[Isolation and purification of flavones from Murraya exotica L. by high-speed counter-current chromatography].

High-speed counter-current chromatography (HSCCC) was used to isolate and purify flavones from Murraya exotica L. The optimum separation conditions were as follows: A two-phase solvent system was petroleum ether-ethyl acetate-methanol-water (5:5:4.8:5, v/v/ v/v). The lower phase as the mobile phase was operated at a flow rate of 2.0 mL/min, while the apparatus rotated at 800 r/min. Each time 200 mg of the sample was loaded. Under these conditions, 54.31 mg of recrystallized 5,7,3',4',5'-pentamethoxyflavone, 107.68 mg of 5-hydroxy-6,7,3',4'-tetramethoxyflavone, 215.54 mg of 5-hydroxy-6,7, 8,3', 4'-pentamethoxyflavone, and 84.36 mg of 5-hydroxy-6,7,8,3',4',5 '-hexamethoxyflavone with their purities over 95% were successfully obtained from 4.0 g of the crude extract of Murraya exotica L. The four compounds were analyzed by high performance liquid chromatography (HPLC), and identified by mass spectrometry (MS), ' H-nuclear magnetic resonance (NMR) and 13C-NMR. The compound 5-hydroxy-6,7,3',4'-tetramethoxyflavone was for the first time isolated and purified from Murraya exotica L.