Preparative isolation and purification of celastrol from Celastrus orbiculatus Thunb. by a new counter-current chromatography method with an upright coil planet centrifuge

A new counter-current chromatography (CCC) method with an upright coil planet centrifuge, which holds four identical multilayer coil columns in the symmetrical positions around the centrifuge axis, was applied to the isolation and purification of celastrol from the roots of Celastrus orbiculatus Thunb. The crude celastrol was obtained by elution with light petroleum from ethanol extracts using 15 cm × 5 cm i.d. silica gel flash chromatography. Preparative CCC with a two-phase system composed of light petroleum (bp 60–90 °C)–ethyl acetate–tetrachloromethane–methanol–water (1:1:8:6:1, v/v) was successfully performed, yielding 798 mg celastrol at 99.5% purity from 1020 mg of the crude sample in one step separation.