Quantitative Determination of Anti-Inflammatory Columbianetin in Rat Plasma by LC-ESI-MS/MS for Pharmacokinetic Studies after Oral Administration of Duhuo Extract

Specific LC-ESI-MS/MS method or procedure was developed and validated for columbianetin quantification in rat plasma using epicatechin as an internal standard (IS). Chromatographic separation was performed on an Eclipse plus C18 (150 x 4.6 mm, 1.8 mu m) at a flow rate of 0.300 mL min(-1), and water-acetonitrile was used as mobile phase. The calibration curve of the method was linear in the concentration range of 5-1,000 ng mL(-1). The lower limit of quantification (LLOQ) was 5 ng mL(-1). The intra-and inter-day precision of the quality control samples was within 15.0%, and the accuracy was within 90.0-110%. The recoveries were more than 90.0% for columbianetin at concentrations of 10, 200 and 1,000 ng mL(-1), respectively. This method was successfully applied for evaluation of the pharmacokinetics of columbianetin after oral doses of 0.60 g kg(-1) Angelica pubescence extract in rats.