LC-Q-TOF/MS-based Fragmentation Behavior Study and In vitro Metabolites Identification of Nine Benzodiazepines

Benzodiazepines (BZDs) are compounds that contain one diazepine ring and two benzene rings, and are widely used to treat central nervous system diseases. However, drug abuse and BZDs' illegal addition may affect normal life and even lead to grave social harm. As BZDs may be metabolized and eliminated quickly, it is of great theoretical and practical significance to clarify their metabolic profile.In this paper, LC-Q-TOF/MS-based fragmentation behavior has been investigated for nine benzodiazepine drugs available and widely used in clinical treatment (diazepam, nitrazepam, clonazepam, oxazepam, lorazepam, alprazolam, estazolam, triazolam, and midazolam), and their metabolic profile has been studied by using in vitro human liver microsomal incubation.A regular human liver microsomal system was used to investigate the potential biotransformation of the nine benzodiazepines in vitro, and an LC-Q/TOF-MS was used to perform fragmentation behavior studies and metabolite identification.As a result, characteristic fragmentation pathway and diagnostic fragment ions of the nine BZDs were analyzed, and 19 metabolites of the 9 benzodiazepines were found and identified, with glucuronidation and hydroxylation considered as their most important metabolic pathways.These experimental data add to our knowledge of the nine benzodiazepine drugs and their metabolism study, which could provide useful information and evidence of their in vivo metabolic profile prediction and help promote their monitoring in both clinical use and social/illegal abuse.