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].

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.