Metabolic profiling of deschloro-N-ethyl-ketamine and identification of new target metabolites in urine and hair using human liver microsomes and high-resolution accurate mass spectrometry.
Islam Amine Larabi, Fanny Zerizer, Alice Ameline, Isabelle Etting, Delphine Joseph, Pascal Kintz, Jean Claude Alvarez
Drug testing and analysis June 1, 2021 DOI: 10.1002/dta.3007 via PubMed
Summary
AI-generated from the abstractA new ketamine analogue, deschloro-N-ethyl-ketamine (O-PCE), involved in severe intoxications and deaths, was metabolically profiled for the first time. After incubating O-PCE with human liver microsomes and analyzing urine and hair from a 43-year-old male user using high-resolution mass spectrometry, 15 metabolites were identified. Nine metabolites detected in urine extended the detection window after O-PCE itself was no longer present. The five most abundant urinary markers were 2-en-PCA-N-Glu (34%), M3 (16%), O-PCA-N-Glu (15.4%), OH-O-PCE (15%), and OH-PCE (11.9%). In hair, nine metabolites appeared; OH-PCA dominated (78%) with a metabolite-to-parent-drug ratio of 6, making it the best marker for long-term monitoring of O-PCE exposure.
Study at a glance
| Characteristics | In vitro and in vivo metabolic profiling study Peer reviewed |
|---|---|
| Sample size | 1 |
| Population | 43-year-old male O-PCE user |
| Keywords | Deschloro-n-ethyl-ketamine Hair High-resolution mass spectrometry Human liver microsomes New psychoactive substances |
| Citations | 23 |
| Key finding | Fifteen O-PCE metabolites were identified, with nine in urine extending the detection window and OH-PCA in hair (78% abundance, ratio 6) serving as the best long-term exposure marker. |
Abstract
The aim of this study was to identify new markers of deschloro-N-ethyl-ketamine (O-PCE), a ketamine analogue that has been involved in acute intoxications with severe outcomes including death and whose metabolism has never been studied before. In vitro study after 2-h incubation with pooled human liver microsomes (HLMs) cross-checked by the analysis of urine and hair from a 43-year-old O-PCE user (male) were performed by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Acquired data were processed by the Compound Discoverer® software, and a full metabolic profile of O-PCE was proposed. In total, 15 metabolites were identified, 10 were detected in vitro (HLMs) and confirmed in vivo (urine and/or hair), two were present only in HLMs, and the remaining three metabolites were identified only in biological specimens. While O-PCE was no longer detected in urine, nine metabolites were identified allowing to increase its detection window. In descending order of metabolites abundance, we suggest using 2-en-PCA-N-Glu (34%, first), M3 (16%, second), O-PCA-N-Glu (15.4%, third), OH-O-PCE (15%, fourth) and OH-PCE (11.9%, fifth) as target metabolites to increase the detection window of O-PCE in urine. In hair, nine metabolites were identified. OH-PCA was the major compound (78%) with a relevant metabolite to parent drug ratio (=6) showing its good integration into hair and making it the best marker for long-term monitoring of O-PCE exposure.