Four new eudesmane-type sesquiterpenoid lactones from atractylenolide II by biotransformation of rat hepatic microsomes

Abstract The biotransformation of atractylenolide II, a major bioactive principle of the rhizomes of Atractylodes macrocephala Koidz., was investigated in vitro by incubation with rat hepatic microsomes pretreated with sodium phenobarbital. The biotransformation products were extracted and purified by chromatographic methods. Seven biotransformation products (BP1–BP7) were obtained and their structures were elucidated by NMR and MS data analyses and by comparison with the previously reported values, including four new compounds, namely 4(R),15-epoxy-atractylenolide II (BP1), 4(R),15-epoxy-13-hydroxyatractylenolide II (BP5), 4(R),15-epoxy-1β-hydroxyatractylenolide II (BP6), and 4(R),15-dihydroxyatractylenolide II (BP7). The biotransformation pathway of atractylenolide II by hepatic microsomes was deducted based on the structure resolution of the products. Keywords: Atractylodes macrocephala atractylenolide IIrat hepatic microsomesbiotransformation Acknowledgements This research was partly supported by the National Key Technology R&D Program of China (2011BAI07B08) and the Program of Improving the Standard of Pharmacopoeia of the People's Republic of China (2015).