PREPARATIVE ISOLATION AND PURIFICATION OF THREE FLAVONOIDS FROM THE CHINESE MEDICINAL PLANT ALPINIA KATSUMADAI HAYATA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY

High-speed counter-current chromatography was applied in the isolation and purification of three flavonoids from the Chinese medicinal plant Alpinia katsumadai Hayata. A two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water at volume ratios of 5:5:7:3 was used, which yielded 17.2 mg of alpinetin, 3.5 mg of pinocembrin, and 25.1 mg of ardamomin from 100 mg of the crude extract in one-step separation. The purities of them were 98.1%, 97.5%, and 99.2%, respectively, as determined by high performance liquid chromatography and their chemical structures were identified by 1H-NMR and 13C-NMR.