Preparative isolation and purification of notopterol and isoimperatorin from Notopterygium forbessi Boiss (Chinese traditional medicinal herb) by high-speed counter-current chromatography.

Preparative high-speed counter-current chromatography was successfully used for isolation and purification of coumarins from Chinese traditional medicinal herb Notopterygium forbessi Boiss (Qianghuo in Chinese) using stepwise elution with a pair of two-phase solvent systems composed of light petroleum-ethyl acetate-methanol-water at volume ratios of 5:5:4.8:5 and 5:5:5:4. Four major components including notopterol and isoimperatorin were isolated, each at over 98% purity.