyer will be entitled to revoke the relevant  Notice of
Conversion  by  delivering a notice to such effect to the Company  whereupon the
Company  and the Buyer  shall each be  restored  to their  respective  positions
immediately  prior to delivery of such Notice of Conversion  (and in such event,
the late payments described above shall not be due and payable).

         6.       DELIVERY INSTRUCTIONS.

         The Series C Preferred  Stock shall be  delivered by the Company to the
Escrow Agent pursuant to Section 1(b) hereof on a delivery against payment basis
at the closing.

         7.       CLOSING DATE

         The date and time of the  issuance  and sale of the Series C  Preferred
Stock (the "Closing Date") and the date and time of the issuance and sale of the
Additional  Preferred Stock (an "Additional  Closing Date") shall occur no later
than  12:00  Noon,  New York  time on the  second  NYSE  trading  day  after the
fulfillment or waiver of all Closing conditions pursuant to Sections 8 and 9, or
such other mutually  agreed to time. The closing shall occur on such date at the
offices of the Escrow Agent.  Notwithstanding anything to the contrary contained
herein,  the Escrow Agent will be authorized  to release the funds  representing
the Purchase Price for the Preferred Stock or 



                                      -12-








Additional  Preferred  Stock (as the case may be), and to release the  Preferred
Stock or Additional  Preferred Stock (as the case may be) only upon satisfaction
of the conditions set forth in Section 8 hereof.

         8.       CONDITIONS TO THE COMPANY'S OBLIGATION TO SELL

         The  Buyer  understands  that  the  Company's  obligation  to sell  the
Preferred  Stock on the  Closing  Date and any  Series D  Preferred  Stock on an
Additional Closing Date pursuant to this Agreement is conditioned upon:

         A. The receipt and acceptance by the Company of Buyer's  agreement,  as
evidenced by its execution of this Agreement, to purchase at least Seven Hundred
Fifty Thousand  ($750,000.00) Dollars in liquidation value of Series C Preferred
Stock (or such  lesser  amount as the  Company,  in its sole  discretion,  shall
determine);

         B.  Delivery by the Buyer to the Escrow  Agent of good funds as payment
in full of an amount  equal to the  purchase  price for the  Series C  Preferred
Stock or  Series D  Preferred  Stock  (as the  case may be) in  accordance  with
Section 1(c) hereof;

         C. The accuracy on the Closing Date or Additional  Closing Date (as the
case may be) of the  representations  and  warranties of the Buyer  contained in
this Agreement as if made on such date,  and the  performance by the Buyer on or
before such date of all  covenants and  agreements  of the Buyer  required to be
performed on or before such date;

         D. There shall not be in effect any law, rule or regulation prohibiting
or restricting the transactions contemplated hereby, or requiring any consent or
approval which shall not have been obtained.

         9.       CONDITIONS TO THE BUYER'S OBLIGATION TO PURCHASE.

         The Company  understands  that the Buyer's  obligation  to purchase the
Preferred  Stock on the  Closing  Date and any  Series D  Preferred  Stock on an
Additional Closing Date is conditioned upon:

         A. Acceptance by Buyer of an Agreement for the sale of Preferred Stock,
as indicated by execution of this Agreement, and Buyer's and Company's execution
of the Registration Rights Agreement;

         B. Delivery by the Company to the Escrow Agent of the Preferred  Stock,
the  Warrants,  and  the  Series  D  Preferred  Stock  (as the  case  may be) in
accordance with this Agreement;

         C.  The  accuracy  in all  material  respects  on the  Closing  Date or
Additional  Closing  Date  (as  the  case  may  be) of the  representations  and
warranties of the Company  contained in this  Agreement as if made on such date,
and the  performance  by the Company on or before such date (as the case may be)
of all  covenants and  agreements of the Company  required to be performed on or
before such date; and


                                      -13-






         D. On the Closing  Date or  Additional  Closing  Date the Buyer  having
received an opinion of counsel for the Company,  dated such date, in form, scope
and substance  reasonably  satisfactory to the Buyer, to the effect set forth in
ANNEX III attached hereto.

         10.      GOVERNING LAW:  MISCELLANEOUS.

         This Agreement  shall be governed by and interpreted in accordance with
laws of the State of Delaware.  Each of the parties consents to the jurisdiction
of the federal courts whose districts encompass any part of the City of New York
or the state  courts of the State of New York sitting in the City of New York in
connection with any dispute  arising under this Agreement and hereby waives,  to
the maximum  extent  permitted by law, any  objection,  including  any objection
based on forum non  convenients,  to the bringing of any such proceeding in such
jurisdictions.  A facsimile transmission of this signed Agreement shall be legal
and binding on all parties  hereto.  This Agreement may be signed in one or more
counterparts,  each of which shall be deemed an  original.  The headings of this
Agreement are for convenience of reference and shall not form part of, or affect
the interpretation of, this Agreement.  If any provision of this Agreement shall
be  invalid  or   unenforceable   in  any   jurisdiction,   such  invalidity  or
unenforceability  shall  not  affect  the  validity  or  enforceability  of  the
remainder of this Agreement or the validity or  enforceability of this Agreement
in any other  jurisdiction.  This Agreement may be amended only by an instrument
in writing  signed by the party to be charged with  enforcement.  This Agreement
supersedes all prior agreements and understandings among the parties hereto with
respect to the subject matter hereof.

         11. NOTICES.  Any notice required or permitted hereunder shall be given
in writing (unless otherwise  specified herein) and shall be deemed  effectively
given upon, (a) personal delivery,  or (b) if advance copy is given by fax, upon
(i) seven  business days after  deposit in the United  states Postal  Service by
regular or certified mail, or (ii) three business days mailing by  international
express courier,  with postage and fees prepaid,  addressed to each of the other
parties  thereunto  entitled  at  the  following  addresses,  or at  such  other
addresses as a party may designate by ten days advance written notice to each of
the other parties hereto.

         COMPANY:            DynaGen, Inc.
                             99 Erie Street
                             Cambridge, Massachusetts 02139
                             Telecopier No. (617) 354-3902

                             with a copy to:

                             John M. Hession, Esq.
                             Testa, Hurwitz & Thibeault, LLP
                             High Street Tower
                             125 High Street
                             Boston, Massachusetts 02110
                             Telecopier No. (617) 248-7100



                                      -14-








      PURCHASER:             At the address set forth on the signature page
                             of this Agreement.

ESCROW AGENT:                Krieger & Prager, Esqs.
                             319 Fifth Avenue
                             New York, New York 10016

         12.   SURVIVAL   OF   REPRESENTATIONS   AND   WARRANTIES.   Purchaser's
representations  and warranties  shall survive the execution and delivery hereof
of this Agreement and the delivery of the preferred Stock.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



                                      -15-










                  IN WITNESS  WHEREOF,  this Agreement has been duly executed by
the Buyer or one of its officers  thereunto  duly  authorized as of the date set
forth below.

NUMBER OF SHARES OF PREFERRED STOCK TO BE PURCHASED:

AGGREGATE PURCHASE PRICE OF SUCH PREFERRED STOCK:    $750,000

                             SIGNATURES FOR ENTITIES

         IN WITNESS  WHEREOF,  the  undersigned  represents  that the  foregoing
statements  are true and  correct  and that it has caused  this  Stock  Purchase
Agreement to be duly executed on its behalf this 21st day of August, 1997




_________________________________           ENDEAVOUR CAPITAL FUND S. A.

Address                                     Printed Name of Subscriber

                                            By:      [illegible]
___________________________________            _______________________________
                                               (Signature of Authorized Person)
Telecopier No. ____________________

                                               _________________________________
                                                     Printed Name and Title
British Virgin Islands
_____________________________
Jurisdiction of Incorporation
or Organization.

        This Agreement has been accepted as of the date set forth below.

DYNAGEN, INC.

By:      /s/ Indu A. Muni
   _______________________________
         Indu A. Muni
Title:   President

Date:    August 21, 1997

                                      -16-








                                                                      Exhibit 4e



                          REGISTRATION RIGHTS AGREEMENT

                  THIS  REGISTRATION  RIGHTS  AGREEMENT,  dated as of August 21,
1997  (this  "Agreement")  is made by and  between  DYNAGEN,  INC.,  a  Delaware
corporation (the  "Company"),  and the person named on the signature page hereto
(the "Initial Investor").

                              W I T N E S S E T H:

                  WHEREAS,  upon the terms and subject to the  conditions of the
Stock  Purchase  Agreement,  dated as of August 21,  1997,  between  the Initial
Investor  and the Company  (the  "Stock  Purchase  Agreement"),  the Company has
agreed to issue and sell to the  initial  investor  Shares of Series C Preferred
Stock and Series D Preferred Stock of the Company  (collectively  the "Preferred
Stock"),  and  warrants to purchase  up to 250,000  shares of Common  Stock (the
"Warrants")  (which may be  increased by an  additional  300,000  warrants  upon
certain circumstances (the "Additional  Warrants") which Preferred Stock will be
convertible  into  shares  of the  common  stock,  $.01 par value  (the  "Common
Stock"), of the Company (the "Conversion  Shares") upon the terms and subject to
the conditions of such Preferred Stock, and the Warrants will be exercisable for
shares of Common Stock (the "Warrant Shares"); and

                  WHEREAS, to induce the Initial Investor to execute and deliver
the  Stock  Purchase  Agreement,  the  Company  has  agreed to  provide  certain
registration rights under the Securities Act of 1933, as amended,  and the rules
and regulations thereunder, or any similar successor statute (collectively,  the
"Securities Act"), with respect to the Conversion Shares and Warrant Shares;

                  NOW,  THEREFORE,  in  consideration  of the  premises  and the
mutual covenants contained herein and other good and valuable consideration, the
receipt and  sufficiency of which are hereby  acknowledged,  the Company and the
Initial Investor hereby agrees as follows:

                  1.       DEFINITIONS.

                  (a) As used in this Agreement,  the following terms shall have
the following meanings:

                  (i)  "Additional  Warrant  Shares"  means the shares of Common
Stock issuable upon exercise of the Additional Warrants.

                  (ii) "Investor"  means the Initial  Investor and any permitted
transferee  or assignee  who agrees to become  bound by the  provisions  of this
Agreement in accordance with Section 9 hereof.

                  (iii)  "Potential  Material Event" means any of the following:
(a)  the  possession  by the  Company  of  material  information  not  ripe  for
disclosure   in  a   registration   statement,   which  shall  be  evidenced  by
determinations  in good  faith by the Board of









                                      -2-

Directors of the company that disclosure of such information in the registration
statement  would be detrimental  to the business and affirms of the Company;  or
(b) any material  engagement or activity by the Company which would, in the good
faith  determination  of the Board of  Directors  of the  Company,  be adversely
affected  by  disclosure  in  a  registration  statement  at  such  time,  which
determination shall be accompanied by a good faith determination by the Board of
Directors of the Company that the  registration  statement  would be  materially
misleading absent the inclusion of such information.

                  (iv) "Register,"  "Registered," and "Registration"  refer to a
registration  effected  by  preparing  and filing a  Registration  Statement  or
Statements in compliance  with the Securities Act and pursuant to Rule 415 under
the Securities Act or any successor rule providing for offering  securities on a
continuous  basis ("Rule 415"), and the declaration or ordering of effectiveness
of such  Registration  Statement by the United  States  Securities  and Exchange
Commission (the "SEC").

                  (v) "Registerable  Securities" means the Conversion Shares and
the Warrant Shares.

                  (vi) "Registration  Statement" means a registration  statement
of the Company under the Securities Act.

                  (b)  Capitalized  terms used herein and not otherwise  defined
herein  shall  have the  respective  meanings  set forth in the  Stock  Purchase
Agreement.

                  2. REGISTRATION.

                  (a) MANDATORY REGISTRATION. The Company shall prepare and file
with the SEC, no later than  forty-five  (45) days following the initial Closing
Date under the Stock  Purchase  Agreement,  and the  issuance of the  Additional
Warrants, if issued, either a Registration Statement on Form S-3 registering for
resale by the  Investor a  sufficient  number of shares of Common  Stock for the
Initial  Investors  (or such lesser number as may be required by the SEC, but in
no event less than the number of shares into which the Preferred  Stock would be
convertible and the Warrants  exercisable at the time of filing of the Form S-3,
or an amendment to any pending Company  Registration  Statement on Form S-3, and
such Registration  Statement or amended Registration Statement shall state that,
in  accordance  with Rule 416 and 457 under the  Securities  Act, it also covers
such  indeterminate  number of  additional  shares of Common Stock as may become
issuable upon conversion of the Preferred Stock and the Exercise of the Warrants
resulting  from  adjustment  in the  Conversion  Price,  or to prevent  dilution
resulting from stock splits, or stock  dividends).  If at any time the number of
shares of Common  Stock into which the  Preferred  Stock may be converted or the
Warrants  or  Additional  Warrants,  if issued,  are  exercisable,  exceeds  the
aggregate number of shares of Common Stock then  registered,  the Company shall,
within  fifteen (15) business  days after  receipt of a written  notice from any
Investor,  either  (i) amend the  Registration  Statement  filed by the  Company
pursuant to the preceding sentence, if such Registration  Statement has not been
declared  effective  by the SEC at that time,  to register  all shares of Common
Stock  into 






                                      -3-


which the  Preferred  Stock may be  converted,  or the  Warrants  or  Additional
Warrants if issued are exercisable,  or (ii) if such Registration  Statement has
been declared effective by the SEC at that time, file with the SEC an additional
Registration  Statement  on Form S-3 to register the shares of Common Stock into
which the  preferred  Stock may be  converted,  or the  Warrants  or  Additional
Warrants, if issued, are exercisable, that exceed the aggregate number of shares
of Common Stock already registered.  If the state of the SEC determines that all
of the  Conversion  Shares cannot be registered by the Company for resale by the
Investor because, in the view of the staff, such registration would constitute a
primary  offering the Company,  then the Company shall have an additional  sixty
(60) days in which to amend such  registration  statement  to another  available
form.

                  (B)      PAYMENTS BY THE COMPANY.

                           (i)  If  the  Registration   Statement  covering  the
Registrable  Securities  is not filed in proper  form  with the  Securities  and
Exchange  Commission with  forty-five  (45) days after the Closing,  the Company
will make payment to the Initial Investor in the amount of $500 per day for each
$10,000  in  principal  amount  of  Preferred  Stock  outstanding  for  each day
thereafter until such Registration  Statement, in proper form, is filed with the
Securities and Exchange Commission.

                           (ii)  If  the  Registration  Statement  covering  the
Registrable  Securities  required to be filed by the Company pursuant to Section
2(a) hereof is not  effective  (x) on the earlier of (i) five days after  notice
from the Securities and Exchange Commission that the Registration  Statement may
be declared  effective,  or (ii) ninety (90) days following the initial  Closing
Date (the "Initial  Date"),  (except as provided by the last sentence of Section
2a), or (y) on the  conclusion of a Suspension  Period as defined in P. 3f, then
the Company  will make  payments to the Initial  Investor in such amounts and at
such times as shall be determined  pursuant to this Section 2(b).  The amount to
be paid by the Company to the Initial  Investor  shall be  determined as of each
Computation  Date,  and such amount  shall be equal to two and one-half (2 1/2%)
percent of the purchase  price paid by the Initial  Investor  for all  Preferred
Stock then purchased and  outstanding  pursuant to the Stock Purchase  Agreement
for any period fro the Initial Date to the first  Computation  Date, and to each
Computation date thereafter,  to the date the Registration Statement is declared
effective by the SEC (pro rated for partial  periods) (the  "Periodic  Amount").
The full Periodic  Amount shall be paid by the Company in immediately  available
funds within three business days after each  Computation  Date.  Notwithstanding
the  foregoing,  the amounts  payable by the Company  pursuant to this provision
shall  not be  payable  to the  extent  any  delay in the  effectiveness  of the
Registration  Statement  occurs  because of an act of, or a failure to act or to
act timely by the Initial  Investor or its  counsel,  or in the event all of the
Registrable  Securities  may be sold  pursuant to Rule 144 or another  available
exemption under the Act.

 





                                      -4-

                 As used in this Section 2(b),  the following  terms shall have
the follow meanings:

                  "Computation  Date" means the date which is the earlier of (i)
five days after  notice from the  Securities  and Exchange  Commission  that the
Registration Statement may be declared effective, or (ii) ninety (90) days after
the initial  Closing  Date  (except as provided by the last  sentence of Section
2(a)),  and, if the Registration  Statement  required to be filed by the Company
pursuant to Section 2(a) has not theretofore been declared  effective by the SEC
or a Suspension  Period is in effect,  each date which is thirty (30) days after
the  previous  Computation  Date (pro  rated for  partial  periods)  until  such
Registration Statement is so declared effective.

                  3.  OBLIGATIONS  OF  THE  COMPANY.   In  connection  with  the
registration  of the  Registrable  Securities,  the Company shall do each of the
following.

                  (a) Prepare promptly, and file with the SEC by forty-five (45)
days after the initial  Closing Date, a  Registration  Statement with respect to
not less than the number of  Registrable  Securities  provided in Section  2(a),
above, and thereafter used its best efforts to cause each Registration Statement
relating to  Registrable  Securities  to become  effective on the earlier of (i)
five days after  notice from the  Securities  and Exchange  Commission  that the
Registration Statement may be declared effective,  or (b) ninety (90) days after
the Closing Date, and keep the  Registration  Statements  effective at all times
until the earliest (the "Registration Period") of (i) the date that is two years
after the Closing Date (ii) the date when the Investors may sell all Registrable
Securities  under Rule 144 or (iii) the date the  Investors no longer own any of
the  Registrable   Securities,   which  Registration  Statement  (including  any
amendments or supplements thereto and prospectuses  contained therein) shall not
contain any untrue statement of a materiel fact or omit to state a material fact
required to be stated  therein or necessary to make the statements  therein,  in
light of the circumstances in which they were made, not misleading;

                  (b) Prepare and file with the SEC such  amendments  (including
post-effective amendments) and supplements to the Registration Statement and the
prospectus  used  in  connection  with  the  Registration  Statement  as  may be
necessary  to  keep  the   Registration   effective  at  all  times  during  the
Registration  Period,  and,  during the  Registration  Period,  comply  with the
provisions  of  the  Securities  Act  with  respect  to the  disposition  of all
Registrable  Securities  of the Company  covered by the  Registration  Statement
until such time as all of such  Registrable  Securities have been disposed of in
accordance  with the intended  methods of  disposition  by the seller or sellers
thereof as set forth in the Registration Statement;

                  (c)  The  Company  shall  permit  a  single  firm  of  counsel
designated by the Initial Investors to review the Registration Statement and all
amendments and supplements  thereto as reasonable  period of time prior to their
filing with the SEC,  and not file any  document in a form to which such counsel
reasonably objects;






                                      -5-

                  (d) Furnish to each Investor whose Registrable  Securities are
included in the Registration  Statement and its legal counsel  identified to the
Company (i) promptly after the same is prepared and publicly distributed,  filed
with the SEC,  or  received  by the  Company,  one (1) copy of the  Registration
Statement,  each  preliminary  prospectus and prospectus,  and each amendment or
supplement  thereto,  and (ii) such  number of copies of a  prospectus,  and all
amendments and supplements  thereto and such other  documents,  as such Investor
may reasonably request in order to facilitate the disposition of the Registrable
Securities owned by such Investor;

                  (e) As promptly as  practicable  after  becoming aware of such
event,  notify each  investor of the happening of any event of which the Company
has knowledge,  as a result of which the prospectus included in the Registration
Statement, as then in effect, includes an untrue statement of a material fact or
omits to state a material  fact  required to be stated  therein or  necessary to
make the statements therein, in light of the circumstances under which they were
made, not misleading,  and use its best efforts promptly to prepare a supplement
or amendment to the Registration  Statement or other appropriate filing with the
SEC to correct such untrue statement or omission, and deliver a number of copies
of such supplement or amendment to each Investor as such Investor may reasonably
request;


                  (f) Notwithstanding the foregoing, if at any time or from time
to time  after the date of  effectiveness  of the  Registration  Statement,  the
Company  notifies  the  Investors  in writing of the  existence  of a  Potential
Material Event, the Investors shall not offer or sell any  Registerable  Shares,
or engage in any other  transaction  involving  or relating  to the  Registrable
Shares,  from the time of the  giving  of notice  with  respect  to a  Potential
Material Event until such Investor receives written notice from the Company that
such  Potential  Material  Event  either has been  disclosed to the public or no
longer  constitutes a Potential  Material  Event;  provided,  however,  that the
Company may not so suspend the right to such holders of  Registrable  Shares for
more than two (2) twenty (20) day periods in the  aggregate  during any 12-month
period with at least a ten (10)  business  day interval  between  such  periods,
during the period the Registration Statement is required to be in effect;


                  (g) As promptly as  practicable  after  becoming aware of such
event, notify each Investor who holds Registrable  Securities being sold (or, in
the  event  of an  underwritten  offering,  the  managing  underwriters)  of the
issuance  by the SEC of a Notice  of  Effectiveness  or any stop  order or other
suspension of the  effectiveness of the  Registration  Statement at the earliest
possible time;


                  (h)  Use  its  commercially   reasonable   efforts  to  secure
designation  of all  the  Registrable  Securities  covered  by the  Registration
Statement as a National  Association of Securities Dealers Automated  Quotations
System ("NASDAQ") "Small  Capitalization"  within the meaning of Rule 11Aa2-1 of
the SEC under the  Securities  Exchange Act of











                                      -6-


1934, as amended (the  "Exchange  Act"),  and the  quotation of the  Registrable
Securities  of the  NASDAQ  Small  Cap  Market;  or if,  despite  the  Company's
commercially  reasonable efforts to satisfy the preceding clause, the Company is
unsuccessful in doing so, to secure NASDAQ/OTC  Bulletin Board authorization and
quotation for such  Registrable  Securities and, without limiting the generality
of the foregoing, to arrange for at least two market makers to register with the
National  Association of Securities Dealers,  Inc. ("NASD") as such with respect
to such Registrable Securities;


                  (i)  Provide a transfer  agent and  registrar,  which may be a
single entity, for the Registrable  Securities not later than the effective date
of the Registration Statement;

                  (j)  Cooperate   with  the  Investors  who  hold   Registrable
Securities  being offered to facilitate the timely  preparation  and delivery of
certificates  for the  Registrable  Securities  to be  offered  pursuant  to the
Registration   Statement  and  enable  such  certificates  for  the  Registrable
Securities  to be in such  denominations  or  amounts as the case may be, as the
Investors may reasonably  request,  and,  within three (3) business days after a
Registration   Statement  which  includes  Registrable   Securities  is  ordered
effective by the SEC, the Company shall  deliver,  and shall cause legal counsel
selected by the  Company to deliver to the  transfer  agent for the  Registrable
Securities  (with  copies to the  Investors  whose  Registrable  Securities  are
included in such Registration  Statement) an appropriate instruction and opinion
of such counsel; and

                  (k) Take all other  reasonable  actions  necessary to expedite
and  facilitate  disposition  by  the  Investor  of the  Registrable  Securities
pursuant to the Registration Statement.

                  4.  OBLIGATIONS  OF THE  INVESTORS.  In  connection  with  the
registration the Registrable Securities,  the Investors shall have the following
obligations:

                  (a) It shall be a condition  precedent to the  obligations  of
the Company to complete the registration pursuant to this Agreement with respect
to the Registrable  Securities of a particular Investor that such Investor shall
furnish to the  Company  such  information  regarding  itself,  the  Registrable
Securities held by it, and the intended method of disposition of the Registrable
Securities  held  by  it,  as  shall  be  reasonably   required  to  effect  the
registration of such Registrable  Securities and shall execute such documents in
connection  with such  registration  as the company may reasonably  request.  At
least  five  (5)  days  prior  to  the  first  anticipated  filing  date  of the
Registration   Statement,   the  Company  shall  notify  each  Investor  of  the
information  the  Company  requires  from each  such  Investor  (the  "Requested
Investment") if such Investor elects to have any of such Investor's  Registrable
Securities included in the Registration  Statement. If at least two (2) business
days  prior to the  filing  date the  Company  has not  received  the  Requested
Information from an Investor (a "Non-Responsive Investor"), then the company may
file the Registration Statement without including Registrable Securities of such
Non-Responsive Investor;









                                      -7-

                  (b)  Each  Investor  by  such  Investor's  acceptance  of  the
Registrable  Securities  agrees to  cooperate  with the  company  as  reasonably
requested by the company in connection  with the  preparation  and filing of the
Registration Statement hereunder,  unless such Investor has notified the Company
in  writing  of such  Investor's  election  to  exclude  all of such  Investor's
Registrable Securities from the Registration Statement; and

                  (c) Each Investor agrees that, upon receipt of any notice from
the Company of the happening of any event of the kind  described in Section 3(e)
or 3(f),  above,  such  Investor will  immediately  discontinue  disposition  of
Registrable  Securities  pursuant to the  Registration  Statement  covering such
Registrable  Securities  until  such  Investor's  receipt  of the  copies of the
supplemented or amended prospectus  contemplated by Section 3(e) or 3(f) and, if
so directed by the Company,  such Investor  shall deliver to the Company (at the
expense of the Company) or destroy (and deliver to the Company a certificate  of
destruction)  all  copies  in  such  Investor's  possession,  of the  prospectus
covering  such  Registrable  Securities  current  at the time of receipt of such
notice.

                  5. EXPENSES OF  REGISTRATION.  All reasonable  expenses (other
that  underwriting   discounts  and  commissions  incurred  in  connection  with
registrations,  filings  or  qualification  pursuant  to Section 3, and fees and
expenses of counsel for the Investors),  but including,  without limitation, all
registration,  listing,  and qualifications  fees, printers and accounting fees,
the fees and  disbursements  of counsel for the  Company,  shall be borne by the
Company.

                  6.  INDEMNIFICATION.  In the event any Registrable  Securities
are included in a Registration Statement under this Agreement:

                  (a) To the extent permitted by law, the company will indemnify
and hold  harmless  each  Investor who holds such  Registrable  Securities,  the
directors,  if any, of such  Investor,  the officers,  if any, of such Investor,
each  person,  if any,  who  controls  any  Investor  within the  meaning of the
Securities Act or the Exchange Act (each, an "Indemnified Person"),  against any
losses,  claims,  damages,  liabilities or expenses (joint or several)  incurred
(collectively,  "Claims")  to which  any of them may  become  subject  under the
Securities  Act,  the  Exchange  Act or  otherwise,  insofar as such  Claims (or
actions or proceedings,  whether  commenced or threatened,  in respect  thereof)
arise out of or are based upon any of the  following  statements,  omissions  or
violations  in  the  Registration  Statement,  or any  post-effective  amendment
thereof, or any prospectus included therein: (i) any untrue statement or alleged
untrue statement of a material fact contained in the  Registration  Statement or
any  post-effective  amendment  thereof or the  omission or alleged  omission to
state therein a material fact required to be stated therein or necessary to make
the  statements  therein not  misleading,  (ii) any untrue  statement or alleged
untrue  statement  of a material  fact  contained  in the final  prospectus  (as
amended  or  supplemented,  if  the  Company  files  any  amendment  thereof  or
supplement  thereto with the SEC) or the  omission or alleged  omission to state
therein any material fact  necessary to make the  statements  made  therein,  in
light of the  circumstances  under which the  statements  therein 












                                      -8-

were made,  not  misleading or (iii) any  violation or alleged  violation by the
Company of the Securities Act, the Exchange Act, any state securities law or any
rule or  regulation  under the  Securities  Act,  the  Exchange Act or any state
securities  law (the matters in the  foregoing  clauses (i) through (iii) being,
collectively, "Violations"). The Company shall reimburse the Investors, promptly
as such  expenses are  incurred  and are due and payable,  for any legal fees or
other reasonable  expenses incurred by them in connection with  investigation or
defending  any such Claim.  Notwithstanding  anything to the contrary  contained
herein, the  indemnification  agreement contained in this Section 6(a) shall not
(I) apply to a Claim  arising out of or based upon a Violation  which  occurs in
reliance upon and in  conformity  with  information  furnished in writing to the
Company  by or on  behalf  of  any  Indemnified  Person  expressly  for  use  in
connection  with  the  preparation  of the  Registration  Statement  or any such
amendment  thereof or supplement  thereto,  if such  prospectus  was timely made
available by the Company  pursuant to Section 3(b) hereof;  (II) be available to
the extent such Claim is based on a failure of the  Investor to deliver or cause
to be delivered the prospectus made available by the Company;  or (III) apply to
amounts paid in settlement of any Claim if such  settlement is effected  without
the  prior  written  consent  of  the  Company,   which  consent  shall  not  be
unreasonably  withheld.  Each  Investor  will  indemnify  the  Company  and  its
officers, directors and agents against any claims arising out of or based upon a
Violation  which  occurs in reliance  upon and in  conformity  with  information
furnished in writing to the Company, by or on behalf of such Investor, expressly
for use in  connection  with  the  preparation  of the  Registration  Statement,
subject  to  such   limitations   and   conditions  as  are  applicable  to  the
Indemnification  provided by the Company to this Section 6. Such indemnity shall
remain in full force and effect  regardless of any  investigation  made by or on
behalf  of  the  indemnified  Person  and  shall  survive  the  transfer  of the
Registrable Securities by the Investors pursuant to Section 9.

                  (b)  Promptly  after  receipt  by  an  Indemnified  Person  or
Indemnified  Party  under this  Section 6 of notice of the  commencement  of any
action  (including  any  governmental   action),   such  Indemnified  Person  or
Indemnified Party shall, if a Claim in respect thereof is to be made against any
indemnifying  party under this  Section 6, deliver to the  indemnifying  party a
written notice of the commencement thereof and the indemnifying party shall have
the right to  participate  in,  and,  to the  extent the  indemnifying  party so
desires,  jointly with any other indemnifying party similarly noticed, to assume
control  of the  defense  thereof  with  counsel  mutually  satisfactory  to the
indemnifying  party and the Indemnified  Person or the Indemnified Party, as the
case may be; provided,  however, that an Indemnified Person or Indemnified Party
shall  have the right to retain its own  counsel  with the  reasonable  fees and
expenses to be paid by the indemnifying  party, if, in the reasonable opinion of
counsel retained by the indemnifying  party, the  representation by such counsel
of the Indemnified  Person or Indemnified Party and the indemnifying party would
be inappropriate  due to actual or potential  differing  interests  between such
Indemnified  Person or Indemnified Party and any other party represented by such
counsel in such  proceeding.  In such event,  the Company shall pay for only one
separate legal counsel for the  Investors;  such legal counsel shall be selected
by the Investors  holding a majority in interest of the  Registrable  Securities
included in the 










                                      -9-


Registration  Statement  to which the Claim  relates.  The  failure  to  deliver
written  notice  to the  indemnifying  party  within  a  reasonable  time of the
commencement of any such action shall not relieve such indemnifying party of any
liability to the Indemnified  Person or Indemnified  Party under this Section 6,
except to the extent that the indemnifying party is prejudiced in its ability to
defend such action. The indemnification required by this Section 6 shall be made
by  periodic   payments  of  the  amount   thereof  during  the  course  of  the
investigation or defense, as such expense, loss, damage or liability is incurred
and is due and payable.

                  7.  CONTRIBUTION.  To the  extent  any  indemnification  by an
indemnifying  party is  prohibited  or limited by law,  the  indemnifying  party
agrees to make the maximum contribution with respect to any amounts for which it
would  otherwise be liable under  Section 6 to the fullest  extent  permitted by
law;  provided,   however,   that  (a)  no  contribution  shall  be  made  under
circumstances  where the maker  would not have been  liable for  indemnification
under the fault  standards set forth in Section 6; (b) no seller of  Registrable
Securities guilty of fraudulent misrepresentation (within the meaning of Section
11(f) of the Securities Act) shall be entitled to  contribution  from any seller
of   Registrable   Securities   who  was   not   guilty   of   such   fraudulent
misrepresentation;  and (c) contribution by any seller of Registrable Securities
shall be limited in amount to the net amount of proceeds received by such seller
from the sale of such Registrable Securities.

                  8. REPORTS UNDER EXCHANGE ACT. With a view to making available
to the Investors the benefits of Rule 144  promulgated  under the Securities Act
or any other  similar rule or  regulation of the SEC that may at any time permit
the  Investors  to  sell  securities  of  the  Company  to  the  public  without
registration ("Rule 144"), the Company agrees to:

                  (a) make and keep public information available, as those terms
are understood and defined in Rule 144;

                  (b) file with the SEC in a timely manner all reports and other
documents required of the Company under the Securities Act and the Exchange act;
and

                  (c)  furnish to each  Investor so long as such  Investor  owns
Registrable  Securities,  promptly upon request,  (i) a written statement by the
Company that it has complied  with the reporting  requirements  of Rule 144, the
Securities  Act and the Exchange  Act,  (ii) a copy of the most recent annual or
quarterly report of the Company and such other reports and documents so filed by
the Company and (iii) such other  information as may be reasonably  requested to
permit  the  Investors  to sell such  securities  pursuant  to Rule 144  without
registration.

                  9. ASSIGNMENT OF THE REGISTRATION  RIGHTS.  The rights to have
the Company register Registrable  Securities pursuant to this Agreement shall be
automatically assigned by the Investors to any transferee of at least 30% of the
Registrable  Securities  (excluding the Additional  Warrant Shares) only if: (a)
the Investor  agrees in writing with







                                      -10-

the  transferee or assignee to assign such rights,  and a copy of such agreement
is furnished to the Company within a reasonable time after such assignment,  (b)
the Company is,  within a  reasonable  time after such  transfer or  assignment,
furnished with written notice of (i) the name and address of such  transferee or
assignee and (ii) the securities with respect to which such registration  rights
are being  transferred or assigned,  (c) immediately  following such transfer or
assignment  the further  disposition  of such  securities  by the  transferee or
assignee is restricted  under the Securities act and applicable state securities
laws,  and (d) at or before the time the Company  received  the  written  notice
contemplated by clause (b) of this sentence the transferee or assignee agrees in
writing with the Company to be bound by all of the provisions  contained herein.
In the  event of any  delay  in  filing  or  effectiveness  of the  Registration
Statement as a result of such  assignment,  the Company  shall not be liable for
any damages  arising from such delay,  or the payments set forth in Section 2(c)
hereof.

                  10. (A)  AMENDMENT OF  REGISTRATION  RIGHTS.  Any provision of
this Agreement may be amended and the  observance  thereof may be waived (either
generally   or  in  a   particular   instance   and  either   retroactively   or
prospectively),  only with the written  consent of the Company and Investors who
hold an  eighty  (80%)  percent  interest  of the  Registrable  Securities.  Any
amendment  or waiver  effective  in  accordance  with this  Section  10 shall be
binding upon each Investor and the Company.

                     (B)  ADDITIONAL  WARRANT  SHARES.  The  obligation  of  the
Company hereunder  including the time period set forth herein shall apply, mutis
mutandis,  to the  Additional  Warrant  Shares upon  issuance of the  Additional
Warrants.

                  11.      MISCELLANEOUS.

                  (a) A person or entity is deemed to be a holder of Registrable
Securities  whenever  such  person or entity  owns of  record  such  Registrable
Securities.  If  the  Company  receives  conflicting  instructions,  notices  or
elections  from  two or more  persons  or  entities  with  respect  to the  same
Registrable  Securities,  the Company shall act upon the basis of  instructions,
notice  or  election  received  from the  registered  owner of such  Registrable
Securities.

                  (b) Notices  required or permitted to be given hereunder shall
be in  writing  and shall be deemed to be  sufficiently  given  when  personally
delivered  (by hand,  by courier,  by  telephone  line  facsimile  transmission,
receipt  confirmed,  or other means) or sent by certified  mail,  return receipt
requested,  properly  addressed and with proper  postage  pre-paid (i) if to the
Company, DYNAGEN, INC., 99 Eric Street,  Cambridge,  Massachusetts 02139, with a
copy to John M.  Hession,  Esq.,  Testa,  Hurwitz & Thibeault,  LLP, High Street
Tower,  125 High Street,  Boston,  Massachusetts  02110;  (ii) if to the Initial
Investor,  at the  address  set  forth  under  its  name in the  Stock  Purchase
Agreement,  with a coy to Samuel  Krieger,  Esq.,  Krieger  & Prager,  319 Fifth
Avenue,  Third Floor, New York, NY 10016 and (iii) if to any other Investor,  at
such address as such Investor shall have provided in writing to the Company,  or
at such other address as each such party 








                                      -11-

furnishes by notice given in accordance  with this Section  11(b),  and shall be
effective,  when  personally  delivered,  upon  receipt  and,  when  so  sent by
certified  mail,  four (4) calendar  days after  deposit with the United  States
Postal Service.

                  (c) Failure of any party to exercise any right or remedy under
this  Agreement or otherwise,  or delay by a party in  exercising  such right or
remedy, shall not operate as a waiver thereof.

                  (d) This  Agreement  shall be governed by and  interpreted  in
accordance with the laws of the State of New York. Each of the parties  consents
to the jurisdiction of the federal courts whose districts  encompass any part of
the City of New York or the state courts of the State of New York sitting in the
City of New York in connection with any dispute arising under this Agreement and
hereby waives, to the maximum extent permitted by law, any objection,  including
any  objection  based on  forum  non  conveniens,  to the  bringing  of any such
proceeding  in such  jurisdictions.  A  facsimile  transmission  of this  signed
Agreement shall be legal and binding on all parties  hereto.  This Agreement may
be  signed  in one or more  counterparts,  each of  which  shall  be  deemed  an
original.  The headings of this  Agreement are for  convenience of reference and
shall not form part of, or affect the interpretation of, this Agreement.  If any
provision  of  this  Agreement  shall  be  invalid  or   unenforceable   in  any
jurisdiction,  such invalidity or unenforceability shall not affect the validity
or  enforceability  of the  remainder  of  this  Agreement  or the  validity  or
enforceability of this Agreement in any other  jurisdiction.  This Agreement may
be amended only by an  instrument  in writing  signed by the party to be charged
with   enforcement.   This  Agreement   supersedes  all  prior   agreements  and
understandings  among the  parties  hereto with  respect to the  subject  matter
hereof.

                  (e) This Agreement  constitutes the entire agreement among the
parties  hereto  with  respect  to  the  subject  matter  hereof.  There  are no
restrictions,  promises, warranties or undertakings,  other than those set forth
or  referred to herein.  This  Agreement  supersedes  all prior  agreements  and
understandings  among the  parties  hereto with  respect to the  subject  matter
hereof.

                  (f)  Subject to the  requirements  of  Section 9 hereof,  this
Agreement  shall inure to the benefit of and be binding upon the  successors and
assigns of each of the parties hereto.

                  (g) All  pronouns  and any  variations  thereof  refer  to the
masculine, feminine or neuter, singular or plural, as the context may require.

                  (h) The  headings in this  Agreement  are for  convenience  of
reference only and shall not limit or otherwise affect the meaning thereof.

                  (i)  This   Agreement   may  be   executed   in  two  or  more
counterparts,  each of which shall be deemed an original  but all of which shall
constitute one and the same agreement. This Agreement, once executed by a party,
may be  delivered  to  the  other









                                      -11-

party  hereto  by  telephone  line  facsimile  transmission  of a copy  of  this
Agreement bearing the signature of the party so delivering this Agreement.

                  (j) The Company  acknowledges  that any failure by the Company
to perform its obligations  under Section 3(a), or any delay in such performance
could result in to the Investors and the Company agrees that, in addition to any
other  liability of the Company may have by reason of any such failure or delay,
the Company shall be liable for all direct damages caused by any such failure or
delay, unless same is the result of force majeure. Neither party shall be liable
for consequential damages.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]
























                                      -13-


                  IN WITNESS WHEREOF,  the parties have caused this Agreement to
be duly executed by their  respective  officers  thereunto duly authorized as of
the day and year first above written.

                                  DYNAGEN, INC.


                                                     By:  /s/ Indu A. Muni
                                                        _______________________
                                                     Name:  Indu A. Muni
                                                     Title:  President

                                                     ENDEAVOUR CAPITAL FUND S.A.


                                                     By:  [illegible]
                                                       _________________________
                                                    Name:
                                                    Title:







                                                                      Exhibit 4f

         THE  SECURITY  REPRESENTED  HEREBY  HAS NOT BEEN  REGISTERED  UNDER THE
SECURITIES ACT OF 1933, AS AMENDED,  OR APPLICABLE  STATE  SECURITIES LAWS. THIS
SECURITY  MAY  NOT  BE  SOLD,  ASSIGNED  OR  TRANSFERRED  WITHOUT  AN  EFFECTIVE
REGISTRATION  STATEMENT FOR SUCH SECURITY  UNDER THE  SECURITIES ACT OF 1933, AS
AMENDED,  OR APPLICABLE STATE  SECURITIES LAWS,  UNLESS THE COMPANY HAS RECEIVED
THE  WRITTEN  OPINION OF COUNSEL  SATISFACTORY  TO THE  COMPANY  THAT SUCH SALE,
ASSIGNMENT OR TRANSFER DOES NOT INVOLVE A TRANSACTION REQUIRING  REGISTRATION OF
SUCH SECURITY UNDER THE SECURITIES ACT OF 1933, AS AMENDED,  OR APPLICABLE STATE
SECURITIES LAWS.


WARRANT NO.:  W-CS-26                  RIGHT TO PURCHASE 250,000
AUGUST 21, 1997                        SHARES OF COMMON STOCK OF DYNAGEN, INC.

                  VOID UNLESS EXERCISED BEFORE AUGUST 21, 2000


                                  DYNAGEN, INC.

                          COMMON STOCK PURCHASE WARRANT


         DYNAGEN, INC., a Delaware corporation (the "COMPANY"), hereby certifies
that, in  consideration  of the  investment by Endeavour  Capital Fund S.A. (the
"HOLDER")  pursuant to the Stock Purchase  Agreement dated the date hereof,  the
Holder is entitled, subject to and in accordance with the terms set forth below,
to purchase from the Company, commencing on the date hereof, at any time or from
time to time before 5:00 P.M. Eastern Standard Time on August 21, 2000,  250,000
fully paid and  non-assessable  shares of Common Stock,  $.01 par value,  of the
Company,  at an exercise price per share of $0.74609 (the "EXERCISE PRICE") (one
hundred  twenty-five  percent  (125%) of the average of the closing bid price of
the Common  Stock of the Company as reported by the Nasdaq  SmallCap  Market for
the ten (10) trading days immediately preceding the date hereof). The number and
character of such shares of Common  Stock and the Exercise  Price are subject to
adjustment as provided herein.

         As used  herein  the  following  terms,  unless the  context  otherwise
requires, have the following respective meanings:

         (a) The term "COMPANY" means DynaGen, Inc., a Delaware corporation, and
any  corporation  that  succeeds  or  assumes  the  obligations  of the  Company
hereunder.

         (b) The term "COMMON STOCK" means (a) the Company's Common Stock,  $.01
par value per share, as authorized,  (b) any other capital stock of any class or
classes (however  designated) of the Company,  authorized on or after such date,
the  holders of which  shall have the right,  without  limitation  as to amount,
either to all or to a share of the balance of current  dividends and liquidating
dividends  after the  payment  of  dividends  and  distributions  on any  shares
entitled  to  preference,  and the  holders of which  shall  ordinarily,  in the
absence of contingencies,  be entitled to



                                      -2-


vote for the election of a majority of directors of the Company (even though the
right so to vote has been suspended by the happening of such a contingency), (c)
any other securities into which or for which any of the securities  described in
(a) or (b) may be converted or exchanged pursuant to a plan of recapitalization,
reorganization,  merger,  sale of  assets or  otherwise,  or the  conversion  of
promissory notes or other obligations of the Company.

         (c) The term  "OTHER  SECURITIES"  means any stock  (other  than Common
Stock) and other  securities  of the Company or any other person  (corporate  or
otherwise)  which the holder of this  Warrant at any time shall be  entitled  to
receive,  or shall have received,  on the exercise of the Warrant, in lieu of or
in  addition  to Common  Stock,  or which at any time shall be issuable or shall
have been  issued in exchange  for or in  replacement  of Common  Stock or Other
Securities pursuant to Sections 3 or 4 or otherwise.

         1.       EXERCISE OF WARRANT.

                  1.1. FULL  EXERCISE.  This Warrant may be exercised in full by
the holder  hereof by surrender of this Warrant,  with the form of  subscription
attached  hereto duly  executed by such holder,  to the Company at its principal
office,  accompanied by payment,  in cash or by certified or official bank check
payable to the order of the Company,  in the amount  obtained by multiplying the
number of shares of Common Stock for which this Warrant is then  exercisable  by
the Exercise Price then in effect.

                  1.2. PARTIAL  EXERCISE.  This Warrant may be exercised in part
by surrender of this Warrant in the manner and at the place  provided in Section
1.1 except that the amount payable by the holder on such partial  exercise shall
be the amount  obtained by multiplying  (a) the number of shares of Common Stock
designated  by the  holder  in the  subscription  at the end  hereof  by (b) the
Exercise Price then in effect. On any such partial exercise,  the Company at its
expense  will  forthwith  issue and  deliver  to or upon the order of the holder
hereof a new Warrant or Warrants of like tenor, in the name of the holder hereof
or as such holder (upon payment by such holder of any applicable transfer taxes)
may  request,  calling in the  aggregate  on the face or faces  thereof  for the
number of shares of Common Stock for which such Warrant or Warrants may still be
exercised.

                  1.3 CASHLESS EXERCISE FEATURE -- RIGHT TO CONVERT WARRANT INTO
COMMON STOCK.  (a) In addition to and without  limiting the rights of the holder
hereof  under the terms of this  Warrant,  the holder  shall have the right (the
"CONVERSION  RIGHT") to convert this Warrant or any portion  thereof into shares
of Common  Stock as  provided  in this  Section at any time or from time to time
prior to its expiration,  subject to the restrictions set forth in paragraph (c)
hereof.  In lieu of  exercising  this warrant for cash,  the holder may elect to
surrender  this  warrant for  conversion  and to receive  shares of Common Stock
equal to the value of this Warrant (or the portion being cancelled,  surrendered
and converted) by surrender of this Warrant to the Company  together with notice
of such  election.  Upon such  event,  the  Company  shall issue to the holder a
number of shares of the Company's  Common Stock  computed by using the following
formula:

                                    X  EQUALS Y (A MINUS B)
                                              -------------
                                                    A






                                      -3-


Where:            X = The  number of shares of Common  Stock to be issued to the
                      holder;
                  Y = The number of shares of Common Stock  exercisable
                      under this  Warrant
                  A = The "Fair Market Value" of one share
                      of the Common Stock on the Conversion Date (as defined
                      below); and
                  B = The Exercise Price of the Warrant (as adjusted to the date
                      of the calculation).

         Upon  exercise of the  Conversion  Right with  respect to a  particular
number of shares  subject to this  Warrant,  the  Company  shall  deliver to the
holder, without payment by the holder of any exercise price or any cash or other
consideration,  that  number  of  shares of  Common  Stock  equal to the  number
computed  using the above formula.  Notwithstanding  anything in this Section to
the contrary,  the Conversion Right cannot be exercised with respect to a number
of Converted  Warrant Shares having a value below $1,000.  No fractional  shares
shall be issuable upon exercised of the Conversion  Right,  and if the number of
shares to be issued in  accordance  with the  foregoing  formula is other than a
whole number, the Company shall pay to the holder an amount in cash equal to the
Fair Market Value of the resulting fractional share.

         (b)  The  Conversion  Right  may  be  exercised  by the  holder  by the
surrender of this Warrant at the principal office of the Company together with a
written  statement  specifying  that the holder thereby  intends to exercise the
Conversion  Right and  indicating  the  number  of  shares  of  Common  Stock or
authorized  Common Stock subject to this Warrant which are being  surrendered in
exercise of the  Conversion  Right.  Such  conversion  shall be  effective  upon
receipt by the  Company of this  Warrant  together  with the  aforesaid  written
statement,  or on such  later  date as is  specified  therein  (the  "CONVERSION
DATE"), but not later than the expiration date of this Warrant.

         (c) In the event the Conversion  Right would,  at any time this Warrant
remains  outstanding,  be deemed by the Company's  independent  certified public
accountants  to give rise to a charge to the  Company's  earnings for  financial
reporting purposes, then the Conversion Right shall automatically terminate upon
the Company's written notice to the holder of such adverse accounting treatment.

         (d) For purposes of this Section, the "FAIR MARKET VALUE" of a share of
Common Stock or authorized Common Stock as of a particular Conversion Date shall
mean:

                  (i) if the  Company's  Common  Stock  is  then  traded  on any
nationally-recognized  stock  exchange or quoted on the Nasdaq  National  Market
System or  SmallCap  Market,  the  average of the  closing bid prices for the 25
trading days  preceding  the  Conversion  Date,  as reported by such exchange or
system,  as  reported  in The Wall  Street  Journal  or any  other  publication,
including the NASD;

                  (ii) if the  Company's  Common  Stock  is then  traded  on the
over-the-counter market, the average of the closing bid and closing asked prices
for the 30 trading days preceding the  Conversion  Date, as reported in The Wall
Street Journal or by any market maker; or



                                      -4-

                  (iii)  if  quotations  for  the  Company's   Common  Stock  or
authorized  Common  Stock are not readily  available as set forth in (i) or (ii)
above, then as determined in good faith by the Company's Board of Directors upon
a review of all relevant factors,  including,  without limitation,  the price at
which  shares of the  Company's  Common Stock or  authorized  Common Stock could
reasonably be expected to be sold in an arms-length transaction, for cash, other
than on an  installment  basis,  to a person not employed by,  controlled by, in
control of or under common control with the Company,  which determination by the
Board of Directors shall give due consideration to recent transactions involving
shares of the Common Stock or  authorized  Common  Stock,  if any,  revenues and
earnings of the Company to the date of such  determination  (if any),  projected
revenues and earnings of the Company, the effect of the transfer restrictions to
which the shares are subject  under law, the absence of a public  market for the
Common Stock or authorized  Common Stock, and such other matters as the Board of
Directors deems pertinent. Such determination by the Board of Directors shall be
conclusive and binding.

         2. DELIVERY OF STOCK  CERTIFICATES ON EXERCISE.  As soon as practicable
after the exercise of this  Warrant in full or in part,  and in any event within
three (3) trading days after each Conversion Date or after the Company  receives
(i) the original  Form of  Subscription  properly  completed,  (ii) the original
Warrant and (iii) payment pursuant to Section 1.1 above, as the case may be, the
Company at its  expense  (including  the payment by it of any  applicable  issue
taxes)  will  cause to be  issued  in the name of and  delivered  to the  holder
hereof,  or as such  holder  (upon  payment  by such  holder  of any  applicable
transfer  taxes) may direct,  a certificate  or  certificates  for the number of
fully paid and  non-assessable  shares of Common Stock (or Other  Securities) to
which such  holder  shall be  entitled on such  exercise,  plus,  in lieu of any
fractional share to which such holder would otherwise be entitled, cash equal to
such fraction multiplied by the then current market value of one full share. The
exercise  date of this Warrant  shall be the date on which the Company  receives
the properly  completed Form of  Subscription  attached  hereto by telecopier or
otherwise.

         3.       ADJUSTMENT FOR REORGANIZATION, CONSOLIDATION OR MERGER.

                  3.1.  REORGANIZATION,  CONSOLIDATION OR MERGER. In case at any
time or from time to time,  the Company shall (a) effect a  reorganization,  (b)
consolidate  with or merge into any other person or entity,  or (c) transfer all
or  substantially  all of its capital  stock,  properties or assets to any other
person  under  any plan or  arrangement  contemplating  the  dissolution  of the
Company,  then, in each such case,  the holder of this Warrant,  on the exercise
hereof as  provided  in  Section 1 at any time  after the  consummation  of such
reorganization,   consolidation   or  merger  or  the  effective  date  of  such
dissolution,  as the case may be,  shall  receive,  upon the proper and rightful
exercise  of this  Warrant,  in lieu of the Common  Stock (or Other  Securities)
issuable on such exercise prior to such consummation or such effective date, the
stock and other  securities and property  (including  cash) to which such holder
would have been  entitled  upon such  consummation  or in  connection  with such
dissolution,  as the case may be, if such holder had so exercised  this Warrant,
immediately  prior  thereto,  all subject to further  adjustment  thereafter  as
provided in Sections 4 and 5.

                  3.2.  CONTINUATION OF TERMS. Upon any corporate event referred
to in this Section 3, this Warrant  shall  continue in full force and effect and
the terms hereof shall be



                                      -5-

applicable to the shares of stock and Other  Securities and property  receivable
on the exercise of this Warrant after the  consummation of such  reorganization,
consolidation  or  merger,  as the case may be,  and shall be  binding  upon the
issuer of any such stock or other securities.

         4. ADJUSTMENTS FOR STOCK DIVIDENDS AND STOCK SPLITS.  In the event that
the Company shall (i) issue additional  shares of the Common Stock as a dividend
or  other   distribution  on  outstanding   Common  Stock,  (ii)  subdivide  its
outstanding  shares of Common Stock, or (iii) combine its outstanding  shares of
the Common Stock into a smaller  number of shares of the Common Stock,  then, in
each such event, the Exercise Price shall,  simultaneously with the happening of
such event, be adjusted by multiplying  the then prevailing  Exercise Price by a
fraction,  the  numerator of which shall be the number of shares of Common Stock
outstanding  immediately prior to such event (calculated assuming the conversion
or exchange of all outstanding shares of convertible or exchangeable  securities
of the Company which are convertible or exchangeable  into, or exercisable  for,
shares of Common  Stock)  and the  denominator  of which  shall be the number of
shares of Common  Stock  outstanding  immediately  after such event  (calculated
assuming the conversion or exchange of all outstanding  shares of convertible or
exchangeable  securities of the Company which are  convertible  or  exchangeable
into, or  exercisable  for,  shares of Common Stock) and the product so obtained
shall thereafter be the Exercise Price then in effect. The Exercise Price, as so
adjusted,  shall be  readjusted  in the same  manner upon the  happening  of any
successive  event or events  described  herein in this  Section 4. The holder of
this Warrant shall thereafter,  on the exercise hereof as provided in Section 1,
be  entitled  to receive  that number of shares of Common  Stock  determined  by
multiplying  the number of shares of Common Stock which would otherwise (but for
the provisions of this Section 4) be issuable on such exercise, by a fraction of
which (i) the numerator is the Exercise Price which would otherwise (but for the
provisions  of this  Section 4) be in effect,  and (ii) the  denominator  is the
Exercise Price in effect on the date of such exercise.

         5.   ADJUSTMENT   FOR   DIVIDENDS   IN  OTHER   STOCK,   PROPERTY   AND
RECLASSIFICATIONS.  In case at any time or from  time to time,  the  holders  of
Common  Stock (or Other  Securities)  shall have  received,  or (on or after the
record date fixed for the  determination  of  stockholders  eligible to receive)
shall have become entitled to receive, without payment therefor,

                  (a) other or additional  stock or other securities or property
(other than cash) by way of dividend, or

                  (b) other or additional  stock or other securities or property
(including   cash)   by   way   of   spin-off,    split-up,    reclassification,
recapitalization, combination of shares or similar corporate rearrangement,

other than additional shares of Common Stock (or Other  Securities)  issued as a
stock dividend or in a stock-split (adjustments in respect of which, in the case
of Common Stock,  are provided for in Section 4), then and in each such case the
holder of this Warrant,  on the exercise  hereof as provided in Section 1, shall
be  entitled  to  receive  the  amount  of other or  additional  stock and other
securities and property  (including cash in the cases referred to in subdivision
(b) of this Section 5) which such holder would hold on the date of such exercise
if on the  date of  distribution  of such  other  or



                                      -6-

additional stock or other  securities and property,  or on the record date fixed
for  determining the  shareholders  entitled to receive such other or additional
stock or other  securities  and  property,  such  holder  had been the holder of
record of the  number of shares of Common  Stock  called for on the face of this
Warrant  and had  thereafter,  during  the period  from the date  thereof to and
including the date of such exercise,  retained such shares and all such other or
additional stock and other securities and property  (including cash in the cases
referred to in  subdivision  (b) of this Section 5) receivable by such holder as
aforesaid during such period, giving effect to all adjustments called for during
such period by Sections 3 and 4.

         6.       NOTICES OF RECORD DATE.  In the event of

                  (a) any taking by the  Company  of a record of the  holders of
any class or securities for the purpose of determining  the holders  thereof who
are  entitled to receive any  dividend  or other  distribution,  or any right to
subscribe for, purchase or otherwise acquire any shares of stock of any class or
any other securities or property, or to receive any other right, or

                  (b)  any   capital   reorganization   of  the   Company,   any
reclassification  or recapitalization of the capital stock of the Company or any
transfer  of  all  or  substantially  all  the  assets  of  the  Company  to  or
consolidation or merger of the Company with or into any other person, or

                  (c) any voluntary or involuntary  dissolution,  liquidation or
winding-up of the Company,

then and in each such event the  Company  will mail or cause to be mailed to the
holder of this Warrant a notice specifying (i) the date on which any such record
is to be taken for the  purpose of such  dividend,  distribution  or right,  and
stating the amount and character of such dividend,  distribution  or right,  and
(ii)   the   date  on   which   any   such   reorganization,   reclassification,
recapitalization,  transfer, consolidation,  merger, dissolution, liquidation or
winding-up is to take place,  and the time,  if any is to be fixed,  as of which
the holders of record of Common Stock (or Other Securities) shall be entitled to
exchange  their shares of Common Stock (or Other  Securities)  for securities or
other   property   deliverable   on   such   reorganization,   reclassification,
recapitalization,  transfer, consolidation,  merger, dissolution, liquidation or
winding-up.  Such notice  shall be mailed at least twenty (20) days prior to the
date specified in such notice on which any such action is to be taken.

         7.  RESERVATION OF STOCK  ISSUABLE ON EXERCISE OF WARRANT.  The Company
will at all times reserve and keep  available,  solely for issuance and delivery
on the  exercise of the  Warrant,  all shares of Common  Stock from time to time
issuable on the exercise of all of the then outstanding Warrants, and the shares
of Common Stock which the holder of this Warrant  shall receive upon exercise of
the  Warrant  will  be  duly   authorized,   validly  issued,   fully  paid  and
non-assessable.

         8.  EXCHANGE OF WARRANT.  On surrender  for  exchange of this  Warrant,
properly  endorsed,  to the  Company,  the Company at its expense will issue and
deliver to or on the order of



                                      -7-


the holder thereof a new Warrant or Warrants of like tenor,  in the name of such
holder or as such holder (on payment by such holder of any  applicable  transfer
taxes) may direct, calling in the aggregate on the face or faces thereof for the
number of shares of Common  Stock called for on the face or faces of the Warrant
or Warrants so surrendered.

         9.   REPLACEMENT  OF  WARRANT.   On  receipt  of  evidence   reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant  and, in the case of any such loss,  theft or  destruction  of this
Warrant,   on  delivery  of  an  indemnity   agreement  or  security  reasonably
satisfactory  in form and  amount  to the  Company  or,  in the case of any such
mutilation,  on surrender and  cancellation of such Warrant,  the Company at its
expense will execute and deliver, in lieu thereof, a new Warrant of like tenor.

         10.  WARRANTHOLDER  NOT DEEMED  STOCKHOLDER;  RESTRICTIONS ON TRANSFER.
This Warrant is issued upon the following  terms, to all of which each holder or
owner hereof by the taking hereof consents and agrees:

                  (a) Except as otherwise  expressly  set forth in Sections 3, 4
and 5 with respect to computing  adjustments  with respect hereto,  no holder of
this Warrant  shall,  as such,  be deemed the holder of Common Stock that may at
any time be issuable upon  exercise of this Warrant for any purpose  whatsoever,
nor shall anything  contained herein be construed to confer upon such holder, as
such,  any of the rights of a stockholder of the Company until such holder shall
have  delivered  formal  notice to the Company of an intention to exercise  this
Warrant, tendered promptly the consideration required for exercise (whether cash
or securities), exercised the Warrant, and been issued shares of Common Stock in
accordance with the provisions hereof.

                  (b) This  Warrant is not  transferable  or  assignable  to any
party other than an affiliate of the Holder without the prior written consent of
the  Company.  A holder that wishes to  transfer  or assign this  Warrant  shall
provide to the Company an opinion of counsel  satisfactory  to the Company  that
such transfer is permissible under applicable law.

         11.  REGISTRATION  RIGHTS.  The Company  shall  register  the shares of
Common Stock issuable upon exercise of this Warrant in accordance with the terms
of the Registration Rights Agreement dated as of the date hereof.

         12. NOTICES.  All notices and other  communications from the Company to
the  holder of this  Warrant  shall be sent by (i)  first  class  mail,  postage
prepaid,  (ii) electronic  facsimile  transmission,  or (iii) express  overnight
courier service,  at such address or facsimile number as may have been furnished
to the Company in writing by such holder or, until any such holder  furnishes to
the  Company an  address or  facsimile  number,  then to, and at the  address or
facsimile  number of, the last holder of this  Warrant who has so  furnished  an
address to the Company.

         13.  MISCELLANEOUS.  This  Warrant  and any term hereof may be changed,
waived,  discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought.  This Warrant and the shares of Common Stock  underlying this Warrant
shall be construed and enforced in  accordance



                                      -8-

with and  governed  by the laws of the  State of  Delaware.  The  invalidity  or
unenforceability  of any provision hereof shall in no way affect the validity or
enforceability of any other provision.

                [REMAINDER OF PAGE IS INTENTIONALLY LEFT BLANK.]






                                      -9-


Dated: August 21, 1997                      DYNAGEN, INC.

ATTEST:

By:    /s/ Dennis R. Bilodeau               By:     /s/ Dhananjay G. Wadekar
   ----------------------------                ---------------------------------

Title: Controller                           Title:  Executive Vice President
      -------------------------                   ------------------------------







                              FORM OF SUBSCRIPTION
                   (TO BE SIGNED ONLY ON EXERCISE OF WARRANT)


TO DynaGen, Inc.

         The undersigned,  the holder of the within Warrant,  hereby irrevocably
elects to exercise this Warrant for, and to purchase thereunder, ........ shares
of Common Stock of DynaGen,  Inc., a Delaware  corporation,  and herewith  makes
payment of $........  therefor,  and  requests  that the  certificates  for such
shares be issued in the name of, and delivered to ..............,  whose address
is ................................

Dated:
                                                   (Signature  must  conform  to
                                                   name of holder  as  specified
                                                   on the face of the Warrant)


                                                   (Address)

                              --------------------

                               FORM OF ASSIGNMENT
                   (TO BE SIGNED ONLY ON TRANSFER OF WARRANT)


         For  value  received,   the  undersigned  hereby  sells,  assigns,  and
transfers unto .................. the right represented by the within Warrant to
purchase  .............  shares of Common  Stock of  DynaGen,  Inc.,  a Delaware
corporation,    to   which   the   within   Warrant   relates,    and   appoints
 ..........................  Attorney  to  transfer  such  right on the  books of
DynaGen,  Inc., a Delaware  corporation,  with full power of substitution in the
premises.


Dated:

                                                   (Signature  must  conform  to
                                                   name of holder  as  specified
                                                   on the face of the Warrant)


                                                   (Address)

Signed in the presence of:



                                                                      Exhibit 4g

50JMH2661/1. #435254
         THE  SECURITY  REPRESENTED  HEREBY  HAS NOT BEEN  REGISTERED  UNDER THE
SECURITIES ACT OF 1933, AS AMENDED,  OR APPLICABLE  STATE  SECURITIES LAWS. THIS
SECURITY  MAY  NOT  BE  SOLD,  ASSIGNED  OR  TRANSFERRED  WITHOUT  AN  EFFECTIVE
REGISTRATION  STATEMENT FOR SUCH SECURITY  UNDER THE  SECURITIES ACT OF 1933, AS
AMENDED,  OR APPLICABLE STATE  SECURITIES LAWS,  UNLESS THE COMPANY HAS RECEIVED
THE  WRITTEN  OPINION OF COUNSEL  SATISFACTORY  TO THE  COMPANY  THAT SUCH SALE,
ASSIGNMENT OR TRANSFER DOES NOT INVOLVE A TRANSACTION REQUIRING  REGISTRATION OF
SUCH SECURITY UNDER THE SECURITIES ACT OF 1933, AS AMENDED,  OR APPLICABLE STATE
SECURITIES LAWS.


WARRANT NO. : W-CS- 31                              RIGHT TO PURCHASE 1,000,000
                                                    SHARES OF COMMON STOCK OF
AUGUST 28, 1997                                     DYNAGEN, INC.

         VOID UNLESS EXERCISED BEFORE 5:00 P.M., EASTERN DAYLIGHT SAVING
                             TIME ON JULY 31, 2004.

                                  DYNAGEN, INC.

                          COMMON STOCK PURCHASE WARRANT


         DYNAGEN, INC., a Delaware corporation (the "COMPANY"), hereby certifies
that, H. J. MEYERS,  INC. is entitled,  subject to the terms set forth below, to
purchase  from the  Company,  at any time or from time to time before 5:00 p.m.,
Eastern  Daylight Saving Time, on or before July 31, 2004,  1,000,000 fully paid
and non-assessable shares of Common Stock, $.01 par value, of the Company, at an
exercise  price  per  share  equal to $0.15.  Such  exercise  price per share as
adjusted  from  time to time as herein  provided  is  referred  to herein as the
"EXERCISE  PRICE".  The number and  character of such shares of Common Stock and
the Exercise Price are subject to adjustment as provided herein. THIS WARRANT IS
EXERCISABLE IN INSTALLMENTS,  SUBJECT TO THE SATISFACTION OF CERTAIN  CONDITIONS
AS SET FORTH IN SECTION 1.3 BELOW.  NO PORTION OF THIS  WARRANT MAY BE EXERCISED
UNLESS  SUCH  CONDITIONS  HAVE BEEN  SATISFIED  WITH  RESPECT TO THE  CONDITIONS
REGARDING EXERCISABILITY.

         THIS  WARRANT IS  EXERCISABLE  FOR 700,000 OF THE  1,000,000  SHARES OF
COMMON STOCK  SUBJECT TO THIS WARRANT FOR  SERVICES  PREVIOUSLY  RENDERED BY THE
HOLDER OF THIS WARRANT.

         As used  herein  the  following  terms,  unless the  context  otherwise
requires, have the following respective meanings:

         (a)  The  term  "COMPANY"  shall  include  DynaGen,  Inc.,  a  Delaware
corporation,  and any corporation  which shall succeed or assume the obligations
of the Company hereunder.


                                      -2-

         (b) The term "COMMON  STOCK"  includes (a) the Company's  Common Stock,
$.01 par value per share,  as  authorized,  (b) any other  capital  stock of any
class or classes  (however  designated)  of the Company,  authorized on or after
such date, the holders of which shall have the right,  without  limitation as to
amount,  either to all or to a share of the  balance  of current  dividends  and
liquidating  dividends after the payment of dividends and  distributions  on any
shares entitled to preference, and the holders of which shall ordinarily, in the
absence of contingencies,  be entitled to vote for the election of a majority of
directors of the Company (even though the right so to vote has been suspended by
the happening of such a contingency), (c) any other securities into which or for
which  any of the  securities  described  in (a)  or  (b)  may be  converted  or
exchanged pursuant to a plan of recapitalization,  reorganization,  merger, sale
of  assets  or  otherwise,  or the  conversion  of  promissory  notes  or  other
obligations of the Company.

         (c) The term "OTHER  SECURITIES" refers to any stock (other than Common
Stock) and other  securities  of the Company or any other person  (corporate  or
otherwise)  which the holder of this  Warrant at any time shall be  entitled  to
receive,  or shall have received,  on the exercise of the Warrant, in lieu of or
in  addition  to Common  Stock,  or which at any time shall be issuable or shall
have been  issued in exchange  for or in  replacement  of Common  Stock or Other
Securities pursuant to Sections 3 or 4 or otherwise.

         1.       EXERCISE OF WARRANT.

                  1.1. FULL  EXERCISE.  This Warrant may be exercised in full by
the holder hereof by surrender of this Warrant, with the form of subscription at
the end hereof duly  executed by such  holder,  to the Company at its  principal
office,  accompanied by payment,  in cash or by certified or official bank check
payable to the order of the Company,  in the amount  obtained by multiplying the
number of shares of Common Stock for which this Warrant is then  exercisable  by
the Exercise Price then in effect.

                  1.2. PARTIAL  EXERCISE.  This Warrant may be exercised in part
by surrender of this Warrant in the manner and at the place  provided in Section
1.1 except that the amount payable by the holder on such partial  exercise shall
be the amount  obtained by multiplying  (a) the number of shares of Common Stock
designated  by the  holder  in the  subscription  at the end  hereof  by (b) the
Exercise Price then in effect.  On any such partial  exercise the Company at its
expense  will  forthwith  issue and  deliver  to or upon the order of the holder
hereof a new Warrant or Warrants of like tenor, in the name of the holder hereof
or as such holder (upon payment by such holder of any applicable transfer taxes)
may  request,  calling in the  aggregate  on the face or faces  thereof  for the
number of shares of Common Stock for which such Warrant or Warrants may still be
exercised.

                  1.3  CONDITIONS  REGARDING  EXERCISABILITY.  Portions  of this
Warrant are exercisable  only upon the satisfaction of certain  conditions,  and
unless such  conditions  are  satisfied,  only that  portion of this Warrant for
which the  conditions  have been  previously  satisfied  may be exercised at any
time.  THE EXACT  NUMBER OF SHARES OF COMMON STOCK FOR WHICH THIS WARRANT MAY BE
EXERCISED  AT ANY TIME  SHALL BE  DETERMINED  BY THE BOARD OF  DIRECTORS  OF THE
COMPANY  AND SET FORTH IN A NOTICE  FROM THE COMPANY TO H.J.  MEYERS,  INC.  THE
NUMBER OF SHARES FOR WHICH THIS  WARRANT  EXERCISABLE  AT ANY TIME IS SUBJECT TO
THE  SATISFACTORY  PERFORMANCE  OF



                                      -3-

SERVICES PURSUANT TO A CERTAIN  INVESTMENT BANKING AGREEMENT BETWEEN THE COMPANY
AND H.J.  MEYERS,  INC. NO PORTION OF THIS WARRANT MAY BE  EXERCISED  ABSENT THE
AFORESAID  NOTICE  FROM THE  COMPANY,  SIGNED BY AN  AUTHORIZED  OFFICER  OF THE
COMPANY.

                  THIS  WARRANT IS  EXERCISABLE  FOR  700,000  OF THE  1,000,000
SHARES OF COMMON STOCK SUBJECT TO THIS WARRANT FOR SERVICES  PREVIOUSLY RENDERED
BY THE HOLDER OF THIS WARRANT.

         2. DELIVERY OF STOCK  CERTIFICATES ON EXERCISE.  As soon as practicable
after the exercise of this  Warrant in full or in part,  and in any event within
thirty (30) days thereafter,  the Company at its expense  (including the payment
by it of any applicable  issue taxes) will cause to be issued in the name of and
delivered to the holder  hereof,  or as such holder (upon payment by such holder
of any applicable  transfer taxes) may direct, a certificate or certificates for
the number of fully  paid and  non-assessable  shares of Common  Stock (or Other
Securities)  to which such holder shall be entitled on such  exercise,  plus, in
lieu of any fractional  share to which such holder would  otherwise be entitled,
cash equal to such fraction  multiplied by the then current  market value of one
full share.

         3.       ADJUSTMENT FOR REORGANIZATION, CONSOLIDATION OR MERGER.

                  3.1.  REORGANIZATION,  CONSOLIDATION OR MERGER. In case at any
time or from time to time,  the Company shall (a) effect a  reorganization,  (b)
consolidate  with or merge into any other person or entity,  or (c) transfer all
or  substantially  all of its capital  stock,  properties or assets to any other
person  under  any plan or  arrangement  contemplating  the  dissolution  of the
Company,  then, in each such case,  the holder of this Warrant,  on the exercise
hereof as  provided  in  Section 1 at any time  after the  consummation  of such
reorganization,   consolidation   or  merger  or  the  effective  date  of  such
dissolution,  as the case may be,  shall  receive,  upon the proper and rightful
exercise  of this  Warrant,  in lieu of the Common  Stock (or Other  Securities)
issuable on such exercise prior to such consummation or such effective date, the
stock and other  securities and property  (including  cash) to which such holder
would have been  entitled  upon such  consummation  or in  connection  with such
dissolution,  as the case may be, if such holder had so exercised  this Warrant,
immediately  prior  thereto,  all subject to further  adjustment  thereafter  as
provided  in Sections 4 and 5. The holder of this  Warrant  must  exercise  this
Warrant prior to the  consummation  of any of the  foregoing  events in order to
obtain the benefits of this Section.

                  3.2.  CONTINUATION OF TERMS. Upon any corporate event referred
to in this Section 3, this Warrant  shall  continue in full force and effect and
the terms hereof shall be applicable to the shares of stock and Other Securities
and property  receivable on the exercise of this Warrant after the  consummation
of such  reorganization,  consolidation or merger, as the case may be, and shall
be binding upon the issuer of any such stock or other securities.

         4. ADJUSTMENTS FOR STOCK DIVIDENDS AND STOCK SPLITS.  In the event that
the Company shall (i) issue additional  shares of the Common Stock as a dividend
or  other   distribution  on  outstanding   Common  Stock,  (ii)  subdivide  its
outstanding  shares of Common Stock, or (iii) combine its outstanding  shares of
the Common Stock into a smaller  number of shares of the



                                      -4-

Common Stock, then, in each such event, the Exercise Price shall, simultaneously
with the happening of such event, be adjusted by multiplying the then prevailing
Exercise  Price by a  fraction,  the  numerator  of which shall be the number of
shares of Common Stock  outstanding  immediately prior to such event (calculated
assuming the conversion or exchange of all outstanding  shares of convertible or
exchangeable  securities of the Company which are  convertible  or  exchangeable
into, or exercisable  for,  shares of Common Stock) and the denominator of which
shall be the number of shares of Common Stock outstanding immediately after such
event (calculated  assuming the conversion or exchange of all outstanding shares
of convertible or  exchangeable  securities of the Company which are convertible
or  exchangeable  into, or exercisable  for,  shares of Common  Stock),  and the
product so obtained shall  thereafter be the Exercise Price then in effect.  The
Exercise Price, as so adjusted,  shall be readjusted in the same manner upon the
happening of any successive  event or events described herein in this Section 4.
The holder of this Warrant shall thereafter,  on the exercise hereof as provided
in  Section 1, be  entitled  to receive  that  number of shares of Common  Stock
determined  by  multiplying  the number of shares of Common  Stock  which  would
otherwise  (but  for the  provisions  of this  Section  4) be  issuable  on such
exercise,  by a fraction of which (i) the numerator is the Exercise  Price which
would  otherwise  (but for the  provisions of this Section 4) be in effect,  and
(ii)  the  denominator  is the  Exercise  Price  in  effect  on the date of such
exercise.

         5.   ADJUSTMENT   FOR   DIVIDENDS   IN  OTHER   STOCK,   PROPERTY   AND
RECLASSIFICATIONS.  In case at any time or from  time to time,  the  holders  of
Common  Stock (or Other  Securities)  shall have  received,  or (on or after the
record date fixed for the  determination  of  stockholders  eligible to receive)
shall have become entitled to receive, without payment therefor,

         (a) other or additional  stock or other  securities or property  (other
than cash) by way of dividend, or

         (b)  other  or  additional   stock  or  other  securities  or  property
(including   cash)   by   way   of   spin-off,    split-up,    reclassification,
recapitalization, combination of shares or similar corporate rearrangement,

other than additional shares of Common Stock (or Other  Securities)  issued as a
stock dividend or in a stock-split (adjustments in respect of which, in the case
of Common Stock,  are provided for in Section 4), then and in each such case the
holder of this Warrant,  on the exercise  hereof as provided in Section 1, shall
be  entitled  to  receive  the  amount  of other or  additional  stock and other
securities and property  (including cash in the cases referred to in subdivision
(b) of this Section 5) which such holder would hold on the date of such exercise
if on the  date of  distribution  of such  other  or  additional  stock or other
securities  and  property,  or on the  record  date  fixed for  determining  the
shareholders  entitled  to  receive  such  other  or  additional  stock or other
securities and property, such holder had been the holder of record of the number
of  shares  of  Common  Stock  called  for on the face of this  Warrant  and had
thereafter, during the period from the date thereof to and including the date of
such exercise,  retained such shares and all such other or additional  stock and
other  securities  and  property  (including  cash in the cases  referred  to in
subdivision (b) of this Section 5) receivable by such holder as aforesaid during
such period,  giving effect to all adjustments  called for during such period by
Sections 3 and 4.



                                      -5-

         6.  RESERVATION OF STOCK  ISSUABLE ON EXERCISE OF WARRANT.  The Company
will at all times reserve and keep  available,  solely for issuance and delivery
on the  exercise of the  Warrant,  all shares of Common  Stock from time to time
issuable on the  exercise of the  Warrant;  the shares of Common Stock which the
holder of this Warrant  shall  receive upon exercise of the Warrant will be duly
authorized, validly issued, fully paid and non-assessable.

         7.  EXCHANGE OF WARRANT.  On surrender  for  exchange of this  Warrant,
properly  endorsed,  to the  Company,  the Company at its expense will issue and
deliver to or on the order of the holder  thereof a new  Warrant or  Warrants of
like  tenor,  in the name of such  holder or as such  holder (on payment by such
holder of any applicable transfer taxes) may direct, calling in the aggregate on
the face or faces thereof for the number of shares of Common Stock called for on
the face or faces of the Warrant or Warrants so surrendered.

         8.   REPLACEMENT  OF  WARRANT.   On  receipt  of  evidence   reasonably
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant  and, in the case of any such loss,  theft or  destruction  of this
Warrant,   on  delivery  of  an  indemnity   agreement  or  security  reasonably
satisfactory  in form and  amount  to the  Company  or,  in the case of any such
mutilation,  on surrender and  cancellation of such Warrant,  the Company at its
expense will execute and deliver, in lieu thereof, a new Warrant of like tenor.

         9. WARRANTHOLDER NOT DEEMED STOCKHOLDER; RESTRICTIONS ON TRANSFER. This
Warrant is issued upon the following terms, to all of which each holder or owner
hereof by the taking hereof consents and agrees:

         (a) No holder of this Warrant  shall,  as such, be deemed the holder of
      Common  Stock  that  may at any time be  issuable  upon  exercise  of this
      Warrant for any purpose whatsoever, nor shall anything contained herein be
      construed  to confer  upon such  holder,  as such,  any of the rights of a
      stockholder of the Company until such holder shall have  delivered  formal
      notice to the Company of an intention to exercise this  Warrant,  tendered
      promptly  the  consideration   required  for  exercise  (whether  cash  or
      securities), exercised the Warrant, and been issued shares of Common Stock
      in accordance with the provisions hereof.

         (b)  Neither  this  Warrant  nor any shares of Common  Stock  purchased
      pursuant to this Warrant shall be registered  under the  Securities Act of
      1933  (the  "SECURITIES   ACT")  and  applicable  state  securities  laws.
      Therefore,  the  Company may  require,  as a  condition  of  allowing  the
      transfer or exchange of this  Warrant or such  shares,  that the holder or
      transferee of this Warrant or such shares,  as the case may be, furnish to
      the Company an opinion of counsel  acceptable to the Company to the effect
      that such transfer or exchange may be made without  registration under the
      Securities  Act and applicable  state  securities  laws. The  certificates
      evidencing  the  shares of Common  Stock  issued  on the  exercise  of the
      Warrant  shall bear a legend to the effect  that the shares  evidenced  by
      such  certificates  have not been registered  under the Securities Act and
      applicable state securities laws.




                                      -6-

         (c) This Warrant is not transferable or assignable to any party without
      the prior written consent of the Company, and accompanied by an opinion of
      counsel  satisfactory  to the Company  that such  transfer is  permissible
      under applicable law.

         10. NOTICES.  All notices and other  communications from the Company to
the holder of this  Warrant  shall be mailed by (i) first  class  mail,  postage
prepaid,  (ii) electronic  facsimile  transmission,  or (iii) express  overnight
courier  service,  at such address as may have been  furnished to the Company in
writing by such  holder or,  until any such holder  furnishes  to the Company an
address, then to, and at the address of, the last holder of this Warrant who has
so furnished an address to the Company.

         11.  MISCELLANEOUS.  This  Warrant  and any term hereof may be changed,
waived,  discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought.  This Warrant and the shares of Common Stock  underlying this Warrant
shall be construed and enforced in  accordance  with and governed by the laws of
the State of Delaware.  The  invalidity  or  unenforceability  of any  provision
hereof  shall in no way  affect  the  validity  or  enforceability  of any other
provision.

         12.      REGISTRATION RIGHTS.

                  12.1 SHORT-FORM  REGISTRATIONS  ON FORM S-3. At the request of
H.J. Meyers, Inc., the Company shall use its best efforts to file a registration
statement  on Form S-3 (to the extent  such form is  available  to the  Company)
covering the resale of the Shares  underlying  this  Warrant  (the  "REGISTRABLE
SHARES").  In addition,  the Company  shall,  subject to the  conditions  listed
below, grant "piggy back" registration  rights to include the Registrable Shares
in any registration statement filed by the Company solely for the account of the
Company under the Securities  Act of 1933 as amended (the "Act")  relating to an
underwriting of the sale of shares of Common Stock. These registration rights do
not apply to securities  issued in connection with any acquisition of any entity
or  business,  shares  issuable  solely upon the exercise of stock  options,  or
pursuant to other employee  benefit plans. In connection with any offering,  the
holders  of the  Registrable  Shares  shall be  subject  to any  limitation  the
underwriter  or the Company  shall impose on the number of shares of such Common
Stock  which  may  be  included  in  any  such  registration  statement.  At its
discretion,  the  Company  may  also  include  the  Registrable  Shares  in  any
registration statement filed on behalf of selling security holders.


         The  Company  shall  not be  required  to  effect  more  than  two  (2)
registrations  on Form S-3. The Company's  obligations  under this Section shall
expire  three (3) years after the  issuance  date of this  Warrant.  The Company
shall not be  required to effect  more than one demand  registration  during any
18-month  period.  Notwithstanding  the  foregoing,  the  Company  shall have no
obligation  to  register  the  Registrable  Shares  under  this  Section if such
Registrable  Shares are  eligible for resale under Rule 144, as so opined by the
Company's outside legal counsel.




                                      -7-

                  12.2  EXPENSES.  In the case of a  registration  under Section
12.1,  the Company  shall bear the  expenses of any filing of any  registration,
including but not limited to printing legal and accounting expenses,  Securities
and Exchange Commission and NASD filing fees and all related "Blue Sky" fees and
expenses.  The Company shall have no obligation to pay or otherwise bear (i) the
cost and expenses of procuring  underwriters'  insurance in connection  with the
sale of Registrable  Shares,  (ii) any portion of the fees or  disbursements  of
counsel for the selling  holders of  Registrable  Shares or (iii) any portion of
the  underwriters'  commission  or  discounts  attributable  to the  Registrable
Shares.  The Company  shall only be obligated to bear the expenses of one filing
for a registration initiated under Section 12.1.

                  12.3 EXPIRATION OF REGISTRATION RIGHTS. The obligations of the
Company  under this  Section 12 to  register  the  securities  shall  expire and
terminate on the earlier of the  expiration  date of the warrant or at such time
as the holder of this  Warrant  shall be entitled or eligible to sell the shares
of Common Stock  underlying this Warrant without  restriction and without a need
for the filing of a  registration  statement  under the  Securities Act of 1933,
including  without  limitation,  for any resales of restricted  securities  made
pursuant to Rule 144 as promulgated by the Securities and Exchange Commission.

                  12.4  DELAY OF  REGISTRATION.  For a period  not to exceed 180
days,  the Company  shall not be obligated to prepare and file,  or be prevented
from delaying or abandoning,  a registration  statement pursuant to this Section
at any time when the Company,  in its good faith  judgment by the  management of
the  Company,  with the advice of  counsel,  reasonably  believes:  (I) that the
filing  thereof at the time  requested,  or the offering of  Registrable  Shares
pursuant  thereto,  would  materially  and  adversely  affect  (a) a pending  or
scheduled public offering or private placement of the Company's securities,  (b)
an  acquisition,  merger,  consolidation  or  similar  transaction  by or of the
Company,  (c) pre-existing and continuing  negotiations,  discussions or pending
proposals  with  respect  to any  of  the  foregoing  transactions,  or (d)  the
financial  condition of the Company in view of the  disclosure of any pending or
threatened litigation, claim, assessment or governmental investigation which may
be  required  thereby;  and (II)  that the  failure  to  disclose  any  material
information  with  respect  to the  foregoing  would  cause a  violation  of the
Securities Act or the Securities Exchange Act of 1934.

         13. EXPIRATION. The right to exercise this Warrant shall expire at 5:00
p.m., Eastern Daylight Saving Time, on July 31, 2004.

DATED: AUGUST 28, 1997                         DYNAGEN, INC.

ATTEST:

By:  /s/ Dennis R. Bilodeau                    By: /s/ Dhananjay G. Wadekar
   ----------------------------                   ------------------------------
Title:  Controller                             Title:  Executive Vice President
      -------------------------                      ---------------------------






                              FORM OF SUBSCRIPTION
                   (TO BE SIGNED ONLY ON EXERCISE OF WARRANT)


TO DynaGen, Inc.

         The undersigned,  the holder of the within Warrant,  hereby irrevocably
elects to exercise this Warrant for, and to purchase thereunder, ........ shares
of Common Stock of DynaGen,  Inc., a Delaware  corporation,  and herewith  makes
payment of $........  therefor,  and  requests  that the  certificates  for such
shares be issued in the name of, and delivered to ..............,  whose address
is ................................

Dated:

                                                   (Signature  must  conform  to
                                                   name of holder  as  specified
                                                   on the face of the Warrant)


                                                   (Address)

                              --------------------

                               FORM OF ASSIGNMENT
                   (TO BE SIGNED ONLY ON TRANSFER OF WARRANT)


         For  value  received,   the  undersigned  hereby  sells,  assigns,  and
transfers unto .................. the right represented by the within Warrant to
purchase  .............  shares of Common  Stock of  DynaGen,  Inc.,  a Delaware
corporation,    to   which   the   within   Warrant   relates,    and   appoints
 ..........................  Attorney  to  transfer  such  right on the  books of
DynaGen,  Inc., a Delaware  corporation,  with full power of substitution in the
premises.


Dated:

                                                   (Signature  must  conform  to
                                                   name of holder  as  specified
                                                   on the face of the Warrant)


                                                   (Address)

Signed in the presence of:







                                                                     Exhibit 10a





                               INDENTURE OF LEASE

                                 BY AND BETWEEN

                            RIVERTECH ASSOCIATES LLC

                                   ("LESSOR")

                                       AND

                                  DYNAGEN, INC.

                                   ("LESSEE")


- --------------------------------------------------------------------------------

                           RIVERSIDE TECHNOLOGY CENTER

                               840 MEMORIAL DRIVE
                            CAMBRIDGE, MASSACHUSETTS


- --------------------------------------------------------------------------------







Lease Dated July 1, 1997









                           RIVERSIDE TECHNOLOGY CENTER
                                COMMERCIAL LEASE
                                     BETWEEN
                            RIVERTECH ASSOCIATES, LLC
                                       AND
                                  DYNAGEN, INC.

         Agreement  entered into this 1st day of July, 1997 in  consideration of
the covenants and other benefits herein  contained,  the receipt and sufficiency
of said consideration being hereby acknowledged.

         Rivertech  Associates LLC, a Massachusetts  limited liability  company,
c/o The Abbey Group 575 Boylston Street Boston, MA 02116 (herein "LESSOR"), does
hereby lease to DynaGen, Inc., a Delaware corporation having its principal place
of business at 99 Erie Street Cambridge, Massachusetts 02139, (herein "Lessee"),
and LESSEE does hereby  lease from said  LESSOR,  certain  space  located at 840
Memorial Drive, Cambridge, Massachusetts (herein "Building"), being that portion
of the forth floor of the Building shown on Exhibit A attached  hereto  (herein,
"Lease  Plan')  consisting  of  approximately  12,262  rentable  square  feet as
appearing on said Lease Plan, (the "Leased or Premises" or "Premises"); with the
right in common with others in the Building to use (a) the parking  areas on the
parcel of land on which  the  Building  is  located  or  otherwise  serving  the
Building (as said parking  areas are  expressly  contemplated  herein);  (b) the
driveways  and  walkways  necessary  for access to the  Building or such parking
areas; (c ) the entrances,  lobbies,  stairs,  passenger elevators and corridors
necessary  for  access  to the  Premises;  (d) the  loading  docks  and  freight
elevators in the Building or such parking areas;  (c) Premises;  (d) the loading
docks and freight  elevators  in the  Building,  subject to LESSOR's  reasonable
rules and regulations promulgated according to section 24 of this Lease; (e) the
lavatories  on the fourth floor of the Building;  (f) the heating,  ventilation,
air conditioning,  plumbing, electrical,  emergency and other mechanical systems
and equipment serving the Premises in common with other portions of the Building
(as more  specifically  set forth  herein);  and (g) such other common areas and
facilities as LESSOR may designate from time to time (collectively,  the "Common
Areas").

         1. TERM. LESSEE leases the Leased Premises for an original Term of five
(5) years  (herein,  "Lease  Term").  The Term of the Lease  shall  begin on the
Commencement Date (as hereinafter defined), and shall end on the last day of the
calendar  month  which  is  sixty  (60)  full  calendar  months  therefrom  (the
"Termination Date").

         The first full twelve (12) month period following the Commencement Date
(or,  if the  Commencement  Date  occurs on a date other than the first day of a
calendar month, the first day of the first calendar month after the Commencement
Date occurs) and each subsequent twelve month period during the Lease Term shall
be called "Lease Years".  To 










                                      -2-


the extent the Commencement  Date occurs on any date other than the first of any
month,  the first Lease Year shall be enlarged to include the period between the
Commencement Date and the beginning of the first full month of the Lease Term.

         The Commencement Date shall be that date upon which the LESSOR delivers
the Office Space (as  hereinafter  defined) to LESSEE,  as evidenced by LESSOR's
tender of its Phase I Delivery Notice as contemplated by paragraph 33 hereof, in
broom clean condition,  and free of all tenants and occupants,  and with Phase I
substantially complete (as those terms are hereinafter defined).

         For example,  if the Commencement Date is September 15, 1997, the first
Lease year begins on October 1, 1997 and ends  September  30,  1998;  the second
Lease Year begins on October 1, 1998 and ends  September 30, 1999;  and so on up
to the Termination Date of September 30, 2002.

         2. RENT.  Beginning as of the  Commencement  Date,  LESSEE shall pay to
LESSOR rent at an annual rate  pursuant to the schedule  below during each Lease
Year (or portion thereof as the case may be) of the Lease Term hereof,  (herein,
"Annual Base  Rent").  Annual Base Rent shall be payable,  in advance,  in equal
monthly  installments,  due on the first day of each calendar month, pursuant to
the schedule below.

         Notwithstanding any other provision of this Lease,  because Annual Base
Rent is to be paid on the basis of a "Lease Year" which is defined  above as the
first  consecutive  twelve (12) months after the Commencement  Date, and because
the  Commencement  Date may be a date  other  than the first  day of a  calendar
month, there shall be an incremental  installment (or installments) of rent (the
"Interim Rent'),  which is based on Annual Base Rent for the first Lease Year as
set forth in the schedule  below and  reflective  of the delivery of the Demised
Premises in two phases; determined as follows:

         The monthly  installment  of Interim Rent shall consist of Phase I Rent
and Phase II Rent. Rent due for each applicable month from the Commencement Date
(i.e.  the "Phase I Delivery  Date")  until the Phase II Delivery  Date shall be
$26,142.53 (the "Phase I Rent"); and accordingly, that monthly rate equals a per
diem rate of $871.42. The "Phase II Delivery Date" shall be that date upon which
the LESSOR  delivers  the balance of the Leased  Premises  other than the Office
Space,  to LESSEE,  as  evidenced  by  LESSOR's  tender of its Phase II Delivery
Notice as contemplated  by paragraph 33 hereof,  in broom clean  condition,  and
free of all tenants and occupants,  and with Phase II substantially complete (as
those terms are  hereinafter  defined).  LESSEE shall pay to LESSOR Phase I Rent
based on the above stated per diem rate,  for each day between the  Commencement
Date and the Phase II Delivery Date.  (Payment shall be made in advance,  by the
first of each calendar  month, in the full amount of the Phase I Rent, (for each
month  starting  September 1, 1997 where the Phase II Delivery  Date has not yet
occurred)  with there to be an  appropriate  adjustment  made by any portions of
that month where Interim Rent  consists of Phase I Rent and Phase II Rent,  said
adjustment to be added to or  subtracted  from the first  installment  of Annual
Base Rent due the next full calendar month, 










                                      -3-

and promptly credited or paid as the case may be). Additionally, for the balance
of any calendar  month in which the Phase II Delivery  Date occurs,  through the
end of said calendar month,  LESSEE's  payment of Interim Rent shall be based on
the full  Annual Base Rent for the first  Lease Year  pursuant  to the  schedule
below, in a monthly amount of $34,231.42 (the "Phase II Rent"), and accordingly,
that  monthly  rate  equals a per diem rate of  $1,141.05.  LESSEE  shall pay to
LESSOR  Phase II Rent  based on the above  stated  per diem  rate,  for each day
between the Phase II Delivery  Date through the last day of the calendar  month.
The next payment then due shall be the first monthly  installment of Annual Base
Rent on or before the first of the calendar month.

         Any and all charges for  Additional  Operating  Expense  Rent and other
Additional Rent as hereinafter defined and due after the Commencement Date shall
also be prorated on a daily basis reflective of the space delivered.

         All payments of Interim Rent (i.e.  Phase I Rent and Phase II Rent) and
Annual Base Rent; and also  Additional  Operating  Expense Rent,  Additional Tax
Escalation Rent, and any and all other sums and may be due from LESSEE to LESSOR
under this Lease, all of which shall be deemed "Additional Rent'; (the foregoing
to be  singularly as to any item or  collectively  referred to herein as "Rent")
shall be made to LESSOR's agent,  the Abbey  Corporation,  575 Boylston  Street,
Boston,  Massachusetts  02116 or to such other  agent or at such other  place as
LESSOR may designate in writing.

         LESSEE  shall  pay  interest  from the date due,  at an annual  rate of
fifteen  (15%) percent for any  installments  of Annual Base Rent, or Additional
Rent or other  payments  due from  LESSEE to LESSOR  which are not  received  by
LESSOR within ten days after  written  notice from LESSOR that Annual Base Rent,
or Additional Rent or other payments were not received

                       SCHEDULE OF ANNUAL BASE RENT

     Lease Year               Annual Base Rent           Monthly Installment

    Lease Year 1                 $410,777.00                $34,231.42  
    Lease Year 2                 $416,908.00                $34,742.33
    Lease Year 3                 $423,039.00                $35,253.25
    Lease Year 4                 $429,170.00                $35,764.17
    Lease Year 5                 $435,301.00                $36,275.08


         3.  ADDITIONAL  RENT.  (Operating  Expenses).   Commencing  as  of  the
Commencement  Date,  LESSEE, in addition to the sums payable to LESSOR as Annual
Base  Rent as  determined  in  Section 2  hereof,  shall pay to LESSOR  for each
calendar  year (or  portion  thereof,  as  applicable)  of the  Lease  Term,  as
additional rent, LESSEE's Allocable  percentage (as hereinafter  defined) of any
and all increases in operating  expenses 









                                      -4-

attributable  to  the  Building  for  said  year  of  the  Lease  Term  (herein,
"Additional Operating Expense Rent').

         The base from which the amount of any  increases in operating  expenses
shall be determined is the operating expense schedule compiled and calculated by
LESSOR,  representing  actual operating  expenses for calendar year 1996, as set
forth as  Exhibit B  attached  hereto  and  incorporated  herein,  which  LESSOR
represents a complete and correct  summary of said  operating  expense  amounts.
LESSEE's  payment  shall be prorated  if the Lease  commences  or is  terminated
(without breach) during any fiscal year.

         Solely for the purpose of calculating  LESSEE's Allocable Percentage of
increases in operating expenses over those shown in Exhibit B hereto,  operating
expense  increases  shall not  include  the  following:  The  costs of  LESSEE's
improvements  performed by LESSOR (if any), or as they may be approved by LESSOR
in  the  future;  all  items  and  services  for  which  LESSEE  or  any  tenant
specifically and directly  reimburses  LESSOR, or pays third persons at LESSOR's
directions;  income or franchise taxes of the LESSOR;  the costs incurred in any
rehabilitation,   reconstruction,  or  other  work  occasioned  by  any  insured
casualty,  or by the  exercise  of the right of  eminent  domain,  except to the
extent of any so-called  "deductible" amount under policies of insurance (not to
exceed  $25,000.00)  or any costs  actually  incurred  for  which any  insurance
company does not  reimburse or  compensate  LESSOR  (unless  LESSOR was required
under this Lease to maintain  insurance  covering  such costs);  and those other
items  listed in  Exhibit  B-1  hereto  Notwithstanding  the  foregoing,  LESSOR
reserves the right to claim as against LESSEE as provided  under this Lease,  or
any other  tenant or  individual  or entity  for any and all costs and  expenses
caused directly or occasioned by their willful  misconduct or other negligent or
wrongful acts or omissions.

         Operating expense escalation is ordinarily invoiced to LESSEE by LESSOR
in January of each calendar year. LESSEE shall not be responsible for payment of
any increase in operating  expense  escalations  for calendar  year 1997 greater
than five (5%) percent over said  operating  expenses for calendar year 1996. If
the Lease Term includes any partial  calendar  year,  the  Additional  Operating
Expense Rent for such calendar year shall be prorated  according to the fraction
of the total days in such  calendar  year that are  included  in the Lease Term.
LESSOR shall have the option to require LESSEE to pay the  Additional  Operating
Expense Rent in any Lease year in equal monthly installments on the first day of
each calendar  month during the Lease Term;  provided  LESSOR first  delivers to
LESSEE its  statement  of the monthly  amount due for the LEASE Year in question
based on LESSOR's reasonable estimates. Within ninety (90) days after the end of
each  calendar  year  included  within the Lease Term,  LESSOR shall  deliver to
LESSEE a written  statement  of the  actual  operating  expenses  and the actual
Additional  Operating  Expense Rent for such year. If such  statement  indicates
that the  actual  Additional  Operating  Expense  Rent for  such  calendar  year
exceeded LESSEE's estimated payments on account of Additional  Operating Expense
Rent for such calendar year,  then LESSEE shall pay such excess to LESSOR within
thirty (30) days of its receipt of such statement from LESSOR. If such statement
indicates that LESSEE's  estimated  payments on account of









                                      -5-

Additional  Operating  Expense Rent for such  calendar  year exceeded the actual
Additional  Operating  Expense Rent for such calendar year,  LESSOR shall credit
the excess against the next installment(s) of Additional  Operating Expense Rent
due from LESSEE,  or at the end of the Lease Term pay such excess to LESSEE when
delivering such statement to LESSEE.

         LESSEE's  Allocable  Percentage for the purpose of this Lease is 9.73%;
provided  however,  for periods up to the Phase II Delivery  Date, the Allocable
Percentage to be applied shall be 7.75%.

         4. ADDITIONAL RENT (Tax Escalation).  Commencing as of the Commencement
Date,  LESSEE,  in addition to the sums payable to LESSOR as Annual Base Rent as
determined in Section 2 hereof, and in addition to the sums payable to LESSOR as
determined  in Section 3 hereof,  shall also pay to LESSOR as  additional  rent,
LESSEE's  Allocable  Percentage  of any increase in the real estate taxes levied
against  the  Building  and the land on which it is  situated,  above  such real
estate  taxes for fiscal tax year 1997  whether  such  increase  is caused by an
increase in the tax rate,  an increase  in  assessed  value,  or a change in the
method of determining real estate taxes, ("Additional Tax Escalation Rent").

         The base  from  which  the  amount of any  increase  in taxes  shall be
determined from the rate and the assessment for fiscal tax year 1997, or, in the
event LESSOR seeks and its granted an abatement of taxes (administratively or by
appeal to the Appellate  Tax Board and/or the courts) for FY 1997,  the tax rate
and  assessment as abated,  whichever  results in a lower base year amount.  The
Additional Tax Escalation  Rent shall be prorated if the Lease Term commences or
terminates (without breach) during any fiscal year,  accordingly to the fraction
of the total days in such tax year that are included in the Lease Term.

         Notwithstanding  the foregoing,  LESSOR shall be under no obligation to
file for any abatement of taxes for FY 1997 or any other fiscal year, and LESSEE
shall pay the entire amount of Additional Tax Escalation Rent for any fiscal tax
year as invoiced  by LESSOR,  receiving  a rebate of such  payments  made by its
based on its  Allocable  Percentage  of any abated real estate  taxes only if an
abatement is sought and received by LESSOR for such fiscal tax year.

         LESSEE shall make  payment  within  thirty (30) days of written  notice
from LESSOR that Additional Tax Escalation  Rent sums are payable,  which notice
shall be accompanied by a copy of the tax bill.

         5. SECURITY  DEPOSIT.  Upon  execution  hereof,  LESSEE shall post with
LESSOR in the manner described below (and maintain at all times during the Lease
Term and any Extended Term as hereinafter  defined),  a Security  Deposit in the
amount of Two Hundred  Thousand  ($200,000.00)  Dollars,  which shall be held as
security for LESSEE's  performance  as herein  provided,  subject to  reductions
described  below,  with the  balance to be returned to LESSEE at the end of this
Lease Term (as may be  extended);  said 






                                      -6-

reductions and return of any balance subject to LESSEE's satisfactory compliance
with the terms and conditions  hereof.  The Security  Deposit shall be posted at
the  option of the  LESSEE  from time to time (but not  changed  as to form more
frequently than each Lease Year) as follows:

         (a) Two Hundred  Thousand  ($200,000.00)  Dollars by  certified or bank
check (the "Cash Deposit"); or

         (b) Two Hundred Thousand  ($200,000.00) Dollars by irrevocable stand-by
Letter of Credit, drawn on Fleet Bank or another commercial bank having branches
in Massachusetts,  reasonably acceptable to LESSOR, (the "Letter of Credit"). If
Lessee elects to post a Letter of Credit,  the Letter of Credit shall:  (i) name
LESSOR  as  beneficiary;  (ii) be for a term  equal  to the  Lease  Term (or any
extended term, as and when appropriate); (iii) be cancelable only with a minimum
30 days prior  notice to LESSOR;  and (iv)  substantially  in the form  attached
hereto  as  Exhibit  G and in all  respects  in form  and  substance  reasonably
satisfactory  to LESSOR,  which at LESSEE's  election  may  provide  therein for
automatic  direct reduction on the basis of the schedule set forth in subsection
(c) below.

         If LESSOR  so draws  upon the  Letter of Credit or if LESSEE  elects to
post the Cash  Deposit,  LESSOR  shall  deposit  the Cash  Deposit in a separate
account for such  deposits,  with no  administrative  costs or expenses  thereof
passed on to LESSEE,  but interest thereon to inure to the benefit of LESSOR. If
LESSEE has elected to post the Cash  Deposit or LESSOR is holding any portion of
the  Security  Deposit in a form  other  than a Letter of Credit,  and if LESSEE
thereafter  delivers  to LESSOR a Letter of Credit in the amount  and  otherwise
then conforming to the requirements of this Section 5, LESSOR shall promptly pay
over to LESSEE the entire  balance  of the Cash  Deposit or such  portion of the
Security  Deposit  being held by LESSOR,  absent any uncured  default  under the
Lease.  If LESSEE  has  elected  to post the  Letter of  Credit  and  thereafter
delivers to LESSOR the Cash Deposit,  LESSOR shall promptly  return the original
Letter of Credit to LESSEE.  If LESSEE defaults in the payment or performance of
its  obligations  under  this  Lease,  and  such  default  continues  after  any
applicable  notice and the  expiration of any  applicable  grace period,  LESSOR
shall have the right to draw upon and apply the  Security  Deposit to the extent
necessary to cure such default. Within ten (10) days after the expiration of the
Lease Term, as it may be extended, LESSOR shall give written notice to LESSEE of
any defaults by LESSEE in the payment or  performance of its  obligations  under
this Lease.  Within thirty (30) days after the  expiration of the Lease Term, as
it may be extended,  LESSOR shall  return the Security  Deposit to LESSEE,  less
such amounts  necessary  to cure any then  outstanding  defaults  claimed in the
notice to  LESSEE.  If LESSEE  thereafter  within a  reasonable  time  under the
circumstances,  cures said  default,  the Security  Deposit shall be released to
LESSEE.

         (c) Provided  there is not then any  material  default by LESSEE in the
payment or performance of its obligations under this Lease which continues after
notice and the








                                      -7-

expiration of the applicable  cure period,  LESSEE at LESSEE's option may reduce
the Security Deposit according to the following schedule:

Amount of Reduction                                                    Balance
- -------------------                                                    -------

End of Lease Year 1                $35,000.00                       $165,000.00
End of Lease Year 2                $35,000.00                       $130,000.00
End of Lease Year 3                $35,000.00                       $ 95,000.00
End of Lease Year 4                $35,000.00                       $ 60,000.00
End of Lease Year 5                N/A                              $ 60,000.00

         6. USE OF  PREMISES.  LESSEE  shall use the Lease  Premises for general
office,  research  and  laboratory  space only,  which uses LESSOR  warrants and
represents  are  currently  allowed under local zoning  regulations  (subject to
compliance with federal,  state and municipal  safety,  healthy,  building,  and
sanitary codes and submission of confirming  plans and  specifications  suitable
for issuance of a building  permit from the City of Cambridge and an appropriate
occupancy  permit upon completion of  construction).  LESSEE will use the Leased
Premises in a careful,  and safe and proper manner and will not do or permit any
act or thing in the Leased  Premises or do any act or thing in or affecting  the
Common Areas which is contrary to any legal or insurance requirement referred to
in Section 17 hereof or which might  impair the value of the Leased  Premises or
the  Building  or any part  thereof or which  constitutes  a risk to the safety,
health or well-being of other tenants in the Building or on the site, or creates
a public or private nuisance or waste.

         7.  UTILITIES.  LESSOR shall  provide at LESSOR's  expense the building
standard facilities for heat,  ventilation,  and air conditioning for the Leased
Premises,  and the common areas and facilities  which LESSEE enjoys the right to
use, as required for  comfortable  occupancy,  during 8 AM to 6 PM each weekday,
other than national or state holidays  (herein  "Normal  Business  Hours").  Any
change in such hours by LESSOR for the Building generally shall inure as well to
the benefit of the LESSEE.  LESSOR shall provide  electrical  connections to the
Leased Premises for general office, research, and laboratory purposes,  pursuant
to its build-out obligations set forth on Exhibit C hereto. If any operations or
activities  in  the  Leased  Premises  use  electricity  in  excess  of  amounts
customarily  required for office purposes,  LESSOR, in its discretion and at its
expense, may install submeters to measure such usage separately. Notwithstanding
any separate  direct metering or general  allocation,  LESSEE shall pay all such
charges for  electricity  used on the Leased  Premises  as it may be  separately
metered,  or absent  separate meters to the whole or part of the Leased Premises
(for  whatever  reason)  based on  tenant's  Allocable  Percentage  of the total
electric bill,  whichever or both as may be applicable,  at the determination of
the LESSOR.  LESSOR shall  determine  said  electrical  charges in a uniform and
non-discriminatory  manner  relative to other lessees in the Building  similarly
situated;  and LESSEE shall pay its proportional  share of said charges relative
to all  occupied  space which is not billed to tenants on a  separately  metered
basis.  All such charges  shall be based on the rates at which LESSOR is charged
for electricity  supplied to











                                      -8-

the  Building  by  the  utility  company.   LESSOR  shall  maintain  an  average
temperature  in the  Building  between  60  degrees  Fahrenheit  and 80  degrees
Fahrenheit  at all times  and an  average  temperature  in the  Leased  Premises
generally between 68 degrees  Fahrenheit and 76 degrees Fahrenheit during Normal
Business   Hours.   LESSOR  shall  make   available   heat,   ventilation,   and
air-conditioning  as may be requested by LESSEE for the Leased  Premises  during
hours  other than Normal  Business  Hours  ("Overtime  HVAC"),  and  (subject to
increase by the same percentage  amount by which the standard electric rates are
increased from time to time by the utility company),  as billed by LESSOR and to
be paid by LESSEE  within  thirty (30) days of said  invoice.  LESSEE shall give
LESSOR  24 hours  prior  notice of any  requirements  for  specialized  overtime
heating  and air  conditioning.  LESSOR  shall not be  liable to LESSEE  for any
interruption,  interference,  damage or loss to LESSEE's  business,  research or
experimentation  occasioned  as a result of any failure or  interruption  in the
heating,   ventilation,  air  conditioning,  or  electrical  services  or  other
utilities  servicing the Building or the Leased  Premises;  unless caused by the
willful  misconduct or negligence of LESSOR;  in which case all  installments of
Annual  Base Rent and  Additional  Rent  shall be abated  based on the amount of
space  within  the  Leased  premises  which is not  available  to LESSEE for its
business  activities,  if the failure or  interruption  continues  for more than
three (3) days after  notice to LESSOR;  and in which case  LESSEE  shall have a
right to terminate this Lease if said failure  resulting  from LESSOR's  willful
misconduct or negligence continues for more than sixty (60) days after notice to
LESSOR).  No  plumbing  or  electrical  work of any type  shall be done  without
LESSOR's  approval which approval shall not be unreasonably  withheld or delayed
and the  appropriate  municipal  permit and inspector's  approval.  Hot and cold
water for domestic type sanitary  purposes (only) shall be supplied by LESSOR at
LESSOR's expense.  LESSOR shall also supply working  connections for non-potable
laboratory  water  and  water  for  other  particularized  uses  in the  Demised
Premises; usage to be separately metered and paid for by LESSEE; and all charges
for such  separately  metered  water  used by  LESSEE to be based on the rate at
which water/sewer charges are billed to the Building by the City of Cambridge.

         8. COMPLIANCE WITH LAWS. LESSEE acknowledges that no trade, occupation,
or activity shall be conducted in the Leased  Premises or use made thereof which
will be unlawful, noisy or offensive, or contrary to any federal or state law or
administrative  regulations,  or any municipal ordinance or regulations in force
at any time in Cambridge.  LESSEE shall keep all employees working in the Leased
Premises covered with Worker's  Compensation  Insurance,  as applicable.  LESSEE
shall be responsible for complying with the  Occupational  Safety and Health Act
of 1970 and any  amendments  thereto,  in  connection  with  LESSEE's use of the
Leased Premises. LESSEE shall strictly adhere to any and all federal, state, and
municipal  laws,  ordinances,  and  regulations  governing  LESSEE's  laboratory
scientific experimentation. LESSEE shall be solely responsible for procuring and
complying at all times with any and all necessary  permits directly  relating or
incident to: the conduct of its office and research  activities on the Premises;
its scientific experimentation; and LESSEE's transportation,  storage, handling,
use and disposal of any low level radioactive or bacteriological or pathological
substances or organisms or other hazardous wastes or  environmentally  dangerous
substances  or











                                      -9-

materials  to, from or at the Leased  Premises.  LESSEE shall  immediately  give
notice to LESSOR of any warnings or  violations  relative to the above  received
from any federal,  state, or municipal  agency or by any court of law, and shall
immediately begin and diligently proceed to cure the conditions causing any such
violations;  and LESSOR shall permit LESSEE to cure said harm or hazard prior to
any  active   intervention   by  LESSOR  (except  where  such   intervention  is
necessitated by the emergency nature or the harm or hazard; or where the harm or
hazard  impairs the value of the  Building,  (directly or as  collateral  on any
debt);  interferes  with  any  other  tenant's  rights;  or is  required  by any
governmental agency or authority.

         LESSEE shall fully  indemnify and hold  harmless in al respects  LESSOR
from any and all claims, demands,  losses,  liabilities,  and damages (including
all   necessary   and   reasonable   expenses  for   contractors,   consultants,
environmental  engineers,  attorneys, and other professionals utilized by LESSOR
to evaluate  and  remediate  any hazard or harm which  LESSEE has failed to cure
after  written  notice from LESSOR;  and further  including any and all fines or
fees assessed by any  governmental  agency relative to any hazard or harm to the
extent  directly  arising  from the conduct of  LESSEE's  research on the Leased
Premises  (especially  relating to research  involving  hazardous  substances),)
resulting  from  LESSEE's  obligations  and  responsibilities  with  respect  to
compliance with environmental  laws and regulations and LESSEE'S  obligations to
cure,  as set forth above and herein,  except for any claims,  demands,  losses,
liabilities  and damages  resulting from the acts or negligence of LESSOR or its
agents or employees or independent contractors.

         LESSOR hereby  represents  and warrants to LESSEE that the Building and
its heating,  ventilation, air conditioning,  plumbing,  electrical, life safety
and other mechanical  systems and equipment  comply with all applicable  federal
state and municipal laws, ordinances, and regulations. LESSOR shall maintain the
Building  and such  systems  and  equipment  in  compliance  with all such laws,
ordinances and  regulations,  except to the extent governing the use of areas or
premises controlled by LESSEE or any other tenants in the Building.

         LESSOR  hereby  represents  and  warrants  to  LESSEE  that the  Leased
Premises  and the  building of which they are a part,  (inclusive  of the Common
Areas) are, to the best of LESSOR's knowledge, in compliance with all applicable
building,  sanitary  and zoning laws,  ordinances  and  regulations,  (including
current  applicable  provisions of the Americans  with  Disabilities  Act);  and
LESSOR has not been cited with any current and outstanding  violations  thereof.
Additionally,  LESSOR  hereby  represents  and  warrants  relative to the Leased
Premises and the building of which they are a part,  (inclusive of Common Areas)
that it has received no  remediation  notices  pertaining  to, nor are there any
outstanding  violations to the best of its knowledge of, the  provisions of G.L.
c.21E  or  the  Massachusetts  Contingency  Plan;  or  any  other  environmental
remediation statutes or regulations.

         9. FIRE AND OTHER  INSURANCE.  LESSEE  shall not  permit any use of the
Leased Premises which will make voidable,  increase any premium, or decrease any













                                      -10-

insurance on the Building and property of which the Leased  Premises are a part,
or on the  contents  of said  Building,  or which  shall be contrary to any law,
regulation,  or order from time to time  established or issued by the local Fire
Department, or any similar body, or any restriction contained in any of LESSOR'S
insurance  policies as to the Building and property;  provided  however,  LESSOR
represents and warrants that LESSOR's  insurance  policies shall not contain any
restrictions or LESSEE's use of the Premises for office, research and laboratory
purposes  and such use,  per se,,  shall not  render  such  insurance  voidable,
increase any premium,  or decrease any of LESSOR's  coverages.  LESSEE shall, on
demand,  reimburse LESSOR all extra insurance premiums caused by LESSEE's use of
the Leased Premises other than for the office,  research and laboratory purposes
contemplated herein.  LESSEE shall not vacate the Leased Premises or permit same
to be  unoccupied  for more than  thirty  (30) days other than  during  LESSEE's
customary non-business days or hours.

         10.   MAINTENANCE   OBLIGATIONS.   LESSOR  shall   perform  all  normal
maintenance,  repairs and  replacements  necessary to keep in good condition and
working order (a) the roof, foundation,  structural columns and other structural
elements  of the  Building,  (b) the  heating,  ventilation,  air  conditioning,
plumbing,  electrical,  life safety and other  mechanical  systems and equipment
servicing  the  Building or the Common  Areas,  (c) the parking  areas,  (d) the
driveways and walkways  necessary for access to the Building and parking  areas,
(e) the entrances,  lobbies, stairs, passenger elevators and corridors necessary
for access to the Leased Premises,  (f) the loading docks and freight  elevators
in the Building,  (g) the  lavatories  on the fourth  floor,  and (h) the Common
Areas,  generally.  Notwithstanding  the  foregoing,  any  damage  caused to the
building or any of the aforesaid  components caused by the careless,  malicious,
willful, or negligent acts of LESSEE; and chemical, water or corrosion damage on
or  emanating  from the Leased  Premises  from any source  within the control of
LESSEE;  shall be repaired by LESSOR and specifically and separately assessed as
against LESSEE.  LESSEE agrees to maintain at its expense all other elements and
components  to the  Leased  Premises  in the same  condition  as they are at the
commencement of the Term or as they may be put in during the Term of this lease,
normal  wear and tear and  damage by fire or  casualty  or eminent  domain  only
excepted,  and whenever  necessary,  to replace light bulbs (after the first six
months of the term),  plate  glass and other  glass  therein,  acknowledging  by
acceptance of the delivered  Leased Premises as of the Phase I Delivery Date and
Phase II Delivery Date that the Leased  Premises upon delivery are in good order
(except for punchlist items, which are to be completed by LESSOR as contemplated
in  paragraph  33  hereof),  and the light  bulbs and glass  whole.  LESSEE will
properly  control or vent all solvents,  degreasers,  and the like and shall not
cause the area  surrounding  the Leased  Premises to be in anything other than a
neat and  clean  condition,  depositing  all waste in  appropriate  receptacles.
LESSEE shall not permit the Leased Premises to be overloaded,  damaged, stripped
or defaced,  suffer any waste of the Leased Premises.  Any maintenance  which is
the  responsibility  of LESSOR and which is necessitated by some specific aspect
of  LESSEE's  negligent  or  reckless  use of the  Leased  Premises  shall be at
LESSEE's  expense,  except to the extent LESSOR receives  reimbursement  for any
such costs or expenses from an insurer. All maintenance provided by LESSOR shall
be performed as reasonably required at 












                                      -11-

LESSOR's  reasonable  discretion  and except for  emergencies,  during  LESSOR's
normal  business  hours.  LESSEE may not keep any animals on the Leased Premises
without prior written notice to the approval from LESSOR in each instance, which
approval may be denied or conditioned in LESSOR's reasonable discretion.  LESSEE
shall be solely  responsible for maintenance and operation of any and all of its
systems  installed  by or for  the  LESSEE  or  servicing  the  Leased  Premises
exclusively,  and shall waive any and all claims  against LESSOR for any damage,
impairment, or loss relative to these systems unless caused by the negligence or
willful misconduct of LESSOR, its agents, employees and independent contractors.
Specifically,  LESSEE shall maintain,  at its sole expense,  and pay all charges
for  electrical  service  (according to section 7 of this Lease) and use of, the
following:  (a) LESSEE's  customized "cold room" or "warm room" (if any) and all
equipment associated with its operation,  and (b) additional HVAC system (to the
extent of the customization of the LESSOR's  building standard HVAC system;  (c)
backflow preventers (other than the Building's  standard equipment  incorporated
in  the  Building's  general  plumbing  and  life  safety  systems);   (d)  acid
neutralization chip tanks; and (e) any other specialized equipment or mechanical
systems serving the Leased Premises exclusively.

         11.  ALTERATIONS.  LESSEE  shall  not make  structural  alterations  or
additions  of any  kind  to the  Leased  Premises,  but may  make  nonstructural
alterations provided LESSOR consents thereto in writing,  said consent not to be
unreasonably  withheld  or  delayed.  Notwithstanding  the  foregoing,  LESSOR's
consent shall not be required for any non-structural alterations or additions to
the  Leased  Premises  which (a) do not affect the  structural  elements  of the
Building, or the Building's heating, ventilation, or air conditioning, plumbing,
mechanical,  electrical, elevator, life safety or other common systems or Common
Areas of the  Building,  and (b) do not cost more than  $10,000.00 in any single
instance.  Plans and  specifications  shall be  submitted by LESSEE to LESSOR in
each  instance  where consent is required,  in advance of any proposed  work, in
sufficient detail and scope to enable LESSOR to make a reasonable  determination
thereon.  All such allowed alterations shall be at LESSEE's expense and shall be
in quality at least equal to the present  construction.  If LESSOR  performs any
services  for LESSEE in  connection  with such  alterations  or  otherwise,  any
invoice  therefore will be promptly paid.  LESSEE shall not permit any mechanics
liens,  or similar liens,  to remain upon the Leased Premises in connection with
work of any  character  performed  or  claimed  to have  been  performed  at the
direction  of LESSEE and shall  cause any such lien to be  released,  removed or
bonded without cost to LESSOR,  within twenty (20) days after  completion of the
work giving rise to such lien.  LESSEE shall not permit any changes for labor or
materials  secured by any such liens to remain  unpaid for more than thirty (30)
days after  receiving  notice of such charges unless LESSEE protects LESSOR from
any such liens by bond or other  assurances  reasonably  satisfactory to LESSOR.
Any  alterations  completed by LESSEE,  including,  without  limitation,  window
blinds or other  window  treatment,  shall be building  standard  unless  LESSOR
expressly agrees otherwise,  which agreement shall not be unreasonably  withheld
or delayed. LESSOR shall have the right at any time to change the arrangement of
parking areas,  stairs,  walkways or other common areas of the








                                      -12-

Building of which the Leased  Premises are a part,  provided such changes do not
interfere with LESSEE's use or access to such areas and facilities.

         Notwithstanding  the foregoing,  prior to the  commencement of the Term
hereof,  and pursuant to Section 33, LESSOR shall, at its sole cost and expense,
deliver the Leased Premises "as is" but  nevertheless  such that they conform to
LESSOR'S  standard  Building  specifications,  except that  LESSOR  specifically
agrees that prior to its delivery of the Premises to the LESSEE, LESSOR shall at
its sole cost and expense: Repaint the Premises; repair/replace carpeting as and
where necessary based on extraordinary  current wear; and prepare LESSOR's basic
and standard  infrastructure  for LESSEE's  laboratory  space,  and otherwise to
construct  and install the  alterations  contained  within  LESSOR's Work as set
forth more  specifically  in section 33 of this Lease.  The space  delivered  to
LESSEE  shall be as set  forth on the  space  plan and  specifications  attached
hereto as Exhibit C. All laboratory  equipment,  (not  specifically  included in
LESSOR's Work as contemplated by paragraph 33 hereof), including but not limited
to hoods,  vacuum pumps and RODI water system(s) shall be provided and installed
at LESSEE's sole cost and expense.

         12.  ASSIGNMENT,  SUBLETTING.  LESSEE covenants and agrees that neither
this Lease,  nor the estate  hereby  granted,  nor any interest  therein will be
assigned,  mortgaged,  pledged,  encumbered or otherwise  transferred,  and that
neither the Leased  Premises,  nor any part  thereof,  will be encumbered in any
manner by reason or by act or omission (where LESSEE has a legal duty to act) of
LESSEE,  or used or occupied,  or  permitted  to be used or occupied,  by anyone
other than LESSEE, its servants, agents and employees, or for any use or purpose
other than as above stated,  or be sublet,  without in each case LESSOR's  prior
written consent, which shall not be unreasonably  withheld.  Notwithstanding the
foregoing, LESSEE shall have the right, without the prior consent of the LESSOR,
to assign  this Lease and to sublet any  portion of the Leased  Premises  to any
person or entity (a)  controlling,  controlled  by, or under common control with
LESSEE,  (b) acquiring all or substantially  all of the assets of the LESSEE, or
(c) with or into which LESSEE merges or consolidates;  provided in each instance
the LESSEE shall remain at all times  directly,  primarily and severally  liable
for the  performance of all terms and  conditions of this Lease,  in conjunction
with any other such entity.

         The grounds upon which LESSOR may  reasonably  withhold its consent are
as follows:

         (i) The  prospective  assignee's  or  sublessee's  intended  use of the
Premises is not identical to the permitted uses set forth in the Lease; or,

         (ii) The nature,  character,  class and  standards  of the  prospective
assignee's or  sublessee's  business will not be consistent  with those of other
lessees in the  Building or will not conform to the mix of other  lessees in the
Building at that time; or,







                                      -13-

         (iii) The  financial  net worth,  and  reliability  of the  prospective
assignee or sublessee,  including any additional  written and direct personal or
corporate  guarantees,  is  not  in  Landlord's  reasonable  judgment  at  least
equivalent  to that of DynaGen,  Inc. as measured at the point of  execution  of
this Lease;  (provided however that if the proposed  assignment or sublet occurs
during the  Extended  Term (i.e.  after the original  five (5) years),  then the
financial net worth of the prospective assignee or sublessee shall be equivalent
to that of DynaGen,  Inc. as measured at the point of  execution  of this Lease,
but said net worth  standard  to be  adjusted by  increasing  by the  cumulative
increases in the Consumer Price Index, All Items, All Urban,  occurring from the
date of this Lease to the date of the proposed  assignment or  subletting).  The
prospective  assignee  or  sub-lessee  must  produce to LESSOR if  available,  a
verified and current audited financial  statement  prepared within the then past
three years,  (or if non has been prepared by said  prospective  assignee within
the then past three years, a CPA certified  current  financial  statement);  and
such  other   reasonable   documentation   as  is  material  in  making  such  a
determination; or,

         (iv) The  operations of the  prospective  assignee or  sub-lessee  will
violate any  exclusive or other rights given any other  lessees in the Building;
or,

         (v) The failure of LESSOR's mortgage lender(s) to consent.

         LESSOR,  in addition to Annual Base Rent and Additional  Rent, shall be
entitled to the full amount of any and all sums  assessed or collected by LESSEE
in whatever form,  attributable  to the assignment or sublease or other transfer
of LESSEE's interest in this Lease or the Leased Premises (except for a sublease
under clause (ii) below),  which exceed said Annual Base Rent or Additional Rent
hereunder,  (therein,  "Rent Mark-Up"),  after deduction of LESSEE's  reasonable
costs and expenses to procure said assignment or sublet, including brokers' fees
and commissions,  attorneys' fees, and any build-out costs (approved by Landlord
in advance,  said approval not to be  unreasonably  withheld or delayed),  which
costs and expenses shall in no event be deducted from any payments to LESSOR due
in the form of Annual Base Rent,  Additional Operating Expense Rent,  Additional
Tax Escalation Rent, or other sums payable to LESSOR under this Lease other than
the aforesaid excess amount on assignment or subletting.

         Notwithstanding  any LESSOR's  consent to any assignment or subletting,
as contemplated  above, or in any circumstances  other than a LESSOR's recapture
of the entire  premises as  contemplated  below,  LESSEE shall remain  primarily
liable to LESSOR  for the  payment  of all  Annual  Base Rent and all other Rent
hereunder,  and for the full performance of the covenants and conditions of this
Lease to be performed  by LESSEE;  and after a default by LESSEE in such payment
or performance  which  continues  after any  applicable  notice and cure period,
LESSOR may collect all sums due as Annual Base Rent or other Rent  directly from
the assignee or subtenant.








                                      -14-

         Notwithstanding  the  foregoing,  in the event that  LESSEE  desires to
sublet any portion of the Leased Premises, then the following shall apply:

         (i) if the proposed  sublet is on the basis where a demising wall is to
be erected by LESSEE or the  subtenant,  separating  their spaces in whole or in
part,  pursuant to an agreement with a bona fide third party  subtenant,  at any
time during the sublet, then LESSOR shall be granted its Recapture Rights as set
forth below as the portion of the Leased Premises to be so sublet; or,

         (ii) if the  proposed  sublet is on the basis  where  there  will be no
demising  wall  erected,  separating  their spaces in whole or in part,  and the
subtenant  is  reasonably  expected  to utilize up to (but not more than)  fifty
(50%) percent of the facilities  comprising the Leased  Premises,  then LESSOR's
Recapture Rights shall not apply; or,

         (iii) if the  proposed  sublet is on the basis  where  there will be no
demising  wall  erected,  separating  their spaces in whole or in part,  and the
subtenant is reasonably expected to utilize more than fifty (50%) percent of the
facilities comprising the Leased Premises,  then LESSOR's Recapture rights shall
apply as to the entire Leased Premises.

         In all  instances  set forth above where  reference is made to LESSOR's
Recapture Rights,  those rights shall consist of the following:  LESSEE, in each
instance where  Landlord's  Recapture  Rights apply,  shall notify the LESSOR in
writing,  stating its  intention  to sublet and the target date of the  proposed
sublet (which shall not be less than one hundred twenty (120) days from the date
of said notice to LESSOR).  LESSOR  shall have a period of ninety (90) days from
the date it receives  such notice to  exercise  an  election to  recapture  that
portion of the Leased  Premises to be sublet,  in LESSOR's sole  discretion  and
without  any   obligation   to  so  elect,   whatsoever,   notwithstanding   the
circumstances,  and without  prejudice to or waiver of any of LESSOR's rights or
LESSEE's continuing obligations hereunder.  LESSEE shall provide LESSOR with all
material  information  relative to LESSOR making an informed decision concerning
said sublet,  immediately upon LESSOR's  request.  If LESSOR elects to recapture
the Leased  Premises  (or  applicable  portion  thereof),  it shall send written
notice thereof to LESSEE; and LESSEE shall be irrevocably bound to surrender and
vacate the Leased Premises (or applicable  portion thereof) as if the Lease Term
had expired on the date set forth in the LESSEE's initial notice to LESSOR;  and
provided LESSEE vacates and surrenders on said date, without being in default of
any  provision  hereof as of said date,  this  Lease  shall be null and void and
without   recourse  to  either  party  hereto  (but  for  terms  and  conditions
contemplated herein to survive  termination of this Lease).  LESSEE shall not be
entitled to any payments,  commissions,  credits, offsets, or any kind or nature
arising from said sublet, nor shall any individual or entity acting by, through,
or under LESSEE be so entitled. Once an election to recapture is made by LESSOR,
LESSEE  shall be subject to the  penalties  for  holding  over set forth in this
Lease,  if it fails to vacate and surrender the Leased  Premises (or  applicable
portion  thereof) by the date stated in the notice,  or if it fails to discharge
(or cause its lenders or others with which  LESSEE has dealt to  discharge)  any
and all liens or other  encumbrances,  notices, or restrictions on its leasehold








                                      -15-


or contractual  interest in and to the Leased Premises as of said date.  Nothing
in this  section  or  paragraph  shall  require  LESSOR to make an  election  to
recapture the Leased Premises (or applicable  portion  thereof),  and nothing in
the aforesaid  process shall  relieve  LESSEE of its inability  under this Lease
should LESSOR elect not to take back the Leased Premises (or applicable  portion
thereof).  Notwithstanding  the foregoing,  LESSEE shall have ten (10) days from
LESSOR's notice of its election to recapture, to withdraw its proposal to sublet
in writing delivered to LESSOR,  whereupon the LESSOR's election shall be deemed
rescinded and LESSEE shall remain in the Leased Premises, without sublet. LESSEE
may only  exercise  this  withdrawal  right a maximum of once  within each Lease
Year.  Should  LESSOR elect not to recapture  the Leased  Premises,  then LESSEE
shall have a period of one hundred  twenty  (120) days from the date of LESSOR's
notice of such election (or if LESSOR  delivers no notice of any election,  then
one hundred  twenty (120) days from the  expiration of LESSOR's  ninety (90) day
response period) to execute its sublease  agreement and commence the subtenancy,
without the necessity for any  additional  notices to LESSOR under this section.
New  notice by  LESSEE to LESSOR  shall be  required  after  expiration  of said
one-hundred  twenty (120) day period.  Time is of the essence in all notices and
elections made hereunder.

         13.  SUBORDINATION.  This Lease shall be subject and subordinate to any
and all instruments of record, mortgages, and other instruments in the nature of
a mortgage,  extant or coming into existence at any time  hereafter,  and LESSEE
shall, when requested, promptly within fifteen (15) days of request, execute and
deliver  such  written  instruments  (on  LESSOR's  lender's  form)  as shall be
necessary to show the subordination of this Lease to said instruments of record,
mortgages, or other such instruments in the nature of a mortgage.  LESSOR, prior
to the Phase I Delivery Date and within 21 days of any refinancing or additional
financing  of  the  building  and/or  property,  shall  provide  LESSEE  with  a
Non-Disturbance,  Attornment and Subordination Agreement, recognizing the rights
of LESSEE under this Lease. LESSEE acknowledges that an agreement  substantially
in  the  form  attached  hereto  as  Exhibit  G,  shall  satisfy  the  foregoing
requirements.

         14. LESSOR'S ACCESS. LESSOR or agents of LESSOR may at reasonable times
and upon advance  reasonable  notice (except in emergency  situations)  enter to
view the Leased  Premises  and may remove any signs not  approved and affixed as
herein provided,  and may make repairs and alterations as LESSOR should elect to
do and repairs  which  LESSEE is  required  but has failed to do (but only after
notice  and an  opportunity  to  repair  being  provided  to LESSEE  within  the
applicable  cure period under this Lease),  and may show the Leased  Premises to
prospective mortgagees,  appraisers, brokers, prospective purchasers, and within
twelve months of the expiration of the Term or on any default other  prospective
tenants.  Additionally,  to the extent  necessary to service other  portions the
Premises or the Common Areas or other tenant spaces in the Building;  LESSOR may
add,  relocate,  or  maintain a chase,  pipes,  conduits,  or ducts,  within the
Premises provided the aforesaid do not materially interfere with LESSEE's use of
the Premises or its aesthetics.  Any entry by LESSOR,  its agents,  employees or
independent contractors onto the Premises under this section 14 shall be done in
such manner as to 








                                      -16-

minimally   interfere  with  the  business  conducted  thereon  by  LESSEE,  and
undertaken with reasonable steps to protect LESSEE's property.

         15. SNOW REMOVAL. LESSOR, at its sole expense, shall keep the walkways,
sidewalks,  entry  ways  and  parking  areas  reasonably  clear of snow and ice.
Notwithstanding the foregoing,  however,  LESSEE shall hold LESSOR harmless from
any and all claims by LESSEE's  agents,  representatives,  employees or business
invitees for damage or personal injury  resulting in any way from snow or ice on
any area servicing the Building, unless such claims arise from the negligence or
willful   misconduct  of  LESSOR  or  its  agents,   employees  or   independent
contractors.

         16. ACCESS AND PARKING.  LESSEE shall be granted the right,  at current
rates (which may be increased form time to time to reflect market increases,  to
park twelve (12) cars in the  building's  on-site indoor parking lot or facility
in  single or  tandem  spaces,  or on a valet  basis,  which  LESSOR in its sole
discretion  shall designate from time to time; (at all times hereunder LESSEE to
be entitled to four single  spaces from among those  twelve).  LESSOR  initially
designates  an  appropriate  proportion of the same single and tandem area as is
used by the lessee  presently  vacating the  Building,  as the LESSEE's  initial
parking area. The initial parking rate therefore shall be $100.00 per month, per
car,  which monthly rate shall be subject to and  reflective of periodic  market
changes.  Additionally,  LESSEE  shall be  entitled  to twelve  (12)  additional
parking  spaces in the  garage  (not  owned by  LESSOR)  at 808  Memorial  Drive
Cambridge,  so long as they are  available  to  LESSOR  during  the Term of this
Lease,  at an initial  parking rate of $90.00 per month,  per car, which monthly
rate shall be subject to and  reflective  of  periodic  market  changes and upon
thirty (30) days prior written notice to LESSEE.  Said garage, lot, or facility,
as the case may be,  plus any  stairs,  walkways  or other  means of  ingress or
egress  controlled by the Lessor shall not in any case be considered  extensions
on the Leased  Premises.  LESSEE will not  obstruct in any manner any portion of
the Building or the walkways or approaches to the Building,  and will conform to
all reasonable and non-discriminatory  rules now or hereafter made by LESSOR for
parking,  (but which rules shall in no event limit  LESSEE's right to its twelve
(12) indoor parking spaces), and for the access and egress, security, care, use,
or alteration of the Building,  its  facilities and  approaches.  LESSEE further
warrants  that LESSEE will not permit any employee or visitor to violate this or
any other covenant or obligation of LESSEE.  No vehicles shall be stored or left
in any  parking  area  for more  than  three  nights  without  LESSOR's  written
approval.  Unregistered or disabled  vehicles,  or storage trailers of any type,
may not be parked  overnight  any time.  LESSEE agrees to assume all expense and
risk for the towing of any  misparked  vehicle  belonging  to LESSEE or LESSEE's
agents,  employees,  business invitees, or callers, at any time. For the purpose
of this  section  the term  "space"  shall  mean  general  access  for one motor
vehicle.  All vehicles shall be parked and left on the premises at their owners'
sole risk and LESSOR shall not be liable for any damages caused to said vehicles
while they are parked or left on the premises.

         Additionally,  both parties  acknowledging that the garage is currently
full,  LESSOR shall make reasonable  efforts to provide an additional  number of
parking spaces within the 








                                      -17-

Building's  garage, as such spaces may become available in the future;  however,
LESSOR shall not be obligated to violate any other  exclusive  rights granted in
existing or future leases.

         17. LESSEE'S AND LESSOR'S LIABILITY  INSURANCE.  LESSEE shall be solely
responsible as between LESSOR and LESSEE for deaths or personal  injuries to all
persons  whomsoever  caused  or  occurring  in or on the  Leased  Premises  from
whatever  cause  arising,  (unless  caused by the negligent acts or omissions or
willful   misconduct  of  LESSOR  or  its   employees,   agents  or  independent
contractors), and damage to property to whomsoever belonging caused or occurring
in or on the Leased  Premises  to the extent  arising  out of the use,  control,
condition or occupation of the Leased  Premises by LESSEE  (except to the extent
such damage arises out of the negligence or willful  misconduct of LESSOR or its
employees,  agents, or independent contractors);  and LESSEE agrees to indemnify
and save  harmless  LESSOR  from  any and all  liability,  reasonable  expenses,
damage,  causes of action, suits, claims or judgments caused by any such deaths,
personal  injuries  or  damages  to  property,  except to  extent  caused by the
negligence or willful misconduct of LESSOR, its employees, agents or independent
contractors.  During  the Lease  Term  LESSEE  will  secure and carry at its own
expense a  comprehensive  general  liability  policy insuring LESSEE against any
claims based on bodily injury  (including death) arising out of the condition of
the Leased Premises or their use by LESSEE, such policy to insure LESSEE against
any claim up to One Million  ($1,000,000.) Dollars for personal injury or damage
to property.  LESSOR and its lenders (of which LESSEE is given  written  notice)
shall be included in such policy as additional insureds,  as their interests may
appear,  from time to time.  LESSEE will promptly file with LESSOR  certificates
showing  that such  insurance  is in force,  and  thereafter  will file  renewal
certificates  prior to the expiration of any such  policies.  All such insurance
certificates  shall provide that such policies shall not be canceled  without at
least thirty (30) days prior written notice to each insured named therein.

         During  the Lease Term  LESSOR  shall  secure and  maintain a policy of
commercial general liability insurance covering LESSOR on an occurrence basis in
an  amount  not less  than  $1,000,000.00  for  claims  based on  bodily  injury
(including death), personal injury, and property damage relating to the Building
and the  property on which the  building is located;  and a policy of  insurance
covering  the  building  and other  improvements  on the  property  on which the
building is located for direct risk of physical loss on an occurrence  basis, in
an  amount  equal to the  replacement  costs  of the  Building  and  such  other
improvements  (exclusive  of tenant  improvements  owned by such  tenants) in at
least the minimums required by LESSOR's lendors.

         LESSOR and LESSEE  covenant that with respect to any  insurance  policy
required hereunder to be carried by either, such insurance shall provide for the
waiver by the insurance  carrier of any  subrogation  rights  against the other;
where such  waiver of  subrogation  rights  does not  require  the payment of an
additional  premium or, if an  additional  premium is required,  the other party
pays such premium  within a reasonable  time after written  notice thereof if it
elects to have the benefits of such protection.









                                      -18-

         18. FIRE, CASUALTY, EMINENT DOMAIN. Should a substantial portion of the
Leased  Premises,  or of the property of which they are a part, be substantially
damaged by fire or other  casualty,  or be taken by eminent  domain,  LESSOR may
elect to terminate  this Lease by written  notice to LESSEE  within  ninety (90)
days after such damage occurs,  provided LESSOR  terminates the leases for other
tenants in the  Building,  similarly  affected by such  damage.  When such fire,
casualty,  or taking renders the Leased  Premises  substantially  unsuitable for
their  intended use and no  termination  has been elected by LESSOR,  a just and
proportionate abatement of rent shall be made from the date of such damage until
repairs  have been  substantially  completed,  and LESSEE may elect to terminate
this Lease if: (a) LESSOR fails to give written  notice  within ninety (90) days
of  intention  to restore  Leased  Premises,  or (b) LESSOR fails to restore the
Leased  Premises to a condition  substantially  suitable for their  intended use
within one hundred  eighty (180) days of said fire,  casualty or taking.  LESSOR
reserves  all rights for all  damages or injury to the Leased  Premises  for any
taking by  eminent  domain;  except for damage to  LESSEE's  moveable  fixtures,
property or equipment,  or moving expenses,  which are specifically allocated to
LESSEE by the taking authority or arbitrators.

         19.  BROKERAGE.  LESSEE and LESSOR each warrants and  represents to the
other that they have dealt with no broker or third  person with  respect to this
Lease or the Leased Premises or Building entitled to a commission as a result of
this Lease  other than The Abbey Corp and  Fallen  Hines &  O'Connor,  whose fee
shall be paid by LESSOR;  and LESSOR and LESSEE each agree to indemnify and hold
harmless the other from any fees,  expenses,  or damages  arising from breach of
the above warranty.

         20. SIGNS. LESSEE shall have the right to have its name included on any
central  directory  maintained by LESSOR listing the  building's  other tenants.
LESSOR  authorizes  LESSEE,  if  desired,  to display  one sign  (which may bear
LESSEE's logo) on LESSEE's office entrance door consistent with similar signs of
other tenants. LESSEE shall obtain the written consent of LESSOR before erecting
any sign on the Leased Premises,  which consent may be conditioned on compliance
with  LESSOR's  requests as to size,  wording,  and location of such signs,  but
which shall not be unreasonably withheld or delayed.

         21.  DEFAULT,  BANKRUPTCY AND  ACCELERATION OF RENT. In the event that:
(a)  LESSEE  shall  default  in the  payment  of  the  security  deposit  or any
installment  of Annual Base Rent or any  Additional  Operating  Expense  Rent or
Additional  Tax  Escalation  Rent or other  Rent or other  payments  due  LESSOR
hereunder,  and such  default  shall  continue  for ten (10) days after  written
notice thereof;  or (b) LESSEE shall default in the observance or performance of
any other of LESSEE's covenants,  agreements,  or obligations hereunder and such
default  shall not be corrected  within  thirty (30) days after  written  notice
thereof,  or such longer  period as is necessary to  effectuate a cure  provided
LESSEE  promptly  proceeds to cure and  diligently  pursues such  resolution  to
completion,  but not longer than ninety (90) days;  (c) LESSEE shall be declared
bankrupt or  insolvent  according  to law, or if any  voluntary  or  involuntary
petition 






                                      -19-

for bankruptcy is filed against  LESSEE and not  discharged  within 60 days from
filing;  or if any assignment shall be made of LESSEE's property for the benefit
of creditors;  then, while such default continues, and without demand or further
notice,  LESSOR shall have the right to re-enter and take complete possession of
the Leased  Premises,  to declare  the term of this Lease  ended,  and to remove
LESSEE's  effects,  without  being  guilty of any manner of trespass and without
prejudice to any remedies  which might be otherwise  used for arrears of rent or
other default or breach of covenant.  LESSEE shall indemnify  LESSOR against all
loss of Annual Base Rent,  Additional Operating Expense Rent, and Additional Tax
Escalation  Rent and all other payments which LESSOR may incur by reason of such
termination  during  the  remainder  of  the  Lease  Term,  it  being  expressly
understood that LESSOR shall use reasonable efforts to relet the Leased Premises
and  collect  all rents from such  reletting.  If LESSEE  shall  default,  after
reasonable notice thereof, in the observance or performance of any conditions or
covenants on LESSEE's part to be observed or performed under or by virtue of any
one of the provisions in any section of this Lease, LESSOR,  without being under
any  obligation to do so and without  thereby  waiving such  default,  may after
notice to LESSEE and the expiration of any applicable  cure period,  remedy same
for the  account  and at the  expense of LESSEE  (including  but not  limited to
application  of any or all of the Security  Deposit held by LESSOR in accordance
with section 5 of this Lease).  If LESSOR pays or incurs any obligations for the
payment  of  money  in  connection  therewith,  including  but  not  limited  to
reasonable  attorney's fees in instituting,  prosecuting or defending any action
or proceeding, such sums paid or obligations incurred, with interest at the rate
of fifteen  percent  per annum and  costs,  shall be paid to LESSOR by LESSEE as
additional  rent. Upon default of this Lease by LESSEE,  and because the payment
of Rent in monthly  installments  is for the sole  convenience  of  LESSEE,  the
entire  balance  of Rent which  would  accrue  hereunder  shall at the option of
LESSOR  become  immediately  due and payable.  LESSOR  hereby  acknowledges  its
obligation  to  mitigate  its  damages  in the  event of a  default  by  LESSEE.
Notwithstanding the foregoing,  LESSEE agrees to pay reasonable  attorney's fees
incurred by LESSOR in  enforcing  any or all  obligations  of LESSEE  under this
Lease at any time.

         22.  NOTICE.  Any notice from  LESSOR to LESSEE  relating to the Leased
Premises or to the occupancy  thereof shall be deemed duly served if left at the
Leased  Premises  addressed  to  LESSEE,  or if sent to the Leased  Premises  by
certified mail, return receipt requested,  postage prepaid, addressed to LESSEE;
with a copy to  Testa,  Hurwitz  &  Thibeault,  LLP,  125 High  Street,  Boston,
Massachusetts  02110.  Any notice from  LESSEE to LESSOR  relating to the Leased
Premises or to the occupancy thereof shall be deemed duly served if delivered to
LESSOR by certified mail, return receipt requested,  postage prepaid,  addressed
to: The Abbey Corp.,  575 Boylston  Street,  Boston,  Massachusetts  02116 or at
LESSOR's last address  designated by written  notice to LESSEE.  Notice shall be
deemed  given at the earlier of the date of actual  delivery or if by  certified
mail,  three (3) business days after posting with the U.S. Postal Service.  Time
is of the  essence  in  delivery  of any  notice,  and  the  performance  of any
obligations relating thereto.












                                      -20-

         23.  OCCUPANCY.  In the event that LESSEE remains on the Premises after
the agreed  termination  date of this Lease  without the written  permission  of
LESSOR,  then all other terms of this Lease shall continue to apply, except that
LESSEE shall be liable to LESSOR for any loss,  damages or expenses  incurred by
LESSOR,  and all Annual  Base Rent and other  Rent shall be due in full  monthly
installments  at a rate of three  hundred  (300%)  percent of that  which  would
otherwise be due under this lease, it being understood  between the parties that
such extended  occupancy as a tenant at sufferance is solely for the benefit and
convenience of LESSEE.

         24. RULES AND  REGULATIONS.  LESSEE and LESSEE's  servants,  employees,
agents, invitees and licensees shall observe faithfully and comply strictly with
such reasonable and  non-discriminatory  rules and regulations governing the use
of the  Building  and site and all common areas as LESSOR may from time to time,
adopt,  provided  LESSEE  receives  reasonable  advance notice of such rules and
regulations  and such rules and  regulations  do not  conflict  with the express
provisions  of this Lease or  unreasonably  interfere  with  LESSEE's use of the
Leased Premises for its permitted purposes hereunder.

         25. OUTSIDE AREA. No goods or things of any type or  description  shall
be held or stored  outside the Leased  Premises at any time  without the express
written  approval of LESSOR,  except  bicycles which shall be stored only in the
bicycle rack to be provided by LESSOR.

         26. ENVIRONMENT. LESSEE will so conduct and operate the Leased Premises
as not to interfere in any way with the use and  enjoyment of other  portions of
the same or  neighboring  buildings  by others,  by reason of  offensive  odors,
smells,  noise,  accumulation  of  garbage  or trash,  vermin or other  pests or
otherwise and will, at its expense,  employ a professional  pest control service
if  necessary  as a result of  LESSEE's  operations.  LESSEE  agrees to maintain
efficient and effective device for preventing  damage to heating  equipment from
harmful  solvents,  degreasers,  cutting oils,  and the like,  which may be used
within the Leased  Premises.  No  hazardous  wastes,  radioactive  materials  or
chemical or harmful  biological  agents or materials of any sort shall be stored
or  allowed  to remain  within the Leased  Premises  at any time,  except  after
written  notice to LESSOR,  with  LESSEE  providing  a general  list of all such
substances  inclusive of approximate  quantities  and "MSDS"  sheets;  LESSEE to
comply  at all  times  with all  applicable  federal,  state,  and  local  laws,
ordinances,  regulations and administrative  orders governing the use, handling,
storage,  transportation and disposal of all such materials, as well as LESSOR's
rules and  regulations  governing  the  handling,  storage,  transportation  and
disposal  of all such  materials  within the  Building  and Common  Areas,  said
LESSOR's   rules  and   regulations  to  be   administered   in  a  uniform  and
non-discriminatory manner as to all tenants similarly situated.

         Prior to  vacating  the Leased  Premises at the end of the Term (or any
applicable extension), or sooner in the event of a default hereunder,  LESSEE at
its sole cost and expense shall provide  LESSOR and Owner with an  environmental
audit by a qualified







                                      -21-

environmental   engineering   firm   satisfactory   to  LESSOR.   The  aforesaid
environmental  audits shall duly  recognize the substances and materials used by
the LESSEE in its laboratory and office operations on the Leased Premises during
the  Lease  Term  (the  "Known  Substances"),  and  shall  confirm  to  LESSOR's
reasonable  satisfaction  that the  Leased  Premises  are free  from any and all
contaminants,  pollutants, radioactive materials, hazardous wastes or materials,
bacteriological  agents or organisms  which would render the Leased  Premises in
violation of G.L. c. 21E,  CERCLA,  or SARA, or any  regulations  of the NRC, as
they may be amended, or supplemented by administrative regulations, from time to
time;  arising  from  and  based  on  the  Known  Substances.  LESSEE  shall  be
responsible  to  LESSOR  (and  any  Lenders  to the  Building)  for  any and all
environmental  hazards or conditions  which  preclude or condition the foregoing
confirmation  due from LESSEE as contemplated  above, to the extent said hazards
or conditions are reasonably  attributable to the Known  Substances and LESSEE's
activities and use of their space.

         27. RESPONSIBILITY.  LESSOR shall not be held liable to anyone for loss
or  damage  caused  in any way by the use,  leakage  or  escape  of water or for
cessation  of any  service  rendered  customarily  to said  Leased  Premises  or
buildings or agreed to by the terms of this Lease,  due to any accident,  to the
making of repairs, alterations or improvements,  to labor difficulties,  weather
conditions,  or mechanical breakdowns, to trouble or scarcity in obtaining fuel,
electricity,  service or supplies  from the sources  from which they are usually
obtained  for said  building,  or to any cause  beyond the  LESSOR's  reasonable
immediate  control,  except to the extent  that such loss or damage is caused by
the  negligence  or willful  misconduct of LESSOR or its agents,  employees,  or
independent contractors.

         28.  SURRENDER.  LESSEE shall at the expiration or other termination of
this Lease remove all of LESSEE's personal property,  goods and effects from the
Leased  Premises.  LESSEE  shall  deliver to LESSOR the Leased  Premises and all
keys,  locks,  thereto,  and other  fixtures and equipment  connected  therewith
(excluding LESSEE's trade fixtures and equipment) and all alterations, additions
and improvements made to or upon the Leased Premises,  including but not limited
to any plumbing and plumbing fixtures,  air conditioning  equipment and ductwork
of any type, exhaust fans or heaters, water coolers,  burglar alarms,  telephone
wiring,  telephone  equipment,  wooden or metal  shelving which has been bolted,
welded or otherwise  attached to any  concrete or steel member of the  Building,
compressors,  air or gas distribution piping, and all electrical work, including
but not  limited  to  lighting  fixtures  of any  type,  wiring,  conduit,  EMT,
distribution panels, bus ducts, raceways,  outlets and disconnects to the extent
that LESSOR  constructs or installs such  fixtures,  alterations,  additions and
improvements at LESSOR's expense. Notwithstanding any contrary provision of this
Lease,  at the end of the Lease Term, and absent any default,  LESSEE shall have
the right to remove from the Leased  Premises  its trade  fixtures  and personal
property and any fixtures, alterations,  additions and improvements installed by
LESSEE or at LESSEE's  cost and expense  subsequent  to the  Commencement  Date,
including  without  limitation  the fixtures and  equipment  listed on Exhibit F
hereto,  provided  that LESSEE  shall  repair any damage to the Leased  Premises
caused thereby. LESSEE shall deliver the Leased Premises in as good condition as








                                      -22-

existed on the Commencement  Date,  reasonable wear and tear and damage by fire,
eminent  domain,  or other  casualty  only  excepted.  In the event of  LESSEE's
failure to remove any of LESSEE's  property from the premises,  LESSOR is hereby
authorized,  without  liability to LESSEE for loss or damages thereto and at the
sole risk of LESSEE to remove and store any such  property at LESSEE's  expense,
or to retain same under  LESSOR's  control or to sell at public or private sale,
any or all of the  property not so removed and to apply the net proceeds of such
sale to the payment of any sum due hereunder,  or to destroy such property which
shall be conclusively deemed to have been abandoned.

         29. QUIET  ENJOYMENT.  So long as LESSEE  keeps,  observes and performs
each of the terms herein  contained  on the part of LESSEE to be kept,  observed
and performed,  LESSEE shall quietly enjoy the Leased Premises without hindrance
or  molestation  by LESSOR,  or any party  claiming any interest in the Building
under or through the LESSOR.

         30. LESSOR'S SERVICES.  LESSOR will provide elevator facilities serving
the Leased Premises at all times, subject to reasonable security regulations for
use at times  other than  Normal  Business  Hours.  LESSOR  shall,  at  LESSOR's
expense,  furnish  LESSEE such  cleaning  service as is  described  in Exhibit D
hereto.  Except as set forth on Exhibit D, LESSOR shall not be  responsible  for
cleaning LESSEE's research laboratories.

         31.  GENERAL.  The invalidity or  unenforceability  of any provision of
this  Lease  shall not  affect  or render  invalid  or  unenforceable  any other
provision  hereof.  The  obligations  of this Lease shall run with the land, and
this Lease shall be binding upon and inure to the benefit of the parties  hereto
and their respective successors and assigns,  except that LESSOR shall be liable
only for  obligations  during  LESSOR's  ownership of the Building or Landlord's
interest  under this Lease,  occurring  as of the  beginning of the term of this
Lease,  or thereafter  while LESSOR of the entire  Property.  The obligations of
LESSOR shall not be binding upon any director,  officer,  shareholder,  partner,
trustee or  beneficiary  of LESSOR.  Notwithstanding  the  definition  herein of
"Commencement  Date," "Termination Date," or "Term," or LESSOR's  obligations to
deliver the Premises, this Lease shall be binding and enforceable as against the
parties hereto as of the date of its execution.

         32. WAIVERS,  ETC. No consent or waiver,  express or implied, by LESSOR
or  LESSEE,  to or of any  other  breach  of the  other  party of any  covenant,
condition  or duty of that party shall be construed as a consent or waiver to or
of any other breach of the same or any other  covenant,  condition  or duty.  If
LESSEE is several  persons or a partnership,  LESSEE's  obligations are joint or
partnership  and also  several.  Unless  repugnant to the context,  "LESSOR" and
"LESSEE" mean the person or persons, natural or corporate, named above as LESSOR
and  as  LESSEE   respectively,   and   their   respective   heirs,   executors,
administrators, successors and assigns.











                                      -23-

         33. LESSOR'S OBLIGATION TO "BUILD OUT" AND DELIVER LEASED PREMISES. The
Leased   Premises   shall  be  delivered  in  an  "as  is"   condition   without
representation  or warranty as to the  suitability  of the Leased  Premises  for
LESSEE's  particular  uses  and  activities  (but  for the  representations  and
warranties set forth in paragraph 8 hereof); except that the LESSOR, at LESSOR's
expense,  shall:  Repaint the  Premises;  repair/replace  carpeting as and where
necessary  based on its current wear to put the carpeting in the Leased Premises
in good  condition;  prepare  LESSOR's  basic and  standard  infrastructure  for
LESSEE's  laboratory space; and provide lighting and electrical  distribution in
the Premises in accordance with the building standards;  as further set forth in
paragraph  11 hereof;  and  otherwise  construct  and install  the  alterations,
improvements, fixtures and equipment shown and or described on Exhibit C (in its
component parts,  inclusive of "Addendum to Exhibit C"),  attached to this Lease
(collectively,  the "LESSOR's Work"). Any specialized  construction  required to
satisfy LESSEE's laboratory needs shall be LESSEE's sole responsibility (and may
be provided by LESSOR based on separate agreement as to cost and timing),  (See,
separate schedule of additional costs dated June 18, 1997 and attached at end of
Exhibit C).

         LESSOR  shall  perform its  LESSOR's  Work on the  Premises,  and shall
deliver said Premises  subsequent to completion of LESSOR's Work, in two phases:
"Phase  I" shall  consist  of  LESSOR's  Work on the  portions  of the  Premises
dedicated  to office and general use (i.e.,  the "Office  Space"  consisting  of
approximately  9,759  square  feet as shown on  Exhibit A - 1  attached  to this
Lease) and other portions of the Building  common areas needed for LESSEE to use
and occupy the Office Space; and "Phase II" shall consist of LESSOR's Work other
than as  included  in Phase I (i.e.,  approximately  2,503  square  feet  mostly
dedicated to laboratory  use). Upon  substantial  completion of LESSOR's Work in
Phase I, it shall  notify  LESSEE in  writing,  in the form  attached  hereto as
Exhibit E - 1, of the  completion of said LESSOR's Work and the delivery of that
portion of the Premises to LESSEE.  The date of  completion  of LESSOR's Work as
stated on said notice to LESSEE is  referred to as the "Phase I Delivery  Date."
Upon substantial completion of LESSOR's Work in Phase II, it shall notify LESSEE
in writing,  in the form attached  hereto as Exhibit E - 2, of the completion of
said  LESSOR's  Work and the delivery of that portion of the Premises to LESSEE.
The date of  completion  of LESSOR's  Work as stated on said notice to LESSEE is
referred to as the "Phase II Delivery Date."

         LESSOR  shall  deliver  its  Phase I  Delivery  Date  notice  upon  its
completion  of LESSOR's  Work on Phase I, on or about  September  1, 1997 but no
later than  September  15, 1997;  and LESSOR shall deliver its Phase II Delivery
Date notice upon  LESSOR's  completion  of LESSOR's Work on Phase II on or about
October 1, 1997,  but no later than November 1, 1997.  LESSOR's  obligations  to
complete  as  stated  above  shall  be  extended  on a day to day  basis  by its
inability  to complete  due to  governmental  restrictions;  strikes;  lockouts;
shortage  or  labor  or  materials;   civil   commotion;   extreme   weather  or
environmental conditions; or acts of God.










                                      -24-

         LESSOR shall complete  LESSOR's Work in a good and workmanlike  manner,
according  to the plans and  specifications  attached  hereto as  Exhibit  C, in
compliance with applicable laws,  codes,  ordinances and  regulations.  The term
"substantial completion" as used herein shall mean the completion of all work in
that  respective  Phase I or Phase II as the case may be, in accordance with the
plans and  specifications;  but for commonly accepted  "punchlist  items," which
shall be in the process of being completed (or which need to be completed at the
end of all the Work) and which do not materially interfere with LESSEE's ability
to use the space being delivered for its intended purpose (e.g. office space for
office use;  laboratory  space for  laboratory  use).  LESSOR shall complete its
punchlist  work within thirty (30) days after the Phase II Delivery  Date.  Upon
completion of LESSOR's Phase I Work and by its delivery  notice  attached hereto
as  Exhibit E - 1.  LESSOR  shall  have  certified  that  portion  of the Leased
Premises is valid for occupancy as office space; and subsequent to completion of
LESSOR's  Phase II Work, it shall  deliver to LESSEE a certificate  of occupancy
for the laboratory space.

         If any  change in the scope or timing of  LESSOR's  Phase I or Phase II
Work is necessitated by any changes in the plans and specifications for LESSOR's
work  requested  by  LESSEE,  or any  additions  thereto,  then  LESSOR  in each
instance, as soon as practicable under the circumstances,  obtain an estimate of
the increase in the cost of such change and/or any  anticipated  delay resulting
therefrom.  LESSEE must decide whether to proceed with such requested  change as
soon as practicable under the  circumstances  after receipt of LESSOR's estimate
of cost and/or delay (but if  occasioned  by a change  requested by LESSEE after
commencement of the actual  construction of the Phase I or Phase II Work, within
forty-eight (48) hours). LESSOR's statement shall set forth the additional costs
for any changes  that result in  additional  work,  and the credits  against the
original  cost of the work for any  changes  that  result in  deletion  from the
original  scope of work.  If LESSEE  decides to  proceed,  then it shall  notify
LESSOR in writing within said timeframes. Upon an affirmative decision by LESSEE
to proceed,  the cost of the change shall be paid to LESSOR  immediately  and in
advance  and the  work  shall  be  performed  as part of the  applicable  Phase.
Additionally,  if LESSEE decides to proceed,  any delay occasioned by the change
shall extend, day for day, LESSOR's delivery obligations and deadlines hereunder
accordingly (but shall not change the date on which the Interim Rent or the full
Annual Base Rent would have commenced under LESSOR's  construction  schedule but
for the change invoked by LESSEE;  and each of those  respective  Rents shall be
paid to LESSOR as of the dates they would  have  become due absent the  LESSEE's
changes,  notwithstanding  the  provisions of the second  paragraph of section 2
hereof to the contrary).

         LESSEE shall pay its pro rata share of Annual Base Rent and  Additional
Rent for any  portion  of the  initial  calendar  month in  which  LESSOR  makes
delivery of the Leased  Premises,  on  delivery,  as  contemplated  in section 2
hereof.

         34.  OPTION TO EXTEND.  LESSEE,  provided  it is not then in default in
each instance  hereunder beyond any applicable cure periods shall have an option
to extend  the Lease  Term,  on the terms  and  conditions  herein,  for one (1)
additional  period of five 








                                      -25-

(5)  years,  with the  Annual  Base Rent to be the then  current  "Market  Rent"
(including annual escalations  thereon for each year of the extended term, based
on increases in the Consumer Price Index or fixed  increases,  as he case may be
as determined by then prevailing market forces),  (herein, the "Extended Term").
Said Extended Term shall  commence,  subject to proper exercise in each instance
of LESSEE's option hereunder,  on the Termination Date of the original Term, and
shall  terminate on that date which is the fifth  anniversary of the Termination
Date.  For  example,  should the  Termination  Date be September  30, 2002,  the
Extended Term terminates on September 30, 2007.

         LESSEE shall  exercise its option by  delivering  to LESSOR its written
notice not later than August 30, 2001.  "Market  Rent" (which term shall include
annual  escalations) shall be that fair market rent charged for comparable first
class  research  laboratory  and office  space in Cambridge as of the end of the
original  Term.  If, after good faith attempts for thirty (30) days after LESSEE
delivers  notice to  LESSOR,  the LESSOR  and  LESSEE  cannot  agree on a figure
representing  Market Rent, then either party,  upon written notice to the other,
may  request  arbitration  of the  issue as  provided  in this  section.  Within
fourteen  (14) days of the request for  arbitration,  each party shall submit to
the other the name of one unrelated  individual or entity with proven  expertise
in the  leasing of  commercial  real  estate in greater  Boston to serve as that
party's  appraiser.  Each appraiser  shall be paid by the party selecting him or
it. The two appraisers  shall meet within  fourteen (14) days of their selection
and   collaboratively   determine  the  Market  Rent.   They  shall  make  their
determination  in writing,  including a statement if such is the case, that they
are at an impasse. Such a statement of impasse shall be submitted to the parties
along with the Market Rent figure  which each  appraiser  has  selected  and his
reasons and  substantiation  therefor.  The  appraisers,  in case of an impasse,
shall  also  agree on one  unrelated  individual  or entity  with  expertise  in
commercial  real  estate  in  greater  Boston  with at  least  seven  (7)  years
experience dealing with real estate appraisals who shall evaluate the reports of
the two original  appraisers and within  fourteen (14) days of submission of the
issue to him,  make his own  determination  as to a figure  representing  Market
Rent. The determination of this individual or entity (i.e.,  arbitrator) absent,
fraud,  bias or undue prejudice  shall be binding upon the parties.  In no event
shall "Market  Rent" for the Extended  Term be less than that figure  payable by
LESSEE  during  the last  year of the Lease  Term  increased  by the  cumulative
increase in the greater Boston Consumer Price Index All Urban, all items,  since
the last increase in Annual Base Rent.

         Annual Base Rent and Additional  Rent during any Extended Term shall be
payable  in  advance,  in equal  monthly  installments  on the first day of each
calendar month.

         35.  EXTENDED  TERM  ADDITIONAL  RENT.  LESSEE in  addition to the sums
payable  annually  to LESSOR as Annual  Base Rent,  shall pay to LESSOR for each
year of any Extended Term, as Additional  Operating Expense Rent, and Additional
Tax  Escalation  Rent,  LESSEE's  Allocable  Percentage  (as  determined  by the
approximate total rentable space leased),  of any and all increases in operating
expenses  and taxes,  as  contemplated  in Section 3 and 4 of this  Lease,  over
Exhibit B attached hereto.











                                      -26-

         36 ESTOPPEL CERTIFICATE.  Upon not less than fifteen days prior written
request by LESSOR,  LESSEE shall  execute,  acknowledge  and deliver to LESSOR a
statement in writing  certifying  if true that this Lease is  unmodified  and in
full  force and  effect and that  LESSEE  has at the time of such  statement  no
defenses,  offsets or  counterclaims  against its obligations to pay Annual Base
Rent and Additional  Operating  Expense Rent and Additional Tax Escalation  Rent
and any other charges and to perform its other  covenants  under this Lease (or,
if there have been any  modifications  that the same is in full force and effect
as  modified  and  stating the  modifications  and,  if there are any  defenses,
offsets or  counterclaims,  setting them forth in  reasonable  detail),  and the
dates to which the Annual Base Rent and any  Additional  Rent and other  charges
have been paid.  Any such  statement  delivered  pursuant to this Section may be
relied upon by any  prospective  purchaser or mortgagee of the Premises,  or any
prospective assignee of any such mortgagee or the LESSOR.

         37. PRIOR NOTICE AS TO ADJACENT SPACE. LESSEE,  provided it is not then
in default  hereunder,  beyond any applicable notice and cure periods,  shall be
provided at least fifteen (15) days written notice prior to LESSOR's remarketing
of the space  adjacent to the Leased  Premises  hereunder on the fourth floor of
the Building;  subject to any existing  exclusive rights to said space conferred
on any other  lessees in the  Building.  During  said  fifteen  (15) day period,
LESSOR shall entertain offers from and negotiate in good faith with LESSEE as to
the market terms and  conditions of any  prospective  occupancy of said adjacent
space by LESSEE.  Once said fifteen (15) day period has lapsed,  LESSOR shall be
free to actively  market and negotiate with any party and, if  discussions  were
initiated by LESSEE  within said fifteen (15) day period,  shall also  negotiate
with  LESSEE in good  faith as to said  space.  Notwithstanding  the  foregoing,
LESSOR  shall not be bound to  consummate  any  transaction  for said space with
LESSEE.

         38. LESSEE'S LENDER.  LESSEE intends to procure financing which will be
secured by various  articles  of  personal  property,  including  inventory  and
equipment  to  be  located  in  and  upon  the  Leased  Premises  (the  "Secured
Personalty"),  which Secured  Personalty is to be covered by or described in one
or more security agreements made and entered into by LESSEE.  LESSOR agrees that
none of the aforesaid collateral which is the subject of any security agreements
granting a security  interest to any of such lenders shall be subject to a claim
for Rent or liable for any lien,  right or claim of LESSOR that is senior to the
claim of the lender.  Furthermore,  in the event the lender,  its  successors or
assigns  shall  at any time  exercise  its or their  right or power  under  said
security  agreements to take possession of or to remove the Secured  Personalty;
and if  LESSOR  receives  at least  ten (10) days  prior  written  notice of the
exercise  of said rights with  respect to any of the Secured  Personalty,  other
than LESSEE's books and records (for which no advance notice shall be required),
said notice to provide the name,  address,  phone number and contact  persons in
charge of the exercise of said lender's rights;  LESSOR will not hinder the same
or object  thereto or interfere  therewith,  and LESSOR hereby  consents to such
taking of possession and removal of said Secured  Personalty,  regardless of the
manner or degree of their attachment to the realty of the improvements  thereon,
and consents to the entry upon said Leased Premises for such purposes;  provided
that the secured lender shall 









                                      -27-

observe  LESSOR's  reasonable  rules and  regulations  governing  the  manner of
removal of the Secured Personalty from the Leased Premises and the building, and
further provided the secured lender will repair any and all damage occasioned by
said  removal,   properly   capping  all  pipes  and  repairing  all  holes  and
protrusions,  and will pay LESSOR Rent at the daily rate set forth in this Lease
for the Leased  Premises if it occupies the Leased  Premises for longer than one
(1) day. At LESSEE's request, LESSOR shall execute an instrument in favor of the
secured lender confirming the terms of this section.

         39.  GOVERNING  LAW.  This  Lease  constitutes  the full  and  complete
agreement  between  the  LESSOR  and  LESSEE  and shall be  construed  under and
according to the laws of the  Commonwealth  of Mass. Any provision of this Lease
which is deemed void or  unenforceable  shall not  invalidate  or render void or
unenforceable the entire Lease. This Lease may only be modified by instrument in
writing  signed by both  parties  hereto  (or  their  permitted  successors  and
assigns).

         IN WITNESS WHEREOF, LESSOR AND LESSEE have hereunto set their hands and
seals this 3rd day of July, 1997.

                                     LESSOR:

                                     RIVERTECH ASSOCIATES, LLC


                                     By:  /s/ Robert Epstein
                                          --------------------------------------
                                          Robert Epstein, Member/Manager

LESSEE:

DYNAGEN, INC.


By:  /s/ Indu A. Muni
   --------------------------
its duly authorized President







<TABLE> <S> <C>


<ARTICLE>                     5
       
<S>                             <C>
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                              DEC-31-1997
<PERIOD-START>                                 JAN-01-1997
<PERIOD-END>                                   SEP-30-1997
<CASH>                                         32,145
<SECURITIES>                                   0
<RECEIVABLES>                                  3,207,355
<ALLOWANCES>                                   71,429
<INVENTORY>                                    8,201,045
<CURRENT-ASSETS>                               12,468,015
<PP&E>                                         1,676,506
<DEPRECIATION>                                 488,640
<TOTAL-ASSETS>                                 29,112,990
<CURRENT-LIABILITIES>                          13,096,164
<BONDS>                                        0
                          0
                                    602
<COMMON>                                       335,101
<OTHER-SE>                                     9,709,675
<TOTAL-LIABILITY-AND-EQUITY>                   29,112,990
<SALES>                                        7,355,636
<TOTAL-REVENUES>                               7,444,380
<CGS>                                          7,352,213
<TOTAL-COSTS>                                  14,517,042
<OTHER-EXPENSES>                               0
<LOSS-PROVISION>                               0
<INTEREST-EXPENSE>                             652,212
<INCOME-PRETAX>                                (7,612,704)
<INCOME-TAX>                                   0
<INCOME-CONTINUING>                            (7,612,704)
<DISCONTINUED>                                 0
<EXTRAORDINARY>                                0
<CHANGES>                                      0
<NET-INCOME>                                   (7,612,704)
<EPS-PRIMARY>                                  (.25)
<EPS-DILUTED>                                  (.25)
        


</TABLE>


                                  Exhibit 99a
                                  -----------


                                  PRESS RELEASE


DynaGen's NicErase-SL  Multi-Center Phase 3 Trial Shows Efficacy in One of Three
Sites

CAMBRIDGE, Massachusetts, August 29, 1997 -- DynaGen, Inc. (Nasdaq:DYGN;BSE:DYG)
today  announced  that the  combined  results  of its  750-subject  multi-center
clinical trial did not yield a statistically  significant difference between the
placebo and  NicErase(R)-SL  groups.  However,  one center, the Tobacco Research
Center  at the  West  Virginia  University  School  of  Medicine,  was  able  to
demonstrate efficacy and achieve statistical significance.  This site, under the
direction of Elbert D. Glover,  Ph.D.,  demonstrated 23% (p = 0.033)  abstinence
rate in subjects  who received  NicErase(R)-SL  compared to 13% rate in subjects
who received placebo treatment.

Dr.  Glover was able to repeat his earlier  success with  NicErase(R)-SL  in the
Company's  prior  pilot Phase 3 trial in which the data from his site showed the
highest trend toward efficacy. The Company believes that his previous experience
with  NicErase(R)-SL may have contributed to the higher  therapeutic  compliance
observed in this pivotal trial, which resulted in the clinical efficacy achieved
at the West  Virginia  site.  The  Company  also  believes  that the overall low
therapeutic  compliance  reported in the pivotal  trial at the other two centers
may have contributed to an overall lack of statistically significant efficacy.

"While we are  disappointed  with the overall results of this trial, the Company
has to-date shown that lobeline is a safe and potentially effective non-nicotine
alternative  smoking  cessation  therapy for some smokers wanting to quit," said
Dr. Indu A. Muni,  President and Chief Executive Officer.  "The results from Dr.
Glover's  site,  together with the pilot Phase 3 results,  should be encouraging
for our alliance partners to proceed with their delivery systems for lobeline."

DynaGen  has  licensed  NicErase(R)  to  Nastech  Pharmaceutical  Company,  Inc.
(Nasdaq:NSTK) for development of a nasally  administered  lobeline  formulation.
Furthermore,  DynaGen has signed a  memorandum  of  understanding  with  Lohmann
Therapie  Systeme GmbH (LTS)  intended to allow LTS to develop  transdermal  and
transbuccal patch formulations of NicErase(R).

In light of these results,  management intends to discontinue the NicErase(R)-SL
(sublingual  tablet)  program at the present time and to focus its  resources on
the multisource drug business and other programs now underway at DynaGen.

Any statements  which are not historical  facts  contained in this press release
are  forward-looking  statements  that involve risks and  uncertainties.  Please
refer to the risk factors  identified  in the  Company's  recent  report on Form
10-K,  including  those  relating  to  commercialization  of  products  and  the
Company's limited manufacturing and marketing experience.






Contacts:
Roger Moore                                               Investor Relations
L.G. Zangani, Inc.                                        DynaGen, Inc.
(908) 788-9660                                            (617) 491-2527





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