EXHIBIT
4.13


 


ARYx
THERAPEUTICS, INC.


 


and


 


                ,
AS WARRANT AGENT


 


FORM OF
COMMON STOCK


WARRANT
AGREEMENT


 


DATED
AS OF
              


 

















 


ARYx
THERAPEUTICS, INC.


 


FORM OF
COMMON STOCK WARRANT AGREEMENT


 


COMMON STOCK WARRANT AGREEMENT (this “Agreement”),
dated as of
                    
between ARYx Therapeutics, Inc. ,  a Delaware
corporation (the “Company”)
and 
                    
, a [corporation] [national banking association] organized and existing under
the laws of 
                    
 and having a corporate trust office in
                    
, as warrant agent (the “Warrant Agent”).


 


WHEREAS, the Company proposes to sell [if Warrants are sold with other
securities—[title of such other securities being offered] (the “Other Securities”) with] warrant
certificates evidencing one or more warrants (the “Warrants” or, individually, a “Warrant”) representing the right to purchase Common Stock of
the Company, par value $0.001 per share (the “Warrant
Securities”), such warrant certificates and other warrant
certificates issued pursuant to this Agreement being herein called the “Warrant
Certificates”; and


 


WHEREAS, the Company desires the Warrant Agent to act on
behalf of the Company, and the Warrant Agent is willing so to act, in
connection with the issuance, registration, transfer, exchange, exercise and
replacement of the Warrant Certificates, and in this Agreement wishes to set
forth, among other things, the form and provisions of the Warrant Certificates
and the terms and conditions on which they may be issued, registered,
transferred, exchanged, exercised and replaced.


 


NOW THEREFORE, in consideration of the premises and of the mutual
agreements herein contained, the parties hereto agree as follows:


 


ARTICLE
1


 


ISSUANCE
OF WARRANTS AND EXECUTION AND DELIVERY OF WARRANT CERTIFICATES


 


1.1           Issuance
Of Warrants.  [If Warrants alone—Upon
issuance, each Warrant Certificate shall evidence one or more Warrants.] [If Other Securities and Warrants—
Warrant Certificates shall be [initially] issued in connection with the
issuance of the Other Securities [but shall be separately transferable on and
after 
                      (the “Detachable
Date”)] [and shall not be separately transferable] and each Warrant
Certificate shall evidence one or more Warrants.] Each Warrant evidenced
thereby shall represent the right, subject to the provisions contained herein
and therein, to purchase one Warrant Security.  [If Other Securities and Warrants—
Warrant Certificates shall be initially issued in units with the Other
Securities and each Warrant Certificate included in such a unit shall
evidence 
                      Warrants for each [$
              principal amount] [
                      shares] of Other Securities included in such
unit.]


 


1.2           Execution
And Delivery Of Warrant Certificates.  Each Warrant Certificate, whenever
issued, shall be in registered form substantially in the form set forth in  Exhibit A  hereto, shall be dated the date of its
countersignature by the Warrant Agent and may have such letters, numbers, or
other marks of identification or designation and such legends or endorsements
printed, lithographed or engraved thereon as the officers of the Company
executing the same may approve (execution thereof to be conclusive evidence of
such approval) and as are not inconsistent with the provisions of this
Agreement, or as may be required to comply with any law or with any rule or
regulation made pursuant thereto or with any rule or regulation of any
securities exchange on which the Warrants may be listed, or to conform to
usage.  The Warrant Certificates shall be signed on behalf of the
Company by any of its present or future chief executive officers, presidents,
senior vice presidents, vice presidents, chief financial officers, chief legal
officers, treasurers, assistant treasurers, controllers, assistant controllers,
secretaries or assistant secretaries under its corporate seal reproduced
thereon.  Such signatures may be manual or facsimile signatures of
such authorized officers and may be imprinted or otherwise reproduced on the
Warrant Certificates.  The seal of the Company may be in the form of
a facsimile thereof and may be impressed, affixed, imprinted or otherwise
reproduced on the Warrant Certificates.


 


No Warrant Certificate
shall be valid for any purpose, and no Warrant evidenced thereby shall be
exercisable, until such Warrant Certificate has been countersigned by the
manual signature of the Warrant Agent.  Such signature by the Warrant
Agent upon any Warrant Certificate executed by the Company shall be conclusive
evidence that the Warrant Certificate so countersigned has been duly issued
hereunder.


 


In case any officer of
the Company who shall have signed any of the Warrant Certificates either
manually or by facsimile signature shall cease to be such officer before the
Warrant Certificates so signed shall have been countersigned and delivered by
the Warrant Agent, such Warrant Certificates may be countersigned and delivered
notwithstanding that the person who signed Warrant Certificates ceased to be
such officer of the Company; and any Warrant Certificate may be signed on
behalf of the Company by such persons as, at the actual date of the execution
of such Warrant Certificate, shall be the proper officers of the Company, although
at the date of the execution of this Agreement any such person was not such
officer.


 


The term “holder” or “holder
of a Warrant Certificate” as used herein shall mean any person in whose name at
the time any Warrant Certificate shall be registered upon the books to be
maintained by the Warrant Agent for that purpose [ If Other Securities 


 

















 


and Warrants are not immediately detachable— or upon the registration of the Other
Securities prior to the Detachable Date.  Prior to the Detachable
Date, the Company will, or will cause the registrar of the Other Securities to,
make available at all times to the Warrant Agent such information as to holders
of the Other Securities as may be necessary to keep the Warrant Agent’s records
up to date].


 


1.3           Issuance
Of Warrant Certificates.  Warrant Certificates evidencing the right to purchase
Warrant Securities may be executed by the Company and delivered to the Warrant
Agent upon the execution of this Warrant Agreement or from time to time
thereafter.  The Warrant Agent shall, upon receipt of Warrant
Certificates duly executed on behalf of the Company, countersign such Warrant
Certificates and shall deliver such Warrant Certificates to or upon the order
of the Company.


 


ARTICLE
2


 


WARRANT
PRICE, DURATION AND EXERCISE OF WARRANTS


 


2.1           Warrant
Price.  During
the period specified in Section 2.2, each Warrant shall, subject to the
terms of this Warrant Agreement and the applicable Warrant Certificate, entitle
the holder thereof to purchase the number of Warrant Securities specified in
the applicable Warrant Certificate at an exercise price of $
              per Warrant Security, subject to adjustment
upon the occurrence of certain events, as hereinafter provided.  Such
purchase price per Warrant Security is referred to in this Agreement as the “Warrant Price.”


 


2.2           Duration
Of Warrants.  Each
Warrant may be exercised in whole or in part at any time, as specified herein,
on or after [the date thereof] [
                    
] and at or before [
             ] p.m.,
[              ]
time, on [
                    ]  or such later date as the Company may
designate by notice to the Warrant Agent and the holders of Warrant
Certificates mailed to their addresses as set forth in the record books of the
Warrant Agent (the “Expiration Date”).  Each
Warrant not exercised at or before [
             ] p.m.,
[              ]
time, on the Expiration Date shall become void, and all rights of the holder of
the Warrant Certificate evidencing such Warrant under this Agreement shall
cease.


 


2.3           Exercise
Of Warrants.


 


(a)           During the period specified in Section 2.2,
the Warrants may be exercised to purchase a whole number of Warrant Securities
in registered form by providing certain information as set forth on the reverse
side of the Warrant Certificate and by paying in full, in lawful money of the
United States of America, [in cash or by certified check or official bank check
in New York Clearing House funds] [by bank wire transfer in immediately
available funds] the Warrant Price for each Warrant Security with respect to
which a Warrant is being exercised to the Warrant Agent at its corporate trust
office, provided that such exercise is subject to receipt within five business
days of such payment by the Warrant Agent of the Warrant Certificate with the
form of election to purchase Warrant Securities set forth on the reverse side
of the Warrant Certificate properly completed and duly executed.  The
date on which payment in full of the Warrant Price is received by the Warrant
Agent shall, subject to receipt of the Warrant Certificate as aforesaid, be
deemed to be the date on which the Warrant is exercised; provided, however,
that if, at the date of receipt of such Warrant Certificates and payment in
full of the Warrant Price, the transfer books for the Warrant Securities
purchasable upon the exercise of such Warrants shall be closed, no such receipt
of such Warrant Certificates and no such payment of such Warrant Price shall be
effective to constitute the person so designated to be named as the holder of
record of such Warrant Securities on such date, but shall be effective to
constitute such person as the holder of record of such Warrant Securities for
all purposes at the opening of business on the next succeeding day on which the
transfer books for the Warrant Securities purchasable upon the exercise of such
Warrants shall be opened, and the certificates for the Warrant Securities in
respect of which such Warrants are then exercised shall be issuable as of the
date on such next succeeding day on which the transfer books shall next be
opened, and until such date the Company shall be under no duty to deliver any
certificate for such Warrant Securities.  The Warrant Agent shall
deposit all funds received by it in payment of the Warrant Price in an account
of the Company maintained with it and shall advise the Company by telephone at
the end of each day on which a payment for the exercise of Warrants is received
of the amount so deposited to its account.  The Warrant Agent shall
promptly confirm such telephone advice to the Company in writing.


 


(b)           The Warrant Agent shall, from time to
time, as promptly as practicable, advise the Company of (i) the number of
Warrant Securities with respect to which Warrants were exercised, (ii) the
instructions of each holder of the Warrant Certificates evidencing such
Warrants with respect to delivery of the Warrant Securities to which such
holder is entitled upon such exercise, (iii) delivery of Warrant Certificates
evidencing the balance, if any, of the Warrants for the remaining Warrant
Securities after such exercise, and (iv) such other information as the
Company shall reasonably require.


 


(c)           As soon as practicable after the exercise
of any Warrant, the Company shall issue to or upon the order of the holder of
the Warrant Certificate evidencing such Warrant the Warrant Securities to which
such holder is entitled, in fully registered form, registered in such name or
names as may be directed by such holder.  If fewer than all of the
Warrants evidenced by such Warrant Certificate are exercised, the Company shall
execute, and an authorized officer of the Warrant Agent shall manually
countersign and deliver, a new Warrant Certificate evidencing Warrants for the
number of Warrant Securities remaining unexercised.


 


(d)           The Company shall not be required to pay
any stamp or other tax or other governmental charge required to be paid in
connection with any transfer involved in the issue of the Warrant Securities,
and in the event that any such transfer is involved, the Company shall not be
required to issue or deliver any Warrant Security until such tax or other
charge shall have been paid or it has been established to the Company’s
satisfaction that no such tax or other charge is due.


 

















 


(e)           Prior to the issuance of any Warrants
there shall have been reserved, and the Company shall at all times through the
Expiration Date keep reserved, out of its authorized but unissued Warrant
Securities, a number of shares sufficient to provide for the exercise of the
Warrants.


 


ARTICLE
3


 


OTHER
PROVISIONS RELATING TO RIGHTS OF HOLDERS OF WARRANT CERTIFICATES


 


3.1           No
Rights As Warrant Securityholder Conferred By Warrants Or Warrant Certificates.  No Warrant Certificate or
Warrant evidenced thereby shall entitle the holder thereof to any of the rights
of a holder of Warrant Securities, including, without limitation, the right to
receive the payment of dividends or distributions, if any, on the Warrant
Securities or to exercise any voting rights, except to the extent expressly set
forth in this Agreement or the applicable Warrant Certificate.


 


3.2           Lost,
Stolen, Mutilated Or Destroyed Warrant Certificates.  Upon receipt by the Warrant
Agent of evidence reasonably satisfactory to it and the Company of the
ownership of and the loss, theft, destruction or mutilation of any Warrant
Certificate and/or indemnity reasonably satisfactory to the Warrant Agent and
the Company and, in the case of mutilation, upon surrender of the mutilated
Warrant Certificate to the Warrant Agent for cancellation, then, in the absence
of notice to the Company or the Warrant Agent that such Warrant Certificate has
been acquired by a bona fide purchaser, the Company shall execute, and an
authorized officer of the Warrant Agent shall manually countersign and deliver,
in exchange for or in lieu of the lost, stolen, destroyed or mutilated Warrant
Certificate, a new Warrant Certificate of the same tenor and evidencing
Warrants for a like number of Warrant Securities.  Upon the issuance
of any new Warrant Certificate under this Section 3.2, the Company may
require the payment of a sum sufficient to cover any tax or other governmental
charge that may be imposed in relation thereto and any other expenses
(including the fees and expenses of the Warrant Agent) in connection
therewith.  Every substitute Warrant Certificate executed and
delivered pursuant to this Section 3.2 in lieu of any lost, stolen or
destroyed Warrant Certificate shall represent an additional contractual
obligation of the Company, whether or not the lost, stolen or destroyed Warrant
Certificate shall be at any time enforceable by anyone, and shall be entitled
to the benefits of this Agreement equally and proportionately with any and all
other Warrant Certificates duly executed and delivered
hereunder.  The provisions of this Section 3.2 are exclusive and
shall preclude (to the extent lawful) all other rights and remedies with
respect to the replacement of mutilated, lost, stolen or destroyed Warrant
Certificates.


 


3.3           Holder
Of Warrant Certificate May Enforce Rights.  Notwithstanding any of the provisions of
this Agreement, any holder of a Warrant Certificate, without the consent of the
Warrant Agent, the holder of any Warrant Securities or the holder of any other
Warrant Certificate, may, in such holder’s own behalf and for such holder’s own
benefit, enforce, and may institute and maintain any suit, action or proceeding
against the Company suitable to enforce, or otherwise in respect of, such
holder’s right to exercise the Warrants evidenced by such holder’s Warrant
Certificate in the manner provided in such holder’s Warrant Certificate and in
this Agreement.


 


3.4           Adjustments.


 


(a)           In case the Company shall at any time
subdivide its outstanding shares of Common Stock into a greater number of
shares, the Warrant Price in effect immediately prior to such subdivision shall
be proportionately reduced and the number of Warrant Securities purchasable
under the Warrants shall be proportionately increased.  Conversely,
in case the outstanding shares of Common Stock of the Company shall be combined
into a smaller number of shares, the Warrant Price in effect immediately prior
to such combination shall be proportionately increased and the number of
Warrant Securities purchasable under the Warrants shall be proportionately
decreased.


 


(b)           If at any time or from time to time the
holders of Common Stock (or any shares of stock or other securities at the time
receivable upon the exercise of the Warrants) shall have received or become
entitled to receive, without payment therefore,


 


(i)           Common Stock or any shares of stock or
other securities which are at any time directly or indirectly convertible into
or exchangeable for Common Stock, or any rights or options to subscribe for,
purchase or otherwise acquire any of the foregoing by way of dividend or other
distribution;


 


(ii)        
    any
cash paid or payable otherwise than as a cash dividend paid or payable out of
the Company’s current or retained earnings;


 


(iii)           any evidence of the Company’s
indebtedness or rights to subscribe for or purchase the Company’s indebtedness;
or


 


(iv)         
  Common
Stock or additional stock or other securities or property (including cash) by
way of spinoff, split-up, reclassification, combination of shares or similar
corporate rearrangement (other than shares of Common Stock issued as a stock
split or adjustments in respect of which shall be covered by the terms of Section 3.4(a) above),
then and in each such case, the holder of each Warrant shall, upon the exercise
of the Warrant, be entitled to receive, in addition to the number of Warrant
Securities receivable thereupon, and without payment of any additional
consideration therefore, the amount of stock and other securities and property
(including cash and indebtedness or rights to subscribe for or purchase
indebtedness) which such holder would 


 

















 


hold on the date of such
exercise had he been the holder of record of such Warrant Securities as of the
date on which holders of Common Stock received or became entitled to receive
such shares or all other additional stock and other securities and property.


 


(c)           In case of (i) any reclassification,
capital reorganization, or change in the Common Stock of the Company (other
than as a result of a subdivision, combination, or stock dividend provided for
in Section 3.4(a) or Section 3.4(b) above), (ii) share
exchange, merger or similar transaction of the Company with or into another
person or entity (other than a share exchange, merger or similar transaction in
which the Company is the acquiring or surviving corporation and which does not
result in any change in the Common Stock other than the issuance of additional
shares of Common Stock) or (iii) the sale, exchange, lease, transfer or
other disposition of all or substantially all of the properties and assets of
the Company as an entirety (in any such case, a “Reorganization Event”), then, as a condition of such
Reorganization Event, lawful provisions shall be made, and duly executed
documents evidencing the same from the Company or its successor shall be
delivered to the holders of the Warrants, so that the holders of the Warrants
shall have the right at any time prior to the expiration of the Warrants to
purchase, at a total price equal to that payable upon the exercise of the
Warrants, the kind and amount of shares of stock and other securities and
property receivable in connection with such Reorganization Event by a holder of
the same number of Warrant Securities as were purchasable by the holders of the
Warrants immediately prior to such Reorganization Event.  In any such
case appropriate provisions shall be made with respect to the rights and interests
of the holders of the Warrants so that the provisions hereof shall thereafter
be applicable with respect to any shares of stock or other securities and
property deliverable upon exercise the Warrants, and appropriate adjustments
shall be made to the Warrant Price payable hereunder provided the aggregate
purchase price shall remain the same.  In the case of any transaction
described in clauses (ii) and (iii) above, the Company shall
thereupon be relieved of any further obligation hereunder or under the
Warrants, and the Company as the predecessor corporation may thereupon or at
any time thereafter be dissolved, wound up or liquidated.  Such
successor or assuming entity thereupon may cause to be signed, and may issue
either in its own name or in the name of the Company, any or all of the
Warrants issuable hereunder which heretofore shall not have been signed by the
Company, and may execute and deliver securities in its own name, in fulfillment
of its obligations to deliver Warrant Securities upon exercise of the
Warrants.  All the Warrants so issued shall in all respects have the
same legal rank and benefit under this Agreement as the Warrants theretofore or
thereafter issued in accordance with the terms of this Agreement as though all
of such Warrants had been issued at the date of the execution
hereof.  In any case of any such Reorganization Event, such changes
in phraseology and form (but not in substance) may be made in the Warrants
thereafter to be issued as may be appropriate.  The Warrant Agent may
receive a written opinion of legal counsel as conclusive evidence that any such
Reorganization Event complies with the provisions of this Section 3.4.


 


(d)           The Company may, at its option, at any
time until the Expiration Date, reduce the then current Warrant Price to any
amount deemed appropriate by the Board of Directors of the Company for any
period not exceeding twenty consecutive days (as evidenced in a resolution
adopted by such Board of Directors), but only upon giving the notices required by
Section 3.5 at least ten days prior to taking such action.


 


(e)           Except as herein otherwise expressly
provided, no adjustment in the Warrant Price shall be made by reason of the
issuance of shares of Common Stock, or securities convertible into or
exchangeable for shares of Common Stock, or securities carrying the right to
purchase any of the foregoing or for any other reason whatsoever.


 


(f)      
     No fractional Warrant Securities shall be issued upon
the exercise of Warrants.  If more than one Warrant shall be
exercised at one time by the same holder, the number of full Warrant Securities
which shall be issuable upon such exercise shall be computed on the basis of
the aggregate number of Warrant Securities purchased pursuant to the Warrants so
exercised.  Instead of any fractional Warrant Security which would
otherwise be issuable upon exercise of any Warrant, the Company shall pay a
cash adjustment in respect of such fraction in an amount equal to the same
fraction of the last reported sale price (or bid price if there were no sales)
per Warrant Security, in either case as reported on the principal registered
national securities exchange on which the Warrant Securities are listed or
admitted to trading on the business day that next precedes the day of exercise
or, if the Warrant Securities are not then listed or admitted to trading on any
registered national securities exchange, the average of the closing high bid
and low asked prices as reported on the OTC Bulletin Board Service (the “OTC Bulletin Board”) operated by the
Financial Industry Regulatory Authority, Inc. (“FINRA”) or, if not available on the OTC Bulletin Board, then
the average of the closing high bid and low asked prices as reported on any
other U.S. quotation medium or inter-dealer quotation system on such date, or
if on any such date the Warrant Securities are not listed or admitted to
trading on a registered national securities exchange, are not included in the
OTC Bulletin Board, and are not quoted on any other U.S. quotation medium or
inter-dealer quotation system, an amount equal to the same fraction of the
average of the closing bid and asked prices as furnished by any FINRA member
firm selected from time to time by the Company for that purpose at the close of
business on the business day that next precedes the day of exercise.


 


(g)           Whenever the Warrant Price then in effect
is adjusted as herein provided, the Company shall mail to each holder of the
Warrants at such holder’s address as it shall appear on the books of the
Company a statement setting forth the adjusted Warrant Price then and
thereafter effective under the provisions hereof, together with the facts, in
reasonable detail, upon which such adjustment is based.


 


3.5           Notice
To Warrantholders.  In
case the Company shall (a) effect any dividend or distribution described
in Section 3.4(b), (b) effect any Reorganization Event, (c) make
any distribution on or in respect of the Common Stock in connection with the
dissolution, liquidation or winding up of the Company, or (d) reduce the
then current Warrant Price pursuant to Section 3.4(d), then the Company
shall mail to each holder of Warrants at such holder’s address as it shall
appear on the books of the Warrant Agent, at least ten days prior to the
applicable date hereinafter specified, a notice stating (x) the record
date for such dividend or distribution, or, if a record is not to be taken, the
date as of which the holders of record of Common Stock that will be entitled to



 

















 


such dividend or
distribution are to be determined, (y) the date on which such
Reorganization Event, dissolution, liquidation or winding up is expected to
become effective, and the date as of which it is expected that holders of
Common Stock of record shall be entitled to exchange their shares of Common
Stock for securities or other property deliverable upon such Reorganization
Event, dissolution, liquidation or winding up, or (z) the first date on
which the then current Warrant Price shall be reduced pursuant to Section 3.4(d).  No
failure to mail such notice nor any defect therein or in the mailing thereof
shall affect any such transaction or any adjustment in the Warrant Price
required by Section 3.4.


 


3.6           [If
The Warrants Are Subject To Acceleration By The Company, Insert—Acceleration Of
Warrants By The Company.


 


(a)           At any time on or after
                    ,
the Company shall have the right to accelerate any or all Warrants at any time
by causing them to expire at the close of business on the day next preceding a
specified date (the “Acceleration Date”),
if the Market Price (as hereinafter defined) of the Common Stock equals or
exceeds 
            
percent (             
%) of the then effective Warrant Price on any twenty Trading Days (as
hereinafter defined) within a period of thirty consecutive Trading Days ending
no more than five Trading Days prior to the date on which the Company gives
notice to the Warrant Agent of its election to accelerate the Warrants.


 


(b)           “Market
Price” for each
Trading Day shall be, if the Common Stock is listed or admitted to trading on
any registered national securities exchange, the last reported sale price,
regular way (or, if no such price is reported, the average of the reported
closing bid and asked prices, regular way) of Common Stock, in either case as
reported on the principal registered national securities exchange on which the
Common Stock is listed or admitted to trading or, if not listed or admitted to
trading on any registered national securities exchange, the average of the
closing high bid and low asked prices as reported on the OTC Bulletin Board
operated by FINRA, or if not available on the OTC Bulletin Board, then the
average of the closing high bid and low asked prices as reported on any other
U.S. quotation medium or inter-dealer quotation system, or if on any such date
the shares of Common Stock are not listed or admitted to trading on a
registered national securities exchange, are not included in the OTC Bulletin
Board, and are not quoted on any other U.S. quotation medium or inter-dealer
quotation system, the average of the closing bid and asked prices as furnished
by any FINRA member firm selected from time to time by the Company for that
purpose. “Trading Day” shall be
each Monday through Friday, other than any day on which securities are not
traded in the system or on the exchange that is the principal market for the
Common Stock, as determined by the Board of Directors of the Company.


 


(c)           In the event of an acceleration of less
than all of the Warrants, the Warrant Agent shall select the Warrants to be
accelerated by lot, pro rata or in such other manner as it deems, in its
discretion, to be fair and appropriate.


 


(d)           Notice of an acceleration specifying the
Acceleration Date shall be sent by mail first class, postage prepaid, to each
registered holder of a Warrant Certificate representing a Warrant accelerated
at such holder’s address appearing on the books of the Warrant Agent not more
than sixty days nor less than thirty days before the Acceleration
Date.  Such notice of an acceleration also shall be given no more
than twenty days, and no less than ten days, prior to the mailing of notice to
registered holders of Warrants pursuant to this Section 3.6, by
publication at least once in a newspaper of general circulation in the City of
New York.


 


(e)           Any Warrant accelerated may be exercised
until
[            ] p.m.,
[            ]
time, on the business day next preceding the Acceleration Date.  The
Warrant Price shall be payable as provided in Section 2.]


 


ARTICLE
4


 


EXCHANGE
AND TRANSFER OF WARRANT CERTIFICATES


 


4.1           Exchange
And Transfer Of Warrant Certificates.  [If Other Securities with Warrants which are immediately
detachable— Upon] [If Other Securities
with Warrants which are not immediately detachable— Prior to the
Detachable Date, a Warrant Certificate may be exchanged or transferred only
together with the Other Security to which the Warrant Certificate was initially
attached, and only for the purpose of effecting or in conjunction with an
exchange or transfer of such Other Security.  Prior to any Detachable
Date, each transfer of the Other Security shall operate also to transfer the
related Warrant Certificates.  After the Detachable Date, upon]
surrender at the corporate trust office of the Warrant Agent, Warrant
Certificates evidencing Warrants may be exchanged for Warrant Certificates in
other denominations evidencing such Warrants or the transfer thereof may be
registered in whole or in part; provided that such other Warrant Certificates
evidence Warrants for the same aggregate number of Warrant Securities as the
Warrant Certificates so surrendered.  The Warrant Agent shall keep,
at its corporate trust office, books in which, subject to such reasonable regulations
as it may prescribe, it shall register Warrant Certificates and exchanges and
transfers of outstanding Warrant Certificates, upon surrender of the Warrant
Certificates to the Warrant Agent at its corporate trust office for exchange or
registration of transfer, properly endorsed or accompanied by appropriate
instruments of registration of transfer and written instructions for transfer,
all in form satisfactory to the Company and the Warrant Agent.  No
service charge shall be made for any exchange or registration of transfer of
Warrant Certificates, but the Company may require payment of a sum sufficient
to cover any stamp or other tax or other governmental charge that may be
imposed in connection with any such exchange or registration of transfer.  Whenever any Warrant Certificates are so
surrendered for exchange or registration of transfer, an authorized officer of
the Warrant Agent shall manually countersign and deliver to the person or
persons entitled thereto a Warrant Certificate or Warrant Certificates duly
authorized and executed by the Company, as so requested.  The Warrant
Agent shall not be required to effect any exchange or registration of transfer
which will result in the issuance of a Warrant Certificate evidencing a Warrant
for a fraction of a 


 

















 


Warrant Security or a
number of Warrants for a whole number of Warrant Securities and a fraction of a
Warrant Security.  All Warrant Certificates issued upon any exchange
or registration of transfer of Warrant Certificates shall be the valid obligations
of the Company, evidencing the same obligations and entitled to the same
benefits under this Agreement as the Warrant Certificate surrendered for such
exchange or registration of transfer.


 


4.2           Treatment
Of Holders Of Warrant Certificates.  [If Other Securities and Warrants are not immediately
detachable— Prior to the Detachable Date, the Company, the
Warrant Agent and all other persons may treat the owner of the Other Security
as the owner of the Warrant Certificates initially attached thereto for any
purpose and as the person entitled to exercise the rights represented by the
Warrants evidenced by such Warrant Certificates, any notice to the contrary
notwithstanding.  After the Detachable Date and prior to due
presentment of a Warrant Certificate for registration of transfer, the] [The]
Company, the Warrant Agent and all other persons may treat the registered
holder of a Warrant Certificate as the absolute owner thereof for any purpose
and as the person entitled to exercise the rights represented by the Warrants
evidenced thereby, any notice to the contrary notwithstanding.


 


4.3           Cancellation
Of Warrant Certificates.  Any Warrant Certificate surrendered for exchange,
registration of transfer or exercise of the Warrants evidenced thereby shall,
if surrendered to the Company, be delivered to the Warrant Agent and all
Warrant Certificates surrendered or so delivered to the Warrant Agent shall be
promptly canceled by the Warrant Agent and shall not be reissued and, except as
expressly permitted by this Agreement, no Warrant Certificate shall be issued
hereunder in exchange therefor or in lieu thereof.


 


The Warrant Agent shall
deliver to the Company from time to time or otherwise dispose of canceled
Warrant Certificates in a manner satisfactory to the Company.


 


ARTICLE
5


 


CONCERNING
THE WARRANT AGENT


 


5.1           Warrant
Agent.  The
Company hereby appoints
                    
as Warrant Agent of the Company in respect of the Warrants and the Warrant
Certificates upon the terms and subject to the conditions herein set forth,
and 
                      hereby accepts such
appointment.  The Warrant Agent shall have the powers and authority
granted to and conferred upon it in the Warrant Certificates and hereby and
such further powers and authority to act on behalf of the Company as the
Company may hereafter grant to or confer upon it.  All of the terms
and provisions with respect to such powers and authority contained in the
Warrant Certificates are subject to and governed by the terms and provisions
hereof.


 


5.2           Conditions
Of Warrant Agent’s Obligations.  The Warrant Agent accepts its obligations
herein set forth upon the terms and conditions hereof, including the following
to all of which the Company agrees and to all of which the rights hereunder of
the holders from time to time of the Warrant Certificates shall be subject:


 


(a)           Compensation
And Indemnification.  The
Company agrees promptly to pay the Warrant Agent the compensation to be agreed
upon with the Company for all services rendered by the Warrant Agent and to
reimburse the Warrant Agent for reasonable out-of-pocket expenses (including
reasonable counsel fees) incurred without negligence, bad faith or willful
misconduct by the Warrant Agent in connection with the services rendered
hereunder by the Warrant Agent.  The Company also agrees to indemnify
the Warrant Agent for, and to hold it harmless against, any loss, liability or
expense incurred without negligence, bad faith or willful misconduct on the
part of the Warrant Agent, arising out of or in connection with its acting as
Warrant Agent hereunder, including the reasonable costs and expenses of
defending against any claim of such liability.


 


(b)           Agent
For The Company.  In
acting under this Warrant Agreement and in connection with the Warrant
Certificates, the Warrant Agent is acting solely as agent of the Company and
does not assume any obligations or relationship of agency or trust for or with
any of the holders of Warrant Certificates or beneficial owners of Warrants.


 


(c)           Counsel.  The Warrant Agent may
consult with counsel satisfactory to it, which may include counsel for the
Company, and the written advice of such counsel shall be full and complete
authorization and protection in respect of any action taken, suffered or
omitted by it hereunder in good faith and in accordance with the advice of such
counsel.


 


(d)           Documents.  The Warrant Agent shall be
protected and shall incur no liability for or in respect of any action taken or
omitted by it in reliance upon any Warrant Certificate, notice, direction,
consent, certificate, affidavit, statement or other paper or document
reasonably believed by it to be genuine and to have been presented or signed by
the proper parties.


 


(e)           Certain
Transactions.  The
Warrant Agent, and its officers, directors and employees, may become the owner
of, or acquire any interest in, Warrants, with the same rights that it or they
would have if it were not the Warrant Agent hereunder, and, to the extent
permitted by applicable law, it or they may engage or be interested in any
financial or other transaction with the Company and may act on, or as
depositary, trustee or agent for, any committee or body of holders of Warrant
Securities or other obligations of the Company as freely as if it were not the
Warrant Agent hereunder.  Nothing in this Warrant Agreement shall be
deemed to prevent the Warrant Agent from acting as trustee under any indenture
to which the Company is a party.


 


(f)   
        No Liability For Interest.  Unless otherwise agreed with
the Company, the Warrant Agent shall have no liability for interest on any
monies at any time received by it pursuant to any of the provisions of this
Agreement or of the Warrant 


 

















 


Certificates.


 


(g)           No
Liability For Invalidity.  The Warrant Agent shall have no liability with respect to
any invalidity of this Agreement or any of the Warrant Certificates (except as
to the Warrant Agent’s countersignature thereon).


 


(h)           No
Responsibility For Representations.  The Warrant Agent shall not be
responsible for any of the recitals or representations herein or in the Warrant
Certificates (except as to the Warrant Agent’s countersignature thereon), all
of which are made solely by the Company.


 


(i)           No
Implied Obligations.  The
Warrant Agent shall be obligated to perform only such duties as are herein and
in the Warrant Certificates specifically set forth and no implied duties or
obligations shall be read into this Agreement or the Warrant Certificates
against the Warrant Agent.  The Warrant Agent shall not be under any
obligation to take any action hereunder which may tend to involve it in any
expense or liability, the payment of which within a reasonable time is not, in
its reasonable opinion, assured to it.  The Warrant Agent shall not
be accountable or under any duty or responsibility for the use by the Company
of any of the Warrant Certificates authenticated by the Warrant Agent and
delivered by it to the Company pursuant to this Agreement or for the
application by the Company of the proceeds of the Warrant
Certificates.  The Warrant Agent shall have no duty or responsibility
in case of any default by the Company in the performance of its covenants or
agreements contained herein or in the Warrant Certificates or in the case of
the receipt of any written demand from a holder of a Warrant Certificate with
respect to such default, including, without limiting the generality of the
foregoing, any duty or responsibility to initiate or attempt to initiate any
proceedings at law or otherwise or, except as provided in Section 6.2
hereof, to make any demand upon the Company.


 


5.3           Resignation,
Removal And Appointment Of Successors.


 


(a)           The Company agrees, for the benefit of the
holders from time to time of the Warrant Certificates, that there shall at all
times be a Warrant Agent hereunder until all the Warrants have been exercised
or are no longer exercisable.


 


(b)           The Warrant Agent may at any time resign
as agent by giving written notice to the Company of such intention on its part,
specifying the date on which its desired resignation shall become effective;
provided that such date shall not be less than three months after the date on
which such notice is given unless the Company otherwise agrees.  The
Warrant Agent hereunder may be removed at any time by the filing with it of an
instrument in writing signed by or on behalf of the Company and specifying such
removal and the intended date when it shall become effective.  Such
resignation or removal shall take effect upon the appointment by the Company,
as hereinafter provided, of a successor Warrant Agent (which shall be a bank or
trust company authorized under the laws of the jurisdiction of its organization
to exercise corporate trust powers) and the acceptance of such appointment by
such successor Warrant Agent.  The obligation of the Company under Section 5.2(a) shall
continue to the extent set forth therein notwithstanding the resignation or
removal of the Warrant Agent.


 


(c)           In case at any time the Warrant Agent
shall resign, or shall be removed, or shall become incapable of acting, or
shall be adjudged a bankrupt or insolvent, or shall commence a voluntary case
under the Federal bankruptcy laws, as now or hereafter constituted, or under
any other applicable Federal or state bankruptcy, insolvency or similar law or
shall consent to the appointment of or taking possession by a receiver,
custodian, liquidator, assignee, trustee, sequestrator (or other similar
official) of the Warrant Agent or its property or affairs, or shall make an
assignment for the benefit of creditors, or shall admit in writing its
inability to pay its debts generally as they become due, or shall take
corporate action in furtherance of any such action, or a decree or order for
relief by a court having jurisdiction in the premises shall have been entered
in respect of the Warrant Agent in an involuntary case under the Federal
bankruptcy laws, as now or hereafter constituted, or any other applicable
Federal or state bankruptcy, insolvency or similar law, or a decree or order by
a court having jurisdiction in the premises shall have been entered for the
appointment of a receiver, custodian, liquidator, assignee, trustee,
sequestrator (or similar official) of the Warrant Agent or of its property or
affairs, or any public officer shall take charge or control of the Warrant
Agent or of its property or affairs for the purpose of rehabilitation,
conservation, winding up or liquidation, a successor Warrant Agent, qualified
as aforesaid, shall be appointed by the Company by an instrument in writing,
filed with the successor Warrant Agent.  Upon the appointment as
aforesaid of a successor Warrant Agent and acceptance by the successor Warrant
Agent of such appointment, the Warrant Agent shall cease to be Warrant Agent
hereunder.


 


(d)           Any successor Warrant Agent appointed
hereunder shall execute, acknowledge and deliver to its predecessor and to the
Company an instrument accepting such appointment hereunder, and thereupon such
successor Warrant Agent, without any further act, deed or conveyance, shall
become vested with all the authority, rights, powers, trusts, immunities,
duties and obligations of such predecessor with like effect as if originally
named as Warrant Agent hereunder, and such predecessor, upon payment of its
charges and disbursements then unpaid, shall thereupon become obligated to
transfer, deliver and pay over, and such successor Warrant Agent shall be
entitled to receive, all monies, securities and other property on deposit with
or held by such predecessor, as Warrant Agent hereunder.


 


(e)           Any corporation into which the Warrant
Agent hereunder may be merged or converted or any corporation with which the
Warrant Agent may be consolidated, or any corporation resulting from any
merger, conversion or consolidation to which the Warrant Agent shall be a
party, or any corporation to which the Warrant Agent shall sell or otherwise
transfer all or substantially all the assets and business of the Warrant Agent,
provided that it shall be qualified as aforesaid, shall be the successor
Warrant Agent under this Agreement without the execution or filing of any paper
or any further act on the part of any of the parties hereto.


 














 


ARTICLE
6


 


MISCELLANEOUS


 


6.1           Amendment.  This Agreement may be
amended by the parties hereto, without the consent of the holder of any Warrant
Certificate, for the purpose of curing any ambiguity, or of curing, correcting
or supplementing any defective provision contained herein, or making any other
provisions with respect to matters or questions arising under this Agreement as
the Company and the Warrant Agent may deem necessary or desirable; provided
that such action shall not materially adversely affect the interests of the
holders of the Warrant Certificates.


 


6.2           Notices
And Demands To The Company And Warrant Agent.  If the Warrant Agent shall receive any
notice or demand addressed to the Company by the holder of a Warrant Certificate
pursuant to the provisions of the Warrant Certificates, the Warrant Agent shall
promptly forward such notice or demand to the Company.


 


6.3           Addresses.  Any communication from the
Company to the Warrant Agent with respect to this Agreement shall be addressed
to 
                
, Attention: 
                  and any communication from the Warrant Agent
to the Company with respect to this Agreement shall be addressed to ARYx
Therapeutics, Inc., 6300 Dumbarton Circle, Fremont, CA 94555, Attention:
Chief Financial Officer (or such other address as shall be specified in writing
by the Warrant Agent or by the Company).


 


6.4           Governing
Law.  This
Agreement and each Warrant Certificate issued hereunder shall be governed by
and construed in accordance with the laws of the State of New York.


 


6.5           Delivery
Of Prospectus.  The
Company shall furnish to the Warrant Agent sufficient copies of a prospectus
meeting the requirements of the Securities Act of 1933, as amended, relating to
the Warrant Securities deliverable upon exercise of the Warrants (the “Prospectus”), and the Warrant Agent agrees
that upon the exercise of any Warrant, the Warrant Agent will deliver to the
holder of the Warrant Certificate evidencing such Warrant, prior to or
concurrently with the delivery of the Warrant Securities issued upon such
exercise, a Prospectus.


 


The Warrant Agent shall
not, by reason of any such delivery, assume any responsibility for the accuracy
or adequacy of such Prospectus.


 


6.6           Obtaining
Of Governmental Approvals.  The Company will from time to time take all action which
may be necessary to obtain and keep effective any and all permits, consents and
approvals of governmental agencies and authorities and securities act filings
under United States Federal and state laws (including without limitation a
registration statement in respect of the Warrants and Warrant Securities under
the Securities Act of 1933, as amended), which may be or become requisite in
connection with the issuance, sale, transfer, and delivery of the Warrant
Securities issued upon exercise of the Warrants, the issuance, sale, transfer
and delivery of the Warrants or upon the expiration of the period during which
the Warrants are exercisable.


 


6.7           Persons
Having Rights Under Warrant Agreement.  Nothing in this Agreement shall give to
any person other than the Company, the Warrant Agent and the holders of the
Warrant Certificates any right, remedy or claim under or by reason of this
Agreement.


 


6.8           Headings.  The descriptive headings of
the several Articles and Sections of this Agreement are inserted for
convenience only and shall not control or affect the meaning or construction of
any of the provisions hereof.


 


6.9           Counterparts.  This Agreement may be
executed in any number of counterparts, each of which as so executed shall be
deemed to be an original, but such counterparts shall together constitute but
one and the same instrument.


 


6.10         Inspection
Of Agreement.  A
copy of this Agreement shall be available at all reasonable times at the
principal corporate trust office of the Warrant Agent for inspection by the
holder of any Warrant Certificate.  The Warrant Agent may require
such holder to submit his Warrant Certificate for inspection by it.


 

















 


IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed, all as of the day and year first above written.


 


	
   

  	
   

  	
  ARYx THERAPEUTICS, INC.

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Its:

  	
   

  
	
   

  	
   

  	
   

  
	
  Attest:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  WARRANT AGENT

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Its:

  	
   

  
	
   

  	
   

  	
   

  
	
  Attest:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  



 


[SIGNATURE PAGE TO
COMMON STOCK WARRANT AGREEMENT]


 

















 


EXHIBIT
A


 


FORM OF
WARRANT CERTIFICATE


[FACE
OF WARRANT CERTIFICATE]


 


	
  [[Form if Warrants
  are attached to Other Securities and are not immediately detachable.]

  	
   

  	
  [Prior to
                  ,
  this Warrant Certificate cannot be transferred or exchanged unless attached
  to a [Title of Other Securities].]

  
	
   

  	
   

  	
   

  
	
  [Form of Legend if
  Warrants are not immediately exercisable.]

  	
   

  	
  [Prior to
                  ,
  Warrants evidenced by this Warrant Certificate cannot be exercised.]

  



 


EXERCISABLE ONLY
IF COUNTERSIGNED BY THE WARRANT AGENT AS PROVIDED HEREIN


 


VOID AFTER
[        ] P.M.,
[            ]
TIME, ON
                    ,


 

















 


ARYx
THERAPEUTICS, INC.


WARRANT
CERTIFICATE REPRESENTING


WARRANTS
TO PURCHASE


COMMON
STOCK, PAR VALUE $0.001 PER SHARE


 


	
  No.                     

  	
  Warrants

  



 


This certifies that
                    
or registered assigns is the registered owner of the above indicated number of
Warrants, each Warrant entitling such owner [if Warrants are attached to Other Securities and are
not immediately detachable— , subject to the registered owner
qualifying as a “Holder” of this Warrant Certificate, as hereinafter defined),]
to purchase, at any time [after [         
] p.m., [
             ]
time, [on 
                  and] on or before [
         ] p.m., [
             ]
time, on
                
,                        shares of Common Stock, par value $0.001 per
share (the “Warrant Securities”),
of ARYx Therapeutics, Inc.  (the “Company”) on the following basis: during the period from 
                    
, through and including 
                    
, the exercise price per Warrant Security will be $
             ,
subject to adjustment as provided in the Warrant Agreement (as hereinafter
defined) (the “Warrant Price”).  The
Holder may exercise the Warrants evidenced hereby by providing certain
information set forth on the back hereof and by paying in full, in lawful money
of the United States of America, [in cash or by certified check or official
bank check in New York Clearing House funds] [by bank wire transfer in
immediately available funds], the Warrant Price for each Warrant Security with
respect to which this Warrant is exercised to the Warrant Agent (as hereinafter
defined) and by surrendering this Warrant Certificate, with the purchase form
on the back hereof duly executed, at the corporate trust office of [name of
Warrant Agent], or its successor as warrant agent (the “Warrant Agent”), which is, on the date
hereof, at the address specified on the reverse hereof, and upon compliance
with and subject to the conditions set forth herein and in the Warrant
Agreement (as hereinafter defined).


 


The term “Holder” as used herein shall mean [if
Warrants are attached to Other Securities and are not immediately
detachable—prior to 
                    
, 
              (the “Detachable
Date”), the registered owner of the Company’s [title of Other
Securities] to which this Warrant Certificate was initially attached, and after
such Detachable Date,] the person in whose name at the time this Warrant
Certificate shall be registered upon the books to be maintained by the Warrant
Agent for that purpose pursuant to Section 4 of the Warrant Agreement.


 


The Warrants evidenced by
this Warrant Certificate may be exercised to purchase a whole number of Warrant
Securities in registered form.  Upon any exercise of fewer than all
of the Warrants evidenced by this Warrant Certificate, there shall be issued to
the Holder hereof a new Warrant Certificate evidencing Warrants for the number
of Warrant Securities remaining unexercised.


 


This Warrant Certificate
is issued under and in accordance with the Warrant Agreement dated as of
                    ,
             (the “Warrant Agreement”), between the Company
and the Warrant Agent and is subject to the terms and provisions contained in
the Warrant Agreement, to all of which terms and provisions the Holder of this
Warrant Certificate consents by acceptance hereof.  Copies of the
Warrant Agreement are on file at the above-mentioned office of the Warrant
Agent.


 


[If Warrants are attached to Other
Securities and are not immediately detachable - Prior to the
Detachable Date, this Warrant Certificate may be exchanged or transferred only
together with the [Title of Other Securities] (the “Other Securities”) to which this Warrant Certificate was
initially attached, and only for the purpose of effecting or in conjunction
with, an exchange or transfer of such Other Security.  Additionally,
on or prior to the Detachable Date, each transfer of such Other Security on the
register of the Other Securities shall operate also to transfer this Warrant
Certificate.  After such date, transfer of this] [If Warrants are attached to Other
Securities and are immediately detachable -  Transfer of this] Warrant Certificate may be
registered when this Warrant Certificate is surrendered at the corporate trust
office of the Warrant Agent by the registered owner or such owner’s assigns, in
the manner and subject to the limitations provided in the Warrant Agreement.


 


[If Other Securities with Warrants
which are not immediately detachable - Except as provided in the
immediately preceding paragraph, after] [If Other Securities with Warrants which are immediately
detachable or Warrants alone - 
After] countersignature by the Warrant Agent and prior to the expiration
of this Warrant Certificate, this Warrant Certificate may be exchanged at the
corporate trust office of the Warrant Agent for Warrant Certificates
representing Warrants for the same aggregate number of Warrant Securities.


 


This Warrant Certificate
shall not entitle the Holder hereof to any of the rights of a holder of the
Warrant Securities, including, without limitation, the right to receive
payments of dividends or distributions, if any, on the Warrant Securities
(except to the extent set forth in the Warrant Agreement) or to exercise any
voting rights.


 


Reference is hereby made
to the further provisions of this Warrant Certificate set forth on the reverse
hereof, which further provisions shall for all purposes have the same effect as
if set forth at this place.


 


This Warrant Certificate
shall not be valid or obligatory for any purpose until countersigned by the
Warrant Agent.


 

















 


IN WITNESS WHEREOF, the Company has caused this Warrant to be executed
in its name and on its behalf by the facsimile signatures of its duly
authorized officers.


 


	
  Dated:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  ARYx
  THERAPEUTICS, INC.

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Its:

  	
   

  
	
   

  	
   

  	
   

  
	
  Attest:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  :

  	
   

  	
  Countersigned

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  As Warrant Agent

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
   

  	
  Authorized
  Signature

  



 

















 


[REVERSE
OF WARRANT CERTIFICATE]


 


(Instructions
for Exercise of Warrant)


 


To exercise any Warrants
evidenced hereby for Warrant Securities (as hereinafter defined), the Holder
must pay, in lawful money of the United States of America, [in cash or by
certified check or official bank check in New York Clearing House funds] [by
bank wire transfer in immediately available funds], the Warrant Price in full
for Warrants exercised, to [Warrant Agent] [address of Warrant Agent],
Attn: 
                    
, which payment must specify the name of the Holder and the number of Warrants
exercised by such Holder.  In addition, the Holder must complete the
information required below and present this Warrant Certificate in person or by
mail (certified or registered mail is recommended) to the Warrant Agent at the
appropriate address set forth above.  This Warrant Certificate,
completed and duly executed, must be received by the Warrant Agent within five
business days of the payment.


 


(To be executed
upon exercise of Warrants)


 


The undersigned hereby
irrevocably elects to exercise
                    
Warrants, evidenced by this Warrant Certificate, to purchase 
                      shares of the Common Stock, par value $0.001
per share (the “Warrant Securities”),
of ARYx Therapeutics, Inc. and represents that he has tendered payment for
such Warrant Securities, in lawful money of the United States of America, [in
cash or by certified check or official bank check in New York Clearing House
funds] [by bank wire transfer in immediately available funds], to the order of
ARYx Therapeutics, Inc., c/o [insert name and address of Warrant Agent],
in the amount of $
              in accordance with the terms
hereof.  The undersigned requests that said Warrant Securities be in
fully registered form in the authorized denominations, registered in such names
and delivered all as specified in accordance with the instructions set forth
below.


 


If the number of Warrants
exercised is less than all of the Warrants evidenced hereby, the undersigned
requests that a new Warrant Certificate evidencing the Warrants for the number
of Warrant Securities remaining unexercised be issued and delivered to the
undersigned unless otherwise specified in the instructions below.


 


	
  Dated:

  	
   

  	
   

  	
   

  	
  Name:

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
  Please Print

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Address:

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  (Insert Social Security
  or Other Identifying Number of Holder)

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Signature Guaranteed:

  	
   

  	
   

  	
   

  
	
   

  	
  Signature

  	
   

  	
   

  
							



 


(Signature must conform
in all respects to name of holder as specified on the face of this Warrant
Certificate and must bear a signature guarantee by a FINRA member firm).


 


This Warrant may be
exercised at the following addresses:


 


	
  By hand at:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  By mail at:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  



 


[Instructions as to form
and delivery of Warrant Securities and, if applicable, Warrant Certificates
evidencing Warrants for the number of Warrant Securities remaining
unexercised—complete as appropriate.]


 

















 


ASSIGNMENT


 


[Form of
assignment to be executed if Warrant Holder desires to transfer Warrant)


 


FOR VALUE RECEIVED,
                    
hereby sells, assigns and transfers unto:


 


	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  (Please print name and
  address including zip code)

  	
   

  	
  Please print Social
  Security or other identifying number

  



 


the right represented by
the within Warrant to purchase
                    
shares of [Title of Warrant Securities] of ARYx Therapeutics, Inc. to
which the within Warrant relates and appoints 
                      attorney to transfer such right on the books
of the Warrant Agent with full power of substitution in the premises.


 


	
  Dated:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Signature

  



 


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


 


	
  Signature Guaranteed