RESUMO
A new oligostilbenoid tetramer, malaysianol B (1), was isolated from the acetone extract of the stem bark of Dryobalanops lanceolata along with seven oligostilbenoids tetramers; hopeaphenol (2), stenophyllol A (3), nepalensinol B (4), vaticanol B (5) and C (6), upunaphenol D (7), and flexuosol A (8). The structures of the isolated compounds were established on the basis of their spectroscopic data evidence. The antibacterial activity of the isolated compounds was evaluated using resazurin microtitre-plate assay.
Assuntos
Dipterocarpaceae/química , Estilbenos/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Estrutura Molecular , Casca de Planta/química , Caules de Planta/química , Estilbenos/farmacologiaRESUMO
A new resveratrol trimer, malaysianol A (1), five known resveratrol oligomers: laevifonol (2), ampelopsin E (3), α-viniferin (4), ε-viniferin (5), diptoindonesin A (6), and bergenin (7) have been isolated from the acetone extract of the stem bark of Dryobalanops aromatica by combination of vacuum and radial chromatography techniques. Their structures were established on the basis of their spectroscopic evidence and comparison with the published data. The cytotoxic activity of the compounds was tested against several cell lines in which compound 4 was found to inhibit strongly the growth of HL-60 cell line.
Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Dipterocarpaceae/química , Flavonoides/isolamento & purificação , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Flavonoides/química , Humanos , Casca de Planta/química , Caules de Planta/química , Resveratrol , Estilbenos/químicaRESUMO
Methanol extracts of seven Malaysian medicinal plants were screened for antioxidant and nitric oxide inhibitory activities. Antioxidant activity was measured by using FTC, TBA and DPPH free radical scavenging methods and Griess assay was used for the measurement of nitric oxide inhibition in lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-treated RAW 264.7 cells. All the extracts showed strong antioxidant activity comparable to or higher than that of alpha-tocopherol, BHT and quercetin in FTC and TBA methods. The extracts from Leea indica and Spermacoce articularis showed strong DPPH free radical scavenging activity comparable with quercetin, BHT and Vit C. Spermacoce exilis showed only moderate activity but other species were weak as compared to the standards. In the Griess assay Lasianthus oblongus, Chasalia chartacea, Hedyotis verticillata, Spermacoce articularis and Leea indica showed strong inhibitory activity on nitric oxide production in LPS and IFN-gamma-induced RAW 264.7 cells. Extracts from Psychotria rostrata and Spermacoce exilis also inhibited NO production but this was due to their cytotoxic effects upon cells during culture.