Preparative Separation of Diterpene Lactones and Flavones from Andrographis paniculate Using Off-Line Two-Dimensional High-Speed Counter-Current Chromatography

Seven diterpene lactones, andrographolide (1), isoandrographolide (2), neo-andrographolide (3), 14-deoxy-11,12-didehydroandrographolide (4), 14-deoxyandrographiside (5), 14-deoxy-11,12-didehydroandrographiside (6), 3,14-dideoxyandrographolide (10), and three flavones, andrographidine C (7), andrographidine A (8), 5-hydroxy-7,8-dimethoxyflavanone (9) have been successfully and efficiently isolated from A. paniculata using an off-line two dimensional (2D) high-speed counter-current chromatography (HSCCC) method for the first time. For the first dimension HSCCC separation, petroleum ether-ethyl acetate-methanol-water 3:7:5:5 (v/v) was employed to isolate 14.4 mg of compound 1, 3.1 mg of compound 2, 7.8 mg of compound 3, and 18.0 mg of compound 4 from 200 mg of the A. paniculata extract. For the second dimension HSCCC separation, petroleum ether-ethyl acetate-methanol-water 2:8:1:9 (v/v) and 5:5:6:4 (v/v) were employed to isolate the collected fractions ranged from 55 to 79 min and the flow out fraction, respectively, which led to 5.1 mg of compound 5, 4.4 mg of compound 6, 2.4 mg of compound 7, 3.3 mg of compound 8, 4.0 mg of compound 9, 7.0 mg of compound 10. The structures of these diterpene lactones and flavones were elucidated by extensive spectroscopic methods.