Reactive Metabolite ScreeningIn vitro Metabolism
• GSH, KCN, semicarbazide trapping
• UPLC with Q-TOF-MS or QE-Orbitrap-MS and UV detection
One of the reasons behind unexpected drug induced toxicity are chemically reactive metabolites that bind covalently to protein or DNA. Due to their high reactivity and short life-span, these metabolites cannot be analysed directly as such, but have to be first stabilised by trapping agents, such as S-glutathione (GSH), cyanide (KCN) or semicarbazide (SCA). Of these, GSH is clearly the most used trapping agent, although KCN and SCA may be used for trapping certain types of reactive metabolites that are not trapped by GSH, such as iminium ions or aldehydes. As in any analysis of unknown drug metabolites, the use of liquid chromatography with high-resolution mass spectrometry delivers the highest quality data with the shortest time consumption also in our reactive metabolite screening assay.