Exhibit 4.18


NEITHER THIS DEBENTURE NOR THE SECURITIES INTO WHICH
THIS DEBENTURE IS CONVERTIBLE HAVE BEEN REGISTERED WITH THE SECURITIES AND
EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE.  THESE SECURITIES HAVE BEEN SOLD 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.


SENESCO TECHNOLOGIES, INC.


SECURED CONVERTIBLE DEBENTURE


	
  Issuance Date: August
        , 2007

  	
   

  	
  Original Principal Amount:   $2,000,000

  
	
  No. SNT-

  	
   

  	
   

  



 


FOR
VALUE RECEIVED, SENESCO TECHNOLOGIES, INC., a Delaware
corporation (the “Company”), hereby promises to pay to the order of STANFORD
VENTURE CAPITAL HOLDINGS, INC. or its registered assigns (the “Holder”)
the amount set out above as the Original Principal Amount (as reduced pursuant
to the terms hereof pursuant to redemption, conversion or otherwise, the “Principal”)
when due, whether upon the Maturity Date (as defined below), acceleration,
redemption or otherwise (in each case in accordance with the terms hereof) and
to pay interest (“Interest”) on any outstanding Principal at the
applicable Interest Rate from the date set out above as the Issuance Date (the “Issuance
Date”) until the same becomes due and payable, whether upon an Interest
Date (as defined below), the Maturity Date, or acceleration, conversion,
redemption or otherwise (in each case in accordance with the terms
hereof).  This Secured Convertible
Debenture (including all Secured Convertible Debentures issued in exchange,
transfer or replacement hereof, this “Debenture”) is one of an issue of Secured
Convertible Debentures issued pursuant to the Securities Purchase Agreement
(collectively, the “Debentures” and such other Senior Convertible
Debentures, the “Other Debentures”). 
Certain capitalized terms used herein are defined in Section 17.


(1)                                  GENERAL TERMS


(a)                                  Payment
of Principal.  On the Maturity Date,
the Company shall pay to the Holder an amount in cash representing all
outstanding Principal, accrued and unpaid Interest.  The “Maturity Date” shall be December
31, 2010, as may be extended at the option of the Holder in the event that, and
for so long as, an Event of Default (as defined below) shall have occurred and
be continuing on the Maturity Date (as may be extended pursuant to this Section
1) or any event shall have occurred and be continuing on the Maturity Date (as
may be extended pursuant to this Section 1) that with the passage of time and
the failure to cure would result in an 



   
 









Event of Default.  Other than as specifically permitted by this
Debenture, the Company may not prepay or redeem any portion of the outstanding
Principal without the prior written consent of the Holder.


(b)                                 Interest.  Interest shall accrue on the outstanding
principal balance hereof at an annual rate equal to eight percent (8%) (“Interest
Rate”).  Interest shall be calculated
on the basis of a 365-day year and the actual number of days elapsed, to the
extent permitted by applicable law. 
Interest hereunder shall be paid on each Interest Date (or sooner as
provided herein) to the Holder or its assignee in whose name this Debenture is
registered on the records of the Company regarding registration and transfers
of Debentures, at the option of the Company, in cash, or converted into Common
Stock (the “Interest Shares”) at the Interest Conversion Price;
provided, that, the issuance of such Interest Shares would not violate any
provisions of this Debenture.


(c)                                  Security.  This Debenture is secured by (i) a security
interest in all of the assets of the Company and of each of the Company’s
subsidiaries as evidenced by the security agreement substantially in the form
agreed to by the Company and the Holder on August 29, 2007 (the “Security
Agreement”) and (ii) a security interest in all of the intellectual
property of the Company and of each of the Company’s subsidiaries as evidenced
by the patent security agreement substantially in the form agreed to by the
Company and the Holder on August 29, 2007 (the “Patent Security Agreement”
and together with the Security Agreement collectively the “Security
Documents”).


(2)                                  EVENTS OF DEFAULT. 


(a)                                  An
“Event of Default”, wherever used herein, means any one 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
Company’s failure to pay to the Holder any amount of Principal, Interest, or
other amounts when and as due under this Debenture (including, without
limitation, the Company’s failure to pay any redemption payments or amounts
hereunder) or any other Transaction Document, subject to the Exchange Cap (as
defined below) and Share Cap (as defined below);


(ii)                                  The
Company or any subsidiary of the Company shall commence any bankruptcy,
insolvency or other similar proceeding under any applicable bankruptcy or
insolvency laws as now or hereafter in effect or any successor thereto, or the
Company or any subsidiary of the Company commences any other proceeding under
any reorganization, arrangement, adjustment of debt, relief of debtors,
dissolution, insolvency or liquidation or similar law of any jurisdiction
whether now or hereafter in effect relating to the Company or any subsidiary of
the Company, or there is commenced against the Company or any subsidiary of the
Company any such bankruptcy, insolvency or other proceeding which remains
undismissed for a period of sixty-one (61) days; or the Company or any
subsidiary of the Company is adjudicated insolvent or bankrupt; or any order of
relief or other order approving any such case or proceeding is entered; or the
Company or any subsidiary of the Company 



 2
 









suffers any appointment of any
custodian, private or court appointed receiver or the like for it or any
substantial part of its property which continues undischarged or unstayed for a
period of sixty-one (61) days; or the Company or any subsidiary of the Company
makes a general assignment for the benefit of creditors; or the Company or any
subsidiary of the Company shall fail to pay, or shall state that it is unable
to pay, or shall be unable to pay, its debts generally as they become due; or
the Company or any subsidiary of the Company shall call a meeting of its
creditors with a view to arranging a composition, adjustment or restructuring
of its debts; or the Company or any subsidiary of the Company shall by any act
or failure to act expressly indicate its consent to, approval of or
acquiescence in any of the foregoing; or any corporate or other action is taken
by the Company or any subsidiary of the Company for the purpose of effecting
any of the foregoing;


(iii)                               The
Company or any subsidiary of the Company shall default in any of its
obligations under any other debenture or any mortgage, credit agreement or
other facility, indenture agreement, factoring agreement or other instrument
under which there may be issued, or by which there may be secured or evidenced,
any indebtedness for borrowed money or money due under any long term leasing or
factoring arrangement of the Company or any subsidiary of the Company in an
amount exceeding $100,000, whether such indebtedness now exists or shall
hereafter be created, and such default shall result in such indebtedness
becoming or being declared due and payable prior to the date on which it would
otherwise become due and payable`;


(iv)                              If
the Common Stock is quoted or listed for trading on any of the following and it
ceases to be so quoted or listed for trading and shall not again be quoted or
listed for trading on any Primary Market within five (5) Trading Days of such
delisting: (a) the American Stock Exchange, (b) New York Stock Exchange, (c)
the Nasdaq Global Market, (d) the Nasdaq Capital Market, or (e) the NASD OTC
Bulletin Board (“OTCBB”) (each, a “Primary Market”);


(v)                                 The
Company or any subsidiary of the Company shall be a party to any Change of
Control Transaction (as defined in Section 17) unless in connection with such
Change of Control Transaction this Debenture is retired;


(vi)                              The
Company shall fail to file the Underlying Shares Registration Statement with
the Commission by the Filing Deadline, or the Underlying Shares Registration
Statement shall not have been declared effective by the Commission because the
Company failed to respond to comments in a timely manner or the Company failed
to use its commercially reasonable efforts to get it effective, in each case
within thirty (30) days of the periods set forth in the Registration Rights
Agreement (“Registration Rights Agreement”) dated August 29, 2007 among
the Company and each Buyer listed on Schedule I attached thereto, or, while the
Underlying Shares Registration Statement is required to be maintained effective
pursuant to the terms of the Registration Rights Agreement, the effectiveness
of the Underlying Shares Registration Statement lapses for any reason
(including, without limitation, the issuance of a stop order) or is unavailable
to the Holder for sale of all of the Holder’s Registrable Securities (as
defined in the Registration Rights Agreement) in accordance with the terms of
the Registration Rights Agreement, and such lapse or unavailability continues
for a period of more 



 3
 









than ten (10) consecutive Trading
Days or for more than an aggregate of twenty (20) days in any 365-day period
(which need not be consecutive);


(vii)                           The
Company’s (A) failure to cure a Conversion Failure by delivery of the required
number of shares of Common Stock within five (5) Business Days after the
applicable Conversion Failure or (B) notice, written or oral, to any holder of
the Debentures, including by way of public announcement, at any time, of its
intention not to comply with a request for conversion of any Debentures into shares
of Common Stock that is tendered in accordance with the provisions of the Debentures,
other than pursuant to Section 4(c), in each case, subject to the Exchange Cap
(as defined below) and Share Cap (as defined below);


(viii)                        The
Company shall fail for any reason to deliver the payment in cash pursuant to a
Buy-In (as defined herein) pursuant to Section 4(b)(ii) within three (3) Business
Days after such payment is due;


(ix)                                The
Company shall fail to observe or perform any other covenant, agreement or warranty
contained in, or otherwise commit any breach or default of any provision of,
this Debenture (except as may be covered by Section 2(a)(i) through 2(a)(vii)
hereof) or any Transaction Document (as defined in Section 17) which is not
cured within the time prescribed.


(x)                                   Any
Event of Default (as defined in the Other Debentures) occurs with respect to
any Other Debentures.


(b)                                 During
the time that any portion of this Debenture is outstanding, if any Event of
Default has occurred, the full unpaid Principal amount of this Debenture,
together with interest and other amounts owing in respect thereof, to the date
of acceleration shall become at the Holder’s election, immediately due and
payable in cash; provided,
however, the Holder may request (but shall have no obligation to request)
payment of such amounts in Common Stock of the Company.  Furthermore, in addition to any other
remedies, the Holder shall have the right (but not the obligation) to convert
this Debenture at any time after (x) an Event of Default or (y) the Maturity
Date at the applicable Conversion Price. 
The Holder need not provide and the Company hereby waives any
presentment, demand, protest or other notice of any kind, (other than required
notice of conversion) and the Holder may immediately and without expiration of
any grace period enforce any and all of its rights and remedies hereunder and
all other remedies available to it under applicable law. Such declaration may
be rescinded and annulled by Holder at any time prior to payment hereunder. No
such rescission or annulment shall affect any subsequent Event of Default or
impair any right consequent thereon.


(c)                                  Accounting
Provision.  For purposes of clarity,
the Company shall not be obligated to settle any conversion of this Debenture
in cash, except as a result of the negligence or willful misconduct of the
Company, then in such case, any cash settlement shall be as per the terms of
this Debenture.


(3)                                  COMPANY REDEMPTION AND FORCED CONVERSION.


(a)                                  Company’s
Optional Cash Redemption.  The Company
at its option shall have the right to redeem (“Optional Redemption”) either
(A) a portion (in 



 4
 









increments of $1,000) or all amounts
outstanding under this Debenture prior to the Maturity Date provided that as of
the date of the Holder’s receipt of a Redemption Notice (as defined herein) (i)
the VWAP of the Common Stock exceeds 130% of the Fixed Conversion Price for at
least 20 trading days of the 30 prior trading days and (ii) the Underlying
Shares Registration Statement filed pursuant to the Registration Rights
Agreement shall be effective and available for the resale of all applicable
shares of Common Stock that may be issued upon conversion of the Optional
Redemption amount, or (B) a portion or all of the amounts outstanding under
this Debenture prior to the Maturity Date provided that as of the date of the
Holder’s receipt of at a Redemption Notice (as defined herein) the VWAP of the
Common Stock is below the Fixed Conversion Price.  In the case of an Optional Redemption pursuant
to clause A above, the Company shall pay an amount equal to the principal
amount being redeemed plus accrued Interest and in the case of an Optional
Redemption pursuant to clause B above, the Company shall pay an amount equal to
the principal amount being redeemed, plus a redemption premium equal to 20% of
such amount, plus accrued Interest, (collectively referred to as the “Company
Additional Redemption Amount”).  In
order to make an Optional Redemption pursuant to this Section, the Company
shall first provide written notice to the Holder of its intention to make a
redemption (the “Redemption Notice”) setting forth the amount of Principal
it desires to redeem, certifying that the conditions to such Optional Redemption
have been satisfied, and setting forth the date of such Optional Redemption
(the “Redemption Date”), which date shall be at least 30 Business Days
but nor more than 60 Business Days from the date of the Redemption Notice.  After receipt of the Redemption Notice and up
to the Redemption Date, the Holder shall have the right to convert all or any
portion of this Debenture, subject to the limitations set forth in Section
4(b).  On the Redemption Date, the
Company shall deliver to the Holder the Company Additional Redemption Amount
with respect to the Principal amount redeemed after giving effect to any
conversions effected during the period between the date of the Redemption
Notice and the Redemption Date.


(b)                                 Company’s
Forced Conversion Right. The Company shall have the right to force the
Holder to convert this Debenture (a “Forced Conversion”) prior to the
Maturity Date by delivering to the Holder a written notice (“Forced
Conversion Notice”) provided that the following conditions have been
satisfied: (i) the Equity Conditions shall have been satisfied, (ii) the number
of shares underlying the Forced Conversion will not exceed the Volume
Limitation, (iii) The effective date of the Forced Conversion is at least 5
Trading Days following the date of the Forced Conversion Notice, (iv) at least
40 Business Days have elapsed since the last Forced Conversion, and (v) the
VWAP of the Common Stock shall have exceeded 150% of the Fixed Conversion Price
for at least 20 trading days of the 30 trading days immediately prior to the
date of the Forced Conversion Notice, and (vi) the Closing Bid Price of the
Common Stock shall have exceeded 150% of the Fixed Conversion Price on the last
Trading Day immediately preceding the Forced Conversion date. The Principal
amount of any Forced Conversion shall be up to (i) 50% of the total Principal
amount outstanding under the Debenture if the VWAP of the Common Stock exceeds
150% of the Fixed Conversion Price for at least 20 trading days of the 30
trading days immediately prior to the date of the Forced Conversion Notice and
(ii) 100% of the total Principal amount outstanding under the Debenture if the
VWAP of the Common Stock exceeds 175% of the Fixed Conversion Price for at
least 20 trading days of the 30 trading days immediately prior to the date of
the Forced Conversion Notice.  On each
occasion that the Company exercises a Forced Conversion, on the date of the
Forced Conversion the Company shall issue to the Holder an additional warrant
(the “Additional Warrants”) in the form of the 



 5
 









Warrants to purchase such number of shares of
Common Stock equal to 50% of the number of shares of Common Stock underlying
such Forced Conversion.  The exercise
price of the Additional Warrants shall be equal to the Fixed Conversion Price
and the Additional Warrants shall have the same expiration date as the Warrants.


(4)                                  CONVERSION OF DEBENTURE.                 This Debenture shall be convertible into
shares of the Company’s Common Stock, on the terms and conditions set forth in
this Section 4.


(a)                                  Conversion
Right.  Subject to the provisions of
Section 4(c), at any time or times on or after the Issuance Date, the Holder
shall be entitled to convert any portion of the outstanding and unpaid
Conversion Amount (as defined below) into fully paid and nonassessable shares
of Common Stock in accordance with Section 4(b), at the Conversion Rate (as
defined below).  The number of shares of
Common Stock issuable upon conversion of any Conversion Amount pursuant to this
Section 4(a) shall be determined by dividing (x) such Conversion Amount by (y)
the Conversion Price (the “Conversion Rate”).  The Company shall not issue any fraction of a
share of Common Stock upon any conversion. 
If the issuance would result in the issuance of a fraction of a share of
Common Stock, the Company shall round such fraction of a share of Common Stock
up to the nearest whole share.  The
Company shall pay any and all transfer, stamp and similar taxes that may be
payable with respect to the issuance and delivery of Common Stock upon
conversion of any Conversion Amount.


(i)                                     “Conversion
Amount” means the portion of the Principal and accrued Interest to be
converted, redeemed or otherwise with respect to which this determination is
being made.


(ii)                                  “Conversion
Price” means, as of any Conversion Date (as defined below) or other date of
determination before the occurrence of any Triggering Event, $0.90, subject to
adjustment as provided herein  (the
“Fixed Conversion Price”), subject to adjustment as provided herein, and
as of any Conversion Date (as defined below) or other date of determination
following the occurrence of any Triggering Event, the lower of (a) the Fixed
Conversion Price or (b) eighty percent (80%) of the lowest daily Volume
Weighted Average Price during the five (5) Trading Days immediately preceding
the Conversion Date (the “Market Conversion Price”).


(b)                                 Mechanics
of Conversion.


(i)                                     Optional
Conversion.  To convert any
Conversion Amount into shares of Common Stock on any date (a “Conversion
Date”), the Holder shall (A) transmit by facsimile (or otherwise deliver),
for receipt on or prior to 11:59 p.m., New York Time, on such date, a copy of
an executed notice of conversion in the form attached hereto as Exhibit I
(the “Conversion Notice”) to the Company and (B) if required by Section 4(b)(iv),
surrender this Debenture to a nationally recognized overnight delivery service
for delivery to the Company (or an indemnification undertaking reasonably
satisfactory to the Company with respect to this Debenture in the case of its
loss, theft or destruction).  On or
before the third Business Day following the date of receipt of a Conversion
Notice (the “Share Delivery Date”), the Company shall (X) if legends are
not required to be placed on certificates of Common Stock pursuant to 



 6
 









the Securities Purchase Agreement and
provided that the Transfer Agent is participating in the Depository Trust
Company’s (“DTC”) Fast Automated Securities Transfer Program, credit
such aggregate number of shares of Common Stock to which the Holder shall be
entitled to the Holder’s or its designee’s balance account with DTC through its
Deposit Withdrawal Agent Commission system or (Y) if the Transfer Agent is not
participating in the DTC Fast Automated Securities Transfer Program, issue and
deliver to the address as specified in the Conversion Notice, a certificate,
registered in the name of the Holder or its designee, for the number of shares
of Common Stock to which the Holder shall be entitled which certificates shall
not bear any restrictive legends unless required pursuant to Section 2(g) of
the Securities Purchase Agreement.  If
this Debenture is physically surrendered for conversion and the outstanding
Principal of this Debenture is greater than the Principal portion of the
Conversion Amount being converted, then the Company shall as soon as
practicable and in no event later than three (3) Business Days after receipt of
this Debenture and at its own expense, issue and deliver to the holder a new Debenture
representing the outstanding Principal not converted.  The Person or Persons entitled to receive the
shares of Common Stock issuable upon a conversion of this Debenture shall be
treated for all purposes as the record holder or holders of such shares of
Common Stock upon the transmission of a Conversion Notice.


(ii)                                  Company’s
Failure to Timely Convert.  If within
three (3) Trading Days after the Company’s receipt of the facsimile copy of a
Conversion Notice the Company shall fail to issue and deliver a certificate to
the Holder or credit the Holder’s balance account with DTC for the number of
shares of Common Stock to which the Holder is entitled upon such holder’s
conversion of any Conversion Amount as a result of the Company’s negligence or
willful misconduct (a “Conversion Failure”), and if on or after such
Trading Day, the Holder purchases (in an open market transaction or otherwise)
Common Stock to deliver in satisfaction of a sale by the Holder of Common Stock
issuable upon such conversion that the Holder anticipated receiving from the
Company (a “Buy-In”), then the Company shall, within three (3) Business
Days after the Holder’s request and in the Holder’s discretion, either (i) pay
cash to the Holder in an amount equal to the Holder’s total purchase price (excluding
brokerage commissions and other out of pocket expenses, if any) for the shares
of Common Stock so purchased (the “Buy-In Price”), at which point the
Company’s obligation to deliver such certificate (and to issue such Common
Stock) shall terminate, or (ii) promptly honor its obligation to deliver to the
Holder a certificate or certificates representing such Common Stock and pay
cash to the Holder in an amount equal to the excess (if any) of the Buy-In
Price over the product of (A) such number of shares of Common Stock, times (B)
the Closing Bid Price on the Conversion Date.


(iii)                               Book-Entry.
Notwithstanding anything to the contrary set forth herein, upon conversion of
any portion of this Debenture in accordance with the terms hereof, the Holder
shall not be required to physically surrender this Debenture to the Company
unless (A) the full Conversion Amount represented by this Debenture is being
converted or (B) the Holder has provided the Company with prior written notice
(which notice may be included in a Conversion Notice) requesting reissuance of
this Debenture upon physical surrender of this Debenture.  The Holder and the Company shall maintain
records showing the Principal and Interest converted and the dates of such
conversions or shall use such other method, reasonably satisfactory to the
Holder and the Company, so as not to require physical surrender of this Debenture
upon conversion.



 7
 









(c)          Limitations on
Conversions; Primary Market Regulation. 
The Company shall not be obligated to issue any shares of Common Stock
upon conversion of this Debenture, exercise of the Warrants or the issuance of
the Interest Shares,  and the Holder of this Debenture shall not have the
right to receive upon conversion of this Debenture any shares of Common Stock,
if the issuance of such shares of Common Stock would exceed the aggregate
number of shares of Common Stock which the Company may issue upon conversion or
exercise, as applicable, of the Debentures and Warrants, or issuance of the
Interest Shares, after giving effect to any adjustments in the amount of shares
of Common Stock issuable as a result of any stock split, reverse stock split,
stock dividend, reorganization, recapitalization, reclassification or other
like change, without breaching the Company’s obligations under the rules or
regulations of the applicable Primary Market (the number of shares which may be
issued without violating such rules and regulations, the “Exchange Cap”),
except that such limitation shall not apply in the event that the Company (A)
obtains the approval of its stockholders as required by the applicable rules of
such Primary Market for issuances of Common Stock in excess of such amount or
(B) obtains a written opinion from outside counsel to the Company that such
approval is not required, which opinion shall be reasonably satisfactory to the
Holder.  Unless and until such approval
or written opinion is obtained, the purchaser of the Debentures pursuant to the
Securities Purchase Agreement (or any subsequent holder) shall not be issued in
the aggregate, upon conversion or exercise or otherwise, as applicable, of
Debenture or Warrants, shares of Common Stock, or issuance of the Interest
Shares, as applicable, in an amount greater than the Exchange Cap.


(i)                                     The
Company shall not issue any shares of Common Stock pursuant to the conversion
of this Debenture, exercise of the Warrants or the issuance of Interest Shares,
and the Holder of this Debenture shall not have the right to receive any shares
of Common Stock pursuant to this Debenture, if the issuance of any such shares
of Common Stock would cause the total shares of Common Stock issued under this
Debenture and Warrants or any Other Debenture and any shares of Common Stock
issued as Liquidated Damages (as defined in the Registration Rights Agreement),
to be greater than 21,888,888 shares of Common Stock (the “Share Cap”); provided, however, that the Share Cap shall be automatically
increased to 31,888,888 shares of Common Stock upon the Company’s receipt of Stockholder
Approval (as defined in the Securities Purchase Agreement); provided further, however, that such numbers of shares shall
be adjusted to reflect appropriately the effect of any adjustments as a result
of any stock split, reverse stock split, stock dividend, reorganization,
recapitalization, reclassification or other like change with respect to the
Common Stock occurring on or after the date hereof.


(d)         Other Provisions.


(i)                                     All
calculations under this Section 4 shall be rounded to the nearest $0.0001 or
whole share.


(ii)                                  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 this Debenture and payment of interest on this
Debenture, each as herein provided, free from preemptive rights or any other
actual contingent purchase rights of persons other than the Holder, not less
than such number of shares of the Common Stock as shall (subject to any
additional requirements of the Company as to reservation of such shares set
forth 



 8
 









in this Debenture or in the Transaction
Documents) be issuable (taking into account the adjustments and restrictions
set forth herein) upon the conversion of the outstanding principal amount of
this Debenture and payment of interest hereunder. Within three (3) Business
Days following the receipt by the Company of a Holder’s notice that such
minimum number of Underlying Shares is not so reserved, the Company shall
promptly reserve a sufficient number of shares of Common Stock to comply with
such requirement. 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 and, if the Underlying Shares Registration
Statement has been declared effective under the Securities Act, registered for
public sale in accordance with such Underlying Shares Registration Statement.


(iii)                               Nothing
herein shall limit a Holder’s right to pursue actual damages or declare an
Event of Default pursuant to Section 2 herein 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 at law or in equity including, without limitation, a
decree of specific performance and/or injunctive relief, in each case without
the need to post a bond or provide other security. The exercise of any such
rights shall not prohibit the Holder from seeking to enforce damages pursuant
to any other Section hereof or under applicable law.


(5)          ADJUSTMENTS TO CONVERSION PRICE


(a)          Adjustment of Conversion Price upon
Issuance of Common Stock.  If the Company, at any time while this
Debenture is outstanding, issues or sells, or in accordance with this Section 5(a)
is deemed to have issued or sold, any shares of Common Stock, excluding shares
of Common Stock deemed to have been issued or sold by the Company in connection
with any Excluded Securities, for a consideration per share (the “New
Issuance Price”) less than a price equal to the Conversion Price in effect
immediately prior to such issue or sale (such price the “Applicable Price”)
(the foregoing a “Dilutive Issuance”), then immediately after such
Dilutive Issuance the Conversion Price then in effect shall be reduced to an
amount equal to the product of (A) the Conversion Price in effect immediately
prior to such Dilutive Issuance and (B) the quotient determined by dividing (1)
the sum of (I) the product derived by multiplying the Conversion Price in
effect immediately prior to such Dilutive Issuance and the number of shares of
Common Stock Deemed Outstanding immediately prior to such Dilutive Issuance
plus (II) the consideration, if any, received by the Company upon such Dilutive
Issuance, by (2) the product derived by multiplying (I) the Conversion Price in
effect immediately prior to such Dilutive Issuance by (II) the number of shares
of Common Stock Deemed Outstanding immediately after such Dilutive
Issuance.  Notwithstanding the forgoing,
in no event shall the number of shares issuable under the Debentures exceed the
Share Cap.  For purposes of determining
the adjusted Conversion Price under this Section 5(a), the following shall be
applicable:


(i)                                     Issuance of Options. 
If the Company in any manner grants or sells any Options and the lowest
price per share for which one share of Common Stock is issuable upon the exercise
of any such Option or upon conversion or exchange or exercise of any
Convertible Securities issuable upon exercise of such Option is less than the
Applicable Price, then such share of Common Stock shall be deemed to be
outstanding and to have been issued and sold by the Company at the time of the
granting or sale of such Option for such price per 



 9
 









share.  For purposes of this
Section, the “lowest price per share for which one share of Common Stock is
issuable upon the exercise of any such Option or upon conversion or exchange or
exercise of any Convertible Securities issuable upon exercise of such Option”
shall be equal to the sum of the lowest amounts of consideration (if any)
received or receivable by the Company with respect to any one share of Common
Stock upon granting or sale of the Option, upon exercise of the Option and upon
conversion or exchange or exercise of any Convertible Security issuable upon
exercise of such Option.  No further
adjustment of the Conversion Price shall be made upon the actual issuance of
such share of Common Stock or of such Convertible Securities upon the exercise
of such Options or upon the actual issuance of such Common Stock upon
conversion or exchange or exercise of such Convertible Securities.


(ii)                                  Issuance of Convertible Securities. 
If the Company in any manner issues or sells any Convertible Securities
and the lowest price per share for which one share of Common Stock is issuable
upon such conversion or exchange or exercise thereof is less than the
Applicable Price, then such share of Common Stock shall be deemed to be
outstanding and to have been issued and sold by the Company at the time of the
issuance or sale of such Convertible Securities for such price per share.  For the purposes of this Section, the “lowest
price per share for which one share of Common Stock is issuable upon such
conversion or exchange or exercise” shall be equal to the sum of the lowest
amounts of consideration (if any) received or receivable by the Company with
respect to any one share of Common Stock upon the issuance or sale of the
Convertible Security and upon the conversion or exchange or exercise of such
Convertible Security.  No further
adjustment of the Conversion Price shall be made upon the actual issuance of
such share of Common Stock upon conversion or exchange or exercise of such
Convertible Securities, and if any such issue or sale of such Convertible
Securities is made upon exercise of any Options for which adjustment of the
Conversion Price had been or are to be made pursuant to other provisions of
this Section, no further adjustment of the Conversion Price shall be made by
reason of such issue or sale.


(iii)                               Change in Option Price or Rate of
Conversion.  If the purchase price provided for in any
Options, the additional consideration, if any, payable upon the issue,
conversion, exchange or exercise of any Convertible Securities, or the rate at
which any Convertible Securities are convertible into or exchangeable or
exercisable for Common Stock changes at any time, the Conversion Price in
effect at the time of such change shall be adjusted to the Conversion Price
which would have been in effect at such time had such Options or Convertible
Securities provided for such changed purchase price, additional consideration
or changed conversion rate, as the case may be, at the time initially granted,
issued or sold.  For purposes of this
Section, if the terms of any Option or Convertible Security that was
outstanding as of the Issuance Date are changed in the manner described in the
immediately preceding sentence, then such Option or Convertible Security and
the Common Stock deemed issuable upon exercise, conversion or exchange thereof
shall be deemed to have been issued as of the date of such change.  No adjustment shall be made if such adjustment
would result in an increase of the Conversion Price then in effect.


(iv)                              Calculation of Consideration
Received.  In case any Option is issued in connection
with the issue or sale of other securities of the Company, together comprising
one integrated transaction in which no specific consideration is allocated to
such Options by the parties thereto, the Options will be deemed to have been
issued for the difference 



 10














of (x) the aggregate fair market value of such Options and other
securities issued or sold in such integrated transaction, less (y) the fair
market value of the securities other than such Option, issued or sold in such
transaction and the other securities issued or sold in such integrated
transaction will be deemed to have been issued or sold for the balance of the
consideration received by the Company. 
If any Common Stock, Options or Convertible Securities are issued or
sold or deemed to have been issued or sold for cash, the consideration received
therefor will be deemed to be the gross amount raised by the Company; provided, however, that such gross amount is not greater
than 110% of the net amount received by the Company therefor.  If any Common Stock, Options or Convertible
Securities are issued or sold for a consideration other than cash, the amount
of the consideration other than cash received by the Company will be the fair
value of such consideration, except where such consideration consists of securities,
in which case the amount of consideration received by the Company will be the
Closing Bid Price of such securities on the date of receipt.  If any Common Stock, Options or Convertible
Securities are issued to the owners of the non-surviving entity in connection
with any merger in which the Company is the surviving entity, the amount of
consideration therefor will be deemed to be the fair value of such portion of
the net assets and business of the non-surviving entity as is attributable to
such Common Stock, Options or Convertible Securities, as the case may be.  The fair value of any consideration other
than cash or securities will be determined jointly by the Company and the
Holder.  If such parties are unable to
reach agreement within ten (10) days after the occurrence of an event requiring
valuation (the “Valuation Event”), the fair value of such consideration
will be determined within five (5) Business Days after the tenth (10th) day following the Valuation Event
by an independent, reputable appraiser jointly selected by the Company and the
Holder.  The determination of such
appraiser shall be deemed binding upon all parties absent manifest error and
the fees and expenses of such appraiser shall be borne by the Company.


(v)                                 Record Date. 
If the Company takes a record of the holders of Common Stock for the
purpose of entitling them (A) to receive a dividend or other distribution
payable in Common Stock, Options or in Convertible Securities or (B) to
subscribe for or purchase Common Stock, Options or Convertible Securities, then
such record date will be deemed to be the date of the issue or sale of the
Common Stock deemed to have been issued or sold upon the declaration of such
dividend or the making of such other distribution or the date of the granting
of such right of subscription or purchase, as the case may be.


(b)         Adjustment of Conversion Price upon
Subdivision or Combination of Common Stock.  If the Company, at any
time while this Debenture is outstanding, shall (a) pay a stock dividend or
otherwise make a distribution or distributions on shares of its Common Stock or
any other equity or equity equivalent securities payable in shares of Common
Stock, (b) subdivide outstanding shares of Common Stock into a larger number of
shares, (c) combine (including by way of reverse stock split) outstanding
shares of Common Stock into a smaller number of shares, or (d) issue by
reclassification of shares of the Common Stock any shares of capital stock of
the Company, then the Conversion Price shall be multiplied by a fraction of
which the numerator shall be the number of shares of Common Stock (excluding
treasury shares, if any) outstanding before such event and of which the
denominator shall be the number of shares of Common Stock outstanding after
such event. Any adjustment made pursuant to this Section shall become effective
immediately after the record date for the determination of 



 11
 








stockholders entitled to receive such dividend or distribution and
shall become effective immediately after the effective date in the case of a
subdivision, combination or re-classification.


(c)          Purchase Rights. 
If at any time the Company grants, issues or sells any Options,
Convertible Securities or rights to purchase stock, warrants, securities or
other property pro rata to the record holders of any class of Common Stock (the
“Purchase Rights”), then the Holder will be entitled to acquire, upon
the terms applicable to such Purchase Rights, the aggregate Purchase Rights
which the Holder could have acquired if the Holder had held the number of
shares of Common Stock acquirable upon complete conversion of this Debenture
(without taking into account any limitations or restrictions on the
convertibility of this Debenture) immediately before the date on which a record
is taken for the grant, issuance or sale of such Purchase Rights, or, if no
such record is taken, the date as of which the record holders of Common Stock
are to be determined for the grant, issue or sale of such Purchase Rights.


(d)         Other Events. 
If any event occurs of the type contemplated by the provisions of this
Section 5 but not expressly provided for by such provisions (including, without
limitation, the granting of stock appreciation rights, phantom stock rights or
other rights with equity features), then the Company’s Board of Directors will
make an appropriate adjustment in the Conversion Price so as to protect the
rights of the Holder under this Debenture; provided that no such adjustment
will increase the Conversion Price as otherwise determined pursuant to this Section
5.


(e)          Other Corporate Events. 
In addition to and not in substitution for any other rights hereunder,
prior to the consummation of any Change of Control Transaction pursuant to
which holders of shares of Common Stock are entitled to receive securities or
other assets with respect to or in exchange for shares of Common Stock (a “Corporate
Event”), the Company shall make appropriate provision to insure that the
Holder will thereafter have the right to receive upon a conversion of this
Debenture, at the Holder’s option, (i) in addition to the shares of Common
Stock receivable upon such conversion, such securities or other assets to which
the Holder would have been entitled with respect to such shares of Common Stock
had such shares of Common Stock been held by the Holder upon the consummation
of such Corporate Event (without taking into account any limitations or
restrictions on the convertibility of this Debenture) or (ii) in lieu of the
shares of Common Stock otherwise receivable upon such conversion, such
securities or other assets received by the holders of shares of Common Stock in
connection with the consummation of such Corporate Event in such amounts as the
Holder would have been entitled to receive had this Debenture initially been
issued with conversion rights for the form of such consideration (as opposed to
shares of Common Stock) at a conversion rate for such consideration
commensurate with the Conversion Rate. 
Provision made pursuant to the preceding sentence shall be in a form and
substance satisfactory to the Holder. 
The provisions of this Section shall apply similarly and equally to
successive Corporate Events and shall be applied without regard to any
limitations on the conversion or redemption of this Debenture.


(f)            Whenever the Conversion Price is
adjusted pursuant to Section 5 hereof, the Company shall promptly mail to the
Holder a notice setting forth the Conversion Price after such adjustment and
setting forth a brief statement of the facts requiring such adjustment.



 12
 








(g)         In case of any (1) merger or consolidation of the Company or any
subsidiary of the Company with or into another Person, or (2) sale by the
Company or any subsidiary of the Company of more than one-half of the assets of
the Company in one or a series of related transactions, a Holder shall have the
right to (A) exercise any rights under Section 2(b), (B) convert the aggregate
amount of this Debenture then outstanding 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 aggregate principal amount of this Debenture could have been
converted immediately prior to such merger, consolidation or sales would have
been entitled, or (C) in the case of a merger or consolidation, require the
surviving entity to issue to the Holder a convertible Debenture with a
principal amount equal to the aggregate principal amount of this Debenture then
held by such Holder, plus all accrued and unpaid interest and other amounts
owing thereon, which such newly issued convertible Debenture shall have terms
identical (including with respect to conversion) to the terms of this
Debenture, and shall be entitled to all of the rights and privileges of the
Holder of this Debenture set forth herein and in the agreements pursuant to
which this Debenture was issued. In the case of clause (C), 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 and
the Conversion Price in effect immediately prior to the effectiveness or
closing date for such transaction. The terms of any such merger, sale or
consolidation shall include such terms so as to continue to give the Holder 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.


(6)                                  REISSUANCE
OF THIS DEBENTURE.


(a)                                  Transfer. 
If this Debenture is to be transferred, the Holder shall surrender this Debenture
to the Company, whereupon the Company will, subject to the satisfaction of the
transfer provisions of the Securities Purchase Agreement, forthwith issue and
deliver upon the order of the Holder a new Debenture (in accordance with
Section 6(d)), registered in the name of the registered transferee or assignee,
representing the outstanding Principal being transferred by the Holder and, if
less then the entire outstanding Principal is being transferred, a new Debenture
(in accordance with Section 6(d)) to the Holder representing the outstanding
Principal not being transferred.  The
Holder and any assignee, by acceptance of this Debenture, acknowledge and agree
that, by reason of the provisions of Section 4(b)(iii) following conversion or
redemption of any portion of this Debenture, the outstanding Principal
represented by this Debenture may be less than the Principal stated on the face
of this Debenture.


(b)                                 Lost, Stolen or Mutilated Debenture. 
Upon receipt by the Company of evidence reasonably satisfactory to the
Company of the loss, theft, destruction or mutilation of this Debenture, and,
in the case of loss, theft or destruction, of any indemnification undertaking
by the Holder to the Company in customary form and, in the case of mutilation,
upon surrender and cancellation of this Debenture, the Company shall execute
and deliver to the Holder a new Debenture (in accordance with Section 6(d))
representing the outstanding Principal.



 13
 








(c)                                  Debenture Exchangeable for
Different Denominations.  This Debenture is exchangeable, upon the
surrender hereof by the Holder at the principal office of the Company, for a
new Debenture or Debentures (in accordance with Section 6(d)) representing in
the aggregate the outstanding Principal of this Debenture, and each such new Debenture
will represent such portion of such outstanding Principal as is designated by
the Holder at the time of such surrender.


(d)                                 Issuance of New Debentures. 
Whenever the Company is required to issue a new Debenture pursuant to
the terms of this Debenture, such new Debenture (i) shall be of like tenor with
this Debenture, (ii) shall represent, as indicated on the face of such new Debenture,
the Principal remaining outstanding (or in the case of a new Debenture being
issued pursuant to Section 6(a) or Section 6(c), the Principal designated by
the Holder which, when added to the principal represented by the other new Debentures
issued in connection with such issuance, does not exceed the Principal
remaining outstanding under this Debenture immediately prior to such issuance
of new Debentures), (iii) shall have an issuance date, as indicated on the face
of such new Debenture, which is the same as the Issuance Date of this Debenture,
(iv) shall have the same rights and conditions as this Debenture, and (v) shall
represent accrued and unpaid Interest from the Issuance Date.


(7)                                  NOTICES.                                         Any
notices, consents, waivers or other communications required or permitted to be
given under the terms hereof must be in writing and will be deemed to have been
delivered:  (i) upon receipt, when
delivered personally; (ii) upon receipt, when sent by facsimile (provided
confirmation of transmission is mechanically or electronically generated and
kept on file by the sending party); or (iii) one (1) Trading Day after deposit
with a nationally recognized overnight delivery service, in each case properly
addressed to the party to receive the same. 
The addresses and facsimile numbers for such communications shall be:


	
  If to the Company, to:

  	
   

  	
  Senesco
  Technologies, Inc.

  
	
   

  	
   

  	
  303 George
  Street, Suite 420

  
	
   

  	
   

  	
  New Brunswick,
  NJ 08901

  
	
   

  	
   

  	
  Attention:

  	
  Chief Executive
  Officer

  
	
   

  	
   

  	
  Telephone:

  	
  (732) 296-8400

  
	
   

  	
   

  	
  Facsimile:

  	
  (732) 296-9292

  
	
   

  	
   

  	
   

  
	
  With a copy to:

  	
   

  	
  Morgan, Lewis
  & Bockius LLP

  
	
   

  	
   

  	
  502 Carnegie
  Center

  
	
   

  	
   

  	
  Princeton, NJ
  08540

  
	
   

  	
   

  	
  Attention:

  	
  Emilio Ragosa,
  Esq.

  
	
   

  	
   

  	
  Telephone:

  	
  (609) 919-6633

  
	
   

  	
   

  	
  Facsimile:

  	
  (609) 919-6701

  
	
   

  	
   

  	
   

  
	
  If to the
  Holder:

  	
   

  	
  Stanford Venture
  Capital Holdings, Inc.

  
	
   

  	
   

  	
  6075 Poplar
  Avenue, Suite 300

  
	
   

  	
   

  	
  Memphis, TN
  38119

  
	
   

  	
   

  	
  Attention:

  	
  James M. Davis,
  President and Director

  



 



 14
 








 


	
  

  	
   

  	
  Telephone:

  	
  (901) 537-1600

  
	
   

  	
   

  	
  Facsimile:

  	
  (901) 680-5265

  
	
   

  	
   

  	
   

  	
   

  
	
  With a copy to:

  	
   

  	
  Akerman
  Senterfitt

  
	
   

  	
   

  	
  One Southeast
  Third Avenue, 25th Floor

  
	
   

  	
   

  	
  Miami, Florida
  33131

  
	
   

  	
   

  	
  Attention:

  	
  Jose Gordo, Esq.

  
	
   

  	
   

  	
  Telephone:

  	
  305-755-5812

  
	
   

  	
   

  	
  Facsimile:

  	
  305-349-4789

  



 


or
at such other address and/or facsimile number and/or to the attention of such
other person as the recipient party has specified by written notice given to
each other party three (3) Business Days prior to the effectiveness of such
change.  Written confirmation of receipt
(i) given by the recipient of such notice, consent, waiver or other
communication, (ii) mechanically or electronically generated by the sender’s
facsimile machine containing the time, date, recipient facsimile number and an
image of the first page of such transmission or (iii) provided by a nationally
recognized overnight delivery service, shall be rebuttable evidence of personal
service, receipt by facsimile or receipt from a nationally recognized overnight
delivery service in accordance with clause (i), (ii) or (iii) above,
respectively.


(8)                                  Except as
expressly provided herein, no provision of this Debenture shall alter or impair
the obligations of the Company, which are absolute and unconditional, to pay
the principal of, interest and other charges (if any) on, this Debenture at the
time, place, and rate, and in the coin or currency, herein prescribed.  This Debenture is a direct obligation of the
Company. As long as this Debenture is outstanding, the Company shall not and
shall cause their subsidiaries not to, without the consent of the Holder,  (i) amend its certificate of incorporation, bylaws or other
charter documents so as to adversely affect any rights of the Holder; (ii)
repay, repurchase or offer to repay, repurchase or otherwise acquire shares of
its Common Stock or other equity securities other than as to the Underlying
Shares to the extent permitted or required under the Transaction Documents; or
(iii) enter into any agreement with respect to any of the foregoing.


(9)                                  This
Debenture shall not entitle the Holder to any of the rights of a stockholder of
the Company, including without limitation, the right to vote, to receive
dividends and other distributions, or to receive any notice of, or to attend,
meetings of stockholders or any other proceedings of the Company, unless and to
the extent converted into shares of Common Stock in accordance with the terms
hereof.


(10)                            No
indebtedness of the Company is senior to this Debenture in right of payment,
whether with respect to interest, damages or upon liquidation or dissolution or
otherwise.  Without the Holder’s consent,
the Company will not and will not permit any of its subsidiaries to, directly
or indirectly, enter into, create, incur, assume or suffer to exist any
indebtedness of any kind, on or with respect to any of its property or assets
now owned or hereafter acquired or any interest therein or any income or profits
there from that is senior in any respect to the obligations of the Company
under this Debenture.



 15
 








(11)                            This
Debenture shall be governed by and construed in accordance with the laws of the
State of New Jersey, without giving effect to conflicts of laws thereof.  Each of the parties consents to the
jurisdiction of the Superior Courts of the State of New Jersey sitting in
Hudson County, New Jersey and the U.S. District
Court for the District of New Jersey sitting in Newark, New Jersey in
connection with any dispute arising under this Debenture and hereby waives, to
the maximum extent permitted by law, any objection, including any objection
based on forum non conveniens to the bringing of any such proceeding in such
jurisdictions.


(12)                            If the
Company fails to strictly comply with the terms of this Debenture, then the
Company shall reimburse the Holder promptly for all fees, costs and expenses,
including, without limitation, attorneys’ fees and expenses incurred by the
Holder in any action in connection with this Debenture, including, without
limitation, those incurred: (i) during any workout, attempted workout, and/or
in connection with the rendering of legal advice as to the Holder’s rights,
remedies and obligations, (ii) collecting any sums which become due to the
Holder, (iii) defending or prosecuting any proceeding or any counterclaim to
any proceeding or appeal; or (iv) the protection, preservation or enforcement
of any rights or remedies of the Holder.


(13)                            Any
waiver by the Holder of a breach of any provision of this Debenture shall not
operate as or be construed to be a waiver of any other breach of such provision
or of any breach of any other provision of this Debenture. The failure of the
Holder to insist upon strict adherence to any term of this Debenture on one or
more occasions shall not be considered a waiver or deprive that party of the
right thereafter to insist upon strict adherence to that term or any other term
of this Debenture. Any waiver must be in writing.


(14)                            If any
provision of this Debenture is invalid, illegal or unenforceable, the balance
of this Debenture shall remain in effect, and if any provision is inapplicable
to any person or circumstance, it shall nevertheless remain applicable to all
other persons and circumstances. If it shall be found that any interest or
other amount deemed interest due hereunder shall violate applicable laws
governing usury, the applicable rate of interest due hereunder shall
automatically be lowered to equal the maximum permitted rate of interest. The Company
covenants (to the extent that it may lawfully do so) that it shall not at any
time insist upon, plead, or in any manner whatsoever claim or take the benefit
or advantage of, any stay, extension or usury law or other law which would
prohibit or forgive the Company from paying all or any portion of the principal
of or interest on this Debenture as contemplated herein, wherever enacted, now
or at any time hereafter in force, or which may affect the covenants or the
performance of this indenture, and the Company (to the extent it may lawfully
do so) hereby expressly waives all benefits or advantage of any such law, and
covenants that it will not, by resort to any such law, hinder, delay or impeded
the execution of any power herein granted to the Holder, but will suffer and
permit the execution of every such as though no such law has been enacted.


(15)                            Whenever
any payment or other obligation hereunder shall be due on a day other than a
Business Day, such payment shall be made on the next succeeding Business Day.



 16
 








(16)                            THE
PARTIES HEREBY KNOWINGLY, VOLUNTARILY AND INTENTIONALLY WAIVE THE RIGHT ANY OF
THEM MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY LITIGATION BASED HEREON OR
ARISING OUT OF, UNDER OR IN CONNECTION WITH THIS AGREEMENT OR ANY TRANSACTION
DOCUMENT OR ANY COURSE OF CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER
VERBAL OR WRITTEN) OR ACTIONS OF ANY PARTY. 
THIS PROVISION IS A MATERIAL INDUCEMENT FOR THE PARTIES’ ACCEPTANCE OF
THIS AGREEMENT.


(17)                            CERTAIN
DEFINITIONS      For purposes of this Debenture, the
following terms shall have the following meanings:


(a)                                  “Approved Stock Plan” means
a stock option plan that has been approved by the Board of Directors of the
Company, pursuant to which the Company’s securities may be issued only to any
employee, officer, or director for services provided to the Company.


(b)                                 “Bloomberg” means Bloomberg
Financial Markets.


(c)                                  “Business Day” means any day
except Saturday, Sunday and any day which shall be a federal legal holiday in
the United States or a day on which banking institutions are authorized or
required by law or other government action to close.


(d)                                 “Change of Control Transaction”
means the occurrence of (a) 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 fifty percent (50%) of the voting securities of the
Company (except that the acquisition of voting securities by the Holder or any
other current holder of convertible securities of the Company shall not
constitute a Change of Control Transaction for purposes hereof), (b) a
replacement at one time or over time of more than one-half of the members of
the board of directors of the Company 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), (c) the merger, consolidation or sale of fifty percent (50%) or more
of the assets of the Company or any subsidiary of the Company in one or a
series of related transactions with or into another entity, or (d) 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 (a), (b)
or (c).


(e)                                  “Closing Bid Price” means
the price per share in the last reported trade of the Common Stock on a Primary
Market or on the exchange  which the
Common Stock is then listed as quoted by Bloomberg.


(f)                                    “Commission” means the
Securities and Exchange Commission.


(g)                                 “Common Stock” means the
common stock, par value $.01, of the Company and stock of any other class into
which such shares may hereafter be changed or reclassified.



 17
 








(h)                                 “Common Stock Deemed Outstanding”
means the Common Stock outstanding, and any Common Stock which may be issued
upon the exercise of outstanding Options or conversion of outstanding
Convertible Securities.


(i)                                     “Convertible Securities”
means any stock or securities (other than Options) directly or indirectly
convertible into or exercisable or exchangeable for Common Stock.


(j)                                     “Equity Conditions” means
that each of the following conditions is satisfied:  (i) on each day during the period beginning
two (2) weeks prior to the applicable date of determination and ending on and
including the applicable date of determination (the “Equity Conditions
Measuring Period”), either (x) the Underlying Shares Registration Statement
filed pursuant to the Registration Rights Agreement shall be effective and available
for the resale of all applicable shares of Common Stock to be issued in
connection with the event requiring determination or (y) all applicable shares
of Common Stock to be issued in connection with the event requiring
determination shall be eligible for sale without restriction and without the
need for registration under any applicable federal or state securities laws;
(ii) on each day during the Equity Conditions Measuring Period, the Common
Stock is designated for quotation on a Primary Market and shall not have been
suspended from trading on such exchange or market nor shall delisting or
suspension by such exchange or market been threatened or pending either (A) in
writing by such exchange or market or (B) by falling below the then effective
minimum listing maintenance requirements of such exchange or market; (iii)
during the Equity Conditions Measuring Period, the Company shall have delivered
Conversion Shares upon conversion of the Debentures to the Holder on a timely
basis as set forth in Section 4(b)(ii) hereof; (iv) any applicable shares of
Common Stock to be issued in connection with the event requiring determination
may be issued in full without violating Section 4(c) hereof and the rules or
regulations of the Primary Market; (v) during the Equity Conditions Measuring
Period, there shall not have occurred either (A) an Event of Default or (B) an
event that with the passage of time or giving of notice would constitute an
Event of Default; and (vii) the Company shall have no knowledge of any fact
that would cause (x) the Registration Statements required pursuant to the
Registration Rights Agreement not to be effective and available for the resale
of all applicable shares of Common Stock to be issued in connection with the
event requiring determination or (y) any applicable shares of Common Stock to
be issued in connection with the event requiring determination not to be
eligible for sale without restriction and without the need for registration
under any applicable federal or state securities laws.


(k)                                  “Equity Conditions Failure”
means that on any applicable date the Equity Conditions have not been satisfied
(or waived in writing by the Holder).


(l)                                     “Exchange Act” means the
Securities Exchange Act of 1934, as amended.


(m)                               “Excluded Securities” means,
(a) shares issued or deemed to have been issued by the Company pursuant to an
Approved Stock Plan (b) shares of Common Stock issued or deemed to be issued by
the Company upon the conversion, exchange or exercise of any right, option,
obligation or security outstanding on the date prior to date of the Securities
Purchase Agreement, provided that the terms of such right, option, obligation
or security are not 



 18
 








amended or otherwise
modified on or after the date of the Securities Purchase Agreement, and provided
that the conversion price, exchange price, exercise price or other purchase
price is not reduced, adjusted or otherwise modified and the number of shares
of Common Stock issued or issuable is not increased (whether by operation of,
or in accordance with, the relevant governing documents or otherwise) on or
after the date of the Securities Purchase Agreement, (c) shares issued in
connection with any (i) acquisition by the Company, whether through an
acquisition of stock or a merger of any business, assets or technologies,
leasing arrangement or any other transaction the primary purpose of which is
not to raise equity capital, or (ii) license agreement, consulting agreement,
strategic partnership or similar business arrangement, and (d) the shares of
Common Stock issued or deemed to be issued by the Company upon conversion of
this Debenture.


(n)                                 “Holder Pro Rata Amount”
means a fraction (i) the numerator of which is the Original Principal Amount of
this Debenture on the Issuance Date and (ii) the denominator of which is the
aggregate Purchase Price (as defined in the Securities Purchase Agreement).


(o)                                 “Interest Conversion Price”
means that price which shall be computed as ninety percent (90%) of the Volume
Weighted Average Price of the Common Stock during the five (5) consecutive
Trading Days immediately preceding the applicable Interest Date.


(p)                                 “Interest Date” means the
last day of each quarter beginning with the quarter during which the First
Closing (as defined in the Securities Purchase Agreement) occurs, and
continuing until the Maturity Date.


(q)                                 “Options” means any rights,
warrants or options to subscribe for or purchase shares of Common Stock or
Convertible Securities.


(r)                                    “Person” means a
corporation, an association, a partnership, organization, a business, an
individual, a government or political subdivision thereof or a governmental
agency.


(s)                                  “Securities Act” means the
Securities Act of 1933, as amended, and the rules and regulations promulgated
thereunder.


(t)                                    “Securities Purchase Agreement”
means the Securities Purchase Agreement dated August 29, 2007 by and among the
Company and the Buyers listed on Schedule I attached thereto.


(u)                                 “Trading Day” means a day on
which the shares of Common Stock are quoted or traded on the Primary Market on
which the shares of Common Stock are then quoted or listed; provided, that in
the event that the shares of Common Stock are not listed or quoted, then
Trading Day shall mean a Business Day.


(v)                                 “Transaction Documents”
means the Securities Purchase Agreement or any other agreement delivered in
connection with the Securities Purchase Agreement, including, without
limitation, the Security Documents, the Irrevocable Transfer Agent
Instructions, and the Registration Rights Agreement.



 19
 








(w)                               “Triggering Event” means the
occurrence of any of the following: (i) August     , 2009, or
(ii) a failure by the Company to achieve all of the Triggering Milestones on or
before January 31, 2008.


(x)                                   “Triggering Milestones”
means each of (i) successful completion of animal studies, other than
toxicology studies, necessary for the advancement of factor 5A 1 in human
clinical trials and (ii) the engagement of a Contract Research Organization for
human clinical studies of factor 5A 1.


(y)                                 “Underlying Shares” means
the shares of Common Stock issuable upon conversion of this Debenture or as
payment of interest in accordance with the terms hereof.


(z)                                   “Underlying Shares Registration
Statement” means a registration statement meeting the requirements set
forth in the Registration Rights Agreement, covering among other things the
resale of the Underlying Shares up to the Required Registration Amount, and
naming the Holder as a “selling stockholder” thereunder.


(aa)                            “Volume Limitation” means the
number of shares equal to (i) 25% of the aggregate dollar trading volume (as
reported on Bloomberg) of the Common Stock on the Primary Market over the
thirty (30) consecutive Trading Day period ending on the Trading Day
immediately preceding the applicable measurement date, divided by (ii) the VWAP
over the same 30-day Trading Period.


(bb)                          “Volume Weighted Average Price”
or “VWAP” means, for any security as of any date, the daily dollar
volume-weighted average price for such security on the Primary Market as
reported by Bloomberg through its “Historical Prices – Px Table with Average
Daily Volume” functions, or, if no dollar volume-weighted average price is
reported for such security by Bloomberg, the average of the highest closing bid
price and the lowest closing ask price of any of the market makers for such
security as reported in the “pink sheets” by Pink Sheets LLC.


(cc)                            “Warrants” has the meaning
ascribed to such term in the Securities Purchase Agreement, and shall include
all warrants issued in exchange therefor or replacement thereof.


[Signature
Page Follows]



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IN
WITNESS WHEREOF, the Company
has caused this Secured Convertible Debenture to be duly executed by a duly
authorized officer as of the date set forth above.


 


	
  

  	
   

  	
  COMPANY:

  
	
   

  	
   

  	
  SENESCO
  TECHNOLOGIES, INC.

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  	
   

  
	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
  Title:

  



 



   















EXHIBIT I

CONVERSION NOTICE


(To be executed by the Holder in order to Convert the
Debenture)


TO: 


The undersigned hereby irrevocably elects to convert $                                                                          
of the principal amount of Debenture No. SNT-1-      
into Shares of Common Stock of SENESCO TECHNOLOGIES, INC.,
according to the conditions stated therein, as of the Conversion Date written
below.


	
  Conversion Date:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Conversion Amount
  to be converted:

  	
   

  	
  $

  
	
   

  	
   

  	
   

  
	
  Conversion Price:

  	
   

  	
  $

  
	
   

  	
   

  	
   

  
	
  Number of shares of
  Common Stock to be issued:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Amount of Debenture
  Unconverted:

  	
   

  	
  $

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Please issue the
  shares of Common Stock in the following name and to the following address:

  
	
   

  	
   

  	
   

  
	
  Issue to:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Authorized
  Signature:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Name:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Title:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Broker DTC
  Participant Code:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Account Number: