Validated LC–MS/MS method for quantitation of demethylbellidifolin in rat plasma and its application to pharmacokinetic and bioavailability studies

Abstract

Demethylbellidifolin, a major xanthone compound of Swertia davidi Franch, shows many beneficial pharmacological effects including antioxidation, anti-inflammation, anti-fibrosis and cardiovascular protection effects. In this research, a rapid and sensitive LC-MS/MS method for the quantitative analysis of demethylbellidifolin in rat plasma was developed. The demethylbellidifolin and internal standard of aurantio-obtusin were extracted from 50 μL of rat plasma samples with ethyl acetate, then the dried residue was reconstituted and injected in an HPLC system with Zorbax SB-C analytical column (2.1 × 100 mm, 3.5 μm) and eluted with the mobile phase consisting of methanol and 0.2% formic acid aqueous solution (80:20, v/v). Quantification was performed using a TSQ Quantum Ultra mass spectrometer in negative ESI using selected reaction monitoring mode of the transitions m/z 259.1 → 215.1 for demethylbellidifolin and 329.0 → 314.2 for the IS. Excellent linearity was observed between 1.92 and 960 ng/mL with a limit of quantitation of 1.92 ng/mL. Intra- and inter-day precision (RSD) values of quality control samples were both <8.3%. This study was successfully utilized for the pharmacokinetic profiles of demethylbellidifolin in rats after oral or intravenous administration. The oral bioavailability of demethylbellidifolin was 3.6%.

Pharmacokinetics and tissue distribution study of obtusifolin in rats by liquid chromatography–tandem mass spectrometry

“…Choosing an appropriate IS is the key to bioanalysis. A previous study has demonstrated that aurantio‐obtusin is suitable for use as an internal standard owing to its stability, accessibility throughout the whole analysis procedure, extraction efficiency and consistency with the analyte at the retention time (J. Zhang, Yan, Qu, & Zhou, 2018). In order to apply the analytical method for obtusifolin pharmacokinetics and tissue distribution studies, aurantio‐obtusin was selected as the IS for the assay because of its similar retention time and ionization response with obtusifolin.…”