Separation and purification of baicalin and wogonoside from the Chinese medicinal plant Scutellaria baicalensis Georgi by high-speed counter-current chromatography

A preparative high-speed counter-current chromatography (HSCCC) method for isolation and purification of baicalin and wogonoside from the Chinese medicinal plant Scutellaria baicalensis Georgi (Huang-qin in Chinese) was successfully established by using ethyl acetate–methanol–1% acetic acid water (5:0.5:5, v/v) as the two-phase solvent system. The upper phase of ethyl acetate–methanol–1% acetic acid water (5:0.5:5, v/v) was used as the stationary phase of HSCCC. Baicalin (58.1 mg) and wogonoside (17.0 mg) with the purity of 99.2 and 99.0%, respectively, were separated successfully in one-step separation from 120 mg of crude sample from S. baicalensis Georgi. The structures of baicalin and wogonoside were identified by 1H NMR and 13C NMR.