Correlation between structure of dihydropyridine calcium antagonists and their retention behavior and enantioseparation on the β-cyclodextrin stationary phase in HPLC

Chromatographic data for five dihydropyridine calcium antagonists (CAs) were obtained on β-cyclodextrin column in the reversed phase HPLC. Interaction energies of solute-cyclodextrin complexes formed by docking of different parts of the CAs' molecules into the cyclodextrin cavity were calculated. Results from the HPLC experiments and molecular modeling were compared. It was found that several types of inclusion complexes are energetically possible and contribute to the retention simultaneously. Only certain inclusion complex are assumed to be responsible for enantioseparation of CAs. Nevertheless molecular modeling studies are a useful tool for explaining the enantioselectivity and predicting the elution order of enantiomers.