Simultaneous Determination of Five Compounds of Clinopodium chinense in Rat Plasma by LC-MS/MS and its Application to a Pharmacokinetic Study

Clinopodium chinense (Benth.) O. Kuntze, was a traditional folk herbal medicine for a variety of causes of gynecologic bleeding. In this research, we developed a simple, rapid and stable LC-MS/MS analytic method to simultaneously determinate hesperidin, naringenin, apigenin, sakosaponin a and buddlejasaponin IVb in the plasma of rat after intragastric administration of the extract of C. chinense. We used the method of methanol precipitation to remove protein in the plasma sample. Chromatographic separation was practiced using a C18 column (Agilent, 2.1 x 100 mm, 1.7 mu m) and a gradient elution with 0.1% formic acid water and methanol. The total time of LC-MS/MS analysis was 15 min. The relative standard deviation (RSD) of intra-day and inter-day precision for quality control samples was less than 13.36%, and the relative error of accuracy ranged from 93.74 to 108.48%. The lower limits of quantification (LLOQ) were 4.7, 1, 1.85, 10.5, and 5.3 ng/mL for hesperidin, naringenin, apigenin, sakosaponin a, and buddlejasaponin IVb, respectively. This method was successfully utilized to a pharmacokinetic study of the multicomponents after intragastric administration of the extract of C. chinense.