Simultaneous determination of skimmin, apiosylskimmin, 7-hydroxycoumarin and 7-hydroxycoumarin glucuronide in rat plasma by liquid chromatography-Orbitrap mass spectrometry and its application to pharmacokinetics.

Abstract

The effective fraction of coumarin glycosides from Hydrangea paniculata Sieb (HP) has been under development for the treatment of chronic kidney disease for years. Skimmin and apiosylskimmin are the main coumarin glycosides of HP, and the major metabolites in rats are 7-hydroxycoumarin (7-HC) and 7-hydroxycoumarin glucuronide (7-HCG). In this study, a sensitive and reliable liquid chromatography-Orbitrap mass spectrometry method was developed for the simultaneous determination of skimmin, apiosylskimmin, 7-HC and 7-HCG in rat plasma. The chromatographic separation was performed on a Zobax SB C18 column (2.1 × 100 mm, 3.5μm) at a flow rate of 0.3ml/min with a gradient mobile phase of water and acetonitrile containing 0.2% formic acid. Skimmin, apiosylskimmin and 7-HCG were detected in targeted-selected-ion-monitoring mode at positive ions m/z of 325.0911, 457.1331 and 339.0703, respectively. 7-HC and the internal standard were detected in parallel-reaction-monitoring mode at m/z 163.0387 → 119.0492 and 260.1641 → 116.1071 to overcome the carryover of 7-HC. Linearity was obtained for the analytes within the ranges 20-2,000 ng/ml for skimmin, 5-500 ng/ml for apiosylskimmin and 7-HC and 100-10,000 ng/ml for 7-HCG. Validation parameters were all in line with the criteria of international guidance. The method has been applied to the pharmacokinetic study of HP in rats.