A novel UPLC/MS/MS method for rapid determination of murrayone in rat plasma and its pharmacokinetics

Murraya paniculata (L.) is a traditional Chinese medicine (TCM) wildly grown in southeast China, and used for abortion in folk. Murrayone, a coumarin-containing compound extracted from M. paniculata, is the most bioactive substance in this species and is being developed as a novel cancer metastasis chemopreventive agent based on its unique pharmacological properties. In the present study, a novel rapid and sensitive method for quantitative analysis of murrayone in rat plasma and for determining its pharmacokinetics in rats was developed and validated using UPLC/MS/MS. Plasma samples were subjected to protein precipitation and then directly analyzed by UPLC/MS/MS. Both murrayone and coumarin as an internal standard (I.S.) were carried on a C₁₈ column with a gradient mobile phase consisting of acetonitrile and water at a flow rate of 0.3 mL/min. Several gradient elution procedures were evaluated to achieve effective chromatography resolution and a sensitive response to murrayone and the I.S.. Mass spectrometry was carried out using a triple-quadrupole system via positive electrospray ionization and multiple reaction monitoring (MRM). Good linearity (r ² = 0.9987) was achieved over a linear range of 4.0-1600 ng/mL with a lower limit of quantitation (LLOQ) of 4.0 ng/mL for murrayone. The inter- and intraday accuracy and precision ranged from 90.0 to 99.7% and 1.1 to 12.3% at four quality control concentrations, respectively. The average absolute recoveries of murrayone and the I.S. were determined to be 85.9-92.4% and 86.5-90.7%, respectively, at 10.0, 80.0, and 800 ng/mL. Murrayone was stable under a variety of storage and processing conditions that may be routinely encountered in laboratories based on all the stability tests. This newly developed method was successfully applied to the pharmacokinetic study of murrayone in rats for the first time, and the current assay methodology could provide important insights into potential therapeutics and facilitate further pharmacodynamic explorations of murrayone.