Simultaneous Determination of Two Epimeric Furofuran Lignans (Sesamin and Asarinin) of Asarum heterotropoides Extract in Rat Plasma by LC/MS/MS: Application to Pharmacokinetic Study

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometry was developed to determine two epimeric furofuran lignans (sesamin and asarinin) simultaneously from Asarum heterotropoides extract in rat plasma. Simple protein precipitation with acetonitrile was performed to extract analytes by using alantolactone as an internal standard. Chromatographic separation was achieved using a DIKMA Diamonsil C18 analytical column (4.6 mm × 150 mm, i.d., 5 µm) by isocratically eluting with a mobile phase consisting of methanol/5 mM ammonium acetate/formic acid (75:25:0.1, v/v/v) at a flow rate of 0.8 mL/min. Tandem mass spectrometric detection with an electrospray ionization interface was performed by multiple reaction monitoring in positive ionization mode. This method was validated according to specificity, sensitivity, linearity, intra- and inter-day precision (<10.7%) and accuracy (<2.3%) and recovery and stability in a concentration range of 25.0-15 000 ng/mL for sesamin and 5.00-3 000 ng/mL for asarinin. This method has been successfully applied in a pharmacokinetic study of A. heterotropoides extract containing sesamin and asarinin after this extract was orally administrated in rats.