Separation and purification of dl-tetrahydropalmatine from Corydalis yanhusuo by high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) was applied to preparative separation and purification of dl-tetrahydropalmatine from Corydalis yanhusuo by a one-step separation. The two-phase system consisted of petroleum ether–ethyl acetate–methanol–water (15:30:21:20, v/v) was employed. An orthogonal design was used for optimizing the revolution speed of the separation column, flow rate of the mobile phase and separation temperature, which was 850 rpm, 1.2 ml/min and 20 °C, respectively. HPLC analysis of the fractions collected by preparative HSCCC of 200 mg of crude extracts showed that the purity of dl-tetrahydropalmatine (8.6 mg) was 96.4%. The chemical identity of the component was confirmed by 1H NMR and EI-MS.