APPLICATION OF HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY TO THE SEPARATION OF COUMARIN AND RELATED COMPOUNDS

摘要

Coumarin and related compounds were successfully separated by high-speed counter-current chromatography (CCC). Using the conventional technique with the cross-axis coil planet centrifuge, coumarin, esculin, 2- and 3- or 4-hydroxycinnamic acids were well resolved with a solvent system composed of ethyl acetate-10 mM potassium phosphate (1:1, v/v) at pH 6.5, while the separation between 3- and 4-hydroxycinnamic acids was difficult. The separation of 2-, 3- and 4-hydroxycinnamic acids, was achieved by pH-zone-refining CCC using a type-J multilayer coil planet centrifuge with a methyl-tert.-butyl ether-acetonitrile-water (1:0:1, or 4:1:5, v/v) system where trifluoroacetic acid was added to the organic mobile phase as an eluter and while ammonia was added to the aqueous stationary phase as a retainer.