Chemical constituents from Clausena excavata and their inhibitory activities against proliferation of synoviocytes

The chemical constituents from the stems and leaves of Clausena excavata were isolated and purified by column chromatography with silica gel, ODS, Sephadex LH-20 and RP-HPLC. The chemical structures of the isolated compounds were identified on the basis of physicochemical properties, spectroscopic analysis, as well as the comparisons with the data reported in literature. Nineteen compounds were isolated from the 90% ethanol extract of the stems and leaves of C. excavata, which were identified as methyl orsellinate(1), syringaresinol(2), lenisin A(3), scopoletin(4), osthenol(5), N-benzoyltyrarnine methyl ether(6), N-p-coumaroyltyramine(7), aurantiamide acetate(8), 1H-indole-3-carboxaldehyde(9), furostifoline(10), clausenalansine E(11), 3-formylcarbazole(12), clausine L(13), clausine E(14), methyl carbazole-3-carboxylate(15), glycosinin(16), murrayafoline A(17), clausine H(18) and 2,7-dihydroxy-3-formyl-1-(3'-methyl-2'-butenyl)carbazole(19). Among these isolated compounds, compounds 1-11 were isolated from C. excavata for the first time, and compounds 1, 2 and 10 were isolated from the genus Clausena for the first time. In addition, this study evaluated the anti-rheumatoid arthritis activities of compounds 1-19 by measuring their anti-proliferative effects on synoviocytes in vitro according to MTS method. Compounds 10-19 displayed remarkable anti-rheumatoid arthritis activities, which exhibited the inhibitory effects on the proliferation of MH7 A synovial fibroblast cells with the IC_(50) values ranging from(27.63±0.18) to(235.67±2.16) μmol·L~(-1).