Sulphated flavones and pregnane-type steroids from Helicteres viscida.

In our search for anti-inflammatory constituents from Vietnamese plants, the methanolic extract of Helicteres viscida was found to exhibit inhibitory effect on LPS-induced NO production in RAW264.7 cells. Phytochemical investigation of this plant led to isolation of four sulphated flavones (1-4), including one new compound 5,3',4'-trihydroxy-7-methoxy-8-O-sulphate flavone (1), and two pregnane-type steroids (5 and 6), including one new compound 7-epi-heligenin B (5). Their structures were elucidated by 1D and 2D NMR as well as HR-QTOF-MS experiments. Among isolated compounds, heligenin B (6) exhibited potent inhibitory effect on LPS-induced NO production in RAW264.7 cells with IC50 of 1.23 ± 0.05 µM. The activity of 6 was comparable to that of the positive control cardamonin.

Cytotoxic constituents from Isotrema tadungense.

In our search for cytotoxic constituents from Vietnamese plants, the methanolic extract of Isotrema tadungense was found to exhibit significant cytotoxic effect. Subsequent phytochemical investigation of ethyl acetate fractions of this plant led to isolation of 11 compounds including one new arylbenzofuran rhamnoside namely aristolochiaside (1), two aristololactams (2 and 3), three lignanamides (4-6) and five phenolic amides (7-11). Their structures were elucidated by 1 D and 2 D NMR and HR-QTOF-MS experiments. Among the isolated compounds, aristolochiaside (1), aristolactam AIIIa (2) and N-trans-sinapoyltyramine (10) exhibited strong and selective cytotoxicity on the HeLa human cancer cell line with IC50 values of 7.59 ± 1.03, 8.51 ± 1.73 and 9.77 ± 1.25 µM, respectively.[Formula: see text].

Four new sucrose diesters of substituted truxinic acids from Trigonostemon honbaensis with their anoctamin-1 inhibitory activity.

Truxinic acid sucrose diesters analogs possess interesting chemical structure by the presence of cyclobutane-ring and macrocyclic sucrose diesters moieties which are rarely found from natural sources. This paper describes the isolation and structural elucidation of four new sucrose diesters of substituted truxinic acids, trigohonbanosides A-D (1-4), from the leaves of Trigonostemon honbaensis. Their chemical structures were elucidated by HR-ESI-MS, NMR, and CD spectroscopic methods. At a concentration of 30 µM, compounds 1-4 moderately inhibited ANO-1 activity with inhibitory percentages of 27.7 ± 1.10%, 35.6 ± 0.92%, 43.7 ± 1.61%, and 40.8 ± 1.25%, respectively.

Acridone alkaloids from the rhizomes of Luvunga scandens (Roxb.) Buch. Ham.

The ethyl acetate extract of the rhizomes of Luvunga scandens (Roxb.) Buch. - Ham. ex Wight & Arn (Rutaceae) delivered one new acridone alkaloid named Luvungaside A (1) together with three known acridone alkaloids, namely 1,3-dihydroxy-2-methoxy-10-methyl-9-acridone (2), arborinine (3) and 1-hydroxy-3-methoxy-10-methyl-9-acridone (4). Compounds were reported for the first time from the species L. scandens applying various chromatography methods. Chemical structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D & 2D experiments and comparison with the literature. The cytotoxicity and hepatoprotective activity of compounds 1-4 in human hepatoma cell line HepG2 was measured by MTT assay. At 10-100 µM, compounds expressed significant hepatoprotective effect with prevention percentage ranging from 81.1% to 194.3%, compared to the positive control quercetin displaying 49.0%.

New cerebroside and chondrocyte proliferation activity of Caryota mitis L.

Caryota mitis L., a flowering plant, belongs to the family Arecaceae. In Vietnam, its fruits were used to treat joint pain. The present study was designed to investigate the phytochemicals and chondrocyte proliferation activity of C. mitis L. fruits on young human chondrocyte. The results showed that all of extracts (crude extract as well as n-hexane, chloroform, ethyl acetate and methanol fractions) were stimulated the growth of chondrocyte at 0.1 µg/mL; 0.01 µg/mL concentrations, of which the n-hexane and methanol fractions significantly increased the proliferation of chondrocyte by 30.75 and 24.42% at concentrations of 0.01 µg/mL, respectively. Repeated chromatography of the methanol fraction on silica gel, Sephadex LH-20 and ODS columns afforded a new cerebroside and eight known ones. Their structures were elucidated by analysis of spectral data and in comparison with the published reports.

Anti-inflammatory coumarins from Paramignya trimera.

CONTEXT: Paramignya trimera (Oliv.) Burkill (Rutaceae) has been used to treat liver diseases and cancer. However, the anti-inflammatory effects of this medicinal plant and its components have not been elucidated. OBJECTIVE: This study investigated chemical constituents of the P. trimera stems and evaluated anti-inflammatory effects of isolated compounds. MATERIALS AND METHODS: Cytotoxicity of isolated compounds (5-40 µM) toward BV2 cells was tested using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) for 24 h. Inhibitory effects of isolated compounds (5-40 µM) on nitrite and PGE2 concentrations were determined using Griess reaction and PGE2 ELISA kit, respectively (pretreated with the compounds for 3 h and then stimulated for 18 h with LPS). Inhibitory effects of compounds (5-40 µM) on iNOS and COX-2 protein expression were evaluated by Western blot analysis (pretreated with the compounds for 3 h and then stimulated for 24 h with LPS). RESULTS: Seven coumarins were isolated and identified as: ostruthin (1), ninhvanin (2), 8-geranyl-7-hydroxycoumarin (3), 6-(6',7'-dihydroxy-3',7'-dimethylocta-2'-enyl)-7-hydroxycoumarin (4), 6-(7-hydroperoxy-3,7-dimethylocta-2,5-dienyl)-7-hydroxycoumarin (5), 6-(2-hydroxyethyl)-2,2-dimethyl-2H-1-benzopyran (6), and luvangetin (7). Compounds 1-4 and 7 inhibited NO and PGE2 production in LPS-stimulated BV2 cells, with IC50 values ranging from 9.8 to 46.8 and from 9.4 to 52.8 µM, respectively. Ostruthin (1) and ninhvanin (2) were shown to suppress LPS-induced iNOS and COX-2 protein expression. DISCUSSION AND CONCLUSION: The present study provides a scientific rationale for the use of P. trimera in the prevention and treatment of neuroinflammatory diseases. Ostruthin and ninhvanin might have potential therapeutic effects and should be considered for further development as new anti-neuroinflammatory agents.

Triterpene saponins and megastigmane glucosides from Camellia bugiamapensis.

Two new triterpene saponins, camelliosides I and J (1 and 2), two new megastigmane glycosides, camellistigosides A and B (3 and 4), and two known megastigmane glycosides, icariside B1 (5) and (6S,9R)-roseoside (6), were isolated from a methanol extract of the Camellia bugiamapensis leaves using various chromatographic separation techniques. Their structures were elucidated based on spectroscopic analyses, including HR ESI MS, CD, 1D and 2D NMR. Their inhibitory effects on LPS-induced NO production in RAW264.7 cells were evaluated. This is the first report of the chemical constituents and biological activity of C. bugiamapensis.