HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH TANDEM MASS SPECTROMETRY APPLIED FOR METABOLIC STUDY OF SPINOSIN BY RAT INTESTINAL FLORA

Abstract

A rapid, sensitive, and selective liquid chromatography–tandem mass spectrometric (HPLC-MS/MS) method was developed and validated for the determination of spinosin, a pharmacologically active constituent isolated from Zizyphi Spinosi Semen (ZSS). This method was used to examine the degradation kinetics of spinosin by rat intestinal flora and to elucidate the structure of its metabolite. The analysis was performed using an aqueous mobile phase (containing 0.1% formic acid) modified by acetonitrile at a flow rate of 0.30 mL/min. Triple quadrupole mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via multiple reaction monitoring (MRM) and single ion monitor (SIM) under negative ionization mode. The result of degradation experiment showed that spinosin can be metabolized in vitro by rat intestinal bacteria and its metabolite was swertisin. This may affect bioavailability of spinosin.

Keywords:

• biotransformation
• degradation kinetics
• HPLC-MS/MS
• rat intestinal flora
• spinosin
• swertisin

ACKNOWLEDGMENT

The authors greatly appreciate the financial support from the National Natural Science Foundation of China (Grant No. 31101235 and No. 31000749).