Biotransformation of columbianadin by rat hepatic microsomes and inhibition of biotransformation products on NO production in RAW 264.7 cells in vitro

► CBN was metabolized by rats liver microsomes in vitro. ► Thirteen metabolites containing eight new compounds were obtained. ► Four types of biotransformation pathways of CBN were proposed. ► CBN and the main metabolites exhibited satisfactory anti-inflammatory activities.