Sec Form 4 Filing - Xmark Opportunity Partners, LLC @ AEOLUS PHARMACEUTICALS, INC. - 2013-02-19

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Xmark Opportunity Partners, LLC 2. Issuer Name and Ticker or Trading Symbol AEOLUS PHARMACEUTICALS, INC. [ AOLS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 90 GROVE STREET, SUITE 201 3. Date of Earliest Transaction (MM/DD/YY) 02/19/2013 (Street) RIDGEFIELD, CT06877 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, $0.01 par value per share 02/19/2013 X 59,149,999 A 98,725,838 ( 5 ) ( 6 ) ( 7 ) I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Common Stock, $0.01 par value per share 02/19/2013 S( 5 ) 1,793,894 D $ 0.33 ( 5 ) 96,931,944 ( 5 ) ( 6 ) ( 7 ) I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Warrants (right to buy) $ 0.5 02/19/2013 J 1,875,000 08/11/2010 08/11/2017 Common Stock 1,875,000 ( 3 ) ( 4 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.5 02/19/2013 J 1,875,000 12/28/2010 12/28/2017 Common Stock 1,875,000 ( 3 ) ( 4 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.28 02/19/2013 J 43,614,285 10/06/2009 10/06/2016 Common Stock 43,614,285 ( 3 ) ( 4 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.28 02/19/2013 J 11,785,714 07/30/2010 07/30/2017 Common Stock 11,785,714 ( 3 ) ( 4 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 J 1,875,000 02/19/2013 08/11/2017 Common Stock 1,875,000 ( 3 ) ( 4 ) 1,875,000 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 J 1,875,000 02/19/2013 12/28/2017 Common Stock 1,875,000 ( 3 ) ( 4 ) 1,875,000 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 J 43,614,285 02/19/2013 10/06/2016 Common Stock 43,614,285 ( 3 ) ( 4 ) 43,614,285 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 J 11,785,714 02/19/2013 07/30/2017 Common Stock 11,785,714 ( 3 ) ( 4 ) 11,785,714 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 X 1,875,000 02/19/2013 08/11/2017 Common Stock 1,875,000 $ 0 ( 3 ) ( 4 ) ( 5 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 X 1,875,000 02/19/2013 12/28/2017 Common Stock 1,875,000 $ 0 ( 3 ) ( 4 ) ( 5 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 X 43,614,285 02/19/2013 10/06/2016 Common Stock 43,614,285 $ 0 ( 3 ) ( 4 ) ( 5 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Warrants (right to buy) $ 0.01 02/19/2013 X 11,785,714 02/19/2013 07/30/2017 Common Stock 11,785,714 $ 0 ( 3 ) ( 4 ) ( 5 ) 0 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Xmark Opportunity Partners, LLC 90 GROVE STREET SUITE 201 RIDGEFIELD, CT06877 X Signatures Xmark Opportunity Partners, LLC, By: Xmark Capital Partners, LLC, its Managing Member, By: /s/ David C. Cavalier, its Co-Managing Member 02/21/2013 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The reporting person, Xmark Opportunity Partners, LLC, a Delaware limited liability company ("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, together with Opportunity LP, the "Investors"), and, as such, possesses the sole power to vote and the sole power to direct the disposition of all securities of Aeolus Pharmaceuticals, Inc., a Delaware corporation (the "Company"), held by the Investors. ( 2 )Opportunity Partners is the investment manager of Xmark JV Investment Partners, LLC, a Delaware limited liability company ("JV Partners"), and, as such, possesses the sole power to vote and the sole power to direct the disposition of all securities of the Company held by JV Partners. Collectively, Opportunity LP and Opportunity Ltd. hold a majority of the membership interests in Goodnow Capital, L.L.C., a Delaware limited liability company ("Goodnow"), and, as such, possesses the sole power to vote and the sole power to direct the disposition of all securities of the Company held by Goodnow. David C. Cavalier ("Mr. Cavalier") and Mitchell D. Kaye are Co-Managing Members of Xmark Capital Partners, LLC, a Delaware limited liability company, which is the Managing Member of Opportunity Partners, and share voting and dispositive power with respect to all securities beneficially owned by Opportunity Partners. ( 3 )On February 19, 2013, prior to the transactions reported herein, in addition to shares of the Company's common stock, $0.01 par value per share ("Common Stock"), (a) Opportunity LP held (i) warrants to purchase up to 17,304,642 shares of Common Stock at an exercise price of $0.28 per share, subject to certain adjustments (the "Opportunity LP $0.28 Warrants"), and (ii) warrants to purchase up to 1,125,000 shares of Common Stock at an exercise price of $0.50 per share, subject to certain adjustments (the "Opportunity LP $0.50 Warrants"); (b) Opportunity Ltd. held (i) warrants to purchase up to 37,595,357 shares of Common Stock at an exercise price of $0.28 per share, subject to certain adjustments (the "Opportunity Ltd. $0.28 Warrants"), and (ii) warrants to purchase up to 2,625,000 shares of Common Stock at an exercise price of $0.50 per share, subject to certain adjustments (together with the Opportunity LP $0.50 Warrants, the "$0.50 Warrants"); ( 4 )and (c) JV Partners held warrants to purchase up to 500,000 shares of Common Stock at an exercise price of $0.28 per share, subject to certain adjustments (together with the Opportunity LP $0.28 Warrants and the Opportunity Ltd. $0.28 Warrants, the "$0.28 Warrants"). On February 19, 2013, the Company, the Investors and JV Partners entered into that certain Warrant Repricing, Exercise and Lockup Agreement, pursuant to which, among other things, the Company, the Investors and JV Partners agreed to decrease the exercise price of the $0.28 Warrants and the $0.50 Warrants to an exercise price of $0.01 per share (collectively, with such decreased exercise price, the "Amended Warrants"). ( 5 )On February 19, 2013, the Investors and JV Partners exercised the Amended Warrants to purchase 59,149,999 shares of Common Stock at an exercise price of $0.01 per share. The Investors and JV Partners paid the exercise price on a cashless basis pursuant to the terms of the Amended Warrants, resulting in the Company's withholding of 1,793,894 shares of Common Stock to pay the exercise price and issuing to the Investors and JV Partners an aggregate total of 57,356,105 shares of Common Stock. ( 6 )As of February 19, 2013, following the transactions reported herein, (a) Opportunity LP held 29,095,832 shares of Common Stock, including 957,326 shares of Common Stock held by Goodnow but attributed to Opportunity LP; (b) Opportunity Ltd. held 63,680,084 shares of Common Stock, including 2,475,490 shares of Common Stock held by Goodnow but attributed to Opportunity Ltd.; (c) JV Partners held 1,508,567 shares of Common Stock; and (d) Goodnow held 2,647,463 shares of Common Stock in addition to the (i) 957,326 shares of Common Stock held by Goodnow but attributed to Opportunity LP and (ii) 2,475,490 shares of Common Stock held by Goodnow but attributed to Opportunity Ltd. In addition, as of February 19, 2013, Mr. Cavalier held options to purchase 172,750 shares of Common Stock, all of which such options are currently exercisable by him. ( 7 )Opportunity Partners' interest in the securities reported herein is limited to the extent of its pecuniary interest in Opportunity LP, Opportunity Ltd. and JV Partners, if any, and neither the filing of this Form 4 nor any of its contents shall be deemed to constitute an admission by Opportunity Partners or any other person/entity that he, she or it was or is the beneficial owner of any of the securities referred to herein for purposes of Section 16 of the Securities Exchange Act of 1934, or for any other purpose.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.