Mechanism study on the Oligomerization of Amino Acids into Peptides by Phosphorus Trichloride

Abstract

As treated by phosphorus trichloride, amino acids could oligomerize into polypeptides. Based on the results obtained by ³¹P-NMR and ESI-MS/MS, a possible reaction mechanism was proposed. The mechanism might undergo a penta-coordinated phosphorus intermediat. The activated amino acid was a five-membered cyclic penta-coordinated phosphorus intermediate. The nucleophilic attack of the amino group from an amino acid or peptide on the carbonyl group of intermediate led to the formation of peptide and released one equivalent dichloride phosphoric acid. The repetition of the reaction sequence generated a series of oligopeptides.

Keywords:

• Mechanism
• penta-coordinated phosphorus
• peptides
• phosphorus trichloride

Acknowledgments

The authors would like to thank the financial supports from the Chinese National Science Foundation (No. 20272055, 20572016), Henan Province Science Foundation for Prominent Youth (No. 0312000900), and Office of Education of Henan Province (No. 2006KYCX017).