title: Application of 2-chlorotrityl resin in solid phase synthesis of (Leu15)-gastrin I and unsulfated cholecystokinin octapeptide. Selective O-deprotection of tyrosine.
abstract: The carboxyl terminal dipeptide amide, Fmoc-Asp-Phe-NH2, of gastrin and cholecystokinin (CCK) has been attached in high yield through its free side chain carboxyl group to the acid labile 2-chlorotrityl resin. The obtained peptide resin ester has been applied in the solid phase synthesis of partially protected (Leu15)-gastrin I utilising Fmoc-amino acids. Quantitative cleavage of this peptide from resin, with the t-butyl type side chain protection intact is achieved using mixtures of acetic acid/trifluoroethanol/dichloromethane. Under the same conditions complete detritylation of the tyrosine phenoxy function occurs simultaneously. Thus, the solid-phase synthesis of peptides selectively deprotected at the side chain of tyrosine is rendered possible by the use of 2-chlorotrityl resin and Fmoc-Tyr(Trt)-OH. The efficiency of this approach has been proved by the subsequent high-yield synthesis of three model peptides and the CCK-octapeptide.
authors.affiliation: Department of Chemistry, University of Patras, Greece.
authors.forename: K
authors.initials: K
authors.lastname: Barlos
authors.forename: D
authors.initials: D
authors.lastname: Gatos
authors.forename: S
authors.initials: S
authors.lastname: Kapolos
authors.forename: C
authors.initials: C
authors.lastname: Poulos
authors.forename: W
authors.initials: W
authors.lastname: Schäfer
authors.forename: W Q
authors.initials: WQ
authors.lastname: Yao
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids; D005449:Fluorenes; D005755:Gastrins / Q000138:chemical synthesis* / Q000737:chemistry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry; D012117:Resins, Synthetic; D012844:Sincalide / Q000138:chemical synthesis* / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry
chemical_list: D000596:Amino Acids; D005449:Fluorenes; D005755:Gastrins; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D009842:Oligopeptides; D012117:Resins, Synthetic; C037856:gastrin heptadecapeptide, Leu(15)-; D014443:Tyrosine; D012844:Sincalide