Simultaneous determination of six triterpenoid saponins in beagle dog plasma by UPLC-MS/MS and its application to a pharmacokinetic study after oral administration of the extract of the Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves

A rapid and simple ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and validated for simultaneous determination of six analytes from the Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves (ESL) in beagle dog plasma for the first time, including 3-O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside-29-hydroxy oleanolic acid, 3-O-β-d-glucopyranosyl-(1→2)-α-l-arabinopyranoside-29-hydroxy oleanolic acid, 3-O-β-d-glucopyranosyl-(1→2)-α-l-arabinopyranosyl-30-norlean-12,20 (29) –dien-28-olic acid, ciwujianoside E, guaianin N, and eleutheroside K. The chromatographic separation was performed using an ACQUITY UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) using a gradient elution way with a mobile phase of acetonitrile-water containing 0.1% formic acid. Analytes were detected on a triple-quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source with multiple reaction monitoring (MRM) mode. Calibration curves were all linear (r ≥ 0.9933) over the concentration range. The mean extraction recoveries and matrix effect of analytes and I.S. were ranged from 80.26% to 98.32% and from 91.27% to 111.67%, respectively. The intra-day and inter-day precision were ranged from 2.20% to 14.81%, and the accuracy range was 1.60–14.60%. The analytical method was successfully applied for the pharmacokinetic characteristics of the six analytes in beagle plasma after oral administration of ESL extracts. The T 1/2 of six analytes was more than 3.09 ± 0.78 h.