In vitro biotransformation of dehydrotumulosic acid in rat liver microsomes

Objective: To study the in vitro biotransformation of dehydrotumulosic acid,one of main chemical constituents in the sclerotium of Poria cocos(Schw.) Wolf(a traditional Chinese medicine),in phenobarbital-induced rat liver microsomes.Methods: The constitution of the incubation system was optimized.After dehydrotumulosic acid was incubated with drug-metabolized enzymes prepared from the phenobarbital-induced rat liver microsomes at 37 ℃,high-performance liquid chromatography was applied to analyze and prepare original dehydrotumulosic acid and its biotransformated products.The chemical structures were identified by NMR and MS techniques,and compared with their purified compounds.Results: Dehydrotumulosic acid was transformed by drug-metabolized enzymes in rat liver microsomes to tumulosic acid and dehydropachymic acid.Conclusion: Dehydrotumulosic acid can be transformed by drug-metabolized enzymes in rat liver microsomes to tumulosic acid and dehydropachymic acid.