Preparation and conformational analysis of C-glycosyl β 2- and β/β 2-peptides

Abstract

Ten C-glycosyl β 2- and β/β 2- peptides with three to eight amino acid residues have been prepared. Solution and solid-phase peptide syntheses were employed to assemble β 2-amino acids in which C-glycosylic substituents are attached to the C-2 position of β-amino acids. Conformational analysis of the C-glycosyl β 2-peptides using NMR and CD spectra indicates that the tripeptide can form a helical secondary structure. Besides, helix directions of the C-glycosyl β/β 2-peptides are governed by the configuration at the α-carbon of the peptide backbone that originates from the stereocenter of the C-glycosyl β 2-amino acids.