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.
[Show abstract][Hide abstract] 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. DOI:10.1590/S0102-695X2012005000108 · 0.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gegen-Qinlian-Wan (GQW) is a popular traditional Chinese patent medicine for the treatment of diarrhea. It is composed of four herbal medicines, Puerariae Radix, Scutellariae Radix, Coptidis Rhizoma, and Glycyrrhizae Radix. In this study, a rapid and sensitive method based on ultra high-performance liquid chromatography coupled with diode-array detection and quadrupole time-of-flight mass spectrometry (UHPLC-DAD-qTOF-MS) was established to characterize the chemical constituents and rats metabolites of GQW. Samples were separated on an Agilent Zorbax Eclipse Plus-C(18) column (100mm×2.1mm, 1.8μm) by gradient elution using acetonitrile and water containing 0.1% formic acid as the mobile phase. On the basis of UV and qTOF high-accuracy mass spectral analysis, a total of 62 compounds were identified or tentatively characterized from GQW, including 42 flavonoids, 8 alkaloids, 6 triterpenoids, 3 phenylethanoid glycosides, and 3 other types. Among them, 27 compounds were confirmed by comparing with reference standards. Furthermore, metabolites in rats plasma and urine after oral administration of GQW were also analyzed. A total of 42 compounds were identified, including 29 prototypes and 13 metabolites through metabolic pathways of demethylation, methylation, hydrolysis, sulfate conjugation, and glucuronide conjugation. Glucuronidated flavonoids were the main constituents in the plasma, and were then transformed into aglycones and excreted from urine. This is the first systematic study on the chemical constituents and metabolic profiling of GQW.
Journal of pharmaceutical and biomedical analysis 01/2013; 72:99-108. DOI:10.1016/j.jpba.2012.09.015 · 2.98 Impact Factor
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