Chemical constituents from stems and leaves of Cratoxylum cochinchinense and their inhibitory effects on proliferation of synoviocytes in vitro / 中国中药杂志

The chemical constituents from the stems and leaves of Cratoxylum cochinchinense were isolated and purified using silica gel, ODS gel, and Sephadex LH-20 gel column chromatography, as well as preparative HPLC. The chemical structures of all isolated compounds were identified on the basis of their physicochemical properties, spectroscopic analyses, and the comparison of their physicochemical and spectroscopic data with the reported data in literature. As a result, 21 compounds were isolated from the 90% ethanol extract of the stems and leaves of C. cochinchinense, which were identified as cratocochine(1), 1-hydroxy-3,7-dimethoxyxanthone(2), 1-hydroxy-5,6,7-trimethoxyxanthone(3), ferrxanthone(4), 3,6-dihydroxy-1,5-dimethoxyxanthone(5), 3,6-dihydroxy-1,7-dimethoxyxanthone(6), 1,2,5-trihydroxy-6,8-dimethoxyxanthone(7), securixanthone G(8), gentisein(9), 3,7-dihydroxy-1-methoxyxanthone(10), pancixanthone B(11), garcimangosxanthone A(12), pruniflorone L(13), 9-hydroxy alabaxanthone(14), cochinchinone A(15), luteolin(16), 3,5'-dimethoxy-4',7-epoxy-8,3'-neolignane-5,9,9'-triol(17), N-benzyl-9-oxo-10E,12E-octadecadienamide(18), 15-hydroxy-7,13E-labdadiene(19), stigmasta-4,22-dien-3-one(20), and stigmast-5-en-3β-ol(21). Among these isolates, compound 1 was a new xanthone, compounds 2-5, 7, 8, 12, and 16-21 were isolated from the Cratoxylum plant for the first time, and compounds 11 and 13 were obtained from C. cochinchinense for the first time. Furthermore, all isolated compounds 1-21 were appraised for their anti-rheumatoid arthritis activities by MTS method through measuring their anti-proliferative effect on synoviocytes in vitro. As a result, xanthones 1-15 displayed notable anti-rheumatoid arthritis activities, which showed inhibitory effects on the proliferation of MH7A synoviocytes with the IC_(50) values ranging from(8.98±0.12) to(228.68±0.32) μmol·L~(-1).

Phytochemical and antioxidant studies of Laurera benguelensis growing in Thailand

The aim of this study was to investigate metabolites of the lichen Laurera benguelensis. A high-performance liquid chromatographic (HPLC) method has been developed for the characterization of xanthones and anthraquinones in extracts of this lichen. Lichexanthone, secalonic acid D, norlichexanthon, parietin, emodin, teloschistin and citreorosein were detected in the lichen samples, which were collected from two places in Thailand. Components of the lichen were identifed by relative retention time and spectral data. This is the frst time that a detailed phytochemical analysis of the lichen L. benguelensis was reported and this paper has chemotaxonomic signifcance because very little has been published on the secondary metabolites present in Laurera species. Some of the metabolites were detected for the frst time in the family Trypetheliaceae. The results of preliminary testing of benzene extract and its chloroform and methanol fractions showed that all samples showed a weak radical scavenging activity. The chloroform extract showed the highest antioxidant activity.