Simultaneous determination of five bioactive secolignans in rat plasma by LC–MS/MS for pharmacokinetic studies following oral administration of Peperomia dindygulensis Miq. extract

A rapid and sensitive ultra fast performance liquid chromatography–tandem mass spectrometry method was developed for the simultaneous determination of five bioactive secolignans in Peperomia dindygulensis extract, including peperomin A, peperomin B, peperomin C, 4″-hydroxypeperomin B and 4″-hydroxypeperomin C in rat plasma. Arctigenin was used as the internal standard. The separation was performed on an Innovation™ Polar-RP C18 column by a gradient elution within a runtime of 7 min. The mobile phase consisted of A (methanol) and B (0.1% formic acid in water) at a flow rate of 0.4 mL/min. The detection was accomplished by using positive ion TurboIonSpray ionization in multiple reaction monitoring mode. The method was linear for all analytes over investigated range with all correlation coefficients greater than 0.9972. The lower limits of quantification were 1.1 ng/mL for peperomin A, 1.24 ng/mL for peperomin B, 1.02 ng/mL for peperomin C, 1.91 ng/mL for 4″-hydroxypeperomin B and 1.27 ng/mL for 4″-hydroxypeperomin C. The intra- and inter-day precision (RSD%) was within 15% and the accuracy (RE%) ranged from −11.7% to 10.3%. This simple and sensitive method was fully validated and successfully applied to the pharmacokinetic study of peperomin A, peperomin B, peperomin C, 4″-hydroxypeperomin B and 4″-hydroxypeperomin C in rat plasma after oral administration of P. dindygulensis extract.