RESUMO
By bioactive-guided fractionation of methanol extract of the Ficus microcarpa leaves, one new C-glucosylflavone, ficuflavoside (1), one new megastigmane glycoside, ficumegasoside (8), and twelve known compounds including flavonoids (2-6), phenylpropanoids (7), megastigmanes (9-11) and sterol derivatives (12-14) were isolated. Their chemical structures were elucidated by mass, 1D, and 2D NMR spectroscopies. The antioxidant activities of these compounds were measured using the oxygen radical absorbance capacity methods. Compounds 1-6 exhibited potent antioxidant activities of 6.6-9.5µM Trolox equivalents at the concentration of 2.0µM. The results indicated 2, 3, and 5 having meaningful reducing capacity of copper (I) ions concentration of 6.1-8.4µM.
Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Ficus/química , Flavonoides/química , Flavonoides/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/isolamento & purificação , Cromanos/farmacologia , Flavonoides/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Folhas de Planta/químicaRESUMO
The chemical study of Momordica charantia fruits led to the isolation of three new cucurbitane triterpene glycosides, momordicosides U, V, and W (1-3). The structures of these compounds were determined to be (19R, 23R)-5beta, 19-epoxy-19-methoxycucurbita-6,24-diene-3beta, 23-diol 3-O-beta-D-allopyranoside (1), (23R)-5beta, 19-epoxycucurbita-6,24-diene-3beta, 23-diol 3-O-beta-D-allopyranoside (2), and (19R)-5beta, 19-epoxy-19,25-dihydroxycucurbita-6,23(E)-diene-3beta-ol 3-O-beta-D-glucopyranoside (3), by chemical and spectroscopic methods.