Qian T[1,2], Leong PK, Ko KM, Chan W.
 Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong SAR, China
 Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
 Division of Life Science, Hong Kong University of Science & Technology, Hong Kong, China.
Schisandrin B (Sch B) is one of the active dibenzocyclooctadiene lignans found in the Schisandrae Fructus. Experimental studies have shown that Sch B possesses various pharmacological properties, including anti-cancer, neuroprotective and nephroprotective activities. However, no detailed information on its biotransformation was reported in the literature. Here, we investigated the in vitro and in vivo metabolism of Sch B by using ultra-performance liquid chromatography coupled with tandem mass spectrometry. In vitro study detected and identified one oxygenated metabolite. Four metabolites were detected and identified from the in vivo study. The results indicated that the metabolism of Sch B mainly involved the demethylation of methoxy groups, the opening of five-member ring and the glucuronidation of metabolites in rats. The metabolites were identified for the first time by MS/MS analyses.