Screening and Identification of the Main Metabolites of Schisantherin a In Vivo and In Vitro by Using UHPLC-Q-TOF-MS/MS

Schisantherin A is an active ingredient originating from Schisandra chinensis (Turcz.) which has hepatoprotective and anti-oxidation activities. In this study, in vitro metabolisms investigated on rat liver microsomes (RLMs) and in vivo metabolisms explored on male Sprague Dawley rats of Schisantherin A were tested, respectively. The metabolites of Schisantherin A were identified using ultra-high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). Based on the method, 60 metabolites were successfully identified and structurally characterized including 48 phase-I and 12 phase-II metabolites. Among the metabolites, 45 metabolites were reported for the first time. Moreover, 56 and eight metabolites were detected in urine and bile and 19 metabolites were identified in rats’ plasma. It demonstrated that hepatic and extra-hepatic metabolic pathways were both involved in Schisantherin A biotransformation in rats. Five in vitro metabolites were structurally characterized for the first time. The results indicated that the metabolic pathways mainly include oxidation, reduction, methylation, and conjugation with glucuronide, taurine, glucose, and glutathione groups. This study provides a practical strategy for rapidly screening and identifying metabolites, and the results provide basic data for future pharmacological and toxicology studies of Schisantherin A and other lignin ingredients.