Amendment No. 2 to Business Combination Agreement, dated as of March 30, 2023, by and among Mountain Crest Acquisition Corp. V, AUM Biosciences Pte. Ltd., AUM Biosciences Limited, AUM Biosciences Subsidiary Pte. Ltd., and AUM Biosciences Delaware Merger Sub, Inc

Exhibit 2.1

AMENDMENT #2 TO BUSINESS COMBINATION AGREEMENT

THIS AMENDMENT #2 TO BUSINESS COMBINATION AGREEMENT (this “Amendment #2”) is made as of March 30, 2023 (the “Amendment Date”) by and among Mountain Crest Acquisition Corp. V, a Delaware corporation (“SPAC”), AUM Biosciences Limited, a Cayman Islands exempted company (“Holdco”), AUM Biosciences Subsidiary Pte. Ltd., a private company limited by shares incorporated in Singapore, with company registration number 202238778Z and a direct wholly-owned subsidiary of Holdco (“Amalgamation Sub”), AUM Biosciences Delaware Merger Sub, Inc., a Delaware corporation and a direct wholly-owned subsidiary of Holdco (“Merger Sub”), and AUM Biosciences Pte. Ltd., a private company limited by shares incorporated in Singapore, with company registration number 201810204D (the “Company”). Each of SPAC, the Company, Holdco, Amalgamation Sub and Merger Sub shall individually be referred to herein as a “Party” and, collectively, the “Parties.” Capitalized terms used herein and not otherwise defined shall have the meanings ascribed to them in the Agreement (as defined below).

WHEREAS, SPAC and the Company entered into that certain Business Combination Agreement dated as of October 19, 2022 (as may be amended, restated, supplemented or otherwise modified from time to time in accordance with the terms thereof, the “Agreement”);

WHEREAS, the Parties entered into that certain joinder agreement dated as of January 27, 2023, pursuant to which Holdco, Amalgamation Sub and Merger Sub joined the Agreement as parties;

WHEREAS, pursuant to Section 11.11 of the Agreement, the Agreement may be amended in whole or in part, by a duly authorized agreement in writing executed in the same manner as the Agreement and which makes reference to the Agreement;

WHEREAS, the Parties entered into that certain Amendment to Business Combination Agreement dated as of February 10, 2023 (“Amendment #1” and together with this Amendment #2, the “Amendments”), pursuant to which the Agreement was amended in the manner described therein; and

WHEREAS, the Parties wish to further amend the Agreement as set forth in this Amendment #2.

NOW, THEREFORE, intending to be legally bound and in consideration of the mutual provisions set forth in the Amendments and the Agreement and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties hereby agree as follows:

ARTICLE 1

AMENDMENT TO THE AGREEMENT

Section 1.1 Amendment to Section 3.4(b) of the Agreement. Section 3.4(b) of the Agreement is hereby amended and revised to read as, “(b) As of immediately prior to the Amalgamation Effective Time, (i) no Company Preferred Shares shall be outstanding, (ii) the only Company Interests issued and paid-up shall be 9,841,118 Company Ordinary Shares, and (iii) the Company Preferred Shares shall have been converted into Company Ordinary Shares in compliance with the Company’s Governing Documents and the terms of such Company Preferred Shares.”

Section 1.2 Amendment to Section 6.4(a) of the Agreement. Section 6.4(a) of the Agreement is hereby amended and revised to read as, “(a) the Holdco Board shall consist of no less than five (5) directors, all of whom shall be designated by the Company, and which shall comply with all diversity requirements under applicable Law, each such director to hold office in accordance with the Holdco Governing Documents; and”.

Section 1.3 Amendment to Section 9.1(i) of the Agreement. Section 9.1(i) of the Agreement is hereby deleted and shall be replaced with “[Reserved].”

Section 1.4 Addition of Section 11.18 to the Agreement. Section 11.18 is hereby added to the Agreement and shall read as, “11.18 Termination of Stock Escrow Agreement. Each of SPAC, the Acquisition Entities and the Company hereby determine in their reasonable business judgment that in order to satisfy Section 9.1(e) of this Agreement, SPAC shall seek termination of that certain stock escrow agreement, dated as of November 21, 2021, as amended, restated or otherwise modified from time to time, originally entered by and among SPAC, the initial shareholders listed on the signature pages thereto and Continental Stock Transfer & Trust Company, as escrow agent, and hereby consent to such termination thereof.”

ARTICLE 2

MISCELLANEOUS

Section 2.1 No Other Amendment. Except to the extent that any provisions of or any Exhibits or Schedules to the Agreement are expressly amended by Article 1 of this Amendment #2, all terms and conditions of the Agreement and all other documents, instruments and agreements executed thereunder, shall remain in full force and effect pursuant to the terms thereof. In the event of any inconsistency or contradiction between the terms of this Amendment #2 and the Agreement, the provisions of this Amendment #2 shall prevail and control.

Section 2.2 Reference to the Agreement. On and after the date hereof, each reference in the Agreement to “this Agreement,” “hereof,” “herein,” “herewith,” “hereunder” and words of similar import shall, unless otherwise stated, be construed to refer to the Agreement as amended by the Amendments. No reference to the Amendments need be made in any instrument or document at any time referring to the Agreement and a reference to the Agreement in any such instrument or document shall be deemed to be a reference to the Agreement as amended by the Amendments.

[Signature Page Follows]

IN WITNESS WHEREOF, the Parties have caused this Agreement to be executed as of the date first written above by their respective officers thereunto duly authorized.

[Signature Page to the Amendment to the Business Combination Agreement]