RESUMO
The biological activity of extracts from the leaves, bark and roots of Muellera frutescens, an Amazonian ichtyotoxic plant, were evaluated to find new environmentally safe insecticides. The n-hexane extracts of bark, leaf, and root showed a strong toxic activity against Aedes aegypti mosquito larvae. Bioguided fractionation of the bark extract led to the isolation of seven isoflavonoids (12a-hydroxyelliptone, elliptone, (-)-variabilin, rotenone, rotenolone, tephrosin and deguelin). Rotenone and deguelin are responsible for the larvicidal activity of the plant. M frutescens leaves contain up to 0.6%, w/w, deguelin. These results justify the traditional ichtyotoxic use of M frutescens. The leaves contain a relatively high proportion of deguelin and, therefore, can be considered as a renewable source of this environmentally friendly insecticidal isoflavonoid.
Assuntos
Aedes/fisiologia , Fabaceae/química , Inseticidas/toxicidade , Isoflavonas/toxicidade , Larva/fisiologia , Animais , Cromatografia Líquida de Alta Pressão , Guiana Francesa , Resistência a Inseticidas , Casca de Planta/química , Extratos Vegetais/toxicidade , Folhas de Planta/química , Raízes de Plantas/química , Rotenona/análogos & derivados , Rotenona/química , Solventes , Espectrofotometria UltravioletaRESUMO
A phytochemical study of the ethyl acetate extract of the roots and adventitious roots of Spirotropis longifolia, a monodominant tree species of the Guianan rainforest, has allowed the isolation of three compounds: 2-hydroxy-8,9-methylenedioxy-2',2'-dimethylpyrano-[5',6':4,3]-6a-prenyl-[6aS,11aS]-pterocarpan (spirotropin A), 2-hydroxy-8,9-methylenedioxy-2',2'-dimethyl-3',4'-dihydropyrano-[5',6':4,3]-6a-prenyl-[6aS,11aS]-pterocarpan (spirotropin B), and 5,7-dihydroxy-6,8-diprenyl-2'''',2''''-dimethylpyrano[5'''',6'''': 3',4']-isoflavone (spirotropone). In addition, 10 known compounds, trans-oxyresveratrol, trans-resveratrol, piceatannol, daidzein, genistein, isoprunetin, lupeol, latifolol, gnetin D and gnetin E, were also isolated. These compounds were evaluated for their antifungal activity and their cytotoxicity, and their structures were established by 1D and 2D NMR, HRMS, CD and optical rotation measurements.
Assuntos
Antifúngicos/farmacologia , Fabaceae/química , Fungos/efeitos dos fármacos , Isoflavonas/farmacologia , Extratos Vegetais/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Fabaceae/metabolismo , Humanos , Isoflavonas/química , Isoflavonas/isolamento & purificação , Estrutura Molecular , Extratos Vegetais/química , Raízes de PlantasRESUMO
Research on antifungal compounds from the durable wood from French Guiana Amazonian forest trees highlights the correlation between the activity of their extracts against wood-rotting fungi and human pathogens. The fractionation of an ethyl acetate extract of Sextonia rubra wood led to the isolation of rubrenolide (1) and rubrynolide (2). The potential of compounds 1 and 2 is described through the evaluation of their activity against 16 pathogenic fungi and their cytotoxicity toward NIH-3T3 mammalian fibroblast cells.
