title: Application of acetamidomethyl and 9-fluorenylmethyl groups for efficient side protection of penicillamine in solid-phase peptide synthesis.
abstract: Synthesis of S-acetamidomethyl and S-fluorenylmethyl derivatives of penicillamine is described. Both groups are completely stable to all the usual reagents in solid-phase peptide synthesis, including the HF cleavage step, and show an excellent degree of orthogonality to each other. Treatment of the protected peptides Ac-L-Pen(X)-L-Pro-D-Val-L-Cys(X)-NH2 with thallium (III) trifluoroacetate or iodine for X = Acm or piperidine/DMF (1:1) for X = Fm induced with good yield the formation of the intramolecular disulfide bridge. This cyclic peptide appears to assume a type II beta-turn conformation in d6-DMSO as evidenced by 1H-NMR spectra.
authors.affiliation: Department of Organic Chemistry, University of Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: García-Echeverría
authors.forename: M A
authors.initials: MA
authors.lastname: Molins
authors.forename: F
authors.initials: F
authors.lastname: Albericio
authors.forename: M
authors.initials: M
authors.lastname: Pons
authors.forename: E
authors.initials: E
authors.lastname: Giralt
mesh_terms: D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010396:Penicillamine / Q000138:chemical synthesis*; D010446:Peptide Fragments / Q000138:chemical synthesis*
chemical_list: D010446:Peptide Fragments; D010396:Penicillamine