Search

Hexahydrocannabinol (HHC), hexahydrocannabiphorol (HHCP) and their acetates, HHC-O and HHCP-O, respectively, are emerging in Europe as alternatives to tetrahydrocannabinol (THC). This study aimed to elucidate the metabolic pathways of the semi-synthetic cannabinoids HHC, HHCP, HHC-O and HHCP-O from incubation with human hepatocytes. The metabolites of HHC were also identified in authentic urine samples. HHC, HHCP, HHC-O and HHCP-O were incubated with primary human hepatocytes for 1, 3 and 5 h. Authentic urine samples from cases screened positive for cannabis in blood using ELISA but confirmed negative were analysed both non-hydrolysed and hydrolysed for HHC metabolites. Potential metabolites were identified using ultra-high performance liquid chromatography (UHPLC) coupled to a quadrupole time-of-flight mass spectrometer (QToF-MS). HHC and HHCP were primarily metabolised through monohydroxylation (monoOH), followed by oxidation to a carboxylic acid metabolite. HHC-O and HHCP-O were rapidly metabolised to HHC and HHCP, respectively. In authentic urine samples, 18 different metabolites were identified, and 99.3% of hydroxylated metabolites were glucuronidated. 11-OH-HHC, 5 ' OH-HHC and another metabolite with a monoOH on the side chain were the only metabolites present in all 16 urine samples. The metabolism of HHC and HHCP were similar, although the longer alkyl side chain of HHCP (heptyl) led to greater hydroxylation on the side chain than HHC (pentyl). The use of HHC and HHCP can be differentiated from the use of THC and other phytocannabinoids, but the use of the acetate analogues may not be differentiable from their non-acetate analogues. Metabolism of HHC was elucidated in human hepatocytes and urine samples. Metabolites were extensively glucuronidated in non-hydrolysed urine samples. 11-OH-HHC and 5'OH-HHC determined to be most abundant metabolites in urine samples after hydrolysis. image, Funding Agencies|European Commission [E! 113377]; Sweden's Innovation Agency [2019-03566]; Strategic Research Areain Forensic Sciences (Strategiomradetforensiska vetenskaper) at Linkoeping University; Leverhulme Trust [RC-2015-011]

Acetylbenzylfentanyl, benzoylbenzylfentanyl, 3-fluoro-methoxyacetylfentanyl, and 3-phenylpropanoylfentanyl are fentanyl analogs that have been reported to the European Monitoring Centre for Drugs and Drug Addiction in recent years. The aim of this study was to identify metabolic pathways and potential biomarker metabolites of these fentanyl analogs. The compounds were incubated (5 mu M) with cryopreserved hepatocytes for up to 5 h in vitro. Metabolites were analyzed with liquid chromatography-quadrupole time of flight-high-resolution mass spectrometry (LC-QTOF-HRMS). The experiments showed that acetylbenzylfentanyl, benzoylbenzylfentanyl, and 3-phenylpropanoylfentanyl were mainly metabolized through N-dealkylation (forming nor-metabolites) and 3-fluoro-methoxyacetylfentanyl mainly through demethylation. Other observed metabolites were formed by mono-/dihydroxylation, dihydrodiol formation, demethylation, dehydrogenation, amide hydrolysis, and/or glucuronidation. The experiments showed that a large number of metabolites of 3-phenylpropanoylfentanyl were formed. The exact position of hydroxy groups in formed monohydroxy metabolites could not be established solely based upon recorded MSMS spectra of hepatocyte samples. Therefore, potential monohydroxy metabolites of 3-phenylpropanoylfentanyl, with the hydroxy group in different positions, were synthesized and analyzed together with the hepatocyte samples. This approach could reveal that the beta position of the phenylpropanoyl moiety was highly favored; beta-OH-phenylpropanoylfentanyl was the most abundant metabolite after the nor-metabolite. Both metabolites have the potential to serve as biomarkers for 3-phenylpropanoylfentanyl. The nor-metabolites of acetylbenzylfentanyl, benzoylbenzylfentanyl, and 3-fluoro-methoxyacetylfentanyl do also seem to be suitable biomarker metabolites, as do the demethylated metabolite of 3-fluoro-methoxyacetylfentanyl. Identified metabolic pathways and formed metabolites were in agreement, Funding Agencies|Eurostars-2 Joint Programme (European Commission) [E! 113377]; European Unions Horizon 2020 research and innovation program; Swedens Innovation Agency VINNOVA [2019-03566]; Strategic Research Area in Forensic Sciences (Strategiomradet forensiska vetenskaper) at Linkoeping University

Synthetic cannabinoid receptor agonists (SCRAs) remain a major public health concern, with their use implicated in intoxications and drug-related deaths worldwide. Increasing our systematic understanding of SCRA metabolism supports clinical and forensic toxicology casework, facilitating the timely identification of analytical targets for toxicological screening procedures and confirmatory analysis. This is particularly important as new SCRAs continue to emerge on the illicit drug market. In this work, the metabolism of ADB-HEXINACA (ADB-HINACA, N-[1-amino-3,3-dimethyl-1-oxobutan-2-yl]-1-hexyl-1H-indazole-3-carboxamide), which has increased in prevalence in the United Kingdom and other jurisdictions, was investigated using in vitro techniques. The (S)-enantiomer of ADB-HEXINACA was incubated with pooled human hepatocytes over 3 hours to identify unique and abundant metabolites using liquid chromatography-quadrupole time-of-flight mass spectrometry. In total, 16 metabolites were identified, resulting from mono-hydroxylation, di-hydroxylation, ketone formation (mono-hydroxylation then dehydrogenation), carboxylic acid formation, terminal amide hydrolysis, dihydrodiol formation, glucuronidation and combinations thereof. The majority of metabolism took place on the hexyl tail, forming ketone and mono-hydroxylated products. The major metabolite was the 5-oxo-hexyl product (M9), while the most significant mono-hydroxylation product was the 4-hydroxy-hexyl product (M8), both of which were confirmed by comparison to in-house synthesized reference standards. The 5-hydroxy-hexyl (M6) and 6-hydroxy-hexyl (M7) metabolites were not chromatographically resolved, and the 5-hydroxy-hexyl product was the second largest mono-hydroxylated metabolite. The structures of the terminal amide hydrolysis products without (M16, third largest metabolite) and with the 5-positioned ketone (M13) were also confirmed by comparison to synthesized reference standards, along with the 4-oxo-hexyl metabo, Funding Agencies|Eurostars-2 joint programme [E! 113377]; Eurostars-3 [E! 2297]; European Union [201903566]; Strategic Research Area in Forensic Sciences (Styrkeomradet forensiska vetenskaper) at Linkoeping University; Leverhulme Trust [RC-2015-01]

Fentanyl analogues have appeared on the recreational drug market during the last ten years and caused many fatal overdoses around the world due to their high potencies. Their metabolites are of great interest for toxicology, metabolism and identification studies. According to the literature, fentanyl analogues with similar structures have similar metabolism profile. Therefore, a synthetic route that enables synthesis of the corresponding metabolites for several fentanyl analogues would be valuable. Fentanyl analogue metabolites are often polar and tailing on silica gel. Hence, the purification of these substances could be challengeable. In this work, a general synthetic route was developed and described for the multi-gram scale synthesis of 14 potential metabolites of seven fentanyl analogues. The synthetic route is concise and optimized, does not require any use of silica gel purification and is therefore convenient for large-scale synthesis. The overall yields of the metabolites were in the range of 25-57%., Funding Agencies|Strategic Research Area Forensic Sciences; Swedish Governmental Agency for Innovation SystemsVinnova; Eurostars-2 Joint Programme [E! 113377]; European UnionEuropean Commission

Fentanyl analogues constitute a particularly dangerous group of new psychoactive compounds responsible for many deaths around the world. Little is known about their metabolism and studies utilizing LC-QTOF-MS analysis of hepatocyte incubations and/or authentic urine samples does not allow for determination of the exact metabolite structures, especially when it comes to hydroxylated metabolites. In this study seven motifs (2-, 3-, 4- and β-OH as well as 3,4-diOH, 4-OH-3-OMe and 3-OH-4-OMe) of fentanyl and five fentanyl analogues, acetylfentanyl, acrylfentanyl, cyclopropylfentanyl, isobutyrylfentanyl and 4F-isobutyrylfentanyl were synthesized. The reference standards were analyzed by LC-QTOF-MS, which enabled identification of the major metabolites formed in hepatocyte incubations of the studied fentanyls. By comparison with our previous data sets, major urinary metabolites could tentatively be identified. For all analogues, β-OH, 4-OH and 4-OH-3-OMe were identified after hepatocyte incubation. β-OH was the major hydroxylated metabolite for all studied fentanyls, except for acetylfentanyl where 4-OH was more abundant. However, the ratio 4-OH/β-OH was higher in urine samples than in hepatocyte incubations for all studied fentanyls. Also, 3-OH-4-OMe was not detected in any hepatocyte samples, indicating a clear preference for the 4-OH-3-OMe, which was also found to be more abundant in urine compared to hepatocytes. The patterns appear to be consistent across all studied fentanyls and could serve as a starting point in the development of methods and synthesis of reference standards of novel fentanyl analogues where nothing is known about the metabolism., Funding agencies: Strategiomradet Forensiska Vetenskaper (Strategic Research Area Forensic Sciences) at Linkoping University; Swedish Governmental Agency for Innovation SystemsVinnova; Eurostars-2 Joint Programme; European UnionEuropean Commission [E!10628]

Cyclopropylfentanyl is a fentanyl analog implicated in 78 deaths in Europe and over 100 deaths in the United States, but toxicological information including metabolism data about this drug is scarce. The aim of this study was to provide the exact structure of abundant and unique metabolites of cyclopropylfentanyl along with synthesis routes. In this study, metabolites were identified in 13 post-mortem urine samples using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Samples were analyzed with and without enzymatic hydrolysis, and seven potential metabolites were synthesized in-house to provide the identity of major metabolites. Cyclopropylfentanyl was detected in all samples, and the most abundant metabolite was norcyclopropylfentanyl (M1) that was detected in 12 out of 13 samples. Reference materials were synthesized (synthesis routes provided) to identify the exact structure of the major metabolites 4-hydroxyphenethyl cyclopropylfentanyl (M8), 3,4-dihydroxyphenethyl cyclopropylfentanyl (M5) and 4-hydroxy-3-methoxyphenethyl cyclopropylfentanyl (M9). These metabolites are suitable urinary markers of cyclopropylfentanyl intake as they are unique and detected in a majority of hydrolyzed urine samples. Minor metabolites included two quinone metabolites (M6 and M7), not previously reported for fentanyl analogs. Interestingly, with the exception of norcyclopropylfentanyl (M1), the metabolites appeared to be between 40% and 90% conjugated in urine. In total, 11 metabolites of cyclopropylfentanyl were identified, including most metabolites previously reported after hepatocyte incubation., Funding Agencies|Strategiomradet Forensiska Vetenskaper (Strategic Research Area Forensic Sciences) at Linkoping University; Eurostar project Psychomics