Structure‐enantioselectivity relationships for the study of chiral recognition in peptide enantiomer separation on cinchona alkaloid‐based chiral stationary phases by HPLC: Influence of the N‐terminal protecting group

摘要: Eleven different N-terminal protecting groups (acetyl, benzoyl, FMOC, etc.) were employed for the HPLC separation of oligoalanine peptide enantiomers containing up to six amino acids. Isocratic separations performed using a hydro-organic buffered mobile phase and 4 mm ID columns three chiral anion exchange stationary phases based on cinchona alkaloid-derived selectors. For most peptides successful could be obtained with all groups, although those comprising aromatic moieties found yield higher enantioselectivities than aliphatic residues, since they are capable undergoing favourable π-π interactions selector. Systematic investigations concerning presence or absence structural features related showed that use optimally adjusted binding pocket selector effects significant gain in enantioselectivity. At same time these studies provided new insights into recognition mechanism.