Studies on Peptides. XVI. Regeneration of Lysine from Nε-Formyllysine by Aqueous Hydrazine or Hydroxylamine and Their Application to the Synthesis of α-Melanocyte-stimulating Hormone

Abstract

Treatment of N^ε-formyllysine with dilute aqueous hydrazine acetate or hydroxylamine hydrochloride in aqueous pyridine regenerated lysine in satisfactory yield. These methods were adopted to convert N^α-acetylseryltyrosylserylmethionylglutamylhistidylphenyl-alanylarginyltryptophylglycyl-N^ε-formyllysylprolylvaline amide to α-melanocyte-stimulating hormone (MSH). The products prepared by two alternate methods behaved quite identically with natural α-MSH on paper and thin-layer chromatographies and their infrared spectra were both identical with that of natural α-MSH. Their in vitro MSH activities were 2.3-5.4×10¹² and 2.4-4.1×10¹² U/g respectively.