Studies on Peptides. CLI. Syntheses of Cystine-Peptides by Oxidation of S-Protected Cysteine-Peptides with Thallium (III) Trifluoroacetate

• Published in: Chemical & pharmaceutical bulletin Vol. 35; no. 6; pp. 2339 - 2347
• Main Authors: FUJII, NOBUTAKA, OTAKA, AKIRA, FUNAKOSHI, SUSUMU, BESSHO, KIYOSHI, WATANABE, TOSHIHIRO, AKAJI, KENICHI, YAJIMA, HARUAKI
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 01.01.1987; Maruzen; Japan Science and Technology Agency
• Subjects: calcitonin gene-related peptide; Chemistry; cysteine; Cystine - analysis; cystine-peptide synthesis; Exact sciences and technology; Fluoroacetates; intramolecular disulfide bond-forming reaction; Organic chemistry; Oxidation-Reduction; oxytocin; peptide synthesis; Peptides; Peptides - chemical synthesis; Preparations and properties; S-1-adamantylcysteine; S-acetamidomethylcysteine; S-ρ-methoxybenzylcysteine; soft-acid metal; Thallium; thallium trifluoroacetate; Trifluoroacetic Acid; urotensin II; Organic disulfide; Cyclic peptides; Sulfur peptide; Deprotection; Neurohypophyseal hormone; Peptide hormone; Oxidation; Liquid phase; Calcitonine gene related peptide
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.35.2339

Thallium (III) trifluoroacetate, a mild oxidant with a soft-acid character, was found to cleave various S-protecting groups of cysteine in trifluoroacetic acid, with spontaneous formation of cystine. Except for unmasked Trp and Met, other amino acids, including His and Tyr, remained intact in the presence of this oxidant. The usefulness of this oxidant for intramolecular disulfide bond-forming reactions was demonstrated by direct conversion of three model S-protected cysteine-peptides into cystine-peptides, i.e., oxytocin, urotensin II and human calcitonin generelated peptide.