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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
Author(s) -
Czerwenka Christoph,
Lämmerhofer Michael,
Lindner Wolfgang
Publication year - 2003
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200301577
Subject(s) - cinchona , enantiomer , chemistry , high performance liquid chromatography , chiral column chromatography , alkaloid , chiral derivatizing agent , peptide , protecting group , chromatography , enantioselective synthesis , chiral stationary phase , combinatorial chemistry , organic chemistry , catalysis , biochemistry , alkyl
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 HPLC separations were performed using a hydro‐organic buffered mobile phase and 4 mm ID columns containing three different chiral anion exchange stationary phases based on cinchona alkaloid‐derived chiral selectors. For most peptides successful separations could be obtained with all protecting groups, although those comprising aromatic moieties were found to yield higher enantioselectivities than those with aliphatic residues, since they are capable of undergoing favourable π‐π interactions with the selector. Systematic investigations concerning the presence or absence of structural features of related protecting groups showed that the use of protecting groups that are optimally adjusted to the binding pocket of the chiral selector effects a significant gain in enantioselectivity. At the same time these studies provided new insights into the chiral recognition mechanism.