DIRECT OPTICAL RESOLUTION OF VESAMICOL AND A SERIES OF BENZOVESAMICOLANALOGS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The direct optical resolution of the vesicular acetylcholine uptake in hibitors vesamicol and benzovesamicol and nine benzovesamicol analogue s were performed by HPLC on a commercially available cellulose tris(3, 5-di-methyrphenyl carbamate) chiral stationary phase. Separation of ea ch enantiomeric pair was optimized with respect to solvent strength an d flow-rate, using mobile phase mixtures of hexane-2-propanol-diethyla mine. The method has been successfully applied to the analysis of the optical purity of benzovesamicol intermediates and products, including (-)-5-[I-123]iodobenzovesamicol which is currently undergoing clinica l evaluation as a tracer for mapping central cholinergic neurons, and the purification of both antipodes of (+/-)-7-[I-125]iodobenzovesamico l.