quercetin-3-o-glucopyranoside and kaempferol

Adenanthera pavonina is a plant belonging to family Fabaceae. The 95% ethanol extract (EtOH) of the dried powdered leaves of the plant and successive extracts with solvents of increasing polarities were prepared. Fractionation of the successive aqueous EtOH extract on polyamide column and purification of the isolated compounds on Sephadex LH20 led to the isolation of a new methoxy flavonol glycoside named as quercetin 3-O-α-dirhamnopyranosyl-(1‴ → 2″,1″″ → 6″)-β-glucopyranoside-4'-methoxy (1), as well as kaempferol-3-O-α-dirhamnopyranosyl-(1‴ → 2″,1″″ → 6″)-β-glucopyranoside (2), isovitexin (3), quercetin-3-O-rhamnopyranosyl(1‴ → 4″)-β-glucopyranoside (4), quercetin-3-O-β-glucopranoside-4'-O-rhamnopyranoside (5), kaempferol-3-O-α-rhamnopyranosyl(1‴ → 2″)-β-glucopyranoside (6), quercetin-3-O-rhamnopyranosyl(1‴ → 2″)-β-glucopyranoside (7), quercetin-3-O-β-glucopyranoside (8), kaempferol (9) and quercetin (10). Structures of the isolated compounds were established by spectroscopic analysis. Antioxidant activities of EtOH extract, successive extracts and compounds 1 and 2 were evaluated. The ethyl acetate (EtOAc) extract and EtOH extract showed 62.67% and 49.30% free radical scavenging activity, respectively. Cytotoxic activities of the EtOH extract and compounds (1) and (2) were evaluated. The EtOH extract showed a significant cytotoxic activity against Hep G-2 (IC50 = 2.50 μg) as compared with cisplatin (IC50>10 μg).

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Cisplatin; Drug Screening Assays, Antitumor; Egypt; Fabaceae; Flavonoids; Flavonols; Free Radical Scavengers; Glucosides; Glycosides; Hep G2 Cells; Humans; Kaempferols; Plant Leaves; Quercetin; Stereoisomerism

Annona crassiflora, a native tree from Brazilian Cerrado, is reported to possess several ethnomedical uses. Here, we report the isolation and unambiguous characterisation of the flavonoids quercetin-3-O-β-D-glucopyranosil(1 → 6)-O-α-L-arabinoside (1), known as peltatoside, kaempferol-3-O-β-D-galactopyranoside (2), quercetin-3-O-β-D-galactopyranoside (3), quercetin-3-O-β-L-arabinopiranoside (4) and the ( - )-epicatechin (5) from the hydroalcoholic portion of the leaf ethanolic extract. Their structures were elucidated by using 1D and 2D NMR, ESI-MS, UV/Vis spectroscopy, optical rotation analysis and literature data comparison. The leaf ethanolic extract and its isolated compounds were evaluated by using antimicrobial, antioxidant and larvicidal assays, expressing antimicrobial and antioxidant activities. This is the first report on flavonoid isolation from A. crassiflora.

Topics: Annona; Antioxidants; Bacillus cereus; Brazil; Candida albicans; Escherichia coli; Flavonoids; Galactosides; Glycosides; Kaempferols; Microbial Sensitivity Tests; Plant Leaves; Quercetin; Salmonella typhimurium; Staphylococcus aureus

Phytochemical investigation of the whole plant of Lepisorus contortus (Christ) Ching led to the isolation of five new phenylethanoid glycosides (1-5), each containing a caffeoyl group, a new flavonoid glycoside (10), and 14 known compounds (6-9 and 11-15, syringic acid, vanillic acid, phloretic acid, diplopterol, and β-sitosterol). This is the first report of phenylethanoid glycosides from the family Polypodiaceae. Compounds 1-15 were evaluated for their cancer chemopreventive potential based on their ability to inhibit tumor necrosis factor alpha (TNF-α)-induced NF-κB activity, nitric oxide (NO) production, and aromatase, quinone reductase 2 (QR-2), and COX-1/-2 activities. Quercetin-3-O-β-d-glucoside (15) demonstrated inhibition against QR2 with an IC(50) value of 3.84 μM, which confirmed kaempferol/quercetin glycosides as the active compounds to inhibit QR2. The compound also demonstrated NF-κB activity with an IC(50) value of 33.6 μM. In addition, compounds 1, 2, 4, and 6 showed aromatase activity with IC(50) values of 30.7, 32.3, 26.8, and 35.3 μM, respectively.

Topics: Animals; Anticarcinogenic Agents; Antineoplastic Agents; Aromatase Inhibitors; Caffeic Acids; Cyclooxygenase Inhibitors; Drug Screening Assays, Antitumor; Flavonoids; Glycosides; Humans; Inhibitory Concentration 50; Kaempferols; Mice; Molecular Structure; NF-kappa B; Nitric Oxide; Polypodiaceae; Quercetin; Tumor Necrosis Factor-alpha