SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                 --------------


                    Under the Securities Exchange Act of 1934

                                  SCHEDULE 13G


             INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934




                         Manhattan Pharmaceuticals, Inc.
                       -----------------------------------
                                (Name of Issuer)



                         Common Stock, $0.001 par value
                       ----------------------------------
                         (Title of Class of Securities)



                                    563118207
                                 (CUSIP Number)

                                February 21, 2003
                ------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)



Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

      |_|  Rule 13d-1(b)
      |X|  Rule 13d-1(c)
      |_|  Rule 13d-1(d)



                                Page 1 of 7 Pages




                                  SCHEDULE 13G

CUSIP No. 563118207                                           Page 2 of 7 Pages
-------------------------------------------------------------------------------

1)     NAME OF REPORTING PERSON
       S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

       Oleoyl-Estrone Developments SL
--------------------------------------------------------------------------------
2)     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP          (a) |_|

                                                                 (b) |_|
--------------------------------------------------------------------------------
3)     SEC USE ONLY


--------------------------------------------------------------------------------
4)     CITIZENSHIP OR PLACE OF ORGANIZATION

       Barcelona, Spain
-------------------------------------------------------------------------------
                         5)     SOLE VOTING POWER

                                4,157,037
       NUMBER            ------------------------------------------------------
       OF                6)     SHARED VOTING POWER
       SHARES
       BENEFICIALLY             0
       OWNED BY          ------------------------------------------------------
       EACH              7)     SOLE DISPOSITIVE POWER
       REPORTING
       PERSON                   4,157,037
       WITH              ------------------------------------------------------
                         8)     SHARED DISPOSITIVE POWER

                                0
-------------------------------------------------------------------------------
9)     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       4,157,037
-------------------------------------------------------------------------------
10)    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

                                                                   |_|
-------------------------------------------------------------------------------
11)    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

       17.8%
-------------------------------------------------------------------------------
12)    TYPE OF REPORTING PERSON

       CO
-------------------------------------------------------------------------------



                                  SCHEDULE 13G

CUSIP No. 563118207                                           Page 3 of 7 Pages
-------------------------------------------------------------------------------

1)     NAME OF REPORTING PERSON
       S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

       Joan Pons Gimbert
-------------------------------------------------------------------------------
2)     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP          (a) |_|

                                                                 (b) |_|
-------------------------------------------------------------------------------
3) SEC USE ONLY


-------------------------------------------------------------------------------
4) CITIZENSHIP OR PLACE OF ORGANIZATION

       Spain
-------------------------------------------------------------------------------
                         5)     SOLE VOTING POWER

       NUMBER                   4,157,037(1)
       OF                ------------------------------------------------------
       SHARES            6)     SHARED VOTING POWER
       BENEFICIALLY
       OWNED BY                 0
       EACH              ------------------------------------------------------
       REPORTING         7)     SOLE DISPOSITIVE POWER
       PERSON
       WITH                     4,157,037(1)
                         ------------------------------------------------------
                         8)     SHARED DISPOSITIVE POWER

                                0
-------------------------------------------------------------------------------
9)     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       4,157,037(1)
-------------------------------------------------------------------------------
10)    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

                                                                   |_|
-------------------------------------------------------------------------------
11)    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

       17.8%
-------------------------------------------------------------------------------

12)    TYPE OF REPORTING PERSON

       IN
-------------------------------------------------------------------------------


--------------------------------
(1) Voting and dispositive power is exercised by Mr. Pons in his capacity as
Chief Executive Officer of Oleoyl-Estrone Developments SL ("OED"). Mr. Pons
disclaims beneficial ownership of the shares owned by OED.




Schedule 13G
------------
Item 1(a).  Name of Issuer:

Manhattan Pharmaceuticals, Inc.

Item 1(b).  Address of Issuer's Principal Executive Offices:

787 Seventh Avenue, 48th Floor
New York, New York 10019

Item 2(a).  Name of Persons Filing:

Oleoyl-Estrone Developments SL

Joan Pons Gimbert

Item 2(b).  Address of Principal Business Office or, if None, Residence:

The business address of Oleoyl-Estrone Developments SL is:

      Josep Samitier 1-5
      Barcelona Science Park
      08028 Barcelona, Spain

The business address of Joan Pons Gimbert is:

      c/o Oleoyl-Estrone Developments
      Josep Samitier 1-5
      Barcelona Science Park
      08028 Barcelona, Spain

Item 2(c).  Citizenship or Place of Organization:

Oleoyl-Estrone Developments SL is a company of unlimited duration registered in
the Registro Mercantil of Barcelona.

Joan Pons Gimbert is a citizen of Spain.

Item 2(d).  Title of Class of Securities:

Common Stock, $0.001 par value per share

Item 2(e).  CUSIP Number:

563118207

Item 3.     If this statement is filed pursuant to ss.ss. 240.13d-1(b), or
            240.13d-2(b) or (c), check whether the person filing is a:

            (a)  |_| Broker or Dealer Registered Under Section 15 of the Act
                     (15 U.S.C. 78o)

            (b)  |_| Bank as defined in section 3(a)(6) of the Act (15 U.S.C.
                     78c)



            (c)  |_| Insurance Company as defined in section 3(a)(19) of the
                     Act (15 U.S.C. 78c)

            (d)  |_| Investment Company registered under section 8 of the
                     Investment Company Act of 1940 (15 U.S.C. 80a-8)

            (e)  |_| Investment Adviser in accordance with ss.
                     240.13d-1(b)(1)(ii)(E)

            (f)  |_| Employee benefit plan or endowment fund in accordance with
                     ss. 240.13d-1(b)(1)(ii)(F)

            (g)  |_| Parent Holding Company or control person in accordance
                     with ss.240.13d-1(b)(ii)(G)

            (h)  |_| Savings Association as defined in ss.3(b) of the Federal
                     Deposit Insurance Act (12 U.S.C. 1813)

            (i)  |_| Church plan that is excluded from the definition of an
                     investment company under ss.3(c)(15) of the Investment
                     Company Act of 1940 (15 U.S.C. 80a-3)

            (j)   |_| Group, in accordance with ss.240.13d-1(b)(ii)(J)

Item 4.     Ownership.

            (a)   Amount beneficially owned: 4,157,037

            (b)   Percent of class: 17.8%

            (c)   Number of shares as to which such person has:

                  (i)   Sole power to vote or to direct the vote: 4,157,037

                  (ii)  Shared power to vote or to direct the vote: 0

                  (iii) Sole power to dispose or to direct the disposition of:
                        4,157,037

                  (iv)  Shared power to dispose or to direct the disposition of:
                        0

Item 5.     Ownership of Five Percent or Less of a Class.

Not applicable

Item 6.     Ownership of More than Five Percent on Behalf of Another Person.

Not applicable

Item 7.     Identification and Classification of the Subsidiary Which
            Acquired the Security Being Reported on by the Parent Holding
            Company.

Not applicable

Item 8.     Identification and Classification of Members of the Group.




Not applicable

Item 9.     Notice of Dissolution of Group.

Not applicable

Item 10.    Certification.

By signing below, each of the undersigned certifies that, to the best of its
knowledge and belief, the securities referred to above were not acquired and are
not held for the purpose of or with the effect of changing or influencing the
control of the issuer of the securities and were not acquired and are not held
in connection with or as a participant in any transaction having that purpose or
effect.




                                   SIGNATURES
                                   ----------


         After reasonable inquiry and to the best knowledge and belief of the
undersigned, each of the undersigned certifies that the information set forth in
this Statement is true, complete and correct.


                                       Oleoyl-Estrone Developments SL


                                       By: /s/ Joan Pons Gimbert
                                          -------------------------------
                                          Joan Pons Gimbert
                                          Chief Executive Officer



                                       Joan Pons Gimbert

                                       /s/ Joan Pons Gimbert
                                       ---------------------------------
                                       Joan Pons Gimbert


Dated as of March 25, 2004



                            Agreement of Joint Filing


      Pursuant to 13d-1(k) promulgated under the Securities Exchange Act of
1934, as amended, the undersigned hereby confirm the agreement by and among them
to join in the filing on behalf of each of them of a Statement on Schedule 13G
and any and all amendments thereto, and that this Agreement be included as an
Exhibit to such filing.

      This Agreement may be executed in any number of counterparts each of which
shall be deemed to be an original and all of which together shall be deemed to
constitute one and the same Agreement.

      IN WITNESS WHEREOF, each of the undersigned has executed this Agreement.



                                    OLEOYL-ESTRONE DEVELOPMENTS SL


Dated: March 25, 2004               By: /s/ Joan Pons Gimbert
                                       ---------------------------------
                                       Joan Pons Gimbert
                                       Chief Executive Officer




                                    JOAN PONS GIMBERT


Dated: March 25, 2004
                                    /s/ Joan Pons Gimbert
                                    ------------------------------------
                                    Joan Pons Gimbert