Document:

EXHIBIT 4.5
                                                                     -----------

         CONVERTIBLE PREFERRED STOCK PURCHASE AGREEMENT (this "Agreement"),
dated as of July 17, 2000, among DynaGen, Inc., a Delaware corporation (the
"Company"), and the investors signatory hereto (each such investor is a
"Purchaser" and all such investors are, collectively, the "Purchasers").

         WHEREAS, subject to the terms and conditions set forth in this
Agreement, the Company desires to issue and sell to the Purchasers and the
Purchasers, severally and not jointly, desire to purchase from the Company,
shares of the Company's 4% Series M Convertible Preferred Stock, $.01 par value
per share (the "Preferred Stock"), which are convertible into shares of the
Company's common stock, $.01 par value per share (the "Common Stock");

         WHEREAS, on June 1, 2000 the Purchasers loaned to the Company an
aggregate of $500,000 and on June 7, 2000, the Purchasers loaned the Company an
aggregate of $250,000 which are evidenced by two demand promissory notes
(collectively, the "Notes");

         WHEREAS, on the Closing Date (as defined herein), the aggregate
purchase price for the Preferred Stock shall be reduced by the principal amount
and interest due under the Notes and the Notes shall be canceled; and

         WHEREAS, the Company is obligated to pay the Purchasers an aggregate of
$550,000 in liquidated damages which payment shall be made in the form of the
issuance by the Company of shares of Preferred Stock in addition to the shares
of Preferred Stock purchased pursuant to the terms hereof.

         IN CONSIDERATION of the mutual covenants contained in this Agreement,
and for other good and valuable consideration the receipt and adequacy of which
are hereby acknowledged, the Company and the Purchasers agree as follows:

                                    ARTICLE I
                                PURCHASE AND SALE

         1.1      The Closing.
                  -----------

                  (a) The Closing. (i) Subject to the terms and conditions set
forth in this Agreement, the Company shall issue and sell to the Purchasers and
the Purchasers shall, severally and not jointly, purchase shares of Preferred
Stock for an aggregate purchase price of $2,120,000. The closing of the purchase
and sale of the Shares (the "Closing") shall take place at the offices of
Robinson Silverman Pearce Aronsohn & Berman LLP ("Robinson Silverman"), 1290
Avenue of the Americas, New York, New York 10104, immediately following the
execution hereof or such later date as the parties shall agree. The date of the
Closing is hereinafter referred to as the "Closing Date."

<PAGE>

                           (ii) On the Closing Date, the parties shall deliver
or shall cause to be delivered the following: (A) the Company shall deliver to
each Purchaser (1) stock certificates, registered in the name of such Purchaser,
representing a number of Shares equal to the sum of (x) the quotient obtained by
dividing the purchase price indicated below such Purchaser's name on the
signature page to this Agreement by 100 and (y) 4,400 (collectively, the
"Shares"), (2) the legal opinion of Foley, Hoag & Eliot LLP, outside counsel to
the Company in the form of Exhibit C, (3) an executed Registration Rights
Agreement, dated the date hereof, among the Company and the Purchasers, in the
form of Exhibit B (the "Registration Rights Agreement"), and (4) executed
Transfer Agent Instructions, in the form of Exhibit E, delivered to and
acknowledged by the Company's transfer agent (the "Transfer Agent
Instructions"); and (B) each Purchaser shall deliver: (1) the purchase price
indicated below such Purchaser's name on the signature page to this Agreement
less the principal amount and interest due under its Notes on the Closing Date,
in United States dollars in immediately available funds by wire transfer to an
account designated in writing by the Company for such purpose, (2) an executed
Registration Rights Agreement and (3) the canceled Notes.

         1.2 Terms of Preferred Stock. The Preferred Stock shall have the rights
preferences and privileges set forth in Exhibit A, and shall be incorporated
into a Certificate of Designation (the "Certificate of Designation") to be filed
prior to the Closing by the Company with the Secretary of State of Delaware, in
form and substance mutually agreed to by the parties.

         1.3 Certain Defined Terms. For purposes of this Agreement: (a)
"Original Issue Date" and "Trading Day" shall have the meanings set forth in
Exhibit A, (b) "Business Day" shall mean any day except Saturday, Sunday and any
day which shall be a federal legal holiday or a day on which banking
institutions in the State of New York or the Commonwealth of Massachusetts are
authorized or required by law or other governmental action to close, and (c)
"Person" means an individual or corporation, partnership, trust, incorporated or
unincorporated association, joint venture, limited liability company, joint
stock company, government (or an agency or subdivision thereof) or other entity
of any kind.

                                      -2-
<PAGE>

                                   ARTICLE II
                         REPRESENTATIONS AND WARRANTIES

         2.1 Representations and Warranties of the Company. The Company hereby
makes the following representations and warranties to the Purchasers:

                  (a) Organization and Qualification. The Company is a
corporation duly incorporated, validly existing and in good standing under the
laws of the State of Delaware, with the requisite corporate power and authority
to own and use its properties and assets and to carry on its business as
currently conducted. The Company has no subsidiaries other than as set forth in
Schedule 2.1(a) (collectively the "Subsidiaries"). Each of the Subsidiaries is
an entity, duly incorporated or otherwise organized, validly existing and in
good standing under the laws of the jurisdiction of its incorporation or
organization (as applicable), with the requisite power and authority to own and
use its properties and assets and to carry on its business as currently
conducted. Each of the Company and the Subsidiaries is duly qualified to do
business and is in good standing as a foreign corporation in each jurisdiction
in which the nature of the business conducted or property owned by it makes such
qualification necessary, except where the failure to be so qualified or in good
standing, as the case may be, would not reasonably be expected to, individually
or in the aggregate, (x) adversely affect the legality, validity or
enforceability of the Securities (as defined below) or any of this Agreement,
the Registration Rights Agreement or the Transfer Agent Instructions
(collectively, the "Transaction Documents"), (y) have or result in a material
adverse effect on the results of operations, assets, prospects, or condition
(financial or otherwise) of the Company and the Subsidiaries, taken as a whole,
or (z) adversely impair the Company's ability to perform fully on a timely basis
its obligations under any of the Transaction Documents (any of (x), (y) or (z),
a "Material Adverse Effect").

                  (b) Authorization; Enforcement. The Company has the requisite
corporate power and authority to enter into and to consummate the transactions
contemplated by each of the Transaction Documents and otherwise to carry out its
obligations thereunder. The execution and delivery of each of the Transaction
Documents by the Company and the consummation by it of the transactions
contemplated thereby have been duly authorized by all necessary corporate action
on the part of the Company. Each of the Transaction Documents has been duly
executed by the Company and, when delivered (or filed, as the case may be) in
accordance with the terms hereof, will constitute the valid and binding
obligation of the Company enforceable against the Company in accordance with its
terms. Neither the Company nor any Subsidiary is in violation of any of the
provisions of its respective certificate or articles of incorporation, by-laws
or other organizational or charter documents.

                  (c) Capitalization. The number of authorized, issued and
outstanding capital stock of the Company is set forth in Schedule 2.1(c). Except
as disclosed in the SEC Documents (as defined herein), the Company owns all of
the capital stock of each Subsidiary. No shares of Common Stock are entitled to
preemptive or similar rights, nor is any holder of securities of the Company or
any Subsidiary entitled to preemptive or similar rights arising out of

                                      -3-
<PAGE>

any agreement or understanding with the Company or any Subsidiary by virtue of
any of the Transaction Documents. Except as a result of the purchase and sale of
the Shares and except as disclosed in the SEC Documents, there are no
outstanding options, warrants, script rights to subscribe to, calls or
commitments of any character whatsoever relating to, or securities, rights or
obligations convertible into or exchangeable for, or giving any Person any right
to subscribe for or acquire, any shares of Common Stock, or contracts,
commitments, understandings, or arrangements by which the Company or any
Subsidiary is or may become bound to issue additional shares of Common Stock, or
securities or rights convertible or exchangeable into shares of Common Stock.

                  (d) Issuance of the Shares. The Shares are duly authorized
and, when issued and paid for in accordance with the terms hereof, will be duly
and validly issued, fully paid and nonassessable, free and clear of all liens,
encumbrances and rights of first refusal of any kind (collectively, "Liens").
The Company has on the date hereof and will, at all times while the Shares are
outstanding, maintain an adequate reserve of duly authorized shares of Common
Stock, reserved for issuance to the holders of the Shares, to enable it to
perform its conversion, exercise and other obligations under this Agreement and
the Certificate of Designation. Such number of reserved and available shares of
Common Stock is not less than 200% of the number of shares of Common Stock which
would be issuable upon conversion in full of the Shares on the Closing Date,
assuming that the Shares remain outstanding for five years and that all accrued
dividends are added to the Stated Value (as defined in the Certificate of
Designation) (the "Initial Minimum"). All such authorized shares of Common Stock
shall be duly reserved for issuance to the holders of the Shares. The shares of
Common Stock issuable upon conversion of the Shares are referred to herein as
the "Underlying Shares." The Shares and the Underlying Shares are collectively
referred to herein as, the "Securities." When issued in accordance with the
Certificate of Designation, the Underlying Shares will be duly authorized,
validly issued, fully paid and nonassessable, free and clear of all Liens.

                  (e) No Conflicts. The execution, delivery and performance of
the Transaction Documents by the Company and the consummation by the Company of
the transactions contemplated thereby do not and will not (i) conflict with or
violate any provision of the Company's or any Subsidiary's certificate or
articles of incorporation, bylaws or other charter documents (each as amended
through the date hereof), or (ii) subject to obtaining the Required Approvals
(as defined below), conflict with, or constitute a default (or an event which
with notice or lapse of time or both would become a default) under, or give to
others any rights of termination, amendment, acceleration or cancellation (with
or without notice, lapse of time or both) of, any agreement, credit facility,
debt or other instrument (evidencing a Company or Subsidiary debt or otherwise)
or other understanding to which the Company or any Subsidiary is a party or by
which any property or asset of the Company or any Subsidiary is bound or
affected, or (iii) result in a violation of any law, rule, regulation, order,
judgment, injunction, decree or other restriction of any court or governmental
authority to which the Company or a Subsidiary is subject (including federal and
state securities laws and regulations), or by which any property or asset of the
Company or a Subsidiary is bound or affected; except in the case of each of
clauses (ii) and (iii), as would not reasonably be expected to, individually or
in the aggregate, have or result in a Material Adverse Effect. The business of
the Company is not being conducted in violation of any law, ordinance or

                                      -4-
<PAGE>

regulation of any governmental authority, except for violations which,
individually or in the aggregate, would not reasonably be expected to have or
result in a Material Adverse Effect.

                  (f) Filings, Consents and Approvals. Neither the Company nor
any Subsidiary is required to obtain any consent, waiver, authorization or order
of, give any notice to, or make any filing or registration with, any court or
other federal, state, local or other governmental authority or other Person in
connection with the execution, delivery and performance by the Company of the
Transaction Documents, other than (i) the filing of the Certificate of
Designation with the Secretary of State of Delaware, (ii) the filings required
pursuant to Section 3.10, (iii) the filing with the Securities and Exchange
Commission (the "Commission") of a registration statement meeting the
requirements set forth in the Registration Rights Agreement and covering the
resale of the Underlying Shares by the Purchasers (the "Underlying Shares
Registration Statement"), (iv) applicable Blue Sky filings, and (v) in all other
cases where the failure to obtain such consent, waiver, authorization or order,
or to give such notice or make such filing or registration would not reasonably
be expected to have or result in, individually or in the aggregate, a Material
Adverse Effect (collectively, the "Required Approvals").

                  (g) Litigation; Proceedings. There is no action, suit,
inquiry, notice of violation, proceeding or investigation pending or, to the
knowledge of the Company, threatened against or affecting the Company or any of
its Subsidiaries or any of their respective properties before or by any court,
arbitrator, governmental or administrative agency or regulatory authority
(federal, state, county, local or foreign) (collectively, an "Action") which (i)
adversely affects or challenges the legality, validity or enforceability of any
of the Transaction Documents or the Securities or (ii) could, individually or in
the aggregate, have or result in a Material Adverse Effect.

                  (h) No Default or Violation. Except as described in the SEC
Documents, neither the Company nor any Subsidiary (i) is in default under or in
violation of (and no event has occurred which has not been waived which, with
notice or lapse of time or both, would result in a default by the Company or any
Subsidiary under), nor has the Company or any Subsidiary received notice of a
claim that it is in default under or that it is in violation of, any indenture,
loan or credit agreement or any other agreement or instrument to which it is a
party or by which it or any of its properties is bound, (ii) is in violation of
any order of any court, arbitrator or governmental body, or (iii) is in
violation of any statute, rule or regulation of any governmental authority, in
each case of clauses (i), (ii) or (iii) above, except as would not reasonably be
expected to individually or in the aggregate, have or result in a Material
Adverse Effect.

                  (i) Private Offering. Assuming the accuracy of the
representations and warranties of the Purchasers set forth in Sections
2.2(b)-(g), the offer, issuance and sale of the Securities to the Purchasers as
contemplated hereby are exempt from the registration requirements of the
Securities Act of 1933, as amended (the "Securities Act"). Neither the Company
nor any Person acting on its behalf has taken or is, to the knowledge of the
Company, contemplating taking any action which could subject the offering,
issuance or sale of the Securities to the registration requirements of the
Securities Act including soliciting any offer to buy or sell the Securities by
means of any form of general solicitation or advertising.

                                      -5-
<PAGE>

                  (j) SEC Documents; Financial Statements. The Company has filed
all reports required to be filed by it under the Securities Exchange Act of
1934, as amended (the "Exchange Act"), including pursuant to Section 13(a) or
15(d) thereof, for the two years preceding the date hereof (or such shorter
period as the Company was required by law to file such material) (the foregoing
materials being collectively referred to herein as the "SEC Documents" and,
together with the Schedules to this Agreement, the "Disclosure Materials") on a
timely basis or has received a valid extension of such time of filing and has
filed any such SEC Documents prior to the expiration of any such extension. As
of their respective dates, the SEC Documents complied in all material respects
with the requirements of the Securities Act and the Exchange Act and the rules
and regulations of the Commission promulgated thereunder, and none of the SEC
Documents, when filed, contained any untrue statement of a material fact or
omitted to state a material fact required to be stated therein or necessary in
order to make the statements therein, in light of the circumstances under which
they were made, not misleading. All material agreements to which the Company is
a party or to which the property or assets of the Company are subject have been
filed as exhibits to the SEC Documents as required. The financial statements of
the Company included in the SEC Documents comply in all material respects with
applicable accounting requirements and the rules and regulations of the
Commission with respect thereto as in effect at the time of filing. Such
financial statements have been prepared in accordance with generally accepted
accounting principles applied on a consistent basis during the periods involved
("GAAP"), except as may be otherwise specified in such financial statements or
the notes thereto, and fairly present in all material respects the financial
position of the Company and its consolidated subsidiaries as of and for the
dates thereof and the results of operations and cash flows for the periods then
ended, subject, in the case of unaudited statements, to normal, immaterial,
year-end audit adjustments. Since March 31, 2000, except as specifically
disclosed in the SEC Documents, (a) there has been no event, occurrence or
development that has resulted or that could result in a Material Adverse Effect,
(b) the Company has not incurred any liabilities (contingent or otherwise) other
than (x) liabilities incurred in the ordinary course of business consistent with
past practice and (y) liabilities not required to be reflected in the Company's
financial statements pursuant to GAAP or otherwise required to be disclosed in
filings made with the Commission, (c) the Company has not altered its method of
accounting or the identity of its auditors and (d) the Company has not declared
or made any payment or distribution of cash or other property to its
stockholders or officers or directors (other than in compliance with existing
compensation agreements or Company stock option plans) with respect to its
capital stock, or purchased, redeemed (or made any agreements to purchase or
redeem) any shares of its capital stock.

                  (k) Investment Company. The Company is not, and is not an
Affiliate (as defined in Rule 405 under the Securities Act) of, an "investment
company" within the meaning of the Investment Company Act of 1940, as amended.

                  (l) Certain Fees. No fees or commissions will be payable by
the Company to any broker, financial advisor or consultant, finder, placement
agent, investment banker, bank or other Person with respect to the transactions
contemplated by this Agreement. The Purchasers shall have no obligation with
respect to any fees or with respect to any claims made by or on behalf of other
Persons for fees of a type contemplated in this Section that may be due in

                                      -6-
<PAGE>

connection with the transactions contemplated by this Agreement. The Company
shall indemnify and hold harmless the Purchasers, their employees, officers,
directors, agents, and partners, and their respective Affiliates, from and
against all claims, losses, damages, costs (including the costs of preparation
and attorney's fees) and expenses suffered in respect of any such claimed or
existing fees, as such fees and expenses are incurred.

                  (m) Solicitation Materials. Neither the Company nor any Person
acting on the Company's behalf has solicited any offer to buy or sell the
Securities by means of any form of general solicitation or advertising.

                  (n) Exclusivity. The Company shall not issue and sell the
Shares to any Person other than the Purchasers without specific prior written
consent of the Purchasers.

                  (o) Listing and Maintenance Requirements Compliance. The
Company's Common Stock has been deleted from the Nasdaq SmallCap Market. Except
for the foregoing or as set forth in the SEC Documents, the Company has not, in
the two years preceding the date hereof, received notice (written or oral) from
any stock exchange, market or trading facility on which the Common Stock is or
has been listed (or on which it has been quoted) to the effect that the Company
is not in compliance with the listing or maintenance requirements of such
exchange or market. The Company is currently in compliance with all the listing
and maintenance requirements of the Boston Stock Exchange.

                  (p) Patents and Trademarks. The Company and its Subsidiaries
have, or have rights to use, all patents, patent applications, trademarks,
trademark applications, service marks, trade names, copyrights, licenses and
rights which are necessary or material for use in connection with their
respective business as described in the SEC Documents and which the failure to
so have would have a Material Adverse Effect (collectively, the "Intellectual
Property Rights"). Neither the Company nor any Subsidiary has received a written
notice that the Intellectual Property Rights used by the Company or its
Subsidiaries violates or infringes upon the rights of any Person, to the best
knowledge of the Company. All such Intellectual Property Rights are enforceable
and there is no existing infringement by another Person of any of the
Intellectual Property Rights.

                  (q) Registration Rights; Rights of Participation. Except as
disclosed under Section 6(c) of the Registration Rights Agreement, the Company
has not granted or agreed to grant to any Person any rights (including
"piggy-back" registration rights) to have any securities of the Company
registered with the Commission or any other governmental authority which have
not been satisfied. No Person, has any right of first refusal, preemptive right,
right of participation, or any similar right to participate in the transactions
contemplated by the Transaction Documents.

                  (r) Regulatory Permits. The Company and its Subsidiaries
possess all certificates, authorizations and permits issued by the appropriate
Federal, state or foreign regulatory authorities necessary to conduct their
respective businesses as described in the SEC Documents, except where the
failure to possess such permits would not reasonably be expected to,
individually or in the aggregate, have or result in a Material Adverse Effect
("Material Permits"), and

                                      -7-
<PAGE>

neither the Company nor any such Subsidiary has received any notice of
proceedings relating to the revocation or modification of any Material Permit.

                  (s) Title. The Company and the Subsidiaries have good and
marketable title in fee simple to all real property owned by them which is
material to the business of the Company and its Subsidiaries and good and
marketable title in all personal property owned by them which is material to the
business of the Company and its Subsidiaries, in each case free and clear of all
Liens, except for Liens as do not materially affect the value of such property
and do not interfere with the use made and proposed to be made of such property
by the Company and its Subsidiaries. Any real property and facilities held under
lease by the Company and its Subsidiaries are held by them under valid,
subsisting and enforceable leases of which the Company and its Subsidiaries are
in compliance and do not interfere with the use made and proposed to be made of
such property and buildings by the Company and its Subsidiaries.

                  (t) Absence of Certain Proceedings. Except as described in the
SEC Documents, (i) there is no Action pending or, to the knowledge of the
Company, threatened against the Company, in any such case wherein an unfavorable
decision, ruling or finding could have or result in a Material Adverse Effect;
(ii) neither the Company nor any Subsidiary, nor any director or officer
thereof, is or has been the subject of any Action involving (A) a claim of
violation of or liability under federal or state securities laws or (B) a claim
of breach of fiduciary duty; (iii) the Company does not have pending before the
Commission any request for confidential treatment of information and the Company
has no knowledge of any expected such request that would be made prior to the
Effectiveness Date (as defined in the Registration Rights Agreement); and (iv)
there has not been, and to the best of the Company's knowledge there is not
pending or contemplated, any investigation by the Commission involving the
Company or any current or former director or officer of the Company.

                  (u) Labor Relations. No material labor problem exists or, to
the knowledge of the Company, is imminent with respect to any of the employees
of the Company.

                  (v) Disclosure. The Company confirms that neither it nor any
other Person acting on its behalf has provided any of the Purchasers or its
agents or counsel with any information that constitutes or might constitute
material non-public information. The Company understands and confirms that the
Purchasers shall be relying on the foregoing representations in effecting
transactions in securities of the Company. All disclosure provided to the
Purchasers regarding the Company, its business and the transactions contemplated
hereby, including the Schedules to this Agreement, furnished by or on behalf of
the Company are true and correct in all material respects and do not contain any
untrue statement of a material fact or omit to state any material fact necessary
in order to make the statements made therein, in light of the circumstances
under which they were made, not misleading.

         2.2 Representations and Warranties of the Purchasers. Each Purchaser
hereby for itself and for no other Purchaser represents and warrants to the
Company as follows:

                                      -8-
<PAGE>

                  (a) Organization; Authority. Such Purchaser is an entity duly
organized, validly existing and in good standing under the laws of the
jurisdiction of its organization with the requisite corporate or partnership
power and authority to enter into and to consummate the transactions
contemplated by the Transaction Documents and otherwise to carry out its
obligations thereunder. The purchase by such Purchaser of the Securities
hereunder has been duly authorized by all necessary corporate action on the part
of such Purchaser. Each of this Agreement and the Registration Rights Agreement
has been duly executed by such Purchaser, and when delivered by such Purchaser
in accordance with the terms hereof, will constitute the valid and legally
binding obligation of such Purchaser, enforceable against it in accordance with
its terms.

                  (b) Investment Intent. Such Purchaser is acquiring the
Securities as principal for its own account for investment purposes only and not
with a view to or for distributing or reselling such Securities or any part
thereof, without prejudice, however, to such Purchaser's right, subject to the
provisions of this Agreement and the Registration Rights Agreement, at all times
to sell or otherwise dispose of all or any part of such Securities pursuant to
an effective registration statement under the Securities Act or under an
exemption from such registration and in compliance with applicable federal and
state securities laws. Nothing contained herein shall be deemed a representation
or warranty by such Purchaser to hold Securities for any amount of time. Such
Purchaser is acquiring the Securities hereunder in the ordinary course of its
business. Such Purchaser does not have any agreement or understanding, directly
or indirectly, with any Person to distribute any Securities.

                  (c) Purchaser Status. At the time such Purchaser was offered
the Securities, it was, and at the date hereof it is, an "accredited investor"
as defined in Rule 501(a) under the Securities Act.

                  (d) Experience of such Purchaser. Such Purchaser, either alone
or together with its representatives, has such knowledge, sophistication and
experience in business and financial matters so as to be capable of evaluating
the merits and risks of the prospective investment in the Securities, and has so
evaluated the merits and risks of such investment. Such Purchasers has been
advised by counsel in connection with the transactions contemplates hereby.

                  (e) Ability of such Purchaser to Bear Risk of Investment. Such
Purchaser is able to bear the economic risk of an investment in the Securities
and, at the present time, is able to afford a complete loss of such investment.

                  (f) Access to Information. Such Purchaser acknowledges that it
has reviewed the Disclosure Materials and has been afforded (i) the opportunity
to ask such questions as it has deemed necessary of, and to receive answers
from, representatives of the Company concerning the terms and conditions of the
offering of the Securities and the merits and risks of investing in the
Securities; (ii) access to information about the Company and the Company's
financial condition, results of operations, business, properties, management and
prospects sufficient to enable it to evaluate its investment; and (iii) the
opportunity to obtain such

                                      -9-
<PAGE>

additional information which the Company possesses, or can acquire without
unreasonable effort or expense that is necessary to make an informed investment
decision with respect to the investment and to verify the accuracy and
completeness of the information contained in the Disclosure Materials. Neither
such inquiries nor any other investigation conducted by or on behalf of such
Purchaser or its representatives or counsel shall modify, amend or affect such
Purchaser's right to rely on the truth, accuracy and completeness of the
Disclosure Materials and the Company's representations and warranties contained
in the Transaction Documents.

                  (g) General Solicitation. Such Purchaser is not purchasing the
Securities as a result of or subsequent to any advertisement, article, notice or
other communication regarding the Securities published in any newspaper,
magazine or similar media or broadcast over television or radio or presented at
any seminar or any other general solicitation or general advertisement.

                  (h) Reliance. Such Purchaser understands and acknowledges that
(i) the Securities are being offered and sold to it without registration under
the Securities Act in a private placement that is exempt from the registration
provisions of the Securities Act and (ii) the availability of such exemption,
depends in part on, and the Company will rely upon the accuracy and truthfulness
of, the foregoing representations and such Purchaser hereby consents to such
reliance.

          The Company acknowledges and agrees that no Purchaser makes or has
made any representations or warranties with respect to the transactions
contemplated hereby other than those specifically set forth in this Section 2.2.

                                   ARTICLE III
                         OTHER AGREEMENTS OF THE PARTIES

         3.1 Transfer Restrictions. (a) Securities may only be disposed of
pursuant to an effective registration statement under the Securities Act, to the
Company or pursuant to an available exemption from or in a transaction not
subject to the registration requirements of the Securities Act, and in
compliance with any applicable federal and state securities laws. In connection
with any transfer of Securities other than pursuant to an effective registration
statement or to the Company, except as otherwise set forth herein, the Company
may require the transferor thereof to provide to the Company an opinion of
counsel selected by the transferor, the form and substance of which opinion
shall be reasonably satisfactory to the Company, to the effect that such
transfer does not require registration of such transferred Securities under the
Securities Act. Notwithstanding the foregoing, the Company, without requiring a
legal opinion as described in the immediately preceding sentence, hereby
consents to and agrees to register on the books of the Company and with any
transfer agent for the securities of the Company any transfer of Securities by a
Purchaser to an Affiliate of such Purchaser or to one or more funds or managed
accounts under common management with such Purchaser, and any transfer among any
such Affiliates or one or more funds or managed accounts, provided that the
transferee certifies to the Company that it is an "accredited investor" as
defined in Rule 501(a) under the Securities Act and that it is acquiring the
Securities solely for investment purposes (subject to the qualifications
hereof). Any such transferee shall agree

                                      -10-
<PAGE>

in writing to be bound by the terms of this Agreement and shall have the rights
of a Purchaser under this Agreement and the Registration Rights Agreement.

                  (b) The Purchasers agree to the imprinting, so long as is
required by this Section 3.1(b), of the following legend on the Securities:

                  NEITHER THESE SECURITIES NOR THE SECURITIES INTO WHICH THESE
         SECURITIES ARE [CONVERTIBLE] HAVE BEEN REGISTERED WITH THE SECURITIES
         AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN
         RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT
         OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND, ACCORDINGLY, MAY NOT
         BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION
         STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE
         EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION
         REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE
         STATE SECURITIES LAWS.

                  The Underlying Shares shall not contain the legend set forth
above nor any other legend at any time while an Underlying Shares Registration
Statement is effective under the Securities Act or the holder of any such
security is relying on Rule 144 promulgated under the Securities Act ("Rule
144") in connection with the resale of such Underlying Shares or, in the event
there is not an effective Underlying Shares Registration Statement at such time
and Rule 144 is not then available, if, in the opinion of counsel to the
Company, such legend is not required under applicable requirements of the
Securities Act (including judicial interpretations and pronouncements issued by
the staff of the Commission). The Company shall cause its counsel to issue the
legal opinion included in the Transfer Agent Instructions to the Company's
transfer agent on the day that the Underlying Shares Registration Statement is
declared effective by the Commission (the "Effective Date"). The Company further
agrees that if any Underlying Shares are issued with a legend in accordance with
this Section 3.1(b), it will, within three (3) Trading Days after request
therefor by a Purchaser, provide such Purchaser with a certificate or
certificates representing such Underlying Shares, free from such legend at such
time as such legend would not have been required under this Section 3.1(b) had
such issuance occurred on the date of such request. The Company may not make any
notation on its records or give instructions to any transfer agent of the
Company which enlarge the restrictions of transfer set forth in this Section.

         3.2 Acknowledgment of Dilution. The Company acknowledges that the
issuance of the Underlying Shares upon conversion of the Shares in accordance
with the terms of the Certificate of Designation, will result in dilution of the
outstanding shares of Common Stock, which dilution may be substantial under
certain market conditions. The Company further acknowledges that its obligation
to issue Underlying Shares upon conversion of the Shares in accordance with the
terms of the Certificate of Designation, is unconditional and absolute, subject
to the limitations set forth herein, in the Certificate of Designation,
regardless of the effect of any such dilution.

         3.3 Furnishing of Information. As long as the Purchasers own
Securities, the Company covenants to timely file (or obtain extensions in
respect thereof and file within the applicable grace period) all reports
required to be filed by the Company after the date hereof pursuant to Section

                                      -11-
<PAGE>

13(a) or 15(d) of the Exchange Act. As long as the Purchasers own Securities, if
the Company is not required to file reports pursuant to such sections, it will
prepare and furnish to the Purchasers and make publicly available in accordance
with Rule 144(c) promulgated under the Securities Act such information as is
required for the Purchasers to sell the Securities under Rule 144 promulgated
under the Securities Act. The Company further covenants that it will take such
further action as any holder of Securities may reasonably request, all to the
extent required from time to time to enable such Person to sell Underlying
Shares without registration under the Securities Act within the limitation of
the exemptions provided by Rule 144 promulgated under the Securities Act,
including causing its attorneys to render and deliver any legal opinion required
in order to permit a Purchaser to receive Underlying Shares free of all
restrictive legends and to subsequently sell Underlying Shares under Rule 144
upon receipt of a notice of an intention to sell or other form of notice having
a similar effect. Upon the request of any such Person, the Company shall deliver
to such Person a written certification of a duly authorized officer as to
whether it has complied with such requirements.

         3.4 Integration. The Company shall not, and shall use its best efforts
to ensure that, no Affiliate of the Company shall, sell, offer for sale or
solicit offers to buy or otherwise negotiate in respect of any security (as
defined in Section 2 of the Securities Act) that would be integrated with the
offer or sale of the Securities in a manner that would require the registration
under the Securities Act of the sale of the Securities to the Purchasers.

         3.5 Increase in Authorized Shares. If on any date the Company would be,
if a notice of conversion or exercise (as the case may be) were to be delivered
on such date, precluded from (a) issuing 200% of the number of Underlying Shares
as would then be issuable upon a conversion in full of the Shares (the "Current
Required Minimum"), in either case, due to the unavailability of a sufficient
number of authorized but unissued or reserved shares of Common Stock, then the
Board of Directors of the Company shall promptly (and in any case, within 30
Business Days from such date) prepare and mail to the stockholders of the
Company proxy materials requesting authorization to amend the Company's
certificate or articles of incorporation to increase the number of shares of
Common Stock which the Company is authorized to issue to at least such number of
shares as reasonably requested by the Purchasers in order to provide for such
number of authorized and unissued shares of Common Stock to enable the Company
to comply with its issuance, conversion, exercise and reservation of shares
obligations as set forth in this Agreement and the Certificate of Designation
(the sum of (x) the number of shares of Common Stock then outstanding plus all
shares of Common Stock issuable upon exercise of all outstanding options,
warrants and convertible instruments, and (y) the Current Required Minimum, is
deemed for purposes hereof to be a reasonable number). In connection therewith,
the Board of Directors shall (a) adopt proper resolutions authorizing such
increase, (b) recommend to and

                                      -12-
<PAGE>

otherwise use its best efforts to promptly and duly obtain stockholder approval
to carry out such resolutions (and hold a special meeting of the stockholders no
later than the earlier to occur of the 60th day after delivery of the proxy
materials relating to such meeting and the 90th day after request by a holder of
Securities to issue the number of Underlying Shares in accordance with the terms
hereof) and (c) within five Business Days of obtaining such stockholder
authorization, file an appropriate amendment to the Company's certificate or
articles of incorporation to evidence such increase. The Company shall also use
its best efforts to cause Company management to vote shares of Common Stock held
by Management in favor of all resolutions to increase the authorized stock of
the Company hereunder.

         3.6 Reservation and Listing of Underlying Shares. (a) The Company shall
(i) in the time and manner required by any exchange, market or quotation system
on which the Common Stock is traded, prepare and file with such securities
exchange or market or trading or quotation facility on which the Common Stock is
listed an additional shares listing application covering a number of shares of
Common Stock which is not less than the Initial Minimum, (ii) take all steps
necessary to cause such shares of Common Stock to be approved for listing on any
such securities exchange or market or trading or quotation facility as soon as
possible thereafter, and (iii) provide to the Purchasers evidence of such
listing, and the Company shall maintain the listing of its Common Stock thereon.
If the number of Underlying Shares issuable upon conversion in full of the then
outstanding Shares exceeds 85% of the number of Underlying Shares previously
listed on account thereof, then the Company shall take the necessary actions to
immediately list a number of Underlying Shares as equals no less than the then
Current Required Minimum.

                  (b) The Company shall maintain a reserve of shares of Common
Stock for issuance upon the conversion in full of the Shares in accordance with
this Agreement and the Certificate of Designation, respectively, in such amount
as may be required to fulfill its obligations in full under the Transaction
Documents, which reserve shall equal no less than the then Current Required
Minimum.

         3.7 Conversion and Exercise Procedures. The Transfer Agent Instructions
and Conversion Notice (as defined in the Certificate of Designation) set forth
the totality of the procedures with respect to the conversion of the Shares,
including the form of legal opinion, if necessary, that shall be rendered to the
Company's transfer agent and such other information and instructions as may be
reasonably necessary to enable the Purchasers to convert their Shares as
contemplated in the Certificate of Designation.

         3.8 Conversion Obligations of the Company. The Company shall honor
conversion of the Shares and shall deliver Underlying Shares in accordance with
the respective terms, conditions and time periods set forth in the Certificate
of Designation.

         3.9 Right of First Refusal; Subsequent Registrations. (a) The Company
shall not, directly or indirectly, without the prior written consent of
Purchasers holding a majority of the Shares, offer, sell, grant any option to
purchase, or otherwise dispose of (or announce any offer, sale, grant or any
option to purchase or other disposition) any of its or its Affiliates' equity or
equity-

                                      -13-
<PAGE>

equivalent securities including the issuance of any debt or other instrument at
any time over the life thereof convertible into or exchangeable for Common
Stock, or any other transaction intended to be exempt or not subject to
registration under the Securities Act (collectively, a "Subsequent Placement")
for a period of 180 days after the Effective Date, provided, that such 180 day
period shall be extended for the number of Trading Days during such period (A)
in which trading in the Common Stock is suspended by any securities exchange or
market or quotation system on which the Common Stock is then listed, or (B)
during which the Underlying Shares Registration Statement is not effective, or
(C) during which the prospectus included in the Underlying Shares Registration
Statement may not be used by the holders thereof for the resale of Underlying
Shares, unless (A) the Company delivers to each of the Purchasers a written
notice (the "Subsequent Placement Notice") of its intention to effect such
Subsequent Placement, which Subsequent Placement Notice shall describe in
reasonable detail the proposed terms of such Subsequent Placement, the amount of
proceeds intended to be raised thereunder, the Person with whom such Subsequent
Placement shall be effected, and attached to which shall be a term sheet or
similar document relating thereto and (B) such Purchaser shall not have notified
the Company by 6:30 p.m. (New York City time) on the seventh day after its
receipt of the Subsequent Placement Notice of their willingness to provide,
subject to completion of mutually acceptable documentation, financing to the
Company in the amount and on the same terms set forth in the Subsequent
Placement Notice. If the Purchasers shall fail to notify the Company of their
intention to enter into such negotiations within such time period, the Company
may effect the Subsequent Placement substantially upon the terms and to the
Persons (or Affiliates of such Persons) set forth in the Subsequent Placement
Notice; provided, that the Company shall provide the Purchasers with a second
Subsequent Placement Notice, and the Purchasers shall again have the right of
first refusal set forth above in this paragraph (a), if the Subsequent Placement
subject to the initial Subsequent Placement Notice shall not have been
consummated for any reason on the terms set forth in such Subsequent Placement
Notice within thirty Trading Days after the date of the initial Subsequent
Placement Notice with the Person (or an Affiliate of such Person) identified in
the Subsequent Placement Notice. If the Purchasers shall indicate a willingness
to provide financing in excess of the amount set forth in the Subsequent
Placement Notice, then each Purchaser shall be entitled to provide financing
pursuant to such Subsequent Placement Notice up to an amount equal to such
Purchaser's pro-rata portion of the aggregate number of Shares purchased by such
Purchaser under this Agreement, but the Company shall not be required to accept
financing from the Purchasers in an amount in excess of the amount set forth in
the Subsequent Placement Notice. The right of firs refusal set forth in this
Section shall not apply to (i) the granting of options or warrants to employees,
officers and directors, and the issuance of shares upon exercise of options
granted, under any stock option plan heretofore or hereinafter duly adopted by
the Company, (ii) shares of Common Stock issuable upon exercise of any currently
outstanding warrants and upon conversion of any currently outstanding
convertible securities of the Company, in each case disclosed in the SEC
Documents, but not with respect to any amendment or modification thereto, and
(iii) shares of Common Stock issuable upon conversion of Shares in accordance
with the Certificate of Designation in accordance with its respective terms.

                  (b) Except for (x) Underlying Shares, (y) other "Registrable
Securities" (as such term is defined in the Registration Rights Agreement) to be
registered, and securities of the Company permitted pursuant to Section 6(c) of
the Registration Rights Agreement to be registered, in the Underlying Shares
Registration Statement in accordance with the Registration Rights

                                      -14-
<PAGE>

Agreement, and (z) Common Stock permitted to be issued pursuant to paragraph
(a)(i) - (iii) of Section 3.9 (a), the Company shall not, for a period of not
less than 90 Trading Days after the Effective Date, without the prior written
consent of Purchasers holding a majority of the Shares (i) issue or sell any of
its or any of its Affiliates' equity or equity-equivalent securities pursuant to
Regulation S promulgated under the Securities Act, or (ii) register any
securities of the Company. Any days after the Effective Date that a Purchaser is
unable to sell Underlying Shares under the Underlying Shares Registration
Statement shall be added to such 90 Trading Day period.

         3.10 Certain Securities Laws Disclosures; Publicity. The Company shall:
(i) on the Closing Date issue a press release acceptable to the Purchasers
disclosing the transactions contemplated hereby and (ii) timely file with the
Commission a Form D promulgated under the Securities Act as required under
Regulation D promulgated under the Securities Act and provide a copy thereof to
the Purchasers promptly after the filing thereof. The Company shall, no less
than two Business Days prior to the filing of the Form D required by clause
(ii), provide a copy thereof to the Purchasers. The Company and the Purchasers
shall consult with each other in issuing any press releases or otherwise making
public statements or filings and other communications with the Commission or any
regulatory agency or stock market or trading facility with respect to the
transactions contemplated hereby and neither party shall issue any such press
release or otherwise make any such public statement, filings or other
communications without the prior written consent of the other, which consent
shall not be unreasonably withheld or delayed, except that no prior consent
shall be required if such disclosure is required by law, in which such case the
disclosing party shall provide the other party with prior notice of such public
statement, filing or other communication. Notwithstanding the foregoing, the
Company shall not publicly disclose the names of the Purchasers, or include the
names of the Purchasers in any filing with the Commission, or any regulatory
agency, trading facility or stock market without the prior written consent of
the Purchasers, except to the extent such disclosure (but not any disclosure as
to the controlling Persons thereof) is required by law, in which case the
Company shall provide the Purchasers with prior notice of such disclosure.

         3.11 Use of Proceeds. The Company shall use the net proceeds from the
sale of the Securities hereunder for working capital and general corporate
purposes.

         3.12 Reimbursement. If any Purchaser becomes involved in any capacity
in any Action brought by or against any Person, including stockholders of the
Company, solely as a result of the acquisition of the Securities hereunder, the
Company will reimburse such Purchaser for its reasonable legal and other
expenses (including the cost of any investigation, preparation and travel in
connection therewith) incurred in connection therewith, as such expenses are
incurred. The reimbursement obligations of the Company under this paragraph
shall be in addition to any liability which the Company may otherwise have,
shall extend upon the same terms and conditions to any Affiliates of the
Purchasers who are actually named in such action, proceeding or investigation,
and partners, directors, agents, employees and controlling persons (if any), as
the case may be, of the Purchasers and any such Affiliate, and shall be binding
upon and inure to the benefit of any successors, assigns, heirs and personal
representatives of the Company, the Purchasers and any such Affiliate and any
such Person. The Company also agrees that neither the Purchasers nor any such
Affiliates, partners, directors, agents, employees or controlling persons shall
have any
                                      -15-

<PAGE>

liability to the Company or any Person asserting claims on behalf of or in right
of the Company solely as a result of the acquisition of the Securities
hereunder.

                                   ARTICLE IV
                                  MISCELLANEOUS

         4.1 Fees and Expenses. At the Closing, the Company shall reimburse the
Purchasers for their legal fees and expenses incurred in connection with the
preparation and negotiation of the Transaction Documents by paying to Robinson
Silverman $30,000 for the preparation and negotiation of the Transaction
Documents. The amount contemplated by the immediately preceding sentence shall
be retained by the Purchasers and shall not be delivered to the Company at the
Closing. Other than the amount contemplated herein, and except as otherwise set
forth in the Registration Rights Agreement, each party shall pay the fees and
expenses of its advisers, counsel, accountants and other experts, if any, and
all other expenses incurred by such party incident to the negotiation,
preparation, execution, delivery and performance of this Agreement. The Company
shall pay all stamp and other taxes and duties levied in connection with the
issuance of the Securities.

         4.2 Entire Agreement; Amendments. The Transaction Documents, together
with the Exhibits and Schedules thereto and the Transfer Agent Instructions
contain the entire understanding of the parties with respect to the subject
matter hereof and supersede all prior agreements and understandings, oral or
written, with respect to such matters, which the parties acknowledge have been
merged into such documents, exhibits and schedules.

         4.3 Notices. Any and all notices or other communications or deliveries
required or permitted to be provided hereunder shall be in writing and shall be
deemed given and effective on the earliest of (i) the date of transmission, if
such notice or communication is delivered via facsimile at the facsimile
telephone number specified in this Section prior to 6:30 p.m. (New York City
time) on a Business Day, (ii) the Business Day after the date of transmission,
if such notice or communication is delivered via facsimile at the facsimile
telephone number specified in this Agreement later than 6:30 p.m. (New York City
time) on any date and earlier than 11:59 p.m. (New York City time) on such date,
(iii) the Business Day following the date of mailing, if sent by nationally
recognized overnight courier service, or (iv) upon actual receipt by the party
to whom such notice is required to be given. The address for such notices and
communications shall be as follows:

         If to the Company:                   DynaGen, Inc.
                                              1000 Winter Street, Suite 2700
                                              Waltham, MA 02451
                                              Facsimile No.: (781) 890-0118
                                              Attn:  Chief Financial Officer

         With copies to:                      Foley, Hoag & Eliot LLP
                                              One Post Office Square
                                              Boston, Massachusetts
                                              Facsimile No.: (617) 832-7000
                                              Attn: David Broadwin

                                      -16-
<PAGE>

         If to a Purchaser:                   To the address set forth under
                                              such Purchaser's name on the
                                              signature pages hereto;

or such other address as may be designated in writing hereafter, in the same
manner, by such Person.

         4.4 Amendments; Waivers. No provision of this Agreement may be waived
or amended except in a written instrument signed, in the case of an amendment,
by the Company and each of the Purchasers or, in the case of a waiver, by the
party against whom enforcement of any such waiver is sought. No waiver of any
default with respect to any provision, condition or requirement of this
Agreement shall be deemed to be a continuing waiver in the future or a waiver of
any other provision, condition or requirement hereof, nor shall any delay or
omission of either party to exercise any right hereunder in any manner impair
the exercise of any such right accruing to it thereafter.

         4.5 Headings. The headings herein are for convenience only, do not
constitute a part of this Agreement and shall not be deemed to limit or affect
any of the provisions hereof.

         4.6 Successors and Assigns. This Agreement shall be binding upon and
inure to the benefit of the parties and their successors and permitted assigns.
The Company may not assign this Agreement or any rights or obligations hereunder
without the prior written consent of the Purchasers. Except as set forth in
Section 3.1(a), the Purchasers may not assign this Agreement or any of the
rights or obligations hereunder without the consent of the Company. This
provision shall not limit any Purchaser's right to transfer securities or
transfer or assign rights under the Registration Rights Agreement.

         4.7 No Third-Party Beneficiaries. This Agreement is intended for the
benefit of the parties hereto and their respective successors and permitted
assigns and is not for the benefit of, nor may any provision hereof be enforced
by, any other Person.

         4.8 Governing Law. The corporate laws of the State of Delaware shall
govern all issues concerning the relative rights of the Company and its
stockholders. All other questions concerning the construction, validity,
enforcement and interpretation of this Agreement shall be governed by and
construed and enforced in accordance with the internal laws of the State of New
York, without regard to the principles of conflicts of law thereof. Each party
hereby irrevocably submits to the exclusive jurisdiction of the state and
federal courts sitting in the City of New York, borough of Manhattan, for the
adjudication of any dispute hereunder or in connection herewith or with any
transaction contemplated hereby or discussed herein (including with respect to
the enforcement of any of the Transaction Documents), and hereby irrevocably
waives, and agrees not to assert in any suit, action or proceeding, any claim
that it is not personally subject to the jurisdiction of any such court, that
such suit, action or proceeding is improper. Each party hereby irrevocably
waives personal service of process and consents to process being served in

                                      -17-
<PAGE>

any such suit, action or proceeding by mailing a copy thereof via registered or
certified mail or overnight delivery (with evidence of delivery) to such party
at the address in effect for notices to it under this Agreement and agrees that
such service shall constitute good and sufficient service of process and notice
thereof. Nothing contained herein shall be deemed to limit in any way any right
to serve process in any manner permitted by law.

         4.9 Survival. The representations, warranties, agreements and covenants
contained herein shall survive the Closing and the delivery and conversion of
the Shares.

         4.10 Execution. This Agreement may be executed in two or more
counterparts, all of which when taken together shall be considered one and the
same agreement and shall become effective when counterparts have been signed by
each party and delivered to the other party, it being understood that both
parties need not sign the same counterpart. In the event that any signature is
delivered by facsimile transmission, such signature shall create a valid and
binding obligation of the party executing (or on whose behalf such signature is
executed) the same with the same force and effect as if such facsimile signature
page were an original thereof.

         4.11 Severability. In case any one or more of the provisions of this
Agreement shall be invalid or unenforceable in any respect, the validity and
enforceability of the remaining terms and provisions of this Agreement shall not
in any way be affecting or impaired thereby and the parties will attempt to
agree upon a valid and enforceable provision which shall be a reasonable
substitute therefor, and upon so agreeing, shall incorporate such substitute
provision in this Agreement.

         4.12 Remedies. In addition to being entitled to exercise all rights
provided herein or granted by law, including recovery of damages, each of the
Purchasers will be entitled to specific performance of the obligations of the
Company under the Transaction Documents. The Company and each of the Purchasers
agree that monetary damages may not be adequate compensation for any loss
incurred by reason of any breach of its obligations described in the foregoing
sentence and hereby agrees to waive in any action for specific performance of
any such obligation the defense that a remedy at law would be adequate.

         4.13 Independent Nature of Purchasers' Obligations and Rights. The
obligations of each Purchaser under any Transaction Document is several and not
joint with the obligations of any other Purchaser and no Purchaser shall be
responsible in any way for the performance of the obligations of any other
Purchaser under any Transaction Document. Nothing contained herein or in any
Transaction Document, and no action taken by any Purchaser pursuant thereto,
shall be deemed to constitute the Purchasers as a partnership, an association, a
joint venture or any other kind of entity, or create a presumption that the
Purchasers are in any way acting in concert with respect to such obligations or
the transactions contemplated by the Transaction Document. Each Purchaser shall
be entitled to independently protect and enforce its rights, including without
limitation the rights arising out of this Agreement or out of the other
Transaction Documents, and it shall not be necessary for any other Purchaser to
be joined as an additional party in any proceeding for such purpose.

                   [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                            SIGNATURE PAGES FOLLOWS]

                                      -18-
<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have caused this
Convertible Preferred Stock Purchase Agreement to be duly executed by their
respective authorized signatories as of the date first indicated above.

                                DYNAGEN, INC.

                                By:_____________________________________
                                    Name:
                                    Title:

                   [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                      SIGNATURE PAGE FOR PURCHASER FOLLOWS]

                                      -19-
<PAGE>

                                KENILWORTH LLC

                                By:_____________________________________
                                    Name:
                                    Title:

                                Purchase Price for Shares to be
                                acquired at Closing:            $2,120,000

         Address for Notice:    Kenilworth LLC

                                c/o Citco Trustees (Cayman) Limited
                                Commercial Centre
                                P.O. Box 31106 SMB
                                Grand Cayman
                                Cayman Islands
                                British West Indies
                                Facsimile No.: (345) 945-7566

         With copies to:        Robinson Silverman Pearce Aronsohn & Berman LLP
                                1290 Avenue of the Americas
                                New York, NY  10104
                                Facsimile No.: (212) 541-4630 and (212) 541-1432
                                Attn:  Eric L. Cohen, Esq.

                   [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                      SIGNATURE PAGE FOR PURCHASER FOLLOWS]

                                      -20-
<PAGE>

                 CONVERTIBLE PREFERRED STOCK PURCHASE AGREEMENT

                                      Among

                                  DYNAGEN, INC.

                                       and

                         THE INVESTORS SIGNATORY HERETO

                            Dated as of July 17, 2000

                                      -21-
<PAGE>

                                 Schedule 2.1(c)

1. Authorized shares of Common Stock - 125,000,000

2. Issued and outstanding shares of Common Stock - 74,251,546

                                      -22-EXHIBIT 4.6
                                                                     -----------

                        TERMS OF SERIES M PREFERRED STOCK

                  Section 1. Designation, Amount and Par Value. The series of
preferred stock shall be designated as its 4% Series M Convertible Preferred
Stock (the "Series M Preferred Stock") and the number of shares so designated
shall be 25,600 (which shall not be subject to increase without the consent of
the holders of the Series M Preferred Stock (each, a "Holder" and collectively,
the "Holders")). Each share of Series M Preferred Stock shall have a par value
of $.01 per share and a stated value equal to the sum of $100 plus all unpaid
and accrued dividends to the date of determination to the extent not previously
paid in cash in accordance with the terms hereof (the "Stated Value").

                  Section 2.        Dividends.
                                    ---------

                  (a) Holders shall be entitled to receive, out of funds legally
available therefor, and the Company shall pay, cumulative dividends at the rate
per share (as a percentage of the Stated Value per share) of 4% per annum,
payable on each Conversion Date (as defined herein) for such share, in cash or
by accretion of the Stated Value. Subject to the terms and conditions herein,
the decision whether to accrete dividends hereunder to the Stated Value or to
pay for dividends in cash shall be at the discretion of the Company. The Company
shall provide the Holders written notice of its intention to accrete dividends
hereunder to the Stated Value or pay dividends in cash not less than ten days
prior to each Conversion Date for so long as shares of Series M Preferred Stock
are outstanding (the Company may indicate in such notice that the election
contained in such notice shall continue for later periods until revised).
Failure to timely provide such written notice shall be deemed (if permitted
hereunder) an election by the Company to accrete dividends hereunder to the
Stated Value. Dividends on the Series M Preferred Stock shall be calculated on
the basis of a 360-day year, shall accrue daily commencing on the Original Issue
Date (as defined in Section 8), and shall be deemed to accrue from such date
whether or not earned or declared and whether or not there are profits, surplus
or other funds of the Company legally available for the payment of dividends.
Except as otherwise provided herein, if at any time the Company pays less than
the total amount of dividends then accrued on account of the Series M Preferred
Stock, such payment shall be distributed ratably among the Holders based upon
the number of shares of Series M Preferred Stock held by each Holder. Any
dividends to be paid in cash hereunder that are not paid within three Trading
Days (as defined in Section 8) following a Dividend Payment Date shall continue
to accrue and shall entail a late fee, which must be paid in cash, at the rate
of 18% per annum or the lesser rate permitted by applicable law (such fees to
accrue daily, from the date such dividend is due hereunder through and including
the date of payment).

                  (b) Notwithstanding anything to the contrary contained herein,
the Company must pay dividends in cash if:

<PAGE>

                           (i) the number of shares of Common Stock (as defined
in Section 8) at the time authorized, unissued and unreserved for all purposes
is insufficient to accrete such dividends to the Stated Value to permit
conversion in full of all outstanding Stated Value;

                           (ii) after the Dividend Effectiveness Date (as
defined in Section 8), Underlying Shares (as defined in Section 8) (x) are not
registered for resale pursuant to an effective Underlying Shares Registration
Statement (as defined in Section 8) and (y) may not be sold without volume
restrictions pursuant to Rule 144 promulgated under the Securities Act (as
defined in Section 8), as determined by counsel to the Company pursuant to a
written opinion letter, addressed to the Company's transfer agent in the form
and substance acceptable to the applicable Holder and such transfer agent;

                           (iii) the Common Stock is not then eligible for
quotation on the OTC Bulletin Board (the "OTC") or listed for trading on the
Nasdaq National Market, the New York Stock Exchange, the American Stock Exchange
or the Nasdaq SmallCap Market (each, a "Subsequent Market"); or

                           (iv) the accretion of such dividends to the Stated
Value and subsequent conversions of all then outstanding Stated Value would
result in a violation of any rules and regulations governing any Subsequent
Market on which the Common Stock is then listed or quoted for trading.

                  (c) So long as any Series M Preferred Stock shall remain
outstanding, neither the Company nor any subsidiary thereof shall redeem,
purchase or otherwise acquire directly or indirectly any Junior Securities (as
defined in Section 8), nor shall the Company directly or indirectly pay or
declare any dividend or make any distribution (other than a dividend or
distribution described in Section 5 or dividends due and paid in the ordinary
course on preferred stock of the Company at such times when the Company is in
compliance with its payment and other obligations hereunder) upon, nor shall any
distribution be made in respect of, any Junior Securities, nor shall any monies
be set aside for or applied to the purchase or redemption (through a sinking
fund or otherwise) of any Junior Securities or shares pari passu with the Series
M Preferred Stock.

                  Section 3. Voting Rights. Except as otherwise provided herein
and as otherwise required by law, the Series M Preferred Stock shall have no
voting rights. However, so long as any shares of Series M Preferred Stock are
outstanding, the Company shall not, without the affirmative vote of the Holders
of a majority of the shares of the Series M Preferred Stock then outstanding,
(a) alter or change adversely the powers, preferences or rights given to the
Series M Preferred Stock or alter or amend this Certificate of Designation, (b)
authorize or create any class of stock ranking as to dividends or distribution
of assets upon a Liquidation (as defined in Section 4) senior to the Series M
Preferred Stock, (c) amend its certificate or articles of incorporation or other
charter documents so as to affect adversely any rights of the Holders, (d)
increase the authorized number of shares of Series M Preferred Stock, or (e)
enter into any agreement with respect to the foregoing.

                  Section 4. Liquidation. Upon any liquidation, dissolution or
winding-up of the Company, whether voluntary or involuntary (a "Liquidation"),
the Holders shall be entitled to receive out of the assets of the Company,
whether such assets are capital or surplus, for each share

                                       -2-
<PAGE>

of Series M Preferred Stock an amount equal to the Stated Value per share before
any distribution or payment shall be made to the holders of any Junior
Securities, and if the assets of the Company shall be insufficient to pay in
full such amounts, then the entire assets to be distributed to the Holders shall
be distributed among the Holders ratably in accordance with the respective
amounts that would be payable on such shares if all amounts payable thereon were
paid in full. A Change of Control (as defined in Section 8) shall not be treated
as a Liquidation, but instead shall be subject to the provisions of Sections 5
and 7. The Company shall mail written notice of any such Liquidation, not less
than 45 days prior to the payment date stated therein, to each record Holder.

                  Section 5.        Conversion.
                                    ----------

                  (a)(i) Conversions at Option of Holder. Each share of Series M
Preferred Stock shall be convertible into shares of Common Stock (subject to the
limitations set forth in Section (a)(ii)) at the Conversion Ratio (as defined in
Section 8), at the option of the Holder, at any time and from time to time from
and after the Original Issue Date. Holders shall effect conversions by
surrendering the certificate or certificates representing the shares of Series M
Preferred Stock to be converted to the Company, together with the form of
conversion notice attached hereto as Exhibit A (a "Conversion Notice"). Each
Conversion Notice shall specify the number of shares of Series M Preferred Stock
to be converted and the date on which such conversion is to be effected, which
date may not be prior to the date the Holder delivers such Conversion Notice by
facsimile (the "Conversion Date"). If no Conversion Date is specified in a
Conversion Notice, the Conversion Date shall be the date that such Conversion
Notice is deemed delivered hereunder. If the Holder is converting less than all
shares of Series M Preferred Stock represented by the certificate or
certificates tendered by the Holder with the Conversion Notice, or if a
conversion hereunder cannot be effected in full for any reason, the Company
shall promptly deliver to such Holder (in the manner and within the time set
forth in Section 5(b)) a certificate representing the number of shares of Series
M Preferred Stock as have not been converted.

                           (ii) Certain Conversion Restrictions.

                           (A) A Holder may not convert shares of Series M
Preferred Stock or receive shares of Common Stock as payment of dividends
hereunder to the extent such conversion or receipt of such dividend payment
would result in the Holder, together with any affiliate thereof, beneficially
owning (as determined in accordance with Section 13(d) of the Exchange Act (as
defined in Section 8) and the rules promulgated thereunder) in excess of 4.999%
of the then issued and outstanding shares of Common Stock, including shares
issuable upon conversion of, and payment of dividends on, the shares of Series M
Preferred Stock held by such Holder after application of this Section. Since the
Holder will not be obligated to report to the Company the number of shares of
Common Stock it may hold at the time of a conversion hereunder, unless the
conversion at issue would result in the issuance of shares of Common Stock in
excess of 4.999% of the then outstanding shares of Common Stock without regard
to any other shares which may be beneficially owned by the Holder or an
affiliate thereof, the Holder shall have the authority and obligation to
determine whether the restriction contained in this Section will limit any
particular conversion hereunder and to the extent that the Holder determines
that the limitation contained in this Section applies, the determination of
which portion of the shares of Series M Preferred Stock are convertible shall be
the responsibility

                                      -3-
<PAGE>

and obligation of the Holder. If the Holder has delivered a Conversion Notice
for shares of Series M Preferred Stock that, without regard to any other shares
that the Holder or its affiliates may beneficially own, would result in the
issuance in excess of the permitted amount hereunder, the Company shall notify
the Holder of this fact and shall honor the conversion for the maximum number of
shares of Series M Preferred Stock permitted to be converted on such Conversion
Date in accordance with the periods described in Section 5(b) and, at the option
of the Holder, either retain shares of Series M Preferred Stock tendered for
conversion in excess of the permitted amount hereunder for future conversions or
return such excess shares of Series M Preferred Stock permitted to the Holder.
The provisions of this Section may be waived by a Holder (but only as to itself
and not to any other Holder) upon not less than 61 days prior notice to the
Company. Other Holders shall be unaffected by any such waiver.

                           (B) A Holder may not convert shares of Series M
Preferred Stock or receive shares of Common Stock as payment of dividends
hereunder to the extent such conversion or receipt of such dividend payment
would result in the Holder, together with any affiliate thereof, beneficially
owning (as determined in accordance with Section 13(d) of the Exchange Act and
the rules promulgated thereunder) in excess of 9.999% of the then issued and
outstanding shares of Common Stock, including shares issuable upon conversion
of, and payment of dividends on, the shares of Series M Preferred Stock held by
such Holder after application of this Section. Since the Holder will not be
obligated to report to the Company the number of shares of Common Stock it may
hold at the time of a conversion hereunder, unless the conversion at issue would
result in the issuance of shares of Common Stock in excess of 9.999% of the then
outstanding shares of Common Stock without regard to any other shares which may
be beneficially owned by the Holder or an affiliate thereof, the Holder shall
have the authority and obligation to determine whether the restriction contained
in this Section will limit any particular conversion hereunder and to the extent
that the Holder determines that the limitation contained in this Section
applies, the determination of which portion of the shares of Series M Preferred
Stock are convertible shall be the responsibility and obligation of the Holder.
If the Holder has delivered a Conversion Notice for shares of Series M Preferred
Stock that, without regard to any other shares that the Holder or its affiliates
may beneficially own, would result in the issuance in excess of the permitted
amount hereunder, the Company shall notify the Holder of this fact and shall
honor the conversion for the maximum number of shares of Series M Preferred
Stock permitted to be converted on such Conversion Date in accordance with the
periods described in Section 5(b) and, at the option of the Holder, either
retain shares of Series M Preferred Stock tendered for conversion in excess of
the permitted amount hereunder for future conversions or return such excess
shares of Series M Preferred Stock permitted to the Holder. The provisions of
this Section may be waived by a Holder (but only as to itself and not to any
other Holder) upon not less than 61 days prior notice to the Company. Other
Holders shall be unaffected by any such waiver.

                  (b)(i) Not later than three Trading Days after each Conversion
Date, the Company will deliver to the Holder (A) a certificate or certificates
which shall be free of restrictive legends and trading restrictions (other than
those required by Section 3.1(b) of the Purchase Agreement) representing the
number of shares of Common Stock being acquired upon the conversion of shares of
Series M Preferred Stock, (B) one or more certificates representing the number
of shares of Series M Preferred Stock not converted and (C) a bank check in the
amount of accrued and unpaid

                                       -4-
<PAGE>

dividends (if the Company has elected or is required to pay accrued dividends in
cash). Notwithstanding the foregoing or anything to the contrary contained
herein, the Company shall not be obligated to issue certificates evidencing the
shares of Common Stock issuable upon conversion of any shares of Series M
Preferred Stock until one Trading Day after certificates evidencing such shares
of Series M Preferred Stock are delivered for conversion to the Company, or the
Holder of such Series M Preferred Stock notifies the Company that such
certificates have been lost, stolen or destroyed and provides a bond (or other
adequate security) reasonably satisfactory to the Company to indemnify the
Company from any loss incurred by it in connection therewith. The Company shall,
upon request of the Holder, if available, use its best efforts to deliver any
certificate or certificates required to be delivered by the Company under this
Section electronically through the Depository Trust Corporation or another
established clearing corporation performing similar functions. If in the case of
any Conversion Notice such certificate or certificates are not delivered to or
as directed by the applicable Holder by the third Trading Day after the
Conversion Date, the Holder shall be entitled to elect by written notice to the
Company at any time on or before its receipt of such certificate or certificates
thereafter, to rescind such conversion, in which event the Company shall
immediately return the certificates representing the shares of Series M
Preferred Stock tendered for conversion.

                  (ii) If the Company fails to deliver to the Holder such
certificate or certificates pursuant to Section 5(b)(i), by the third Trading
Day after the Conversion Date, the Company shall pay to such Holder, in cash, as
liquidated damages and not as a penalty, $5,000 for each Trading Day after such
third Trading Day until such certificates are delivered. Nothing herein shall
limit a Holder's right to pursue actual damages for the Company's failure to
deliver certificates representing shares of Common Stock upon conversion within
the period specified herein and such Holder shall have the right to pursue all
remedies available to it hereunder, at law or in equity including, without
limitation, a decree of specific performance and/or injunctive relief.

                  (iii) In addition to any other rights available to the Holder,
if the Company fails to deliver to the Holder such certificate or certificates
pursuant to Section 5(b)(i), by the third Trading Day after the Conversion Date,
and if after such third Trading Day the Holder purchases (in an open market
transaction or otherwise) Common Stock to deliver in satisfaction of a sale by
such Holder of the Underlying Shares which the Holder was entitled to receive
upon such conversion (a "Buy-In"), then the Company shall (A) pay in cash to the
Holder the amount by which (x) the Holder's total purchase price (including
brokerage commissions, if any) for the Common Stock so purchased exceeds (y) the
product of (1) the aggregate number of shares of Common Stock that such Holder
was entitled to receive from the conversion at issue multiplied by (2) the
market price of the Common Stock at the time of the sale giving rise to such
purchase obligation and (B) at the option of the Holder, either return the
shares of Series M Preferred Stock for which such conversion was not honored or
deliver to such Holder the number of shares of Common Stock that would have been
issued had the Company timely complied with its conversion and delivery
obligations under Section 5(b)(i). For example, if the Holder purchases Common
Stock having a total purchase price of $11,000 to cover a Buy-In with respect to
an attempted conversion of shares of Series M Preferred Stock with respect to
which the market price of the Underlying Shares on the date of conversion
totaled $10,000, under clause (A) of the immediately preceding sentence the
Company shall be required to pay the Holder $1,000. The Holder shall provide the
Company written notice indicating

                                       -5-
<PAGE>

the amounts payable to the Holder in respect of the Buy-In. Nothing herein shall
limit a Holder's right to pursue any other remedies available to it hereunder,
at law or in equity including, without limitation, a decree of specific
performance and/or injunctive relief with respect to the Company's failure to
timely deliver certificates representing shares of Common Stock upon conversion
of the shares of Series M Preferred Stock as required pursuant to the terms
hereof. Notwithstanding anything herein to the contrary, upon receipt of payment
pursuant to this Section 5(b)(iii) in connection with a particular conversion, a
Holder shall not be entitled to receive payment pursuant to Section 5(b)(ii) in
connection with such conversion.

                  (c)(i) The conversion price for each share of Series M
Preferred Stock in effect on any Conversion Date (the "Conversion Price") shall
be 80% of the average of the three lowest Per Share Market Values during the
period of five consecutive Trading Days preceding the applicable Conversion Date
(which may include Trading Days prior to the Original Issue Date), provided,
that such five Trading Day period shall be extended for the number of Trading
Days during such period in which (A) trading in the Common Stock is suspended by
OTC or a Subsequent Market on which the Common Stock is then listed, or (B)
after the date declared effective by the Commission, the Underlying Shares
Registration Statement is either not effective, or the Prospectus included in
the Underlying Shares Registration Statement may not be used by the Holder for
the resale of Underlying Shares.

                           (ii)     [Intentionally Left Blank].

                           (iii) If the Company, at any time while any shares of
Series M Preferred Stock are outstanding, shall issue rights, warrants or
options to all holders of Common Stock entitling them to subscribe for or
purchase shares of Common Stock at a price per share less than the Per Share
Market Value at the record date mentioned below, then each Holder shall receive
such rights, warrants or options in an amount equal to such amount which would
have been distributed to such Holder had such Holder, on the date of such
issuance, converted all of the shares of Series M Preferred Stock then held by
it into shares of Common Stock.

                           (iv)      [Intentionally Left Blank].

                           (v) If the Company, at any time while shares of
Series M Preferred Stock are outstanding, shall distribute to all holders of
Common Stock (and not to Holders) evidences of its indebtedness or assets or
rights or warrants to subscribe for or purchase any security (excluding those
referred to in Section 5(c)(iii) above), then in each such case each Holder
shall receive such assets, rights or warrants in an amount equal to such amount
which would have been distributed to such Holder had such Holder, on the date of
such distribution, converted all of the shares of Series M Preferred Stock then
held by it into shares of Common Stock.

                           (vi) All calculations under this Section 5 shall be
made to the nearest cent or the nearest 1/100th of a share, as the case may be.
The number of shares of Common Stock outstanding at any given time shall not
include shares owned or held by or for the account of the Company, and the
disposition of any such shares shall be considered an issue or sale of Common
Stock.

                                       -6-
<PAGE>

                           (vii)    [Intentionally Left Blank].

                           (viii) In case of any reclassification of the Common
Stock, or any compulsory share exchange pursuant to which the Common Stock is
converted into other securities, cash or property (other than compulsory share
exchanges which constitute Change of Control Transactions), the Holders of the
Series M Preferred Stock then outstanding shall have the right thereafter to
convert such shares only into the shares of stock and other securities, cash and
property receivable upon or deemed to be held by holders of Common Stock
following such reclassification or share exchange, and the Holders of the Series
M Preferred Stock shall be entitled upon such event to receive such amount of
securities, cash or property as a holder of the number of shares of Common Stock
of the Company into which such shares of Series M Preferred Stock could have
been converted immediately prior to such reclassification or share exchange
would have been entitled. This provision shall similarly apply to successive
reclassifications or share exchanges.

                           (ix) In case of any (1) merger or consolidation of
the Company with or into another Person, or (2) sale by the Company of more than
one-half of the assets of the Company (on an as valued basis) in one or a series
of related transactions, a Holder shall have the right thereafter to (A) convert
its shares of Series M Preferred Stock into the shares of stock and other
securities, cash and property receivable upon or deemed to be held by holders of
Common Stock following such merger, consolidation or sale, and such Holder shall
be entitled upon such event or series of related events to receive such amount
of securities, cash and property as the shares of Common Stock into which such
shares of Series M Preferred Stock could have been converted immediately prior
to such merger, consolidation or sales would have been entitled, or (B) in the
case of a merger or consolidation, (x) require the surviving entity to issue
shares of convertible preferred stock or convertible debentures with such
aggregate stated value or in such face amount, as the case may be, equal to the
Stated Value of the shares of Series M Preferred Stock then held by such Holder,
plus all accrued and unpaid dividends and other amounts owing thereon, which
newly issued shares of preferred stock or debentures shall have terms identical
(including with respect to conversion) to the terms of the Series M Preferred
Stock (except, in the case of debentures, as may be required to reflect the
differences between debt and equity) and shall be entitled to all of the rights
and privileges of a Holder of Series M Preferred Stock set forth herein and the
agreements pursuant to which the Series M Preferred Stock was issued (including,
without limitation, as such rights relate to the acquisition, transferability,
registration and listing of such shares of stock other securities issuable upon
conversion thereof), and (y) simultaneously with the issuance of such
convertible preferred stock or convertible debentures, shall have the right to
convert such instrument only into shares of stock and other securities, cash and
property receivable upon or deemed to be held by holders of Common Stock
following such merger or consolidation. In the case of clause (B), the
conversion price applicable for the newly issued shares of convertible preferred
stock or convertible debentures shall be based upon the amount of securities,
cash and property that each share of Common Stock would receive in such
transaction, the Conversion Ratio immediately prior to the effectiveness or
closing date for such transaction and the Conversion Price stated herein. The
terms of any such merger, sale or consolidation shall include such terms so as
continue to give the Holders the right to receive the securities, cash and
property set forth in this Section upon any conversion or redemption following
such event. This provision shall similarly apply to successive such events.

                                      -7-
<PAGE>

The rights set forth in this Section 5(c)(ix) shall not alter the rights of a
Holder set forth in Section 7, provided, that, a Holder may only exercise the
rights set forth in this Section 5(c)(ix) or the rights set forth in Section 7
with respect to a single event giving rise to such rights.

                           (x) If (a) the Company shall declare a dividend (or
any other distribution) on the Common Stock, (b) the Company shall declare a
special nonrecurring cash dividend on or a redemption of the Common Stock, (c)
the Company shall authorize the granting to all holders of Common Stock rights
or warrants to subscribe for or purchase any shares of capital stock of any
class or of any rights, (d) the approval of any stockholders of the Company
shall be required in connection with any reclassification of the Common Stock,
any consolidation or merger to which the Company is a party, any sale or
transfer of all or substantially all of the assets of the Company, or any
compulsory share of exchange whereby the Common Stock is converted into other
securities, cash or property, or (e) the Company shall authorize the voluntary
or involuntary dissolution, liquidation or winding up of the affairs of the
Company; then the Company shall notify the Holders at their last addresses as
they shall appear upon the stock books of the Company, at least 30 calendar days
prior to the applicable record or effective date hereinafter specified, a notice
stating (x) the date on which a record is to be taken for the purpose of such
dividend, distribution, redemption, rights or warrants, or if a record is not to
be taken, the date as of which the holders of Common Stock of record to be
entitled to such dividend, distributions, redemption, rights or warrants are to
be determined or (y) the date on which such reclassification, consolidation,
merger, sale, transfer or share exchange is expected to become effective or
close, and the date as of which it is expected that holders of Common Stock of
record shall be entitled to exchange their Common Stock for securities, cash or
other property deliverable upon such reclassification, consolidation, merger,
sale, transfer or share exchange. Holders are entitled to convert shares of
Series M Preferred Stock during the 30-day period commencing the date of such
notice to the effective date of the event triggering such notice.

                  (d) The Company covenants that it will at all times reserve
and keep available out of its authorized and unissued shares of Common Stock
solely for the purpose of issuance upon conversion of Series M Preferred Stock
and payment of dividends on Series M Preferred Stock, each as herein provided,
free from preemptive rights or any other actual contingent purchase rights of
persons other than the Holders, not less than such number of shares of Common
Stock as shall be issuable (taking into account the provisions of Section 5(a)
and Section 5(c)) upon the conversion of all outstanding shares of Series M
Preferred Stock. The Company covenants that all shares of Common Stock that
shall be so issuable shall, upon issue, be duly and validly authorized, issued
and fully paid, nonassessable.

                  (e) Upon a conversion hereunder the Company shall not be
required to issue stock certificates representing fractions of shares of Common
Stock, but may if otherwise permitted, make a cash payment in respect of any
final fraction of a share based on the Per Share Market Value at such time. If
any fraction of an Underlying Share would, except for the provisions of this
Section, be issuable upon a conversion hereunder, the Company shall pay an
amount in cash equal to the Conversion Ratio multiplied by such fraction.

                                      -8-
<PAGE>

                  (f) The issuance of certificates for Common Stock on
conversion of Series M Preferred Stock shall be made without charge to the
Holders thereof for any documentary stamp or similar taxes that may be payable
in respect of the issue or delivery of such certificate, provided that the
Company shall not be required to pay any tax that may be payable in respect of
any transfer involved in the issuance and delivery of any such certificate upon
conversion in a name other than that of the Holder of such shares of Series M
Preferred Stock so converted.

                  (g) Shares of Series M Preferred Stock converted into Common
Stock or redeemed in accordance with the terms hereof shall be canceled and may
not be reissued.

                  (h) Any and all notices or other communications or deliveries
to be provided by the Holders of the Series M Preferred Stock hereunder,
including, without limitation, any Conversion Notice, shall be in writing and
delivered personally, by facsimile or sent by a nationally recognized overnight
courier service, addressed to the attention of the Chief Financial Officer of
the Company addressed to 1000 Winter Street, 2700 Suite, Waltham, MA 02451,
Facsimile No.: (781) 900-0118, or to such other address or facsimile number as
shall be specified in writing by the Company for such purpose. Any and all
notices or other communications or deliveries to be provided by the Company
hereunder shall be in writing and delivered personally, by facsimile or sent by
a nationally recognized overnight courier service, addressed to each Holder at
the facsimile telephone number or address of such Holder appearing on the books
of the Company, or if no such facsimile telephone number or address appears, at
the principal place of business of the Holder. Any notice or other communication
or deliveries hereunder shall be deemed given and effective on the earliest of
(i) the date of transmission, if such notice or communication is delivered via
facsimile at the facsimile telephone number specified in this Section prior to
6:30 p.m. (New York City time), (ii) the date after the date of transmission, if
such notice or communication is delivered via facsimile at the facsimile
telephone number specified in this Section later than 6:30 p.m. (New York City
time) on any date and earlier than 11:59 p.m. (New York City time) on such date,
(iii) upon receipt, if sent by a nationally recognized overnight courier
service, or (iv) upon actual receipt by the party to whom such notice is
required to be given.

                                      -9-
<PAGE>

                  Section 6.        Optional Redemption.
                                    -------------------

                  (a) Subject to the provisions of this Section 6, from and
after the Original Issue Date, the Company shall have the right, upon 10
calendar days' notice (an "Optional Redemption Notice"and the date such Optional
Redemption Notice is received by a Holder, an "Optional Redemption Date") to the
Holders, to redeem, from funds available to the Company pursuant to a financing
entered into the between the Company and the Holders subsequent to the Original
Issue Date in accordance with the term sheet between the Company and the
original Holders, dated May 26, 2000, all or any portion of the shares of Series
M Preferred Stock which have not previously been redeemed or for which
Conversion Notices shall not have been delivered, at a price equal to the
Optional Redemption Price (as defined in Section 8). The Company may only
deliver an Optional Redemption Notice if: (i) the number of shares of Common
Stock at the time authorized, unissued and unreserved for all purposes is
sufficient to satisfy the Company's conversion obligations of all shares of
Series M Preferred Stock then outstanding, (ii) the Underlying Shares then
outstanding are registered for resale pursuant to an effective Underlying Shares
Registration Statement pursuant to which the Holders are permitted to sell
Underlying Shares or the Underlying Shares may be resold without volume
restrictions pursuant to Rule 144(k) promulgated under the Securities Act, and
(iii) the Common Stock is listed for trading on the OTC or on a Subsequent
Market. In order for an Optional Redemption Date to remain in effect subsequent
to the Optional Redemption Notice, each of clauses (i) - (iii) of the
immediately preceding sentence must be true during the entire 10 calendar days
between an Optional Redemption Date and the date of payment of the Optional
Redemption Notice. The entire Optional Redemption Price shall be paid in cash. A
Holder may convert (and the Company shall honor such conversions in accordance
with the terms hereof) any or all of the shares of Series M Preferred Stock
subject to an Optional Redemption Notice delivered for conversion on or prior to
the 10th calendar day following the Optional Redemption Date.

                  (b) Failure by the Company to pay any portion of the Optional
Redemption Price by the 10th calendar day following an Optional Redemption Date
shall, at the option of the Holder subject thereto, result in the invalidation
ab initio of the unpaid portion of such optional redemption, and,
notwithstanding anything herein to the contrary, the Company shall thereafter
have no further rights to optionally redeem any shares of Series M Preferred
Stock. In such event, the Company shall, at the option of the Holder, either,
(i) not later than three Trading Days from receipt of Holder's request for such
election, return to the Holder all of the shares of Series M Preferred Stock for
which such Optional Redemption Price has not been paid in full (the "Unpaid
Redemption Shares") or (ii) convert all or any portion of the Unpaid Redemption
Shares in which event the Per Share Market Value for such shares shall be the
lower of the Per Share Market Value calculated on the date the Optional
Redemption Price was originally due and the Per Share Market Value as of the
Holder's written demand for conversion. If the Holder elects option (ii) above,
the Company shall within three Trading Days of its receipt of such election
deliver to the Holder the shares of Common Stock issuable upon conversion of the
Unpaid Redemption Shares subject to such Holder conversion demand and otherwise
perform its obligations hereunder with respect thereto.

         Section 7.        Redemption Upon Triggering Events.
                           ---------------------------------

                                      -10-
<PAGE>

                  (a) Upon the occurrence of a Triggering Event, each Holder
shall (in addition to all other rights it may have hereunder or under applicable
law), have the right, exercisable at the sole option of such Holder, to require
the Company to redeem all or a portion of the Series M Preferred Stock then held
by such Holder for a redemption price, in cash, equal to the sum of (i) the
Mandatory Redemption Amount (as defined in Section 8) plus (ii) the product of
(A) the number of Underlying Shares issued in respect of conversions hereunder
and then held by the Holder and (B) the Per Share Market Value on the date such
redemption is demanded or the date the redemption price hereunder is paid in
full, whichever is greater (such sum, the "Redemption Price"). The Redemption
Price shall be due and payable within five Trading Days of the date on which the
notice for the payment therefor is provided by a Holder. If the Company fails to
pay the Redemption Price hereunder in full pursuant to this Section on the date
such amount is due in accordance with this Section, the Company will pay
interest thereon at a rate of 18% per annum (or the lesser amount permitted by
applicable law), accruing daily from such date until the Redemption Price, plus
all such interest thereon, is paid in full. For purposes of this Section, a
share of Series M Preferred Stock is outstanding until such date as the Holder
shall have received Underlying Shares upon a conversion (or attempted
conversion) thereof that meets the requirements hereof.

                  A "Triggering Event" means any one or more of the following
events (whatever the reason and whether it shall be voluntary or involuntary or
effected by operation of law or pursuant to any judgment, decree or order of any
court, or any order, rule or regulation of any administrative or governmental
body):

                           (i) the failure of an Underlying Shares Registration
Statement to be declared effective by the Commission on or prior to the 180th
day after the Original Issue Date;

                           (ii) if, during the Effectiveness Period, the
effectiveness of the Underlying Shares Registration Statement lapses for any
reason for more than an aggregate of 15 Trading Days (which need not be
consecutive Trading Days), or the Holder shall not be permitted to resell
Registrable Securities under the Underlying Shares Registration Statement for
more than an aggregate of 15 Trading Days (which need not be consecutive Trading
Days);

                           (iii) the Common Stock is not then eligible for
quotation on the OTC or listed for trading on Subsequent Market at the voluntary
approval of the Company;

                           (iv) the Company shall fail for any reason to deliver
certificates representing Underlying Shares issuable upon a conversion hereunder
that comply with the provisions hereof prior to the tenth Trading Day after the
Conversion Date or the Company shall provide notice to any Holder, including by
way of public announcement, at any time, of its intention not to comply with
requests for conversion of any shares of Series M Preferred Stock in accordance
with the terms hereof;

                           (v) the Company shall be a party to any Change of
Control Transaction, shall agree to sell (in one or a series of related
transactions) more than 75% of its assets or shall redeem more than a de minimis
number of Common Stock or other Junior Securities (other than redemptions of
Underlying Shares);

                                      -11-
<PAGE>

                           (vi) an Event (as defined in the Registration Rights
Agreement) shall not have been cured to the satisfaction of the Holders prior to
the expiration of 60 days from the Event Date (as defined in the Registration
Rights Agreement) relating thereto (other than an Event resulting from a failure
of an Underlying Shares Registration Statement to be declared effective by the
Commission on or prior to the 180th day after the Original Issue Date, which
shall be covered by Section 7(a)(i));

                           (vii) the Company shall fail for any reason to pay in
full the amount of cash due pursuant to a Buy-In within seven Business Days
after notice therefor is delivered hereunder or shall fail to pay all amounts
owed on account of an Event within seven Business Days of the date due);

                           (viii) the Company shall fail to have available a
sufficient number of authorized and unreserved shares of Common Stock to issue
to such Holder upon a conversion hereunder; or

                           (ix) the Company shall fail to observe or perform any
other covenant, agreement or warranty contained in, or otherwise commit any
breach of the Transaction Documents (as defined in Section 8) that shall
reasonably be determined to be within the control of the Company, and such
failure or breach shall not, if subject to the possibility of a cure by the
Company, have been remedied within ten Business Days after the date on which
written notice of such failure or breach shall have been given.

                           Section 8. Definitions. For the purposes hereof, the
following terms shall have the following meanings:

                  "Change of Control Transaction" means the occurrence of any of
(i) an acquisition after the date hereof by an individual or legal entity or
"group" (as described in Rule 13d-5(b)(1) promulgated under the Exchange Act) of
effective control (whether through legal or beneficial ownership of capital
stock of the Company, by contract or otherwise) of in excess of 50% of the
voting securities of the Company that it is approved by the board of directors
of the Company, (ii) a replacement at one time or over time of more than
one-half of the members of the Company's board of directors which is not
approved by a majority of those individuals who are members of the board of
directors on the date hereof (or by those individuals who are serving as members
of the board of directors on any date whose nomination to the board of directors
was approved by a majority of the members of the board of directors who are
members on the date hereof), (iii) the merger of the Company with or into
another entity that is not wholly-owned by the Company, consolidation or sale of
75% or more of the assets of the Company in one or a series of related
transactions, or (iv) the execution by the Company of an agreement to which the
Company is a party or by which it is bound, providing for any of the events set
forth above in (i), (ii) or (iii).

                  "Commission" means the Securities and Exchange Commission.

                                      -12-
<PAGE>

                  "Common Stock" means the Company's common stock, $.01 par
value per share, and stock of any other class into which such shares may
hereafter have been reclassified or changed.

                  "Conversion Ratio" means, at any time, a fraction, the
numerator of which is Stated Value and the denominator of which is the
Conversion Price at such time.

                  "Dividend Effectiveness Date" means the earlier to occur of
(x) the Effectiveness Date (as defined in the Registration Rights Agreement) and
(y) the date that an Underlying Shares Registration Statement is declared
effective by the Commission.

                  "Exchange Act" means the Securities Exchange Act of 1934, as
amended.

                  "Junior Securities" means the Common Stock and all other
equity securities of the Company other than: (i) those securities that are
outstanding on the Original Issue Date and which are explicitly senior in rights
or liquidation preference to the Series M Preferred Stock and (ii) all series of
the Company's preferred stock which are outstanding on the Original Issue Date.

                  "Mandatory Redemption Amount" for each share of Series M
Preferred Stock means the sum of (i) the greater of (A) 120% of the Stated Value
and (B) the product of (a) the Per Share Market Value on the Trading Day
immediately preceding (x) the date of the Triggering Event or the Conversion
Date, as the case may be, or (y) the date of payment in full by the Company of
the applicable redemption price, whichever is greater, and (b) the Conversion
Ratio calculated on the date of the Triggering Event, or the Conversion Date, as
the case may be, and (ii) all other amounts, costs, expenses and liquidated
damages due in respect of such share of Series M Preferred Stock.

                  "Optional Redemption Price " shall be the sum of (i) (1) if
the Optional Redemption Date occurs between the Original Issue Date and 120th
day following the Original Issue Date, 105% of the Stated Value of the shares of
Series M Preferred Stock to be redeemed (pursuant to Section 6), (2) if the
Optional Redemption Date occurs between the 121st day and the 180th day
following the Original Issue Date, 107.5% of the Stated Value of the shares of
Series M Preferred Stock to be redeemed (pursuant to Section 6), or (3) if the
Optional Redemption Date occurs at any time after the 181st day following the
Original Issue Date, 110% of the Stated Value of the shares of Series M
Preferred Stock to be redeemed (pursuant to Section 6), and (ii) all other
amounts, costs, expenses and liquidated damages due in respect of such shares of
Series M Preferred Stock.

                  "Original Issue Date" shall mean the date of the first
issuance of any shares of the Series M Preferred Stock regardless of the number
of transfers of any particular shares of Series M Preferred Stock and regardless
of the number of certificates which may be issued to evidence such Series M
Preferred Stock.

                  "Per Share Market Value" means on any particular date (a) the
closing bid price per share of Common Stock on such date on the Subsequent
Market on which the Common Stock is then listed or quoted, or if there is no
such price on such date, then the closing bid price on the Subsequent Market on
the date nearest preceding such date, or (b) if the Common Stock is not then
listed or quoted on a Subsequent Market, the closing bid price for a shares of
Common Stock in the

                                      -13-
<PAGE>

OTC, as reported by the National Quotation Bureau Incorporated or similar
organization or agency succeeding to its functions of reporting prices) at the
close of business on such date, or (c) if the Common Stock is not then reported
by the National Quotation Bureau Incorporated (or similar organization or agency
succeeding to its functions of reporting prices), then the average of the "Pink
Sheet" quotes for the relevant conversion period, as determined in good faith by
the Holder, or (d) if the Common Stock is not then publicly traded the fair
market value of a share of Common Stock as determined by an Appraiser selected
in good faith by the Holders of a majority of the shares of Series M Preferred
Stock.

                  "Person" means a corporation, an association, a partnership,
an organization, a business, an individual, a government or political
subdivision thereof or a governmental agency.

                  "Purchase Agreement" means the Convertible Series M Preferred
Stock Purchase Agreement, dated as of the Original Issue Date, to which the
Company and the original Holders are parties, as amended, modified or
supplemented from time to time in accordance with its terms.

                  "Registration Rights Agreement" means the Registration Rights
Agreement, dated as of the Original Issue Date, to which the Company and the
original Holders are parties, as amended, modified or supplemented from time to
time in accordance with its terms.

                  "Securities Act" means the Securities Act of 1933, as amended.

                  "Trading Day" means (a) a day on which the Common Stock is
traded on a Subsequent Market on which the Common Stock is then listed or
quoted, as the case may be, or (b) if the Common Stock is not listed on a
Subsequent Market, a day on which the Common Stock is traded in the
over-the-counter market, as reported by the OTC, or (c) if the Common Stock is
not quoted on the OTC, a day on which the Common Stock is quoted in the
over-the-counter market as reported by the National Quotation Bureau
Incorporated (or any similar organization or agency succeeding its functions of
reporting prices); provided, however, that in the event that the Common Stock is
not listed or quoted as set forth in (a), (b) and (c) hereof, then Trading Day
shall mean any day except Saturday, Sunday and any day which shall be a legal
holiday or a day on which banking institutions in the State of New York are
authorized or required by law or other government action to close.

                  "Transaction Documents" shall have the meaning set forth in
the Purchase Agreement.

                  "Underlying Shares" means, collectively, the shares of Common
Stock into which the shares of Series M Preferred Stock are convertible in
accordance with the terms hereof.

                  "Underlying Shares Registration Statement" means a
registration statement that meets the requirements of the Registration Rights
Agreement and registers the resale of all Underlying Shares by the Holder, who
shall be named as a "selling stockholder" thereunder.

                                      -14-
<PAGE>

                                    EXHIBIT A

                              NOTICE OF CONVERSION

(To be Executed by the Registered Holder
in order to Convert shares of Series M Preferred Stock)

The undersigned hereby elects to convert the number of shares of 4% Series M
Convertible Preferred Stock indicated below, into shares of common stock, $.01
par value per share (the "Common Stock"), of DynaGen, Inc., a Delaware
corporation (the "Company"), according to the conditions hereof, as of the date
written below. If shares are to be issued in the name of a person other than
undersigned, the undersigned will pay all transfer taxes payable with respect
thereto and is delivering herewith such certificates and opinions as reasonably
requested by the Company in accordance therewith. No fee will be charged to the
Holder for any conversion, except for such transfer taxes, if any.

Conversion calculations:
                              Date to Effect Conversion

                              Number of shares of Series M Preferred Stock to be
                              Converted

                              Stated Value of shares of Series M Preferred Stock
                              to be Converted

                              Number of shares of Common Stock to be Issued

                              Applicable Conversion Price

                              [ ] Check this box if resales of the shares of
                              Common Stock to be issued hereunder will not be
                              made pursuant to the Underlying Shares
                              Registration Statement in which case such shares
                              shall contain a restrictive legend pursuant to the
                              Purchase Agreement. Unless this box is checked,
                              the undersigned will deliver a prospectus in
                              connection with sales of such shares.

                              Signature

                              Name

                              Address

                                       15

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00015-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00015-of-00352.parquet"}]]