Stereochemical recognition of enantiomeric and diastereomeric dipeptides by high-performance liquid chromatography on a chiral stationary phase based upon immobilized α-chymotrypsin

Abstract

A series of 24 enantiomeric and diastereomeric dipeptides were chromatographed on a chiral stationary phase (CSP) based upon immobilized α-chymotrypsin (ACHT). The ACHT-CSP was able to resolve stereochemically a number of the enantiomeric d,d- and l,l-dipeptides as well as the diastereomeric d,d-/ l,l- and l,d-/ d,l-dipeptides. The solutes were also chromatographed on a N-tosyl- l-phenylalanine chloromethyl ketone-deactivated form of the ACHT-CSP, where stereochemical separations were also achieved. The results of this study suggest that binding interactions between the dipeptides and the ACHT-CSP occur at the active site of the ACHT and at other hydrophobic sites on the ACHT molecule.