Chemical constituents of Lobelia chinensis
WANG Pei-pei, LUO Jun, YANG Ming-hua, KONG Ling-yi Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, China
Objective To investigate the chemical constituents in the dried whole plant of Lobelia chinensis. Methods Column chromatography, such as silica gel, MCI, ODS, Sephadex LH-20, C18 reverse-phased silica gel columns, and preparative HPLC were used to isolate the compounds. Spectroscopic methods like MS, 1H-NMR, and 13C-NMR were used to elucidate their structures. Results Fifteen compounds were isolated from 95% ethanol extract of L. chinensis, including twelve flavonoids: quercetin (1), rutin (2), luteolin (3), apigenin (4), hesperidin (5), quercetin-3-O-α-L-rhamnoside (6), quercetin-7-O-α-L-rhamnoside (7), quercetin-3 O-β-D-glucoside (8), amentoflavone (9), naringenin (10), hesperetin (11), and eupafolin (12), and three coumarins: 5, 7 dimethoxy-coumarin (13), isoscopoletin (14), and scoparone (15). Conclusion Compounds 6—12 are isolated from the plants in genus Lobelia L. for the first time. Compounds 5, 13, and 14 are isolated from L. chinensis for the first time.