STEREOSELECTIVITY IN BETA-CYCLODEXTRIN COMPLEXATION OF 1,4-DIHYDROPYRIDINE DERIVATIVES

Structure-interaction relationships, stereoselectivity, and solubility enhancement in inclusion complexation of beta-cyclodextrins (CDs) wit h some racemic and enantiomerically pure 1,4-dihydropyridine derivativ es' (DHPs) were investigated. 1:1 and 1:2 (mole ratio) complexes were prepared and characterized by X-ray powder diffraction, differential s canning calorimetry (DSC), MS-FAB spectrometry, H-1-NMR spectroscopy, water and phase solubility. The solubility studies have revealed diffe rent complexation equilibria for optically pure DHP enantiomers, and c orresponding racemic mixtures in water solutions. By means of H-1-NMR chemical shift measurements, the inclusion of aromatic fragments of ra cemic and enantiomerically pure DHP molecules within the cavities of d ifferent CDs was elucidated. Considerable stereoselectivity in complex ation interactions was observed. The results indicate the potential us e of cyclodextrins as chiral selectors for enantiomeric resolution of 1,4-DHP calcium antagonists. (C) 1993 Wiley-Liss, Inc.