Enantioseparation and molecular modeling study of five β-adrenergic blockers on Chiralpak IC column.

A new high-performance liquid chromatography (HPLC) method was developed for the enantiomeric resolution of five β-adrenergic blockers on a Chiralpak IC column (250 mm × 4.6 mm, 5.0 μm particle size) in normal phase mode. The mobile phase used was n-hexane-ethanol-diethylamine in different proportions at the flow rate of 1.0 mL/min with the column temperature of 25°C using a UV detector at 230 nm. The influences of base additives and alcohol modifiers were evaluated and optimized. The maximum resolution values for bevantolol, propranolol carteolol, esmolol, and metoprolol were 4.80, 2.77, 2.09, 2.30, and 1.11, respectively. To gain a better understanding of the interaction between chiral stationary phase and analyte enantiomers, the molecular docking of chiral stationary phase with five pairs of enantiomer was carried out using AutoDock molecular docking technique. By simulation studies, the mechanism of chiral recognition was determined. According to the results, hydrogen bond interactions and π-π interactions were the chief interactions for the chiral recognition.