Identification of lusianthridin metabolites in rat liver microsomes by liquid chromatography combined with electrospray ionization time-of-flight mass spectrometry.

Lusianthridin, a bioactive component isolated from Dendrobium venustum, has been demonstrated to have many biological properties such as antioxidant and anticancer activities. However, the metabolic profiles remain unknown. This study was carried out to investigate the metabolic profiles of lusianthridin in liver microsomes. Lusianthridin was co-incubated with liver microsomes in the presence of nicotinamide adenine dinucleotide phosphate and UDP-glucuronic acid or glutathione at 37°C for 1 h. The incubation samples were analyzed by liquid chromatography combined with electrospray ionization high-resolution mass spectrometry. The data were acquired and processed. The structures of the metabolites were proposed by comparing their accurate mass and MS spectra with those of the parent compound. A total of 15 metabolites were detected in vitro, including two phase I and 13 phase II metabolites. The phase I metabolic pathways were oxidation, demethylation and dehydrogenation. The phase II metabolic pathways referred to glucuronidation and glutathione conjugation. The present study provides an overview pertaining to the metabolic profiles of lusianthridin in vitro, which is indispensable for understanding the efficacy and safety of lusianthridin, as well as the herbal medicine D. venustum.