Metabolic fate of desomorphine elucidated using rat urine, pooled human liver preparations, and human hepatocyte cultures as well as its detectability using standard urine screening approaches

Abstract

Desomorphine is an opioid misused as "crocodile", a cheaper alternative to heroin. It is a crude synthesis product homemade from codeine with toxic byproducts. The aim of the present work was to investigate the metabolic fate of desomorphine in vivo using rat urine and in vitro using pooled human liver microsomes and cytosol as well as human liver cell lines (HepG2 and HepaRG) by Orbitrap-based liquid chromatography-high resolution-tandem mass spectrometry or hydrophilic interaction liquid chromatography. According to the identified metabolites, the following metabolic steps could be proposed: N-demethylation, hydroxylation at various positions, N-oxidation, glucuronidation, and sulfation. The cytochrome P450 (CYP) initial activity screening revealed CYP3A4 to be the only CYP involved in all phase I steps. UDP-glucuronyltransferase (UGT) initial activity screening showed that UGT1A1, UGT1A8, UGT1A9, UGT1A10, UGT2B4, UGT2B7, UGT2B15, and UGT2B17 formed desomorphine glucuronide. Among the tested in vitro models, HepaRG cells were identified to be the most suitable tool for prediction of human hepatic phase I and II metabolism of drugs of abuse. Finally, desomorphine (crocodile) consumption should be detectable by all standard urine screening approaches mainly via the parent compound and/or its glucuronide assuming similar kinetics in rats and humans.

Trace-Level Screening of Chemicals Related to Clandestine Desomorphine Production with Ambient Sampling, Portable Mass Spectrometry

“…It can be seen that both ionization methods result in a single parent ion [desomorphine + H] + at / 272 (Figures 1(a) and 1(c)), as well as characteristic fragments at / 215 and / 197, corresponding to proposed losses of C 3 H 7 N and C 3 H 7 NH 2 O (as seen in Figures 1(b) and 1(d)). Similar fragmentation pathways have been recently reported using high-resolution LC-MS/MS [12], and high-resolution MS (HR-MS) studies performed in house returned high mass accuracy (≤2.66 ppm) for the proposed assignments; HR-MS data obtained and associated error can be seen in the Supplementary Material (in Supplementary Material available online at https://doi.org/10.1155/2017/8571928). Representative DESI-MS and PSI-MS data for the desomorphine precursor, codeine, can be seen in Figure 2.…”

“…Drug monitoring agencies like the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) rely on analytical methods capable of screening and identifying forensic evidence relevant to "Krokodil" synthesis and distribution [9]. Current analytical methods typically involve the use of gas chromatography/mass spectrometry (GC/MS) or liquid chromatography/mass spectrometry (LC/MS) [10][11][12][13]. While being well-established analytical techniques, both are known to require extensive sample preparation and lengthy separation/analysis times and are primarily restricted to laboratory-based applications.…”

High-resolution mass spectrometry in toxicology: current status and future perspectives

“…For in vitro studies of DoA, various human liver preparations have been applied (Peters and Meyer 2011), such as microsomes and cytosol (Wink et al 2015b;Richter et al 2016), S9 fractions (Meyer et al 2014f), primary hepatocytes (Castaneto et al 2015), cell cultures (Richter et al 2016), or heterologously expressed single phase I and II enzymes, for example, in yeast (Peters et al 2009;Zollner et al 2010) or insects cells for enzyme kinetics (Meyer et al 2014b, d, e;Wink et al 2015a). Other in vitro models included microbiological transformation of NPS in wastewater (Mardal and Meyer 2014).…”

“…HRMS was applied not only for metabolite identification, but also for quantification of the substrates and/or products in enzyme kinetic studies if very low concentration had to be determined, for example, in cytochrome P450 (CYP) initial activity screenings (Meyer et al 2013c(Meyer et al , 2014dRichter et al 2016;Wink et al 2016), for kinetics of CYPs (Meyer et al 2013aWink et al 2015a), N-acetyl transferases (NAT) (Meyer et al 2014b, e), or esterases (Meyer et al 2014f), or in testing for CYP inhibition by DoA (Dinger et al 2014a, b, 2016a. Cece-Esencan et al…”

Highlight report: high-resolution mass spectrometry

“…• Elucidation of metabolite structures in drug metabolism studies (Meyer and Maurer 2012;Castaneto et al 2015) • Studies of pharmacokinetics (Richter et al 2016;Wink et al 2016) • Screening for pharmaceuticals, drugs of abuse and toxins, making use of the flexibility of HRMS to add further compounds easily to existing screening approaches (Peters 2014;Patteet et al 2015) • Quantification of pharmaceuticals, drugs of abuse and toxins, where a reliable quantification is required for clinical decisions or forensic consequences (Maurer 2007). Here, LC-HRMS/MS has become the most applied technique for multi-target quantification (Meyer et al 2014;Meyer and Maurer 2016 …”