ABSTRACT: Magnoflorine, an important aporphine alkaloid in Coptidis Rhizoma, is increasingly attracting research attention because of its pharmacological activities. The in vivo and in vitro metabolism of magnoflorine was investigated by LC LTQ-Orbitrap MS. In vivo samples including rat urine, feces, plasma and bile were collected separately after both oral (50mgkg1) and intravenous administration (10mgkg1) of magnoflorine, along with in vitro samples prepared by incubatingmagnoflorine with rat intestinal flora and liver microsome. As a result, 12 metabolites were found in biological samples.Phase I metabolites were identified in all biological samples, while phase II metabolites were mainly detected in urine, plasmaand bile. In a pharmacokinetic study, rats were not only dosed with magnoflorine via oral (15, 30 and 60mgkg1) and intra-
venous administration (10mgkg1) but also dosed with Coptidis Rhizoma decoction (equivalent to 30mgkg1 ofmagnoflorine) by intragastric administration to investigate the interaction of magnoflorine with the rest of compounds in Coptidis Rhizoma. Studies showed that magnoflorine possessed lower bioavailability and faster absorption and elimination.However, pharmacokinetic parameters altered significantly (p