**[FirstSouth
      Letterhead]**








April
      2,
      2007


Mr. Darrell
      Dubroc, President


Vanguard
      Synfuels, L.L.C.


429
      Murray Street, Suite 700


Alexandria,
      Louisiana 71301





**Re:
      Second** **Amendment** **to** **Loan
      Agreement**





Gentlemen:





This
      confirms that the Loan Committee of First South **Farm** Credit,
      ACA ("First South") has approved the following amendments to the Loan Agreement
      between First South and Vanguard Synfbels, L.L.C. **("Vanguard"),** dated
      January 12, 2006 (and as
      amended September
      19,2006):





|1. | The
              renewal of the existing $2,000,000 revolving line of credit, with the
              funds to be used for general operating purposes. The maturity date
              will be
              July 1,2009. Interest will be payable quarterly. Interest will be at
              prime
              + 100 basis points. The loan will carry an upfront fee of 25 basis
              points.
              The loan will also carry a 25 basis point unused fee, with this to
              be
              billed quarterly in arrears.
|-- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | 
| | 

|2. | Amend
              the working capital covenant to change the threshold level from $750,000
              to $500,000.
|-- | -----------------------------------------------------------------------------------------------------------------------

| | 
| | 

|3. | Amend
              the cash flow coverage ratio covenant, changing the required time frame
              from each fiscal year end to "Achieve by FYE 12/31/08 and maintain
              thereafter."
|-- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | 
| | 

|4. | Amend
              the events of default section to allow the company 15 days after written
              notice of default is given to cure the
              default.
|-- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | 
| | 

|5. | Add
              a covenant allowing the borrower to make inter-company advances and
              distributions to its affiliate, Allegro Biodiesel
              Corporation.
|-- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------




Vanguard
      must provide evidence that its title insurance policy will be increased from
      the
      current level of $3.5 million to the mortgage level of $7.0
      million.





The
      above
      amendments will be set forth in a more formal Second Amendment to the Loan
      Agreement, but this letter is intended to be binding on both of us. Except
      as
      set forth above, the Loan Agreement, as amended, and each of the other Loan
      Documents shall otherwise remain in full force and effect in accordance with
      their respective terms. Capitalized terms used herein and not otherwise defined
      shall have the meanings assigned to them in the Loan Agreement.







Please
      indicate your acceptance by signing below.




Yours
                sincerely,
              
              FIRST
                  SOUTH FARM CREDIT, ACABy:
            /s/
              John
              W. HurtJohn
                W. HurtVice
                President




Agreed
      to
      and accepted:





VANGUARD
      SYNFUELS, L.L.C.





By: /s/
      Darrell J. Dubroc





Darrell
      Dubroc


Chief
      Operating Officer





ALLEGRO
      BIODIESEL CORPORATION





By: /s/
      W.
      Bruce Comer III





W.
      Bruce
      Comer III


Chief
      Executive Officer