title: Studies on peptides CLVIII. Model experiments for the synthesis of open-chain unsymmetrical cystine-peptides.
abstract: Treatment of a mixture of Cys(R)(O) and Cys(R') with an acid was found to generate cystine in fairly good yields, when suitable R, R', and an acid were selected. An unsymmetrical cystine peptide was prepared by treatment of a mixture of Z(OMe)-Cys(R) (0)-Ala-NH2 (R = Acm or MBzl) and Z(OMe)-Cys(MBzl)-Gly-OBzl with TFA or 1 M TFMSA/TFA3. Oxytocin was obtained in an excellent yield by TFA treatment of the protected peptide containing Cys(Acm)(0) and Cys(MBzl). Thus, formation of the disulfide bond was found feasible at the position of Cys(R) (0).
authors.affiliation: Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Fujii
authors.forename: A
authors.initials: A
authors.lastname: Otaka
authors.forename: S
authors.initials: S
authors.lastname: Funakoshi
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: H
authors.initials: H
authors.lastname: Arai
authors.forename: K
authors.initials: K
authors.lastname: Bessho
authors.forename: H
authors.initials: H
authors.lastname: Yajima
mesh_terms: D003553:Cystine; D004220:Disulfides; D066298:In Vitro Techniques; D008956:Models, Chemical; D010455:Peptides / Q000138:chemical synthesis*
chemical_list: D004220:Disulfides; D010455:Peptides; D003553:Cystine