Degradation kinetics of jujuboside b by rat intestinal flora in vitro with an RRLC-MS-MS method.

Jujuboside B (JuB) is a main bioactive saponin constituent of Ziziphi Spinosae Semen, which is a traditional herb for the treatment of insomnia and anxiety. However, the detailed metabolic mechanism of JuB is poorly understood. In this study, a novel method of rapid resolution liquid chromatography-triple quadrupole mass spectrometry was developed and validated for the analysis of JuB. With the method, the degradation kinetics of JuB by rat intestinal flora in vitro was investigated. The analysis was performed with an Agilent Eclipse Plus C18 (2.1 mm × 50 mm, 1.8 μm) column and an aqueous mobile phase (containing 0.1% formic acid) modified by methanol. The analyte was measured by multiple reaction-monitoring (MRM) modes with m/z 1043.3 → m/z 749.2. This method was validated with perfect accuracy, precision and limit of quantitation. It showed that jujuboside B (JuB) degradation started slowly as incubation with rat feces. The rate constant was correlated greatly with the concentration of sample solutions. Furthermore, some metabolites were elucidated with their chromatographic behavior and typical fragment ions. The results might help better interpret the metabolic and pharmacological mechanism of JuB.