title: Determination of genkwanin in rat plasma by liquid chromatography-tandem mass spectrometry: application to a bioavailability study.
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%.
authors.affiliation: School of Pharmaceutical Sciences, Jilin University, Changchun 130021, PR China.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Song
authors.forename: Sixi
authors.initials: S
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Xiangqun
authors.initials: X
authors.lastname: Jin
mesh_terms: D061605:Administration, Intravenous; D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D056148:Chromatography, Reverse-Phase / Q000379:methods; D047309:Flavones / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D059625:Liquid-Liquid Extraction / Q000379:methods; D008297:Male; D010949:Plasma / Q000737:chemistry*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D047309:Flavones; C014568:genkwanin
keywords: Bioavailability; Genkwanin; LC–MS/MS; Pharmacokinetics; Rat plasma