UHPLC-Q-TOF-MS/MS based screening and identification of the metabolites in vivo after oral administration of betulin

Betulin is an active natural pentacyclic triterpene ingredient with valuable anti-cancer and anti-HIV efficacies. In the present study, an efficient approach was developed to screening and identification of metabolites and to assess the metabolic profiles of betulin in vivo using UHPLC-Q-TOF-MS/MS system based on multiple mass defect filter data acquisition (MMDF) and multiple data processing techniques. Based on the proposed method, 56 phase I and 6 phase II metabolites were detected in rats after oral administration of betulin. The main biotransformation routes of betulin were identified as demethylation, dehydroxylation, deoxidization, dehydration. Conjugation with sulfate, taurine, cysteine and N-acetylcysteine groups produced 6 phase II metabolites. This study not only provided useful information for further study of the pharmacology and mechanism of betulin in vivo, but also provided essential data for further pharmaceutical studies of other pentacyclic triterpenes.