Identification of flavonoids in the stems and leaves of Scutellaria baicalensis Georgi.
ABSTRACT Scutellaria baicalensis Georgi (S. baicalensis), a perennial herb of the Labiatae family, is a well-known traditional Chinese medicine. In the present study, a comprehensive qualitative analysis of flavonoids in the stems and leaves of S. baicalensis was performed. Under the optimized experimental conditions, 21 flavonoids were clearly detected. 17 of them were successfully identified based on the on-line UV and MS(n) data and were sequentially confirmed by the literature search. The rest 4 flavonones, which were not on-line identified, were successfully isolated and were identified by 1D and 2D NMR. One of them, 5,6,7,3',4'-pentahydroxy flavanone-7-O-glucuronide (2) is a new compound.
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ABSTRACT: The objective of the current research work was to evaluate the neuroprotective effect of the ethanol extract of Scutellaria baicalensis (S.B.) on the excitotoxic neuronal cell death in primary rat cortical cell cultures. The inhibitory effects of the extract were qualitatively and quantitatively estimated by phase-contrast microscopy and lactate dehydrogenase (LDH) assays. The extract exhibited a potent and dose-dependent inhibition of the glutamate-induced excitotoxicity in the culture media. Further, using radioligand binding assays, it was observed that the inhibitory effect of the extract was more potent and selective for the N-methyl-D-aspartate (NMDA) receptor-mediated toxicity. The S.B. ethanol extract competed with [(3)H] MDL 105,519 for the specific binding to the NMDA receptor glycine site with 50% inhibition occurring at 35.1 μ g/mL. Further, NMDA receptor inactivation by the S.B. ethanol extract was concluded from the decreasing binding capability of [(3)H]MK-801 in the presence of the extract. Thus, S.B. extract exhibited neuroprotection against excitotoxic cell death, and this neuroprotection was mediated through the inhibition of NMDA receptor function by interacting with the glycine binding site of the NMDA receptor. Phytochemical analysis of the bioactive extract revealed the presence of six phytochemical constituents including baicalein, baicalin, wogonin, wogonoside, scutellarin, and Oroxylin A.TheScientificWorldJournal. 01/2014; 2014:459549.
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ABSTRACT: The chromatographic fractionation of the Mauritia flexuosa L. f., Arecaceae, leaves extract, a plant known by the name of buriti palm tree, resulted in the isolation of six flavonoids: tricin-7-O-rutinoside, apigenin-6-C-arabinoside, 8-C-glucoside (isoschaftoside), kaempferol-3-O-rutinoside (nicotiï¬orine), quercetin-3-O-rutinoside (rutin), luteolin-8-C-glucoside (orientin) and luteolin-6-C-glucoside (isoorientin). The flavonoids were found out and previously reported as constituents of the Arecaceae family plants, but the occurrence of C-glucoside flavonoids, in the species being analyzed, is described for the first time on this study. The structural elucidations of all of the isolated compounds were performed by means of the comparison of their spectral data (1H and 13C NMR, UV and ESI-MS) with those ones of the literature.Revista Brasileira de Farmacognosia 08/2013; 23(4):614-620. · 0.80 Impact Factor
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ABSTRACT: The diversified genus Passiflora is well distributed all over Brazil, and many species have been long used as medicinal plants, mainly against anxiety disturbances. This effect has been attributed to its rich flavonoid composition. Flavonoids main class, flavonoid glycosides, has presented central action, particularly as sedative-hypnotic, anxiolytic and analgesic. The objective of the present study was to make a phytochemical screening of five little studied Passiflora species, in order to evaluate their phenolic composition. For this aim, HPLC-DAD-ESI-MS/MS was used. After the preparation of the hydroalcoholic extracts, each species was evaluated by direct injection electrospray ionization (ESI) and tandem mass spectrometry. Although belonging to the same genus, the composition of each species presented particularities; this justifies the importance of studies aiming for the phenolic composition of different Passiflora species. Flavones C-glycosides were detected in all extracts, and are found as the main constituents in P. vitifolia, P. coccinea, P. bahiensis and P. sidifolia. In this last one, flavone-6,8-di-C-glycoside, apigenin-6-C-rhamnosyl-8-C-arabinoside are present in high content. Cyclopassiflosides were found in high content together with cyanogenic glycosides in P. quadrangularis, while in P. coccinea, besides flavones-C-glycosides were also found procyanidins.Revista Brasileira de Farmacognosia 12/2012; 22(6):1219-1232. · 0.80 Impact Factor