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Six new 5,6-dihydro-alpha-pyrone derivatives (1-6), namely, brevipolides A-F, together with seven known compounds, including a 5,6-dihydro-alpha-pyrone derivative (7), three flavonoids, a steroid glycoside, and two triterpenoids, were isolated from the entire plant of Hyptis brevipes. Compounds 1-7 were assigned with the absolute configuration 5R, 6S, 7S, and 9S, as elucidated by analysis of data obtained from their CD spectra and by Mosher ester reactions. Compounds 2, 6, and 7 exhibited ED(50) values of 6.1, 6.7, and 3.6 microM against MCF-7 cells, and compounds 1, 2, 6, and 8 (the known 5,6,3'-trihydroxy-3,7,4'-trimethoxyflavone) gave ED(50) values of 5.8, 6.1, 7.5, and 3.6 microM against HT-29 cells, respectively. However, no significant cytotoxicity was found against Lu1 cells for any of the compounds isolated. When these compounds were subjected to evaluation in a panel of mechanism-based in vitro assays, compound 7 was found to be active in an enzyme-based ELISA NF-kappaB assay, with an ED(50) value of 15.3 microM. In a mitochondrial transmembrane potential assay, compounds 3, 7, and 8 showed ED(50) values of 8.5, 75, and 310 nM, respectively. No potent activity was found in a proteasome inhibition assay for any of the isolated compounds.

Activity-guided fractionation of the petroleum ether and ethyl acetate extracts of the stem bark of Pongamia pinnata, using cultured Hepa 1c1c7 mouse hepatoma cells to evaluate quinone reductase (QR) inducing activity, led to the isolation of four new flavanone derivatives (1-4), one new flavone (5), one new chalcone (6), and 13 known compounds of the flavonoid, terpenoid, and fatty acid types. The structures of 1-6 were characterized on the basis of the interpretation of their spectroscopic data. The absolute stereochemistry of compounds 1-4 was determined from their CD data and by Mosher ester determination. All isolates obtained were evaluated in the quinone reductase induction assay.

Activity-guided fractionation of an ethyl acetate extract of the twigs of Hernandia ovigera, using a soft agar assay with JB6 murine epidermal cells, led to the isolation of two new naturally occurring aryltetralin lignans, (7R,8S,7'R,8'R)-(+)-7'-acetyl-5'-methoxypicropodophyllin (1) and (7R,8S,7'R,8'R)-(+)-7'-acetylpicropodophyllin (2), of which 2 was previously identified as a synthetic product, along with eight known compounds, epiyangambin (3), caruilignan C, diasesartemin, (+)-epimagnolin A, N-methylcorydaldine, (-)-5'-methoxyyatein, (+)-syringaresinol dimethyl ether, and (-)-yatein. The structures and stereochemistry of 1 and 2 were determined using spectroscopic methods. Compounds 2 and 3 exhibited significant inhibition of the transformation of murine epidermal JB6 cells, with IC50 values of 0.15 and 0.4 microg/mL, respectively, while the other isolates were regarded as inactive (IC50 >4 microg/mL).

Fractionation of an ethyl acetate-soluble extract of the bark of Artocarpus dadah has led to the isolation of three new prenylated stilbenoid derivatives, 3-(gamma,gamma-dimethylallyl)resveratrol (1), 5-(gamma,gamma-dimethylallyl)oxyresveratrol (2), 3-(2,3-dihydroxy-3-methylbutyl)resveratrol (3), and a new benzofuran derivative, 3-(gamma,gamma-dimethylpropenyl)moracin M (4), along with six known compounds, oxyresveratrol, (+)-catechin, afzelechin-3-O-alpha-L-rhamnopyranoside, (-)-epiafzelechin, dihydromorin, and epiafzelechin-(4beta-->8)-epicatechin. From an ethyl acetate-soluble extract of the twigs of the same plant were isolated compound 4 and two new neolignan derivatives, dadahols A (5) and B (6), as well as 10 known compounds, oxyresveratrol, (+)-catechin, afzelechin-3-O-alpha-L-rhamnopyranoside, resveratrol, steppogenin, moracin M, isogemichalcone B, gemichalcone B, norartocarpetin, and engeletin. The structures of compounds 1-6 were determined using spectroscopic and chemical methods. Isolates were evaluated for their inhibitory effects against both cyclooxygenase-1 (COX-1) and -2 (COX-2) and in a mouse mammary organ culture assay.