UNITED STATES

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                  SCHEDULE 13D

                   Under the Securities Exchange Act of 1934

                                (Amendment No. 15)*



                          AEOLUS PHARMACEUTICALS, INC.
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                                (Name of Issuer)

                     Common Stock, par value $0.01 per share
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                         (Title of Class of Securities)

                                    00765G109
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                                 (CUSIP Number)

                                  Mary L. King
                         Xmark Opportunity Partners, LLC
                           90 Grove Street, Suite 201
                              Ridgefield, CT 06877
                                 (203) 588-2808
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                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                February 24, 2009
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             (Date of Event which Requires Filing of this Statement)


If the filing person has previously  filed a statement on Schedule l3G to report
the  acquisition  that is the subject of this  Schedule  13D, and is filing this
schedule  because of Sections 240.13d-1(e), 240.13d-1(f)  or 240.13d-1(g), check
the following box. [  ]

Note:  Schedules  filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits.  See Section 240.13d-7 for other
parties to whom copies are to be sent.

* The remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).





Cusip No.       00765G109
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1.  Names of Reporting Persons.  I.R.S. Identification Nos. of above persons
    (entities only):
               Xmark Opportunity Partners, LLC
               20-2052197
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2.  Check the Appropriate Box if a Member of a Group (See Instructions):
         (a)   Not
         (b)   Applicable
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3.  SEC Use Only

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4.  Source of Funds (See Instructions):  AF, WC
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5.  Check if Disclosure  of Legal Proceedings Is Required Pursuant to Items 2(d)
    or 2(e):               Not Applicable
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6.  Citizenship or Place of Organization:    United States

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    Number of                      7. Sole Voting Power:             17,639,011*
                                     -------------------------------------------
    Shares Beneficially            8. Shared Voting Power:
                                     -------------------------------------------
    Owned by
    Each Reporting                 9. Sole Dispositive Power:        16,639,011*
                                      ------------------------------------------
    Person With                    10. Shared Dispositive Power:
                                      ------------------------------------------
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11. Aggregate Amount Beneficially Owned by Each Reporting Person:   17,639,011*

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12. Check if  the Aggregate  Amount in  Row (11) Excludes  Certain  Shares  (See
    Instructions):         [ x ]*
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13. Percent of Class Represented by Amount in Row (11):   51.6%*
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14. Type of Reporting Person (See Instructions):  IA
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* Xmark Opportunity Partners, LLC ("Opportunity Partners") is the sole member of
the  investment  manager of Xmark  Opportunity  Fund,  L.P., a Delaware  limited
partnership  ("Opportunity  LP"),  and Xmark  Opportunity  Fund,  Ltd., a Cayman
Islands exempted company ("Opportunity Ltd"), and, as such, possesses sole power
to vote and direct the disposition of all securities of Aeolus  Pharmaceuticals,
Inc.,  a  Delaware  corporation  (the  "Company"),  held by  Opportunity  LP and
Opportunity  Ltd.  Opportunity  Partners is the  investment  manager of Xmark JV
Investment  Partners,  LLC, a Delaware limited liability company ("JV Partners",
and together with  Opportunity  LP and  Opportunity  Ltd, the "Funds"),  and, as
such,  possesses sole power to vote and direct the disposition of all securities
of the Company held by JV Partners.  Mitchell D. Kaye and David C. Cavalier, the
Co-Managing  Members of Xmark  Capital  Partners,  LLC, the  Managing  Member of
Opportunity  Partners,  share  voting and  investment  power with respect to all
securities  beneficially  owned  by  Opportunity  Partners.  Opportunity  LP and
Opportunity  Ltd,  together,  hold a majority  of the  membership  interests  in
Goodnow Capital, L.L.C., a Delaware limited liability company ("Goodnow"),  and,
as such,  Opportunity  Partners  possesses  sole  power to vote and  direct  the
disposition of all securities of the Company held by Goodnow.

As of February 24, 2009,  Opportunity LP held (i) 3,166,469 common shares, $0.01
par value per share  (the  "Common  Shares"),  of the  Company,  which  includes
1,276,435  Common  Shares of the  Company  owned by  Goodnow,  (ii)  warrants to
purchase up to 660,000  Common  Shares of the  Company at an  exercise  price of
$0.35 per share  subject to  certain  adjustments,  (iii) 7% senior  convertible
notes  (collectively,  "Note 1"), in the aggregate principal amount of $300,000,
which are convertible  into 857,141 Common Shares of the Company at a conversion
price of $0.35 per share  subject  to  certain  adjustments,  and (iv)  warrants
("Warrant  1") to  purchase  up to 600,000  Common  Shares of the  Company at an
exercise price of $0.50 per share subject to certain adjustments. As of February
24, 2009, Opportunity Ltd held (a) 6,768,860 Common Shares of the Company, which
includes  3,300,653 Common Shares of the Company owned by Goodnow,  (b) warrants
to purchase up to 990,000  Common Shares of the Company at an exercise  price of
$0.35 per share subject to certain adjustments,  (c) 7% senior convertible notes
(together  with  Note 1, the  "Notes"),  in the  aggregate  principal  amount of
$700,000, which are convertible into 1,999,998 Common Shares of the Company at a
conversion  price of $0.35 per share  subject  to certain  adjustments,  and (d)
warrants  (together with Warrant 1, the  "Warrants") to purchase up to 1,400,000
Common Shares of the Company at an exercise  price of $0.50 per share subject to
certain  adjustments.  As of February 24, 2009,  JV Partners  held (1) 1,023,731
Common  Shares of the Company and (2) warrants to purchase up to 500,000  Common
Shares of the Company at an exercise price of $0.35 per share subject to certain
adjustments.




All of the Notes and the Warrants contain an issuance limitation prohibiting the
holder from  converting or exercising,  as the case may be, those  securities to
the extent that after giving effect to such  conversion or exercise,  the holder
would  beneficially own more than 9.99% of the Common Shares of the Company then
issued and  outstanding,  which  prohibition  cannot be  modified  by the holder
before the 61st day after such holder's notice to the Company of its election to
modify such prohibition.

As of February 24, 2009,  Goodnow held 3,529,951 Common Shares of the Company in
addition to the Common Shares of the Company held by Goodnow  referenced  above.
As of February 24, 2009,  Opportunity  Partners had the right to vote  1,000,000
Common  Shares of the  Company  pursuant  to a voting  trust  agreement  between
Opportunity  Partners and the holders of record of those shares.  As of February
24, 2009,  Mr.  Cavalier held options to purchase  109,875  Common Shares of the
Company.

Based upon information set forth in the Company's  Quarterly Report on Form 10-Q
for the quarterly  period ended  December 31, 2008, as filed with the Securities
and Exchange Commission on February 6, 2009, there were 32,030,874 Common Shares
of the Company  deemed  issued and  outstanding  as of February 24,  2009.  As a
result of the foregoing,  for purposes of Reg.  Section  240.13d-3,  Opportunity
Partners is deemed to beneficially own 17,639,011  Common Shares of the Company,
or 51.6% of the Common Shares of the Company deemed issued and outstanding as of
February 24, 2009.







Item 3.   Source and Amount of Funds or Other Consideration.
          -------------------------------------------------

          This  Item 3 is hereby  amended  by adding  the  following  at the end
thereof:

          All funds used to purchase the  securities  of the Company held by the
Funds  described in this Schedule  13D, as amended,  have come directly from the
assets of the Funds. See Item 5, as amended, for further information.


Item 5.   Interest in Securities of the Issuer.
          ------------------------------------

          This Item 5 is hereby  amended and restated to read in its entirety as
follows:

          Based upon information set forth in the Company's  Quarterly Report on
Form 10-Q for the  quarterly  period ended  December 31, 2008, as filed with the
Securities and Exchange  Commission on February 6, 2009,  there were  32,030,874
Common Shares of the Company  deemed issued and  outstanding  as of February 24,
2009.

          As of February  24, 2009,  Opportunity  LP held (i)  3,166,469  Common
Shares of the Company,  which  includes  1,276,435  Common Shares of the Company
owned by Goodnow,  (ii) warrants to purchase up to 660,000  Common Shares of the
Company at an exercise price of $0.35 per share subject to certain  adjustments,
(iii) 7% senior  convertible  notes  (collectively,  "Note 1"), in the aggregate
principal  amount of $300,000,  which are convertible into 857,141 Common Shares
of the  Company  at a  conversion  price of $0.35 per share  subject  to certain
adjustments,  and (iv) warrants  ("Warrant 1") to purchase up to 600,000  Common
Shares of the Company at an exercise price of $0.50 per share subject to certain
adjustments.  As of February 24, 2009, Opportunity Ltd held (a) 6,768,860 Common
Shares of the Company,  which  includes  3,300,653  Common Shares of the Company
owned by Goodnow,  (b) warrants to purchase up to 990,000  Common  Shares of the
Company at an exercise price of $0.35 per share subject to certain  adjustments,
(c) 7% senior  convertible  notes  (together  with Note 1, the "Notes"),  in the
aggregate  principal  amount of $700,000,  which are convertible  into 1,999,998
Common Shares of the Company at a conversion price of $0.35 per share subject to
certain adjustments,  and (d) warrants (together with Warrant 1, the "Warrants")
to purchase up to 1,400,000 Common Shares of the Company at an exercise price of
$0.50 per share  subject to certain  adjustments.  As of February 24,  2009,  JV
Partners  held (1)  1,023,731  Common  Shares of the Company and (2) warrants to
purchase up to 500,000  Common  Shares of the  Company at an  exercise  price of
$0.35 per share subject to certain adjustments.

          All of the Notes  and the  Warrants  contain  an  issuance  limitation
prohibiting the holder from converting or exercising,  as the case may be, those
securities  to the  extent  that  after  giving  effect  to such  conversion  or
exercise, the holder would beneficially own more than 9.99% of the Common Shares
of the Company then issued and outstanding, which prohibition cannot be modified
by the holder before the 61st day after such  holder's  notice to the Company of
its election to modify such prohibition.

          As of February 24, 2009,  Goodnow held 3,529,951  Common Shares of the
Company  in  addition  to the  Common  Shares  of the  Company  held by  Goodnow
referenced above. As of February 24, 2009, Opportunity Partners had the right to
vote 1,000,000 Common Shares of the Company pursuant to a voting trust agreement
between  Opportunity  Partners and the holders of record of those shares.  As of
February 24, 2009, Mr.  Cavalier held options to purchase  109,875 Common Shares
of the Company.

          Opportunity  Partners is the sole member of the investment  manager of
Opportunity LP and  Opportunity  Ltd and, as such,  possesses sole power to vote
and direct the  disposition of all securities of the Company held by Opportunity
LP and Opportunity  Ltd.  Opportunity  Partners is the investment  manager of JV
Partners and, as such,  possesses sole power to vote and direct the  disposition
of all securities of the Company held by JV Partners. Mitchell D. Kaye and David
C.  Cavalier,  the  Co-Managing  Members of Xmark  Capital  Partners,  LLC,  the
Managing Member of Opportunity Partners,  share voting and investment power with
respect  to  all  securities   beneficially   owned  by  Opportunity   Partners.
Opportunity LP and Opportunity Ltd, together,  hold a majority of the membership
interests in Goodnow and, as such,  Opportunity Partners possesses sole power to
vote and  direct  the  disposition  of all  securities  of the  Company  held by
Goodnow.

          As a result of the foregoing,  for purposes of Reg. Section 240.13d-3,
Opportunity  Partners is deemed to beneficially own 17,639,011  Common Shares of
the  Company,  or 51.6% of the Common  Shares of the Company  deemed  issued and
outstanding as of February 24, 2009.





          The following  table details all of the  transactions in Common Shares
of the Company, or securities  convertible into, exercisable for or exchangeable
for Common Shares of the Company,  by the persons  referenced in Item 2 (each of
which was effected by the Funds in an ordinary  brokerage  transaction),  during
the sixty (60) day period occurring on or prior to February 24, 2009:







         Date             Type of Transaction     Number of Shares        Security Type      Price per Share ($)
------------------------ ---------------------- --------------------- ---------------------- ---------------------
                                                                                      

      12/26/2008               Purchase                 7,950             Common Shares            $0.3069
      12/29/2008               Purchase                 5,000             Common Shares            $0.3900
      12/30/2008               Purchase                10,000             Common Shares            $0.3200
      12/31/2008               Purchase                 5,000             Common Shares            $0.3500
      01/31/2009            PIK Interest(1)            79,838             Common Shares            $0.3480
      02/10/2009               Purchase                40,000             Common Shares            $0.4338
      02/11/2009               Purchase                20,000             Common Shares            $0.4500
      02/24/2009               Purchase                20,000             Common Shares            $0.4175





Except for the transactions  listed above,  there were no transactions in Common
Shares,  or securities  convertible  into,  exercisable for or exchangeable  for
Common  Shares by the  persons  referenced  in Item 2 during  the sixty (60) day
period on or prior to February 24, 2009.



----------------------------------
(1) On January 31, 2009,  the Company  exercised  its option to pay interest due
under the Notes in Common  Shares of the Company and  accordingly  issued 79,838
Common Shares at $0.348 per share to Opportunity LP and  Opportunity  Ltd in the
aggregate.








                                   Signature
                                   ---------

          After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information  set forth in this statement is true,  complete and
correct.


April 29, 2009                        XMARK OPPORTUNITY PARTNERS, LLC
                                      By:  XMARK CAPITAL PARTNERS, LLC
                                           its Managing Member

                                      By:  /s/ Mitchell D. Kaye
                                           -------------------------------------
                                          Name:  Mitchell D. Kaye
                                          Title: Co-Managing Member



  Attention: Intentional misstatements or omissions of fact constitute Federal
                   criminal violations (See 18 U.S.C. 1001).