Development and validation of an LC/MS/MS method for simultaneous determination of shionone and epi-friedelinol in rat plasma for pharmacokinetic study after oral administration of Aster tataricus extract.

A rapid and sensitive liquid chromatography tandem mass spectrometry (LC/MS/MS) method was developed and validated using spinasterol as the internal standard (IS) for the simultaneous determination of shionone and epi-friedelinol in rat plasma. Plasma samples were pretreated using liquid-liquid extraction with ethyl ether. Chromatographic separation was achieved on a C18 column (100 × 2.1 mm, 5 μm) with an isocratic elution consisting of acetonitrile-0.1% formic acid water (75:25, v/v) at a flow rate of 0.30 mL/min. Detection was performed under the selected reaction monitoring scan using an electrospray ionization in the positive ion mode. The mass transitions were as follows: m/z 427.4 → 95.1 for shionone, m/z 411.4 → 205.2 for epi-friedelinol and m/z 395.3 → 105.2 for IS. All calibration curves exhibited good linearity (r > 0.995) over the concentration range for both components. The intra- and inter-day precisions at three QC and lower limit of quantitation levels were both <10.21% in terms of relative standard deviation, and the accuracy ranged from -7.13 to 8.02% in terms of relative error. The extraction recoveries of the compounds ranged from 82.07 to 89.81%. The developed method was successfully applied to the pharmacokinetic study of shionone and epi-friedelinol after oral administration of Aster tataricus extract to rats.