Amino Acids and Peptides. XL. Synthesis of Ac-Tyr-Val-Ala-Asp-MCA Using Newly Developed Acetylating Reagent

Abstract

2-Acetoxy-3-benzyl-5-methyl-6-isobutylpyrazine was prepared by cyclization of H-Phe-Leu-CH₂Cl, followed by acetylation with acetic anhydride. This pyrazine derivative can react with amino groups of amino acids or peptides to produce acetyl amino acids or acetyl peptides without acetylation of hydroxy group of Tyr, Ser and Thr. Using this acetylating reagent, Ac-Tyr-Val-Ala-Asp-MCA, which is a specific substrate of the interleukin-I (IL-I) processing enzyme, was prepared.