Application of high-speed counter-current chromatography to the preparative separation and purification of baicalin from the Chinese medicinal plant Scutellaria baicalensis

Baicalin was separated and purified for the first time from the traditional Chinese medicinal plant Scutellaria baicalensis Georgi by high-speed counter-current chromatography. Crude baicalin was obtained by extraction with methanol–water (70:30, v/v) from S. baicalensis Georgi. The separation was performed in two steps with a two-phase solvent system composed of n-butanol–water (1:1, v/v), in which the lower phase was used as the mobile phase at a flow-rate of 1.0 ml min−1 in the head-to-tail elution mode. A total of 37.0 mg of baicalin at 96.5% purity was yielded from 200 mg of the crude baicalin (containing 21.6% baicalin) with 86.0% recovery as determined by HPLC analysis.