Simultaneous determination of shanzhiside methyl ester, 8-O-acetylshan- zhiside methyl ester and luteolin-7-O-β-D-glucopyranoside in rat plasma by ultra performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study after oral administration of Lamiophlomis rotata Pill.

A rapid, sensitive and specific ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantification of shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester and luteolin-7-O-β-D-glucopyranoside of Lamiophlomis rotata Pill in rat plasma was developed and validated. After liquid-liquid extraction with n-butyl alcohol/ethyl acetate (70:30, v/v), analytes and paeoniflorin (internal standard, IS) were separated on an Acquity BEH UPLC C18 column (100 × 2.1 mm, 1.7 μm) with gradient elution at a flow rate of 0.2 mL/min. All calibration curves had good linearity (r>0.9929) over the concentration ranges of 1-1000 ng/mL for shanzhiside methyl ester and 8-O-acetylshanzhiside methyl ester, 0.3-150 ng/mL for luteolin-7-O-β-D-glucopyranoside. The intra- and inter-day precisions were all within 11.1% and the accuracy (relative error, RE%) all ranged from -13.6% to 5.3%. The method also guaranteed an acceptable selectivity, recovery and stability, which was successfully applied to a pharmacokinetic study of the three analytes in rats after oral administration of Lamiophlomis rotata Pill.