Isolation and purification of seven lignans from Magnolia sprengeri by high-speed counter-current chromatography

摘要

Seven lignans including (-)-maglifloenone, futoenone, magnoline, cylohexadienone, fargesone C, fargesone A and fargesone B were isolated and purified from Magnolia sprengeri Pamp. using high-speed counter-current chromatography (HSCCC) with two-step separation. In the first step, a stepwise elution mode with the two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (1:0.8:0.6:1.2, 1:0.8:0.8:1, v/v) was used and 15.6mg of (-)-maglifloenone, 19.2mg of futoenone, 10.8mg of magnoline, 14.7mg of cylohexadienone and 217mg residues were obtained from 370mg crude extract. In the second step, the residues were successfully separated by HSCCC with the solvent system composed of petroleum ether-ethyl acetate-methanol-water (1:0.8:1.2:0.6, v/v), yielding 33.2mg of fargesone C, 47.5mg of fargesone A and 17.7mg of fargesone B. The purities of the separated compounds were all over 95% determined by HPLC. The chemical structures of these compounds were confirmed by ~1H NMR, ~(13)C NMR and ESI-MS.