title: Preparation of 'side-chain-to-side-chain' cyclic peptides by Allyl and Alloc strategy: potential for library synthesis.
abstract: Automated and manual deprotection methods for allyl/allyloxycarbonyl (Allyl/Alloc) were evaluated for the preparation of side-chain-to-side-chain cyclic peptides. Using a standard Allyl/Alloc deprotection method, a small library of cyclic peptides with lactam bridges (with seven amino acids) was prepared on an automatic peptide synthesizer. We demonstrate that the Guibe method for removing Allyl/Alloc protecting groups under specific neutral conditions [Pd(PPh3)4/PhSiH3)/DCM] can be a useful, efficient and reliable method for preparing long cyclic peptides on a resin. We have also manually synthesized a cyclic glucagon analogue containing 24 amino acid residues. These results demonstrated that properly controlled palladium-mediated deprotection of Allyl/Alloc protecting groups can be used to prepare cyclic peptides on the resin using an automated peptide synthesizer and cyclic peptides with a long chain.
authors: Department of Chemistry, University of Arizona, Tucson 85721, USA.
authors: P
authors: P
authors: Grieco
authors: P M
authors: PM
authors: Gitu
authors: V J
authors: VJ
authors: Hruby
mesh_terms: D000595:Amino Acid Sequence; D001671:Biochemistry / Q000379:methods*; D005934:Glucagon / Q000737:chemistry; D009074:Melanocyte-Stimulating Hormones / Q000138:chemical synthesis; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000138:chemical synthesis*
chemical_list: D010456:Peptides, Cyclic; D009074:Melanocyte-Stimulating Hormones; D005934:Glucagon