Isolation and purification of oridonin from the whole plant of Isodon rubescens by high-speed counter-current chromatography.

Semi-preparative high-speed counter-current chromatography (HSCCC) was successfully used for isolation and purification of oridonin from Isodon rubescens by using a two-phase-solvent system composed of n-hexane-ethyl acetate-methanol-water (2.8:5:2.8:5, v/v/v/v). The targeted compound isolated, collected and purified by HSCCC was analyzed by high performance liquid chromatography (HPLC). A total of 40.6 mg of oridonin with the purity of 73.5% was obtained in less than 100 min from 100 mg of crude Isodon rubescens extract. The chemical structure of the compound was identified by IR, 1H-NMR and 13C-NMR.