CHIRAL DISCRIMINATION OF COMPLEXES BETWEEN BENZYLOXYCARBONYLGLYCYL-L-PROLINE AND 4-HYDROXY-2-DIPROPYLAMINOINDAN IN ION-PAIR CHROMATOGRAPHY - A MOLECULAR MECHANICS STUDY

The separation of the enantiomers of 4-hydroxy-2-dipropylaminoindan (U SDA-46) was accomplished by ion-pair chromatography using benzyloxycar bonylglycyl-L-proline (L-ZGP) as a chiral selector in the mobile phase . Molecular mechanics calculations (MMX) were performed to model the f ormation of diastereomeric complexes of L-ZGP and the enantiomers of U SDA-46. Complexes were generated by manual dockings of a variety of di fferent conformations of each component and by an automated Monte Carl o search in MacroModel. The complexes were found to be stabilized by a reinforced ionic interaction, inter- and intramolecular hydrogen bond s and attractive aromatic interactions. Geometries and energies of com plex conformations were calculated to determine dynamic measures of to tal and partial surface areas and dipole moments. The results were com bined with data from a study on a series of phenolic aminotetralin der ivatives. The previously established correlation between the separatio n coefficient cu of the tetralin derivatives and the difference in dyn amic unsaturated surface area of the L-ZGP complexes was corroborated by the results obtained with USDA-46.