Amino-acids and peptides. Part XXIX. The use of S-benzylthiomethyl-L-cysteine in peptide synthesis: synthesis of glutathione and homoglutathione

Abstract

The usefulness of benzylthiomethyl as an S-protecting group has been further confirmed by the synthesis of glutathione and ‘homoglutathione’(γ-L-glutamyl-L-cysteinyl-β-alanine). The benzylthiomethyl group was completely stable during the syntheses, and in the final stage was removed cleanly under the standard conditions to give quantitative or near-quantitative yields of glutathione and homoglutathione, which were analytically pure, and chromatographically pure except for traces of the corresponding disulphides, without the necessity for the usual purification by way of mercurous and cuprous salts.