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                                                                     EXHIBIT 3.1

                                    RESTATED

                          CERTIFICATE OF INCORPORATION

                        OF ATLANTIC PHARMACEUTICAL, INC.

                     [AS AMENDED THROUGH FEBRUARY 21, 2003]

         I, the sole director, for purposes of restating the Certificate of
Incorporation of Atlantic Pharmaceuticals, Inc., a Delaware corporation which
has not received payment for any of its stock and which was originally
incorporated on May 18, 1993 under this same name (the "Corporation"), hereby
certificate as follows:

         1.       This Restated Certificate of Incorporation of the Corporation
has been duly adopted in accordance with the provisions of Sections 241 and 245
of the General Corporation Law of the State of Delaware.

         2.       The text of the Certificate of Incorporation of the
Corporation is hereby amended and restated to read in its entirety as follows:

         FIRST: The name of the corporation is Manhattan Pharmaceuticals, Inc.

         SECOND: The address of the registered office of the Corporation in the
State of Delaware is 1209 Orange Street, in the City of Wilmington, County of
New Castle, and the name of its registered agent at that address is The
Corporation Trust Company.

         THIRD: The purpose of the Corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of the State of Delaware.

         FOURTH: A. The corporation is authorized to issue two classes of shares
designated "Common Stock" and "Preferred Stock," respectively. The total number
of shares of Common Stock authorized to be issued is 150,000,000, and each such
share will have a par value of $0.001. The total number of shares of Preferred
Stock authorized to be issued is 10,000,000, and each such share will have a par
value of $0.001. The rights, preferences, privileges and restrictions granted to
and imposed upon the two classes of shares are as set forth in this Article and
in the Certificate of Designations of Series A Convertible Preferred Stock.

                 B. The shares of Preferred Stock may be issued from time to
time in one or more series. The Board of Directors is hereby authorized, by
adopting appropriate resolutions and causing one or more certificates of
amendment to be signed, verified and delivered in accordance with the General
Corporation Law, to establish from time to time the number of shares to be
included in such series, and to fix the designations, relative rights,
preferences and limitations of the shares of each such series. Such
designations, relative rights, preferences and limitations may include, but are
not limited to, the fixing or alteration of the dividend rights, dividend rate,
conversion rights, exchange rights, voting rights, rights and terms of
redemption (including sinking fund provisions), the redemption price or prices,
and the liquidation preferences of any wholly unissued series of shares of
Preferred Stock, or any of them. In accordance with the authority hereby
granted, the Board of Directors may increase or decrease the number of shares of
any series subsequent to the issue of shares of that series, but not above the
total

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number of authorized shares of Preferred Stock and not below the number of
shares of such series then outstanding. In case the number of shares of any
series shall be so decreased, the shares constituting such decrease shall resume
the status that they had prior to the adoption of the resolution originally
fixing the number of shares of such series. Except as may otherwise be required
by law or this Certificate of Incorporation, the terms of any series of
Preferred Stock may be amended without the consent of the holders of any other
series of Preferred Stock, or Common Stock.

         FIFTH: The number of directors which shall constitute the whole Board
of Directors shall be fixed by, or in the same manner provided in, the Bylaws of
the Corporation.

         SIXTH: In furtherance and not in limitation of the powers conferred by
statute, the Board of Directors is expressly authorized to make, repeal, alter,
amend and rescind the Bylaws of the Corporation.

         SEVENTH: Election of directors at an annual or special meeting of
stockholders need not be made by written ballot unless the Bylaws of the
Corporation shall so provide.

         EIGHTH: Whenever a compromise or arrangement is proposed between the
Corporation and its creditors or any class of them and/or between the
Corporation and its stockholders or any class of them, any court of equitable
jurisdiction within the State of Delaware, may, on application in a summary way
of the Corporation or of any creditor or stockholder thereof on the application
or any receiver or receivers appointed for the Corporation under the provisions
of Section 291 of Title 8 of the Delaware Code or on the application of the
trustees in dissolution or of any receiver or receivers appointed for the
Corporation under the provisions of Section 279 of Title 8 of the Delaware Code
order a meeting of the creditors or class of creditors, and/or of the
stockholders or a class of stockholders of the Corporation, as the case may be,
to be summoned in such manner as the said court directs. If a majority in number
representing three-fourths in value of the creditors or class of creditors,
and/or of the stockholders or class of stockholders or class of stockholders of
the Corporation, as the case may be, agree to any compromise or arrangement and
to any reorganization of the Corporation as a consequence of such compromise or
arrangement, the said compromise or arrangement and the said reorganization
shall, if sanctioned by the court to which the said application has been made,
the binding on all the creditors or class of creditors, and/or on all the
stockholders or class of stockholders or class of stockholders, of the
Corporation, as the case may be, and also on the Corporation.

         NINTH: The personal liability of directors of the Corporation is hereby
eliminated to the fullest extent permitted by paragraph 7 of Subsection (b) of
Section 102 of the General Corporation Law of the State of Delaware as the same
may be amended and supplemented.

         TENTH: The Corporation shall, to the full extent permitted by Section
145 of the Delaware General Corporation Law, as amended and supplemented from
time to time, indemnify all persons whom it may indemnify under said section
from and against any and all of the expenses, liabilities, or other matters
referred to in or covered by said section, and the indemnification provided for
herein shall not be deemed exclusive of any other rights to which those
indemnified may be entitled under any Bylaw, agreement, vote of stockholders or
disinterested directors or otherwise, both as to action in his official capacity
and as to action in another capacity while holding such office, and shall
continue as to a person who has ceased to be a director, officer, employee, or
agent and shall inure to the benefit of the heirs, executors, and administrators
of such person.

         ELEVENTH: The Corporation reserves the right to amend, alter, change or
repeal any provision contained in this Certificate of Incorporation, in the
manner now or hereafter prescribed by statute, and al rights conferred on
stockholders herein are granted subject to this reservation.

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         IN WITNESS WHEREOF, the undersigned being the sole member of the Board
of Directors has duly executed this certificate in the name and on behalf of
Atlantic Pharmaceuticals, Inc., and affirms that the statements made herein are
true under the penalties of perjury, this 1st day of July, 1990.

                                           ATLANTIC PHARMACEUTICALS, INC.

                                           By:  /s/ Lindsay A. Rosenwald
                                               ---------------------------
                                               Name: Lindsay A. Rosenwald
                                               Title: Sole Director

[Including amendments filed on or about September 5, 1995, October 6, 1998 and
February 21, 2003, all of which are reflected in the above Restated Certificate
of Incorporation.]

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