title: SPE-HPLC method for the determination of four flavonols in rat plasma and urine after oral administration of Abelmoschus manihot extract.
abstract: A SPE-HPLC method was developed and validated for the simultaneous determination of flavonols, isoquercitrin (1), hibifolin (2), myricetin (3), quercetin-3'-O-d-glucoside (4) and quercetin (5) in rat plasma and urine after oral administration of the total flavonoids from Abelmoschus manihot (TFA). The astragalin (6) and kaempferol (7) were used as internal standards (IS). Plasma and urine samples were pretreated by solid-phase extraction using Winchem C(18) reversed-phase cartridges. Analysis of the plasma and urinary extract was performed on YMC-Pack ODS-A C(18) and Thermo ODS-2HYEPRSIL C(18) reversed-phase column, respectively and a mobile phase of acetonitrile-0.1% phosphoric acid was employed. HPLC analysis was conducted with different elution gradients. The flow rate was 1.0 mL/min and the detection wavelength was set at 370 nm. Calibration ranges in plasma for flavonols 2-5 were at 0.011-2.220, 0.014-2.856, 0.022-4.320, and 0.028-5.600 microg/mL, respectively. In urine calibration ranges for flavonols 1, 2, 4 and 5 were at 2.00-16.00, 8.56-102.72, 2.70-21.60, and 3.00-24.00 microg/mL, respectively. The RSD of intra- and inter-day was less than 5.40% and 4.89% in plasma, and less than 3.96% and 6.85% in urine for all the analyses. A preliminary experiment to investigate the plasma concentration and urinary excretion of the flavonols after oral administration of TFA to rats demonstrated that the present method was suitable for determining the flavonols in rat plasma and urine.
authors.affiliation: Department of Natural Medicines and the State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Centre, Beijing 100083, PR China.
authors.forename: Xianyin
authors.initials: X
authors.lastname: Lai
authors.forename: Yuying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Liang
authors.forename: Yanjing
authors.initials: Y
authors.lastname: Bai
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Dean
authors.initials: D
authors.lastname: Guo
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D044948:Flavonols / Q000008:administration & dosage / Q000097:blood* / Q000652:urine*; D008297:Male; D019660:Malvaceae / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D044948:Flavonols; D010936:Plant Extracts