The preparation of some sequential polypeptides by the p-Nitrophenyl ester method

Abstract

A number of sequential polypeptides have been obtained by polymerization of peptide p-nitrophenyl esters. The majority of the products contained γ-ethyl-L-glutamyl and S-benzyl-L-cysteinyl residues in various proportions. The active ester monomers were synthesized by the mixed carbonic anhydride procedure using p-nitrophenyl as a carboxyl-protecting group. Some of the limitations of this approach are discussed.