EXHIBIT 10.5

         AN INVESTMENT IN THE UNITS OF WHICH THIS NOTE FORMS A PART INVOLVES
SUBSTANTIAL RISKS. THE COMPANY INTENDS TO REPAY THE NOTE WITH THE PROCEEDS OF
FUTURE FINANCINGS. IF THE COMPANY DOES NOT OBTAIN ADDITIONAL FINANCING ON A
TIMELY BASIS, IT MAY NOT BE ABLE TO REPAY THE NOTE ON A TIMELY BASIS. EACH
POTENTIAL INVESTOR SHOULD CAREFULLY REVIEW THE SUBSCRIPTION AGREEMENT AND ALL
EXHIBITS THERETO PRIOR TO MAKING AN INVESTMENT DECISION. IN PARTICULAR,
POTENTIAL INVESTORS SHOULD READ AND CAREFULLY CONSIDER THE INFORMATION SET FORTH
UNDER THE HEADINGS "SPECIAL CONSIDERATIONS" AND "RISK FACTORS" IN THE COMPANY'S
ANNUAL REPORT ON FORM 10-K FOR THE YEAR ENDED DECEMBER 31, 1997, AS AMENDED
THROUGH THE DATE HEREOF (ATTACHED TO THE SUBSCRIPTION AGREEMENT AS EXHIBIT D AND
INCORPORATED HEREIN BY REFERENCE) AND THE COMPANY'S QUARTERLY REPORT ON FORM
10-Q FOR THE QUARTER ENDED SEPTEMBER 30, 1998, AS AMENDED THROUGH THE DATE
HEREOF (ATTACHED TO THE SUBSCRIPTION AGREEMENT AS EXHIBIT E AND INCORPORATED
HEREIN BY REFERENCE).

         THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 NOR
UNDER ANY STATE SECURITIES LAW AND MAY NOT BE PLEDGED, SOLD, ASSIGNED OR
TRANSFERRED UNTIL (I) A REGISTRATION STATEMENT WITH RESPECT THERETO IS EFFECTIVE
UNDER THE SECURITIES ACT OF 1933 AND ANY APPLICABLE STATE SECURITIES LAW OR (II)
THE COMPANY RECEIVES AN OPINION OF COUNSEL TO THE COMPANY OR OTHER COUNSEL TO
THE HOLDER OF SUCH NOTE, WHICH OTHER COUNSEL IS REASONABLY SATISFACTORY TO THE
COMPANY, THAT SUCH NOTE MAY BE PLEDGED, SOLD, ASSIGNED OR TRANSFERRED WITHOUT AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 OR APPLICABLE
STATE SECURITIES LAWS.

                                  DYNAGEN, INC.

                              NOTE DUE MAY 28, 1999

$___________________       February 28, 1999

         FOR VALUE RECEIVED, on May 28, 1999 (the "Maturity Date"), the
undersigned DynaGen, Inc., a Delaware corporation (the "Company"), with its
principal office at 840 Memorial Drive, Cambridge, Massachusetts 02139, promises
to pay to the order of_________________, with a principal place of business
at___________________________________ (the "Payee" or "the holder of this
Note"), or registered assigns, the principal amount of __________________ in
such coin or currency of the United States of America as at the time of payment
shall be legal tender for the payment of public or private debts, together with
interest at a rate equal to 12% per annum.

         This Note is one of several notes of the Company issued in connection
with a bridge financing for the Company of up to $500,000, which notes, together
with this Note, are hereinafter referred to as the "Notes."

         1. Events of Default. Upon the occurrence of any of the following
events (herein called "Events of Default") which shall have occurred and be
continuing:


<PAGE>


                  (a) the Company defaults in the payment of interest on this
         Note when the same becomes due and payable and such Default continues
         for a period of 10 days;

                  (b) the Company defaults in the payment of principal on this
         Note when the same becomes due and payable, at maturity or otherwise
         and such default continues for a period of 10 days;

                  (c) the Company fails to comply with any of the other
         agreements contained in this Note, and the Default continues for the
         period and after the notice specified below; and

                  (d) the Company pursuant to or within the meaning of any
         Bankruptcy Law (as defined below):

                          (i) commences a voluntary case;

                          (ii) consents to the entry of an order against it for
                          relief in an involuntary case; or

                          (iii) makes a general assignment for the benefit of
                          its creditors; or

                  (e) a court of competent jurisdiction enters an order or
         decree under any Bankruptcy Law that:

                          (i) is for relief against the Company in an
                          involuntary case;

                          (ii) appoints a Custodian (as hereinafter defined) for
                          all or substantially all of the assets of the Company;
                          or

                          (iii) orders a liquidation of the Company;

then in any such event the holder of this Note may, by written notice to the
Company, declare the entire unpaid principal amount of this Note outstanding
together with accrued interest thereon due and payable, and the same shall,
unless such default shall be cured within ten (10) days after such notice,
forthwith become due and payable upon the expiration of such ten-day period,
without presentment, demand protest, or other notice of any kind, all of which
are expressly waived.

         The term "Bankruptcy Law" means Title 11, U.S. Code or any similar
federal or state law. The term "Custodian" means any receiver, trustee,
assignee, liquidator, or similar official under any Bankruptcy Law.

         A default under clause (c) above shall not constitute an Event of
Default until the Payee notifies the Company of the Default and the Company does
not cure the Default within 20 days of


<PAGE>

such notice. The notice must specify the Event of Default, demand that it be
remedied, and state that it is a notice of Event of Default.

         2. Non-Waiver and Other Remedies. No course of dealing or delay on the
part of the holder of this Note in exercising any right thereunder shall operate
as a waiver thereof or otherwise prejudice the right of the holder of this Note.
No remedy conferred hereby shall be exclusive of any other remedy referred to
herein or now or hereinafter available at law, in equity, by statute or
otherwise.

         3. Affirmative Covenants. The Company covenants and agrees that, while
this Note is outstanding, it shall:

                  (a) Do all things necessary to preserve its corporate
existence and continue to engage in business of the same general type as
conducted as of the date hereof,

                  (b) Promptly notify the holder of this Note of the occurrence
of any Event of Default under this Note; and

                  (c) Comply in all material respects with all statutes, laws,
ordinances, orders, judgments, decrees, injunctions, rules, regulations,
permits, licenses, authorizations and requirements (collectively,
"Requirements(s)") of all governmental bodies which are applicable to the
Company or its properties, except wherein the failure to comply would not have a
material adverse effect on the Company or its property; provided that nothing
contained herein shall prevent the Company from contesting the validity or the
application of any Requirements.

         4. Voluntary Prepayment. This Note may be called by the Company at any
time in whole or in part from time to time, without penalty at the principal
amount plus accrued but unpaid interest.
Any partial call shall be made pro rata among the holders of the Notes.

         5. Holder as Deemed Owner. The Company may deem and treat the
registered holder hereof as the absolute owner of this Note (whether or not this
Note shall be overdue and notwithstanding any notice of ownership or writing
hereon made by anyone other than the Company) for the purpose of receiving
payment hereof or thereof or on account hereof and for all other purposes, and
the Company shall not be affected by notice to the contrary. The Company will
act as registrar for the Notes and any transfers of Notes may be made through
the Company in such capacity.

         6. Corporate Obligation. It is expressly understood that this Note is
solely a corporate obligation of the Company, and that any and all personal
liability, either at common law or in equity or by constitution or statute, of,
and any and all such rights and claims against, every promoter, subscriber,
incorporator, shareholder, officer or director, as such, are hereby expressly
waived and released by the holder hereof by the acceptance of this Note and as a
part of the consideration for the issue hereof.

         7. Required Consent. The Company may not modify any of the terms of the
Note without the prior written consent of the holders of all of the outstanding
Notes.

<PAGE>

         8. Lost Documents. Upon receipt by the Company of evidence satisfactory
to it of the loss, theft, destruction or mutilation of this Note or any Note
exchanged for it, and (in the case of loss, theft or destruction) of indemnity
satisfactory to it, and upon reimbursement to the Company of all reasonable
expenses incidental thereto, and upon surrender and cancellation of such Note,
if mutilated, the Company will make and deliver to in lieu of such Note a new
Note of like tenor and unpaid principal amount and dated as of the original date
of the Note.

         9.       Miscellaneous

                  (a) Parties in Interest. All covenants, agreements, and
undertakings in this Note by and on behalf of any of the parties hereto shall
bind and inure to the benefit of the respective permitted successors and assigns
of the parties hereto whether so expressed or not.

                  (b) Notices. All notices, requests, consents and demands shall
be made in writing and shall be mailed first class, certified mail, return
receipt requested, to the Company or to the holder of this Note at such
respective addresses as may be furnished in writing to the other party hereto.

                  (c) Construction. This Note shall be construed and enforced in
accordance with, and the rights of the parties shall be governed by, the laws of
The Commonwealth of Massachusetts.

         IN WITNESS WHEREOF, this Note has been executed and delivered on the
date specified above by the duly authorized representative of the Company.

                                                  DYNAGEN, INC.



_____________________                             By:
Attest                                                Dhananjay G. Wadekar
                                                      Executive Vice President