Chiral high-performance liquid chromatographic separations on an α1-acid glycoprotein column. II: Separation of the diastereomeric and enantiomeric analogues of vinpocetine (Cavinton)

Abstract A chiral α 1 -acid glycoprotein column (Chiral-AGP) was used for the separation of vinpocetine and its three diastereomeric and enantiomeric analogues. As a consequence of the extremely large differences between the affinities of the isomers to the chiral stationary phase, gradient elution [up to 35% (v/v) 2-propanol] and a relatively high pH (7.73) were necessary to achieve a good separation within a reasonable time. The elution order of the isomers was cis -(+)- (vinpocetine), trans -(−)-, cis -(−)-, trans -(+)-. Because of the unfavourable elution order the method does not seem to be suitable for the determination of the optical purity of vinpocetine.