A METHOD FOR PREPARATION OF AMINO-ACID THIOHYDANTOINS FROM FREE AMINO-ACIDS ACTIVATED BY ACETYL-CHLORIDE FOR DEVELOPMENT OF PROTEIN C-TERMINAL SEQUENCING

A novel and efficient method to prepare amino acid thiohydantoins, whi ch are required as reference standards for development of C-terminal p rotein sequencing, is reported. Amino acid thiohydantoins were prepare d using a straightforward method involving reaction of 20 free amino a cids with acetyl chloride as activating reagent and trimethylsilyl iso thiocyanate (TMS-ITC) as derivatizing reagent. The products were chara cterized by HPLC, uv spectra, amino acid analysis, MS, and NMR. Differ ent reaction conditions were investigated and the chemical mechanism o f the formation of amino acid thiohydantoins was illustrated. (C) 1997 Academic Press.