Preparative separation of two xanthones from Halenia elliptica by high-speed counter-current chromatography

A high performance method for isolation and purification of two xanthones from a crude extract of Halenia elliptica was successfully established by utilizing high-speed countercurrent chromatography (HSCCC). The separation was performed with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (5:5:7:5, v/v/v/v) with the lower phase as the mobile phase at a flow rate of 1.5 mL/min. The apparatus was rotated at 800 r/min. The effluent was detected at 254 nm. Under the optimized conditions, 18 mg of 1-hydroxy-2,3, 5-trimethoxyxanthone and 14 mg of 1-hydroxy-2,3,4,5-tetramethoxyxanthone were obtained from 100 mg of the crude extract of Halenia elliptica in one-step separation within 360 min. The results of high performance liquid chromatographic (HPLC) analysis showed that the purity of each of the target compounds was over 98%. The chemical structures of the two compounds were confirmed by H-1 nuclear magnetic resonance (H-1 NMR) and C-13 NMR. The established method is simple, highly efficient and suitable for large scale separation of xanthones from Halenia elliptica.