Identification of metabolites of gardenin A in rat liver microsomes using ultra-high performance liquid chromatography coupled with linear ion-trap Orbitrap mass spectrometry.

Purpose: To identify the metabolites of gardenin A (GA) in rat liver microsomes (RLMs) using ultra-high performance liquid chromatography coupled with linear ion-trap Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap). Methods: The sample was prepared by incubating GA (100 μg/mL) with RLMs (0.5 mg/mL) for 8 h. Then 5 μL of the sample was injected into UHPLC-LTQ-orbitrap mass spectrometer. The metabolites of GA were tentatively identified based on accurate mass measurements, fragmentation patterns, chromatographic retention times, and bibliography data. Results: A total of 12 metabolites were detected and identified. Based on their structures, the main reactions in the metabolism of GA are de-methoxylation and de-methylation. Conclusion: This is the first report on in vitro metabolites of GA. These results are considered very helpful for better comprehension of the metabolism of GA and its pharmacological effects. [ABSTRACT FROM AUTHOR]