Oxidative burst inhibitory and cytotoxic amides and lignans from the stem bark of Fagara heitzii (Rutaceae)

Mbaze LM'a, Lado JA, Wansi J, et al. Oxidative burst inhibitory and cytotoxic amides and lignans from the stem bark of Fagara heitzii (Rutaceae). Phytochemistry. 2009;70(11-12):1442-1447.Two amides, heitziamide A and heitziamide B and two phenylethanoids, heitziethanoid A and heitziethanoid B together with thirteen known compounds were isolated from F. heitzii (Letouzey). The structures of all compounds were established by spectroscopic analysis. Nine compounds were evaluated for oxidative burst inhibitory activity in a chemoluminescence assay and for cytotoxicity against PC-3 prostate cancer cells. All compounds exhibited a clear suppressive effect on phagocytosis response upon activation with serum opsonized zymosan at the range of IC50 = 2.0-6.5 mu M, but no cytotoxic effect was observed (IC50 > 100 mu M). (C) 2009 Elsevier Ltd. All rights reserved

Antimicrobial and antioxidant effects of phenolic constituents from Klainedoxa gabonensis

Wansi JD, Chiozem DD, Tcho MT, et al. Antimicrobial and antioxidant effects of phenolic constituents from Klainedoxa gabonensis. PHARMACEUTICAL BIOLOGY. 2010;48(10):1124-1129.Bioassay-guided fractionation of the methanol extract of the stem bark of Klainedoxa gabonensis Pierre ex Engl. (Irvingiaceae) afforded 12 compounds, namely, ellagic acid (1), ellagic acid 3,3'-dimethylether (2), gallic acid (3), methyl gallate (4), lupeol (5), beta-amyrin (7), erythrodiol (8), oleanolic acid (9), betulinic acid (6), hederagenin (10), bayogenin acid (11), and stigmasterol-3-O-beta-D-glucopyranoside (12). Compounds 1-3 and 7-12 were isolated for the first time from this genus. The structures were established on the basis of 1D/2D NMR experiments and mass spectrometric data. Crude extract, fractions (A, B, C and D) and pure compounds were tested for their antimicrobial activity using paper disk agar diffusion assay. The test delivered a range of low to high activities for phenolic compounds 1-4, low or missing activities for terpenoid compounds 5-11, and impressive very high antibacterial/antifungal values for two fractions C and D probably due to synergistic effects of compounds. The broth microdilution assay revealed MICs of 15.4-115.1 mu g/mL for phenolic compounds, MICs higher than 1 mg/mL for terpenoids and MICs of 4.5-30.3 mu g/mL for fractions C and D. The determination of the radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay gave high antioxidant values for the methanol extract and fraction D (IC50 10.45 and 5.50 mu g/mL) as well as for the phenolic compounds 1-4 (IC50 45.50-48.25 mM) compared to the standard 3-t-butyl-4-hydroxyanisole (BHA) (IC50 44.20 mM)