Rapid identification of MDMB-CHMINACA metabolites using Zebrafish and Human Liver microsomes as the Biotransformation system by LC-QE-HF-MS

MDMB-CHMINACA is a newly synthetic cannabinoid which scoped in NMS Lab, USA. Since there are currently no published data on MDMB-CHMINACA metabolism, we aimed to identify its biotransformation pathways and major metabolites. Liquid chromatography Q-Extractive HF Hybrid Quadrupole-Orbitrap mass spectrometry (LC-QE-HF-MS) using full scan positive ion mode and targeted MS/MS (ddms2) techniques with accurate mass measurement were employed to analyze the metabolic sites and pathways. An in vivo metabolic animal model of zebrafish was established to verify the metabolic pathways of MDMB-CHMINACA obtained from human liver microsomal experiment in vitro. The results showed that 29 metabolites were generated in the zebrafish animal model and human liver microsomes model. Biotransformations mainly occurred at the cyclohexylmethyl tail of the compound, minor reactions also occurred at the tert-butyl chain, and no reaction was analysised at the indazole ring. We recommend M1 group (MDMB-CHMINACA ester hydroxylation), and M2 group (MDMB-CHMINACA monohydroxylation) as the potential poisoning markers to document MDMB-CHMINACA intake in clinical and forensic cases. Additionally, this study provides preliminary information regarding the metabolism of MDMB-CHMINACA that will guide analytical standard manufacturers to better provide suitable references for further studies on newly encountered designer drugs.