THIS  WARRANT  HAS NOT BEEN  REGISTERED  UNDER THE  SECURITIES  ACT OF 1933,  AS
AMENDED,  OR ANY  APPLICABLE  STATE  SECURITIES  LAWS,  AND  MAY  NOT BE SOLD OR
TRANSFERRED  UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION
REQUIREMENTS  OF SUCH ACT AND APPLICABLE  LAWS OR SOME OTHER  EXEMPTION FROM THE
REGISTRATION  REQUIREMENTS  OF SUCH ACT AND  APPLICABLE  LAWS IS AVAILABLE  WITH
RESPECT THERETO.

                          COMMON STOCK PURCHASE WARRANT

Warrant No. W-CS-6                                     Number of Shares:  50,000

                                  DynaGen, Inc.

                           Void after January 15, 2002
               (except as otherwise set forth in Section 2 below)


         1. Issuance.  This Warrant is issued to Leonardo G. Zangani by DynaGen,
Inc.,  a  Delaware  corporation  (hereinafter  with its  successors  called  the
"Company").  THIS  WARRANT  IS  EXERCISABLE  IN  INSTALLMENTS,  SUBJECT  TO  THE
SATISFACTION  OF CERTAIN  CONDITIONS AS SET FORTH IN SECTION 2 BELOW. NO PORTION
OF THIS WARRANT MAY BE EXERCISED UNLESS SUCH CONDITIONS HAVE BEEN SATISFIED WITH
RESPECT TO THE CONDITIONS REGARDING EXERCISABILITY.

         2.  Purchase  Price;  Number  of  Shares.  Subject  to  the  terms  and
conditions  hereinafter  set forth,  the registered  holder of this Warrant (the
"Holder") is entitled upon surrender of this Warrant with the subscription  form
annexed  hereto duly  executed,  at the office of the  Company,  99 Erie Street,
Cambridge, Massachusetts 02139, or such other office as the Company shall notify
the Holder of in writing, to purchase from the Company at a price per share (the
"Purchase  Price") of $1.97 an aggregate of fifty  thousand  (50,000) fully paid
and  nonassessable  shares of Common Stock,  $.01 par value, of the Company (the
"Common Stock"),  subject to the conditions stated immediately below. Commencing
on the date  hereof,  the Holder may  exercise  this  Warrant for 25,000 of such
shares.  If, within six months of the date hereof, the Company renews or extends
the  original  term of the  Consulting  Agreement  between  the Company and L.G.
Zangani, Inc. (the "Agreement"), then, commencing on the date that is six months
from the date  hereof,  the Holder may exercise  this Warrant for the  remaining
shares of Common Stock subject  hereto.  If the Company does not renew or extend
the original  term of the Agreement  within six months of the date hereof,  such
remaining  shares  shall not be  exercisable,  and the  portion  of the  Warrant
relating  to  such  remaining  shares  shall  be   automatically   canceled  and
extinguished  and shall be without further effect.  Furthermore,  if the Company
does not renew or extend the original  term of the  Agreement  within six months
hereof,  notwithstanding  anything to the contrary  herein,  this Warrant  shall
expire  at the  close  of  business  on  December  31,  1999  and  shall be void
thereafter. Until such time as this Warrant is exercised in full or expires, the
Purchase  Price and the  securities  issuable  upon exercise of this Warrant are
subject to adjustment as hereinafter provided.





                                      -2-

         3. Payment of Purchase  Price.  Except as set forth in Section 4 below,
the Purchase Price shall be paid in cash or by check.

         4. Net Issue  Election.  The Holder may elect to  receive,  without the
payment by the Holder of any additional consideration, shares equal to the value
of this Warrant or any portion  hereof by the  surrender of this Warrant or such
portion to the Company,  with the net issue election  notice annexed hereto duly
executed,  at the office of the Company.  Thereupon,  the Company shall issue to
the Holder such number of fully paid and nonassessable shares of Common Stock as
is computed using the following formula:

                                   X = Y (A-B)
                                           A

where             X =      the number of shares to be issued to the Holder 
                           pursuant to this Section 4.

                  Y =      the number of shares covered by this Warrant, subject
                           to  Section 2  hereof,  in  respect  of which the net
                           issue election is made pursuant to this Section 4.

                  A =      The "Fair Market Value" of one share of Common Stock.

                  B =      the  Purchase  Price in effect  under this Warrant at
                           the time the net issue  election is made  pursuant to
                           this Section 4.

         For purposes of this  Section 4, the "Fair Market  Value" of a share of
Common Stock as of a particular date (the "Determination Date") means:

                  (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  sale prices for the 10
trading days preceding the  Determination  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 15 trading days  preceding  the  Determination  Date, as reported in The
Wall Street Journal or by any market maker; or

                  (iii) if  quotations  for the  Company's  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 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 





                                      -3-

the 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,  and such other matters as
the Board of  Directors  deems  pertinent.  Such  determination  by the Board of
Directors shall be conclusive and binding.

         5. Partial  Exercise.  This  Warrant may be exercised in part,  and the
Holder  shall be entitled to receive a new  warrant,  which shall be dated as of
the date of this Warrant, covering the number of shares in respect of which this
Warrant shall not have been exercised.

         6.  Issuance  Date.  The  person or  persons in whose name or names any
certificate  representing  shares of Common Stock is issued  hereunder  shall be
deemed to have become the holder of record of the shares represented  thereby as
at the close of business on the date this Warrant is  exercised  with respect to
such shares, whether or not the transfer books of the Company shall be closed.

         7. Expiration  Date. This Warrant shall expire at the close of business
on January 15, 2002 (unless it expires earlier under Section 2 hereof) and shall
be void thereafter.

         8. Reserved Shares; Valid Issuance.  The Company covenants that it will
at all times from and after the date  hereof  reserve  and keep  available  such
number of its  authorized  shares of Common Stock,  free from all  preemptive or
similar  rights  therein,  as will be  sufficient to permit the exercise of this
Warrant in full. The Company further covenants that such shares as may be issued
pursuant to the  exercise  of this  Warrant  will,  upon  issuance,  be duly and
validly issued,  fully paid and nonassessable and free from all taxes, liens and
charges with respect to the issuance thereof.

         9.  Registration  Rights.  The  Company  hereby  grants  the  following
registration  rights with respect to the shares covered by this Warrant (subject
to Section 2 hereof):

                  9.1  "Piggy-Back"  Registrations.  If at any time the  Company
shall  determine  to  register in a public  offering  for the account of selling
stockholders  (and not for its own account) under the Securities Act of 1933, as
amended,  any of its Common Stock, it shall send to the Holder written notice of
such  determination  and, if within 15 days after  receipt of such  notice,  the
Holder  shall so request in writing,  the Company  shall use its best efforts to
include in such registration  statement all or any part of the shares covered by
this Warrant  that the Holder  requests to be  registered.  This right shall not
apply to a  registration  of shares of Common  Stock on Form S-8 or Form S-4 (or
their then  equivalents)  relating to shares of Common Stock to be issued by the
Company in connection  with any  acquisition of any entity or business or shares
of Common Stock issuable in connection with any stock option,  stock purchase or
other employee  benefit plan.  Notwithstanding  anything to the contrary in this
Section 9, the Company shall not be required to effect a  registration  pursuant
to this Section 9 for fewer than the total  number of shares  issuable or issued
pursuant  to this  Warrant  (as set forth in  Section  2 hereof)  at the time of
filing of such registration statement.





                                      -4-

                           If, in  connection  with any offering of Common Stock
to be sold by selling  stockholders,  the  managing  underwriter  or the Company
shall  impose a  limitation  on the number of shares of Common Stock that may be
included in any such  registration  statement  because,  in its  judgment,  such
limitation is necessary to effect an orderly public  distribution  of the Common
Stock and to maintain a stable market for the equity  securities of the Company,
then the Company  shall be obligated to include in such  registration  statement
only such limited  portion of the shares covered by this Warrant with respect to
which the Holder has requested inclusion hereunder.

                  9.2 Expenses. In the case of a registration under this Section
9, the  Company  shall bear all costs and  expenses  of each such  registration,
including,  but  not  limited  to,  printing,  legal  and  accounting  expenses,
Securities  and Exchange  Commission  and  National  Association  of  Securities
Dealers  filing fees and all  related  "Blue Sky" fees and  expenses;  provided,
however,  that the Company shall have no obligation to pay or otherwise bear any
portion of the underwriters' commissions or discounts attributable to the shares
covered by this Warrant  being  offered and sold by the Holder,  or the fees and
expenses of any counsel for the Holder in connection  with the  registration  of
such shares.

                  9.3 Expiration of Registration  Rights. The obligations of the
Company  under  this  Section 9 shall  expire on the  earlier of (i) the date on
which the shares covered by this Warrant shall have become transferable (whether
or not so transferred) in accordance with the resale  provisions of Rule 144, or
any successor  rule or provision,  under the Securities Act of 1933, as amended,
and (ii) the date that this Warrant terminates.

         10. Dividends. If after the date hereof the Company shall subdivide the
Common Stock,  by split-up or otherwise,  or combine the Common Stock,  or issue
additional  shares of Common Stock in payment of a stock  dividend on the Common
Stock,  the number of shares  issuable  on the  exercise of this  Warrant  shall
forthwith be  proportionately  increased in the case of a  subdivision  or stock
dividend,  or  proportionately  decreased in the case of a combination,  and the
Purchase  Price shall  forthwith be  proportionately  decreased in the case of a
subdivision or stock  dividend,  or  proportionately  increased in the case of a
combination.

         11. Mergers and Reclassifications. If after the date hereof there shall
be any  reclassification,  capital  reorganization or change of the Common Stock
(other than as a result of a subdivision, combination or stock dividend provided
for in Section 10 hereof),  or any  consolidation of the Company with, or merger
of the Company into, another  corporation or other business  organization (other
than  a  consolidation  or  merger  in  which  the  Company  is  the  continuing
corporation and which does not result in any  reclassification  or change of the
outstanding  Common Stock), or any sale or conveyance to another  corporation or
other business  organization  of all or  substantially  all of the assets of the
Company (each an "Acquisition Event"),  then, as a condition of such Acquisition
Event,  lawful provisions shall be made, and duly executed documents  evidencing
the same from the Company or its successor shall be delivered to the Holder,  so
that the Holder shall have the right to purchase, at a total price not to exceed
that payable  upon the exercise of this Warrant in full,  the kind and amount of
shares  of  stock  and  other  securities  and  property  receivable  upon  such
Acquisition  Event by a holder of the 






                                      -5-

number of shares of Common  Stock which might have been  purchased by the Holder
immediately  prior to such  Acquisition  Event, and in any such case appropriate
provisions  shall be made with  respect to the rights and interest of the Holder
to the end that the provisions hereof (including without limitation,  provisions
for the  adjustment  of the  Purchase  Price and the  number of shares  issuable
hereunder)  shall thereafter be applicable in relation to any shares of stock or
other securities and property thereafter deliverable upon exercise hereof.

         Notwithstanding  anything  to the  contrary  herein,  the  Holder  must
exercise this Warrant prior to the consummation of the Acquisition Event, and if
this Warrant is not so exercised,  it shall  terminate upon the  consummation of
such Acquisition Event.

         12. Fractional Shares. In no event shall any fractional share of Common
Stock be issued upon any  exercise of this  Warrant.  If, upon  exercise of this
Warrant as an entirety, the Holder would, except as provided in this Section 12,
be  entitled to receive a  fractional  share of Common  Stock,  then the Company
shall issue the next higher  number of full  shares of Common  Stock,  issuing a
full share with respect to such fractional share.

         13. Certificate of Adjustment. Whenever the Purchase Price is adjusted,
as  herein  provided,  the  Company  shall  promptly  deliver  to the  Holder  a
certificate  of the  principal  financial or  accounting  officer of the Company
setting forth the Purchase Price after such adjustment and setting forth a brief
statement of the facts requiring such adjustment.

         14.      Notices of Record Date, Etc.  In the event of:

                  (a) any taking by the  Company  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 stock of any class or
any other securities or property, or to receive any other right,

                  (b) any  reclassification of the capital stock of the Company,
capital  reorganization  of the Company,  consolidation  or merger involving the
Company, or sale or conveyance of all or substantially all of its assets, 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 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, or (ii) the date on which
any  such  reclassification,  reorganization,  consolidation,  merger,  sale  or
conveyance,  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 in respect of
such event are to be  determined.  Such notice  shall be mailed at least 20 days
prior to the date  specified  in such  notice on which any such  action is to be
taken.





                                      -6-

         15.  Amendment.  The terms of this Warrant may be amended,  modified or
waived only with the written consent of the Company.

         16.  Warrant  Register;   Transfers,  Etc.;  Warrantholder  Not  Deemed
Stockholder.

                  A. The Company will  maintain a register  containing  the name
and  address of the  Holder and its  assignees,  if  applicable.  The Holder may
change its  address as shown on the warrant  register  by written  notice to the
Company requesting such change. Any notice or written communication  required or
permitted to be given to the Holder may be given by certified  mail or delivered
to the Holder at its address as shown on the warrant register.

                  B.  Without the prior  written  consent of the  Company,  this
Warrant may not be transferred by the Holder.

                  C. In case this Warrant  shall be mutilated,  lost,  stolen or
destroyed,  the Company shall issue a new warrant of like tenor and denomination
and deliver the same (i) in exchange and substitution for and upon surrender and
cancellation  of any  mutilated  Warrant,  or (ii) in lieu of any Warrant  lost,
stolen or destroyed,  upon receipt of evidence  reasonably  satisfactory  to the
Company  of the  loss,  theft  or  destruction  of  such  Warrant  (including  a
reasonably  detailed  affidavit with respect to the  circumstances  of any loss,
theft or destruction) and of indemnity reasonably satisfactory to the Company.

                  D. No holder of this  Warrant  shall,  as such,  be deemed the
holder of the 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 has 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.

         17.  Governing  Law. The  provisions and terms of this Warrant shall be
governed  by  and  construed  in  accordance  with  the  internal  laws  of  the
Commonwealth of Massachusetts.

         18.  Business  Days. If the last or appointed day for the taking of any
action  required  or the  expiration  of any  right  granted  herein  shall be a
Saturday or Sunday or a legal holiday in Massachusetts,  then such action may be
taken or  right  may be  exercised  on the next  succeeding  day  which is not a
Saturday or Sunday or such a legal holiday.

Dated:  January 15, 1997                         DYNAGEN, INC.


(Corporate Seal)                                 By: /s/ Dhananjay G. Wadekar
Attest:                                          Title: Executive Vice President
/s/ Dennis R. Bilodeau
---------------------------





                                      -7-


                              Form of Subscription


To:____________________                           Date:_________________________


         The undersigned hereby subscribes for __________ shares of Common Stock
covered by this Warrant.  The  certificate(s) for such shares shall be issued in
the name of the undersigned or as otherwise indicated below:



                                    ------------------------------
                                    Signature



                        Form of Net Issue Election Notice

To:____________________                           Date:_________________________


         The undersigned hereby elects under Section 4 to surrender the right to
purchase  _______  shares  of  Common  Stock  pursuant  to  this  Warrant.   The
certificate(s)  for the shares  issuable upon such net issue  election  shall be
issued in the name of the undersigned or as otherwise indicated below.


                                    ------------------------------
                                    Signature