Determination of vitexin-2″-O-rhamnoside in rat plasma by ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry and its application to pharmacokinetic study

A rapid, sensitive and selective ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed for the determination and pharmacokinetic study of vitexin-2″-O-rhamnoside (VOR) in rat plasma. The method involved a simple protein precipitation with methanol. The separation was performed on an ACQUITY UPLC™ BEH C18 column (50 mm × 2.1 mm, i.d., 1.7 μm) with gradient elution using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.25 mL min−1. Electrospray ionization (ESI) in positive ion mode and multiple reaction monitoring (MRM) was used for the quantification of VOR with a monitored transitions m/z 579 → 433 for VOR and m/z 611 → 303 for internal standard (I.S., hesperidin). Linear calibration curves were obtained over the concentration range of 10–2500 ng mL−1 with lower limit of quantification (LLOQ) of 10 ng mL−1. The intra- and inter-day precisions (R.S.D. %) were less than 11% and 2.4%, and accuracy (RE %) between −9.3% and 1.0% (n = 5). The average extraction recovery of VOR was 97.2 ± 2.6%. The developed method was applied for the first time to the pharmacokinetic study of VOR in rats following a single oral dose.