Simultaneous determination and pharmacokinetics studies of five isoflavones in rat plasma by UHPLC-MS/MS after oral administration of Radix Astragali extract

Abstract

Abstract A rapid, sensitive and convenient method based on ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was developed and validated for the simultaneous quantification of calycosin-7-O-β-d-glucoside (CCSG), ononin, calycosin, (6aR,11aR)-9,10-dimethoxypterocarpan-3-O-β-d-glucopyanoside (DPPG), and 7,2′-dihydroxy-3′,4′-dimethoxyisoflavan-7-O-β-d-glucopyanoside (DIFG) in rat plasma after oral administration of the methanol extraction from Radix Astragali. Theophylline played the role of internal standard (IS). Preparation of plasma samples by liquid-liquid extraction method with ethyl acetate after precipitation of protein with methanol. The analytes were detected with a triple quadrupole tandem mass spectrometery (MS) in multiple reaction monitoring (MRM) mode and a positive ion electrospray ionization (ESI). The method was validated with the concentration ranges of 1.96–62.69 ng/mL for CCSG, 1.70–54.5 ng/mL for ononin, 1.85–59.06 ng/mL for calycosin, 2.14–137.24 ng/mL for DPPG and1.96–125.25 ng/mL for DIFG, respectively. The method had the lower limit of quantification (LLOQ) with 0.49, 0.21, 0.92, 1.07, and 0.98 ng/mL for CCSG, ononin, calycosin, DPPG and DIFG respectively, and the precision less than 10%. The RSD of the accuracy was in the range of −4.35–8.91%. The results may be helpful to provide more accurate references to clinical application of this herb.