isorhamnetin-3-o-glucoside and isoquercitrin

Systematic identification and structural characterization of flavonoids and their glycosides in bran extracts of seven Thai black rice varieties were performed by sequential uses of reversed-phase HPLC with a photodiode array detector and a combined electrospray ionization tandem mass spectrometer. Eleven flavonoids were detected, and six of these were found for the first time in rice bran. These were taxifolin-7-O-glucoside, myricetin-7-O-glucoside, isorhamnetin-3-O-acetylglucoside, isorhamnetin-7-O-rutinoside, 5,6,3',4',5'-pentahydroxyflavone-7-O-glucoside, and 5,3',4',5'-tetrahydroxyflavanone-7-O-glucoside. The quantitative results revealed that different rice varieties possessed flavonoids in different concentrations. The most abundant glycoside derivative of flavonoids widely distributed among the rice varieties was monoglucoside, such as quercetin-3-O-glucoside, isorhamnetin-3-O-glucoside, and isorhamnetin-3-O-glucoside.

Topics: Chromatography, High Pressure Liquid; Flavonoids; Flavonols; Oryza; Quercetin; Seeds; Species Specificity; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

Flavonoid glycosides, isorhamnetin 3-capital O, Cyrillic-beta-d-glucoside, and quercetin 3-O-beta-d-glucoside were isolated from Salicornia herbacea and their inhibitory effects on matrix metalloproteinase-9 and -2 (MMP-9 and -2) were evaluated in human fibrosarcoma cell line (HT1080). In zymography experiments, these flavonoid glycosides led to the reduction of the expression levels and activities of MMP-9 and -2 without any significant difference between these flavonoid glycosides. Protein expression levels of both MMP-9 and MMP-2 were inhibited and TIMP-1 (tissue inhibitor of metalloproteinase-1) protein level was enhanced by these flavonoid glycosides. Moreover, a transfection study carried out with AP-1 reporter construct revealed that the reporter activity was suppressed by treatment with isorhamnetin 3-capital O, Cyrillic-beta-d-glucoside. Therefore, these results suggested that these flavonoid glycosides have a potential as valuable natural chemopreventive agents for cancer.

Topics: Antineoplastic Agents; Cell Line, Tumor; Chenopodiaceae; Fibrosarcoma; Flavonoids; Flavonols; Gene Expression Regulation, Enzymologic; Glycosides; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Plant Extracts; Quercetin; Tissue Inhibitor of Metalloproteinase-1; Transcription Factor AP-1; Transfection

To study the chemical constituents of flowers of Prunus mume.. Compounds were separated by silica gel. Their structures were identified and elucidated by spectral analysis and chemical methods.. Eight compounds were obtained and identified as benzoic acid (I), isorhamnetin (II), quercetin (III), kaempferol-3-O-beta-D-galactopyranoside (IV), isorhamnetin-3-O-beta-D-glucopyranoside (V), isoquercitrin (VI), hypericin (VII) and rutin (VIII).. Among them, II-VII are isolated from this plant for the first time.

Topics: Anthracenes; Benzoic Acid; Flavonols; Flowers; Molecular Structure; Perylene; Plants, Medicinal; Prunus; Quercetin

One new and six known flavone glycosides were isolated from the MeOH extract of Melilotus neapolitana Ten. The new compound, identified as 7-O-beta-D-glucopyranosyloxy-4',5-dihydroxy-3-[O-alpha-L-rhamnopyranosyl-(1-->6)-3-O-beta-D-glucopyranosyloxy]flavone (1) by 1D and 2D NMR techniques and mass spectra, was isolated along with kaempferol-3-O-rutinoside (2), kaempferol-3-O-glucoside (3), rutin (4), quercetin-3-O-glucoside (5), isorhamnetin-3-O-rutinoside (6), and isorhamnetin-3-O-glucoside (7). The antioxidant and radical scavenging activities of these compounds and the whole crude methanol extract were evaluated. The organic extract can inhibit MDA marker's synthesis by 57%. All the metabolites displayed good reducing power, with the kaempferol (2,3) and isorhamnetin derivatives (6,7) being less active than the corresponding quercetin derivatives 4,5.

Topics: Antioxidants; Disaccharides; Flavones; Flavonoids; Flavonols; Free Radical Scavengers; Glycosides; Kaempferols; Magnetic Resonance Spectroscopy; Mass Spectrometry; Melilotus; Monosaccharides; Plant Extracts; Quercetin; Reactive Oxygen Species; Rutin