Abstract
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?[RIGHTWARDS ARROW]?95.1 for shionone, m/z 411.4?[RIGHTWARDS ARROW]?205.2 for epi-friedelinol and m/z 395.3?[RIGHTWARDS ARROW]?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. Copyright ? 2015 John Wiley & Sons, Ltd.
Epi-friedelinol (purity >98.0%, Fig. 1) and spinasterol (purity >98.0%) used as internal standard (IS) were purchased from Chengdu Herbpurify Co. Ltd. (Chengdu, China). ...
