Abstract
Dipeptides are stereo-specifically involved in several biological functions that are challenging to separate enantiomerically. Elution order of enantiomers is an important issue in chiral chromatography. Amylose
tris
-(3,5-dimethylphenylcarbamate) chiral stationary phase (CSP) is the best and most-widely-used CSP in chiral separations, but experimental data of enantiomeric separation of dipeptides on this CSP is lacking. Simulation studies were conducted to determine the order of elution and the chiral recognition mechanism of didpetides on this CSP. Results indicated that the docking energy of
SR
-enantiomers were higher than
SS
-antipodes. The range of docking energies for
SR
-enantiomers was −7.44 to −5.92 kcal/mol with CSP, but −7.15 to −5.87 kcal/mol for
SS
-stereoisomers. Therefore it is predicted that
SS
-enantiomer will elute first, followed by
SR
-antipode. Furthermore, hydrogen bondings, van der Waal’s interactions and electrostatic interactions were observed among
SR
- and
SS
-enantiomers and chiral grooves of CSP. The number of hydrogen bonds was one in each enantiomer binding except
S
-Ala-
R
-Tyr, which contained two hydrogen bonds. No hydrogen bond was found in
S
-Ala-
R
-Trp,
S
-Leu-
S
-Trp, and
S
-Leu-
S
-Tyr dipeptides bindings. The chiral recognition mechanisms dictate different strengths of stereoselective bindings of the enantiomers on CSP.