AGREEMENT
      TO SETTLE CERTAIN CLAIMS

     

    THIS
      AGREEMENT TO SETTLE CERTAIN CLAIMS (this “Agreement”)
      is
      hereby entered into and effective on the 13th day of June, 2008 (the
“Effective
      Date”),
      by
      and among:

    


    Allegro
      Biodiesel Corporation,
      a
      Delaware corporation registered to do business in the State of Louisiana
      (hereinafter referred to as “Allegro”);
      and

    


    the
      former members of Vanguard Synfuels, L.L.C.,
      a
      Louisiana limited liability company (hereinafter referred to as the
“Members”),
      represented herein by Darrell Dubroc in his capacity as Member Representative
      (in such capacity, hereinafter referred to as “Member
      Representative”).

    


    The
      parties entering this Agreement are hereinafter collectively referred to as
      “Parties”
and
      individually referred to as “Party”.

    


    RECITALS

     

    WHEREAS,
      on
      September 20, 2006, Allegro’s predecessor, Diametrics Medical, Inc. (hereinafter
      referred to collectively as “Allegro”),
      executed a Contribution Agreement wherein Allegro purchased all of the issued
      and outstanding ownership interest of Vanguard Synfuels, L.L.C. (“Contribution
      Agreement”;
      capitalized terms used herein without definition shall have the meanings
      ascribed thereto in the Contribution Agreement) from the
      Members;

    


    WHEREAS,
      on
      September 20, 2006, as a part of the Contribution Agreement, Allegro, the
      Members and
      the
      Escrow Agent, executed an Escrow Agreement (the “Escrow
      Agreement”)
      and
      deposited the Escrow Amount and the Escrow Shares into the Escrow thereunder
      for
      the purpose of having funds available to Allegro to satisfy any claims by
      Allegro for indemnification pursuant to Article XII of the Contribution
      Agreement; 

    


    WHEREAS,
      Allegro
      has made various claims for indemnification under Article XII of the
      Contribution Agreement and for the release of the Escrow Amount and the Escrow
      Shares to Allegro (hereinafter, all claims Allegro has, had or may have against
      the Members under Article VII of the Contribution Agreement, but excluding
      any
      future claims with respect to breaches of or inaccuracies in the Tax Warranties,
      the Title and Authorization Warranties, the Environmental Warranties, the
      Securities Warranties and claims for fraud are herein referred to as the
“Claims”);
      

    


    WHEREAS,
      cash in
      the amount of Forty Seven Thousand Four Hundred Forty-Eight and 49/100 Dollars
      ($47,448.49) has been released from the Escrow Fund pursuant to the joint
      written instructions of the Allegro and the Members dated May 16, 2008 in full
      and complete satisfaction of an indemnification claim by Allegro relating to
      an
      Internal Revenue Service civil penalty assessed against Vanguard Synfuels,
      L.L.C. (the “Tax
      Penalty Claim”);
      and

     

    
      
        
        

      

      
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    WHEREAS,
      all
      Parties agree that the Claims will be settled pursuant to the following
      procedures set forth in this Agreement.

    


    NOW,
      THEREFORE,
      in
      consideration of the foregoing and of the mutual promises contained herein,
      intending to be legally bound and, for good and valuable consideration, the
      Parties agree as follows:

    


    1.  Payment
      of Claim; Subrogation.
      All
      Parties hereby acknowledge the payment, receipt and sufficiency of the cash
      payment of Forty Seven Thousand Four Hundred Forty-Eight and 49/100 Dollars
      ($47,448.49) from the Escrow Fund in full and complete satisfaction of the
      Tax
      Penalty Claim. The Parties hereby agree that the Members shall be subrogated
      to
      all rights of Vanguard Synfuels, L.L.C. with respect to the Tax Penalty Claim
      in
      order to pursue all claims (if any) against third parties (other than Allegro,
      its shareholders, officers, directors, employees, managers or agents) related
      thereto.

    


    2.  Release
      from Escrow Fund.
      

    


    (a)
      Upon
      the execution of this Agreement, the Parties shall execute joint written escrow
      instructions in the form attached hereto as Exhibit
      A
      which
      shall:

    


    (i)
      authorize the release of Two Hundred One Thousand One Hundred Twenty Nine and
      30/100 Dollars ($201,129.30) cash and 126,250 shares of Allegro common stock
      from the Escrow Fund to the Members; and

    


    (ii)
      authorize the release of One Hundred Fifty One Thousand Six Hundred Twenty
      Eight
      and 08/100 Dollars ($151,628.08) cash and 124,961 shares of Allegro common
      stock
      from the Escrow Fund to Allegro.

    


    (b)
      The
      Parties hereby agree and acknowledge that the cash payments and distributions
      of
      shares described above shall:
      

    


    (i)
      be
made
      in
      consideration of the Parties entering into this Agreement and such payments
      and
      distributions are not contingent upon the settlement of the Claims;
      and

     

    (ii)
      notwithstanding anything in Section 2(b)(i) to the contrary, serve as a credit
      toward any amount of cash or shares awarded to either Party pursuant to any
      settlement agreement and/or Award (as defined below) relating to the Claims.
      Such credit shall be dollar for dollar and share for share.

    


    (c)
      In
      addition, upon the execution of this Agreement, the Parties shall execute joint
      written escrow instruction in the form attached hereto as Exhibit
      B,
      directing the Escrow Agent to release all remaining Escrow Funds and Escrow
      Shares from the Escrow in accordance with the Award of the Arbitrator (as each
      such term is defined below), if any.

    


    3.  Amicable
      Settlement.
      The
      Parties will use their good faith, commercially reasonable efforts to identify
      and settle all Claims on or before July 15, 2008. In furtherance of their
      attempts to settle the Claims, the Parties agree to hold an initial meeting
      no
      later than July 1, 2008 for the purpose of resolving all Claims. Such meeting
      shall be held in Denver, Colorado, or at such other location or telephonically
      as agreed by the Parties. Such meeting may be extended to future dates if the
      Parties are not able to resolve all Claims during the initial meeting.
      Negotiations for the settlement of the Claims, which may include mediation
      by
      mutual agreement of the Parties, shall continue until the later of the date
      that
      all Claims are resolved or July 15, 2008. If the Parties are able to settle
      some, but not all of the Claims as a result of their negotiations, then the
      Parties shall enter into a binding settlement agreement covering the resolved
      Claims and submit the remaining Claims to arbitration pursuant to Section
      4
      below.
      If the Parties are able to settle Claims as a result of their negotiations
      then
      the Parties shall enter into (i) a settlement agreement and release of any
      and
      all Claims that are resolved by the Parties and (ii) joint escrow instructions
      that direct the Escrow Agent to release the Escrow Amount and Escrow Shares
      as
      are agreed to by the Parties in such settlement agreement. Unless otherwise
      agreed by the Parties, the
      participants in all settlement proceedings shall include no more than two
      representatives of Allegro, the Member Representative, no more than one (1)
      other Member and each Party’s attorneys.

     

    
      
        
        

      

      
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    4.  Arbitration.

    


    (a) If
      on
      July 16, 2008, the Parties have not either entered into a binding settlement
      or
      release of all Claims, the Parties agree that all Claims shall be resolved
      by
      private arbitration (the “Arbitration”)
      conducted by one arbitrator (the “Arbitrator”)
      to be
      selected as follows:

    


    (i) On
      or
      prior to July 25, 2008, each Party may propose to the other a list of up to
      five
      persons to serve as the Arbitrator. Neither Party may include in their list
      the
      name of any person who (i) is or was an employee, officer, director, legal
      counsel or other representative of such Party or any affiliate of such Party
      or
      any other person who has a direct or indirect personal or financial interest
      in
      the outcome of the Arbitration, (ii) does not have at least ten years experience
      in either accounting or mergers and acquisitions or (iii) who is not located
      in
      the Denver, Colorado area.

    


    (ii) If
      there
      are one or more names that overlap in the combined list, then the Parties will
      pick the arbitrator from that set of overlaps. If there is only one overlap,
      then that person is automatically the Parties' choice for arbitrator. If there
      are more than one overlapping names, then the arbitrator shall be picked from
      the list of overlapping names by alternately striking names until only one
      name
      remains on the overlapping list (with each such strike to take no more than
      one
      business day to complete). Allegro will strike the first name.

    


    (iii) If
      there
      are no overlapping persons and if the Parties are unable to agree upon one
      arbitrator from the combined list by August 4, 2008, then the arbitrator shall
      be picked from the list of names by alternately striking names until only one
      name remains on the overlapping list (with each such strike to take no more
      than
      one business day to complete). Allegro will strike the first name.

    


    (b) The
      Arbitrator shall set a hearing date for an arbitration (the "Hearing")
      within
      forty-five (45) days from the date the Arbitrator is selected, unless otherwise
      agreed by the Parties, or unless otherwise ordered by the Arbitrator due to
      conflicts with the Arbitrator’s schedule.

     

    
      
        
        

      

      
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    (c) The
      Parties agree that there shall be free and open discovery between the Parties
      during the period from the Effective Date until the date of the Hearing. Neither
      party shall deny or object to, any reasonable request reating to the Claims
      that
      are submitted by the opposing Party for the production of documents or
      depositions and will otherwise cooperate in the discovery process; provided
      that
      the deponent in any deposition shall not be required to travel for purposes
      of
      his or her deposition. The Arbitrator shall have the authority to compel such
      discovery and to order any further discovery, by way of deposition,
      interrogatory, document production, or otherwise, as the Arbitrator considers
      necessary to a full and fair exploration of the issues in dispute. Except as
      otherwise provided herein, the Arbitrator shall administer the discovery process
      pursuant to the Commercial Arbitration Rules of the American Arbitration
      Association.

    


    (d) Unless
      otherwise agreed by the Parties, within fifteen (15) days before the Hearing,
      the Parties shall submit to the Arbitrator, with a copy to the other Party,
      a
      list of all witnesses and exhibits which it intends to present at the
      Hearing.

    


    (e) No
      later
      than ten (10) days before the scheduled Hearing, the Parties shall provide
      to
      the Arbitrator and to the other Party a short (not to exceed five (5)
      single-spaced pages or such other page limit as the Arbitrator permits)
      statement of its respective position with regard to the Claims.

    


    (f) At
      the
      Hearing, each Party shall, unless it waives the opportunity, make an oral
      opening statement, and an oral closing statement.

    


    (g) When
      testimony is complete and each Party has introduced its exhibits, subject to
      the
      provisions of this Agreement, and each has made a closing statement pursuant
      to
      the provisions of this Agreement or waived the opportunity to do so, the
      Arbitrator shall declare the Hearing closed; provided, however, the Parties
      may
      submit post hearing briefs pursuant to an agreed upon schedule or one formulated
      by the Arbitrator.

    


    (h) The
      Hearing shall be held at a location in, or near, the City of Denver, Colorado
      agreed upon by the Parties and convenient for the Arbitrator, or if the Parties
      cannot agree upon a location in the City of Denver, Colorado, designated by
      the
      Arbitrator.

    


    (i) The
      Hearing shall be conducted in private. Attendance at the Hearing shall be
      limited to the following: (i) the Arbitrator; (ii) no more than two
      representatives of Allegro, (iii) the Member Representative, (iv) no more than
      one (1) other Member; (v) each Party's attorneys; (vi) a court reporter if
      requested by either Party; and (vii) any witnesses, including expert
      witnesses.

    


    (j) The
      Hearing shall be conducted in not more two (2) days, beginning at 10:00 AM,
      local time; provided that the Arbitrator may, in his or her sole discretion,
      order the continuance of the Hearing on consecutive succeeding business days
      if
      requested by a Party.

     

    
      
        
        

      

      
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    (k) Within
      thirty (30) days of the close of the Hearing, the Arbitrator shall issue a
      written opinion and award (the "Award")
      based
      on evidence, arguments and post hearing briefs, if any. The Award shall be
      a
      decision of the Arbitrator, shall resolve the Claims submitted to the
      Arbitration, and shall be final and binding on the Parties. The Award shall
      state the amount of the Escrow Amount and the number of Escrow shares to be
      released to Allegro, on the one hand, and the Members, on the other hand. The
      fact that an opinion is issued does not enlarge or restrict the authority of
      a
      court provided in the AAA's Commercial Arbitration Rules to review the
      arbitration proceedings or the Award. The Arbitrator shall then deliver a notice
      to the Escrow Agent, directing the Escrow Agent to release Escrow Funds and
      Escrow Shares in accordance with the Award.

    


    (l) Except
      as
      otherwise provided in this Agreement, there shall be no ex parte communication
      regarding the subject matter of the Hearing between a Party or its attorneys
      and
      the Arbitrator from the time the Arbitrator is appointed until after the Parties
      receive the Award.

     

    (m) The
      Parties agree that the Award can be enforced by any court of competent
      jurisdiction.

     

    (n) Notwithstanding
      any other provision of this Agreement, the Arbitrator shall have no power to
      delete from, add to, or modify the terms of this Agreement, and may not award
      any remedy which effectively conflicts directly or indirectly with any provision
      of this Agreement.

     

    (o) The
      arbitration shall be governed by AAA's Commercial Rules of Arbitration, except
      as otherwise provided in this Agreement.

    


    (p) Each
      Party shall bear its own expenses, costs and attorneys fees incurred in
      connection with the Arbitration. The fees of any court reporter at the Hearing
      shall be paid by the Party that requests the court reporter.

    


    5.  Limitation
      on Claims.
      All
      Parties hereby agree that the aggregate maximum amount recoverable by any Party
      pursuant to any settlement agreement and/or Award relating to the Claims shall
      not exceed the balance of the sum of the Escrow Amount and the Escrow Shares
      as
      of the Effective Date (as approximated in Schedule
      5
      attached
      hereto, the “Escrow Principal Balance”) plus any interest earned on the Escrow
      Amount. This provision shall supersede any provision to the contrary in the
      Contribution Agreement or the Escrow Agreement and shall be deemed to be a
      written amendment or modification thereto as provided in such agreements.


    


    6.  Written
      Agreement.
      This
      Agreement constitutes the agreement and understanding of the Parties relating
      to
      the subject matter contained herein. This Agreement may not be altered, amended
      or modified in any respect whatsoever except by a writing duly executed by
      each
      of the Parties hereto.

    


    7.  Voluntariness.
      The
      Parties agree that they have carefully read this Agreement, that it has been
      fully explained by their attorneys, that they fully understand its final and
      binding effect that the only promises made to sign the Agreement are those
      stated above and that such Agreement is being signed voluntarily.

     

    
      
        
        

      

      
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    8.  Capacity.
      The
      Parties each warrant and represent that each Party has the requisite power
      and
      authority to execute and deliver this Agreement and it has been duly executed
      and delivered by each party and this Agreement is a valid and binding agreement,
      enforceable against each Party in accordance with its terms.

    


    9.  Waiver
      of Compliance.
      The
      failure by any Party at any time to require performance of any provision of
      this
      Agreement will not affect its right later to require such performance. No waiver
      in any one or more instances will (except as stated therein) be deemed to be
      a
      further or continuing waiver of any such condition or breach in other instances
      or a waiver of any condition or breach of any other term, covenant,
      representation or warranty.

    


    10.    
      Notices.
      All
      notices, requests, demands or other communications required or permitted by
      this
      Agreement will be in writing and effective when received, and delivery will
      be
      made personally or by registered or certified mail, return receipt requested,
      postage prepaid, or overnight courier or confirmed facsimile transmission,
      addressed to the Parties at as follows. 

     

     

    
      
        	 	
                If
                  to the Member Representative:

                 

                429
                  Murray Street

                Suite
                  #700

                Alexandria,
                  LA  71301

                Attn :
                  Darrell Dubroc

                Telephone
                  No.: (318) 442-8730

                Facsimile
                  No.: (318) 442-8981

                


                with
                  a copy to:

                


                Phelps
                  Dunbar LLP

                City
                  Plaza

                445
                  North Boulevard, Suite 701

                Baton
                  Rouge , LA 70802 

                Attention:
                  Richard Matheny 

                Telephone
                  No.: (225) 376-0210 

                Facsimile
                  No.: (225) 381-9197 

              


      

       

      
        
          
          

        

        
          6

          
            

          

        

        
          
          

        

      

       

      
        	 	
                and

                


                Breazeale,
                  Sachse & Wilson, L.L.P.

                23rd
                  Floor, One American Place

                301
                  Main Street

                Baton
                  Rouge, LA 70821-3197

                Attn:
                  B. Troy Villa

                Telephone
                  No.: (225) 387-4000

                Facsimile
                  No.: (225) 387-5397

                 

                If
                  to Allegro, addressed as follows:

                 

                Allegro
                  Biodiesel Corporation

                6033
                  West Century Blvd., Suite 1090

                Los
                  Angeles, CA 90045

                Attention:
                  W. Bruce Comer III

                Telephone
                  No.: (310) 670-2721

                Facsimile
                  No.: (310) 670-4107

                 

                with
                  a copy to:

                 

                Sidley
                  Austin LLP

                555
                  West Fifth Street, Suite 4000

                Los
                  Angeles, CA 90013

                Attention:
                  Stephen D. Blevit, Esq.

                Telephone
                  No.: (213) 896-6029

                Facsimile
                  No.: (213) 896-6600

              


      

    

     

    
      
        
        

      

      
        7

        
          

        

      

      
        
        

      

    

     

    or
      to
      such other individual or address as a party hereto may designate for itself
      by
      notice given as herein provided.

    


    11.  Counterparts.
      This
      Agreement may be executed simultaneously in two or more counterparts, each
      of
      which will be deemed an original, but all of which together will constitute
      one
      and the same instrument.

    


    12.  Facsimile
      or Email Signatures.
      Any
      signature page delivered pursuant to this Agreement, any Related Agreement
      or
      any other document delivered pursuant hereto via facsimile or by email of pdf
      signature pages shall be binding to the same extent as an original signature.
      Any party who delivers such a signature page agrees to later deliver an original
      counterpart to any party that requests it.

    


    13.  Headings.
      The
      headings of the Sections in this Agreement are inserted for convenience of
      reference only and are not intended to be a part of or to affect the meaning
      or
      interpretation of this Agreement.

    


    14.  Severability.
      If any
      provision, clause or part of this Agreement, or the application thereof under
      certain circumstances, is held invalid, the remainder of this Agreement, or
      the
      application of such provision, clause or part under other circumstances, shall
      not be affected thereby.

     

     

    
      
        
        

      

      
        8

        
          

        

      

      
        
        

      

    

     

    15.  Interpretation.
      Unless
      the context requires otherwise, all words used in this Agreement in the singular
      number shall extend to and include the plural, all words in the plural number
      shall extend to and include the singular, and all words in either gender shall
      extend to and include both genders. 

    


    16.  Choice
      of Law.
      This
      Agreement shall be governed by and construed in accordance with the laws of
      the
      State of New York exclusive of the conflicts of law provisions thereof.


    


    [Signatures
      on Following Pages]

     

    
      
        
        

      

      
        9

        
          

        

      

      
        
        

      

    

    


    IN
      WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed
      and delivered as of the date first above written.

     

    
      	 	 	 
	 	ALLEGRO
              BIODIESEL CORPORATION
	 
 	 
 	 
 
	 	By:     /s/ 
W.
              Bruce Comer,
              II                                                
	 	
              Name:      W.
                Bruce Comer, III

              Title:        Chief
                Executive Officer

            
	 	 	 
	 	
            
	 	 


    

     

    
      
        	 	 	 
	 	MEMBERS:
	 
 	 
 	 
 
	 	By:  /s/ Darrell
                Dubroc                                                                
                
	 	
                Darrell
                  Dubroc, as Member
                  Representative

              
	 	 


      

    

     

    
      
        
        

      

      
        10