AIMTo study the metabolite of stilbene glucoside in the Chinese traditional medicine Polygonum multiflornm in mice and elucidate its chemical structure by liquid chromatography tandem-mass spectrometry.

METHODSThe stilbene glucoside was injected into the tail vein of mice. Blood samples were collected from artery in the eyepit. The methanol-protein-precipitated plasma sample was introduced into the liquid chromatography-tandem mass spectrometer directly. The analytical column was C18 column (250 mm x 4.6 mm ID, 5 microns). The mobile phase consisted of acetonitrile-methanol-water-formic acid (15:18:66:1) for ES+, acetonitrile-methanol-water (15:18:67) for ES-. The UV detection wavelength was set at 320 nm. The mass ion source type was ESI. HV capillary was 3 kV. The dry gas was nitrogen gas and the flow rate was set at 318 L.h-1. The ion source temperature was 150 degrees C.

RESULTSThe stilbene glucoside and its metabolite were separated completely under the chromatography condition. The ions at m/z 600 and m/z 605 were detected under positive ion polarity while the ions at m/z 581 and m/z 402 were detected under negative ion polarity.

CONCLUSIONIt was proposed that the metabolite of stilbene glucoside injected in vein was its glucuronide conjugate.