Comparative pharmacokinetic study of pyranocoumarins and khellactone in normal and acute lung injury rats after oral administration of Peucedanum praeruptorum Dunn extracts using a rapid and sensitive liquid chromatography-tandem mass spectrometry method.

Pyranocoumarins are the main constitutes in Peucedanum praeruptorum Dunn and possess various biological activities. In this article, we developed and validated a rapid and sensitive liquid chromatography-tandem mass spectrometry method for the targeted quantification of the pyranocoumarins, praeruptorin A, praeruptorin B and praeruptorin E, and khellactone, which is a common metabolite of these pyranocoumarins in rat plasma samples. We then performed a comparative pharmacokinetic study of these pyranocoumarins and khellactone in normal and lipopolysaccharide-induced acute lung injury (ALI) in rats following oral administration of P. praeruptorum Dunn extracts. Calibration curves gave desirable linearity (r > 0.99) and the lower limit of quantifications were sufficient for quantitative analysis. The precision and accuracy were assessed by intra-batch and inter-batch assays, and the relative standard deviations were all within 10.23% and the accuracy (relative error) was between -5.52% and 8.68%. The extraction recoveries, matrix effects and stability were also acceptable. The pharmacokinetic study revealed that the area under the concentration-time curve (0-t) of khellactone in ALI rats was significantly decreased compared with the normal rats. Meanwhile, the systemic exposures of these pyranocoumarins were slightly higher in the ALI rats than those in normal rats were. The pharmacokinetic study in the pathological state might provide information that was more comprehensive to guide the clinical usage of P. praeruptorum Dunn.

Simultaneous quantification of three pyranocoumarins of Peucedanum praeruptorum in rat plasma by liquid chromatography-tandem mass spectrometry: application to pharmacokinetic study.

A simple, rapid and robust liquid chromatography-tandem mass spectrometry was established and validated for simultaneous quantifications of three pyranocoumarins (praeruptorin A-C) in rat plasma. Following a single-step liquid-liquid extraction, the analytes were separated on a reversed-phase C18 column with a mobile phase consisting of methanol and 10 mM ammonium acetate solution (70 : 30, v/v) at a constant flow rate of 0.3 mL/min. The linear calibration curves were obtained over the concentration ranges 2.93-1470 ng/mL for praeruptorin A, 1.47-734 ng/mL for praeruptorin B and 2.00-1000 ng/mL for praeruptorin C. The within-batch accuracy was -8.6 to 7.5% for praeruptorin A, -9.5 to 12.0% for praeruptorin B and -10.5 to 12.5% for praeruptorin C, respectively. The between-batch accuracy was -3.5 to 1.4% for praeruptorin A, -8.7 to 3.4% for praeruptorin B and -6.0 to 4.3% for praeruptorin C, respectively. The within-batch and between-batch precisions were ≤13.1 and ≤8.2%, respectively. This method is suitable to simultaneously determine the three pyranocoumarins in plasma and thus to investigate the pharmacokinetics of the pyranocoumarins of Peucedanum praeruptorum in rats.

Determination of 10-chloromethyl-11-demethyl-12-oxo-calanolide A in rat plasma using liquid chromatography-tandem mass spectrometry and its application to pharmacokinetics.

A rapid and specific liquid chromatography-tandem mass spectrometry for the quantitation of 10-chloromethyl-11-demethyl-12-oxo-calanolide A (F18), a small-molecule nonnucleoside reverse transcriptase inhibitor, was developed and validated in rat plasma. F18 was monitored by positive electrospray ionization in the selected reaction monitoring mode. The standard curve was linear over the range of 2-1000 ng/mL. The method was used to determine the plasma concentration of F18 after a single oral dose of 50 mg/kg in rats.