Toxicokinetic studies of the four new psychoactive substances 4-chloroethcathinone, N-ethylnorpentylone, N-ethylhexedrone, and 4-fluoro-alpha-pyrrolidinohexiophenone

Abstract

The presented study aimed to elucidate the toxicokinetics of the four synthetic cathinones 4chloroethcathinone (4-CEC), N-ethylnorpentylone (N-ethylpentylone, ephylone), N-ethylhexedrone (NEH), and 4-fluoro-alpha-pyrrolidinohexiophenone (4-fluoro-alpha-pyrrolidinohexanophenone, 4-F-PHP, 4F-alpha-PHP, 4F-PHP). Methods First, their metabolism was studied using human urine and blood samples. Analysis of specimens was performed by liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS) and gas chromatography-mass spectrometry (GC-MS). LC-HRMS/MS was also used to analyze in vitro incubations of the new psychoactive substances using pooled human liver S9 fraction (pS9), to identify the monooxygenases involved in the initial metabolic steps, and determination of plasma concentrations after standard addition method. Metabolic stability was tested in pooled human liver microsomes incubations analyzed by LC-ion trap MS. Results Using LC-HRMS/MS, in total 47 metabolites were found in patient samples and pS9 incubations. Using GC-MS, 4-CEC, ephylone, NEH, and five of their metabolites were detectable in urine. The following main phase I reactions were observed: carbonyl group reduction, N-deethylation, hydroxylation, lactam formation (4F-PHP), and demethylenation (ephylone). Mainly glucuronidations were observed as phase II reactions besides conjugates with the dicarboxylic acids malonic, succinic, and glutaric acid (4-CEC), sulfation, methylation (both ephylone), and Nacetylation (NEH). A broad range of monooxygenases was involved in the initial steps with exception of NEH (only CYP1A2 and CYP2C19). 4F-PHP had the shortest in vitro half-life (38 min) and highest intrinsic clearance (15.7 mL×min-1 ×kg-1). Plasma concentrations ranged from 0.8 to 8.5 ng/mL. Conclusions Our results are expected to help toxicologists to reliably identify these substances in case of 3 suspected abuse and allow them a thorough risk assessment.

Toxicokinetics and toxicodynamics of the fentanyl homologs cyclopropanoyl-1-benzyl-4´-fluoro-4-anilinopiperidine and furanoyl-1-benzyl-4-anilinopiperidine

“…Metabolic stability was determined by declining substrate concentration (Wagmann et al 2019), plotting the natural logarithm of the absolute peak area ratios of 4F-Cy-BAP or Fu-BAP versus time, respectively. In vitro half-lives were calculated by the slope of the respective linear regression.…”

How to Study the Metabolism of New Psychoactive Substances for the Purpose of Toxicological Screenings—A Follow-Up Study Comparing Pooled Human Liver S9, HepaRG Cells, and Zebrafish Larvae

“…The amphetamine-based NBOMe 3,4-DMA-NBOMe (also known as 3,4-dimethoxyamphetamine-NBOMe and 1-[3,4-dimethoxy]- N -[ ortho -methoxybenzyl]propane-2-amine), the synthetic cathinone ephylone (also known as N -ethylnorpentylone and N -ethylpentylone), the synthetic cannabinoid 4F-MDMB-BINACA (also known as methyl 2-[1-(4-fluorobutyl)-1 H -indazole-3-carbonyl]amino-3,3-dimethylbutanoate and 4-fluoro MDMB-BUTINACA), the pyrrolidinophenone analog 4F-PHP (also known as 4-fluoro-alpha-pyrrolidinohexiophenone, 4-fluoro-alpha-pyrrolidinohexanophenone, 4-F-α-PHP, and 4F-alpha-PHP), and the lysergamide 1P-LSD (1-propionyl- d -lysergic acid diethylamide) were included. The five NPS were already shown to be extensively metabolized and therefore suitable for the current comparative metabolism study (Caspar et al, 2018b ; Haschimi et al, 2019 ; Krotulski et al, 2019 ; Wagmann et al, 2019b , c ). Caspar et al used pHLS9 incubations and rat urine to investigate the metabolism of 3,4-DMA-NBOMe (Caspar et al, 2018b ; Wagmann et al, 2019b , c ).…”

“…The five NPS were already shown to be extensively metabolized and therefore suitable for the current comparative metabolism study (Caspar et al, 2018b ; Haschimi et al, 2019 ; Krotulski et al, 2019 ; Wagmann et al, 2019b , c ). Caspar et al used pHLS9 incubations and rat urine to investigate the metabolism of 3,4-DMA-NBOMe (Caspar et al, 2018b ; Wagmann et al, 2019b , c ). Wagmann et al identified metabolites of ephylone and 4F-PHP in human blood and urine as well as in pHLS9 incubations (Caspar et al, 2018b ; Wagmann et al, 2019b , c ).…”

Phenethylamine‐derived new psychoactive substances 2C‐E‐FLY, 2C‐EF‐FLY, and 2C‐T‐7‐FLY: Investigations on their metabolic fate including isoenzyme activities and their toxicological detectability in urine screenings

“…Toxicological detectability of 2C-E-FLY, 2C-EF-FLY, and 2C-T-7-FLY in rat urine by the GC-MS standard urine screening approach. BW, body weight; +, detected; −, not detected; AC, acetylated , time consuming, and expensive 26. Nevertheless, human biosamples after intake of NPS derived from authentic cases are sometimes available and should then be used for a comparative study summarizing all metabolites detected in vitro and in vivo.…”