A monomethoxyflavone that is apigenin in which the hydroxy group at position 7 is methylated.
Identification
5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-4H-chromen-4-one
5,4'-Dihydroxy-7-methoxyflavone
7-methylapigenin
Apigenin 7-methyl ether
Species
Europe PubMed Central results
PREPARATIVE ISOLATION AND PURIFICATION OF FOUR FLAVONOIDS FROM DAPHNE GENKWA SIEB. ET ZUCC. BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY.
Author: Xie H, Liang Y, Ito Y, Wang X, Chen R, He J, Li H, Zhang T.
Abstract: Four flavonoids including luteolin, apigenin, 3'-hydroxygenkwanin and genkwanin were isolated and purified from Daphne genkwa Sieb. et Zucc. by high-speed countercurrent chromatography (HSCCC). Preparative HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (5:7:5:5, v/v) was successfully performed by increasing the flow rate of the mobile phase from 1.2 to 2.0 mL/min after 260 min. In a one-step operation, 150 mg of the extracts of D. genkwa was separated to yield 8 mg of luteolin, 25.8 mg of apigenin, 23.6 mg of 3'-hydroxygenkwanin and 35.3 mg genkwanin with the purities of 91.2, 97.4, 94.3 and 95.8%, respectively, analyzed by HPLC using area normalization method. The chemical structures of the four compounds were identified by HPLC, ESI-MS, and (1)H NMR.
Determination of genkwanin in rat plasma by liquid chromatography-tandem mass spectrometry: application to a bioavailability study.
Author: Song Y, Zhang S, Liu H, Jin X.
Abstract: We developed and validated a sensitive, rapid, and specific liquid chromatography tandem mass spectrometry method to determine genkwanin in rat plasma. Genistein was used as the internal standard. After liquid-liquid extraction with ethyl acetate, the chromatographic separation of genkwanin was achieved by using a reversed-phase HPLC using Agela Venusil MP-C18 analytical column (2.1 mm × 50 mm, 5 μm particles) with a mobile phase of methanol (A)-water (B) (65:35, v/v) containing 5mM ammonium acetate and 0.1% formic acid. The detection was performed by negative ion electrospray ionization in multiple-reaction monitoring mode by using transitions of m/z 283.1→268.1 and m/z 269.1→133.0 for genkwanin and IS, respectively. Good linearity was observed in the concentration range of 3.84 ng/ml to 3,840 ng/ml (r(2)>0.99), and the lower limit of quantification was 3.84 ng/ml in 100 μl of rat plasma. The intra- and inter-day accuracy and precision of genkwanin were both within acceptable limits. This present method was successfully applied to a pharmacokinetic study of genkwanin in rats following oral (50mg/kg) and intravenous (5mg/kg) administration. For the oral administration group, the maximum mean concentration of genkwanin in plasma (Cmax, 36.9 ± 9.4 ng/ml) was achieved at 3.83 ± 1.33 h (Tmax), and the area under the plasma concentration versus time curve from 0 h to 12h (AUC0-12h) was 218 ± 40 ngh/ml. For the intravenous administration group, essential pharmacokinetic parameters such as Cmax (1,755 ± 197 ng/ml) and AUC0-12h (2,349 ± 573 ngh/ml) were shown. The result showed that the compound was poorly absorbed with an absolute bioavailability of approximately 1.1%.
Isolation of anticancer constituents from flos genkwa (Daphne genkwa Sieb.et Zucc.) through bioassay-guided procedures.
Author: Li S, Chou G, Hseu Y, Yang H, Kwan H, Yu Z.
Abstract: <h4>Background</h4>Flos Genkwa (yuanhua in Chinese), the dried flower buds of Daphne genkwa Sieb.et Zucc. (Thymelaeaceae), is a traditional Chinese medicinal herb mainly used for diuretic, antitussive, expectorant, and anticancer effects. However, systematic and comprehensive studies on Flos Genkwa and its bioactivity are limited.<h4>Results</h4>After confirmation of the anti-tumor activity, the 95% ethanolic extract was subjected to successive solvent partitioning to petroleum ether, dichloromethane, n-butanol, and water soluble fractions. Each fraction was tested using the same biological activity model, and the dichloromethane fraction had the highest activity. The dichloromethane fraction was subjected to further chromatographic separation for the isolation of compounds 1-13. Among the 13 compounds, the diterpene esters (compounds 10-13) showed anticancer activity, whereas the flavonoids, lignanoids, and peptides showed moderate activity. Compound 13 was a new daphnane diterpenoid, which was named genkwanin VIII.The preliminary antitumor mechanism of yuanhuacine was studied by protein expression and cell cycle analysis in MCF-7 cancer cells.<h4>Conclusion</h4>The present investigation tends to support the traditional use of Flos Genkwa for treating cancer. Through bioassay-guided fractionation and isolation techniques, the CH2Cl2 fraction was determined as the active fraction of the flower buds of D. genkwa, and the anti-tumor activity was ascribable to the compounds 10-13.