SUPERCRITICAL-FLUID CHROMATOGRAPHIC-SEPARATION OF BETA-BLOCKERS ON CHYROSINE-A - INVESTIGATION OF THE CHIRAL RECOGNITION MECHANISM USING MOLECULAR MODELING

Using supercritical fluid chromatography (SFC), the direct separation of a series of beta-blockers has been carried out on the commercially available ChyRoSine-A and on its improved version. Surprisingly, these solutes appeared to be poorly resolved using normal phase liquid chro matography (NPLC). The chromatographic behaviors (both in SFC and NPLC ) of various analogues of propranolol have been studied, and further s pectroscopic investigations have been carried out, Starting from these data, a detailed chiral recognition mechanism has been elaborated bas ed on molecular modeling, It appeared that the solvating effect of car bon dioxide induces a change of the propranolol conformations that is geometrically favorable to the chiral discrimination, this change of c onformation occurs in the presence of carbon dioxide only if the solut e bears both an amino proton and an ether function separated the one f rom the other by three carbon atoms.