[Chemical constituents of Rabdosia japonica var. glaucocalyx and their anti-complementary activity]

To study the chemical constituents of Rabdosia japonica var. glaucocalyx and their anti-complementary activity on the basis of preliminary studies. Target isolation guided by anti-complementary activity test, compounds in the chloroform and n-butanol fractions were isolated and purified by silica gel and Sephadex LH-20 column chromatographies, and preparative HPLC. The structures were identified by various spectroscopic data including ESI-MS, 1H-NMR and 13C-NMR data. The compounds were evaluated for anti-complementary activity in vitro. Eleven compounds were isolated from the chloroform and n-butanol soluble fractions and identified as stigmasterol (1), stigmas-9 (11) -en-3-ol (2), glaucocalyxin D (3), kamebakaurin (4), maslinic acid (5), corosolic acid (6), minheryins I (7), diosmetin (8), caffeic acid ethylene ester (9), caffeic acid (10) and vitexin (11). Isoquercetrin, rutin, quercetin, 3-methylquercetin, luteolin, 7-methylluteolin, and apigenin which were isolated from the preliminary studies together with compounds 9 and 10 showed inhibition of the complement system by the classical pathway. Compounds 2, 4, 6-9 and 11 were obtained from this plant for the first time. Caffeic acid (10) showed the strongest activity in vitro with a CH50 value of 0.041 g x L(-1).