Aim To 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. Methods The 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 C_ 18 column (250 mm×4.6 mm ID, 5 μm). 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 ℃. Results The 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. Conclusion It was proposed that the metabolite of stilbene glucoside injected in vein was its glucuronide conjugate.
