ABSTRACT
The chemical constituents from the fruits of Morinda citrifolia were systematically explored by chromatographic fractionation methods including silica gel, octadecylsilyl(ODS) gel, Sephadex LH-20 gel, and preparative high performance liquid chromatography(pre-HPLC). The chemical structures of all isolated compounds were identified on the basis of their physicochemical properties, spectroscopic analyses, as well as the comparisons of their physicochemical and spectroscopic data with the reported data in literature. As a result, 22 isolated compounds from the 90% ethanol extract of the fruits of M. citrifolia were identified, which were moricitritone(1), 2'-deoxythymidine(2), cyclo-(L-Pro-L-Tyr)(3), methyl-5-hydroxy-2-pyridinecarboxylate(4), methyl pyroglutamate(5), bisbenzopyran(6), epipinoresinol(7), 3, 3'-bisdemethyl pinoresinol(8), 3, 3'-bisdemethyltanegool(9), trimesic acid(10), crypticin B(11), kojic acid(12), vanillic acid(13), protocatechoic acid(14), 5-hydroxymethyl furfural(15), blumenol A(16), 1-O-(9Z, 12Z-octadecadienoyl) glycerol(17), mucic acid dimethylester(18), methyl 2-O-β-D-glucopyranosylbenzoate(19), 2-phenylethyl-O-β-D-glucoside(20), scopoletin(21), and quercetin(22). Among them, compound 1 was a new pyrone derivative, compounds 2, 4-7, 10-12, and 17 were isolated from the plants belonging to Morinda genus for the first time, and compound 18 was obtained from M. citrifolia for the first time. Moreover, on the basis of testing the activities of all isolated compounds on inhibiting the proliferation of synovial fibroblasts in vitro by MTS assay, the anti-rheumatoid arthritis activities of all isolated compounds were initially evaluated. The results showed that compounds 1-6, 9, 19, and 20 exhibited remarkable anti-rheumatoid arthritis activities, which displayed the inhibitory effects on the proliferation of MH7A synovial fibroblast cells with the IC_(50) values in the range of(3.69±0.08) to(168.96±0.98) μmol·L~(-1).