Metabolism of synthetic cannabinoids PB-22 and its 5-fluoro analog, 5F-PB-22, by human hepatocyte incubation and high-resolution mass spectrometry

Identification of phase-I and phase-II metabolites and the metabolic pathway of the novel synthetic cannabinoid 5F-EDMB-PICA in vitro

5F-EDMB-PICA is a newly emerged synthetic cannabinoid which has been characterized in relevant literature in recent years. Although phase-I metabolites of 5F-EDMB-PICA have been partly reported, the phase-II metabolism of this synthetic cannabinoid has not been studied yet. In this study, we established a phase-I and phase-II metabolism model in vitro by using pooled human liver microsomes, NADPH regeneration system, and UGT incubation system, with 1 mg/ml 5F-EDMB-PICA added and incubated at 37 °C for 60 min. The metabolites were analyzed by Q Exactive™ Hybrid Quadrupole-Orbitrap™ Mass Spectrometer, via which we discovered and identified 14 phase-I metabolites and 4 phase-II metabolites of 5F-EDMB-PICA, involving pathways such as ester hydrolysis, dehydrogenation, hydrolytic defluorination, hydroxylation, dihydroxylation, glucuronidation, and combinations of the pathways mentioned above. We recommend considering the monohydroxylation metabolites (M9, M10) with higher content and intact ester and 5-fluoropentyl structures as potential biomarkers of 5F-EDMB-PICA.

5-HT2A receptors are involved in the pharmaco-toxicological effects of the synthetic cannabinoids JWH-018 and 5F-PB22: In vivo studies in mice

Over the last years, Synthetic Cannabinoids (SCs) have been among the largest and most frequently seized groups of Novel Psychoactive Substances (NPS). These substances have been frequently detected in biological samples from patients involved in several intoxication and death cases. Their serious adverse effects have been related to their action as potent agonist of cannabinoid CB1 receptors. However, evidence concerning the potential interaction between SCs and serotoninergic mechanisms has emerged. Therefore, this study aims to evaluate the involvement of 5-HT2A receptors in the effects induced by acute systemic administration of 1-pentyl-3-(1-naphthoyl)indole (JWH-018; 1 mg/kg) and quinolin-8-yl 1-pentyfluoro-1H-indole-3-8-carboxylate (5F-PB22; 1 mg/kg). Sensorimotor (visual, acoustic, and tactile) responses, pain threshold (acute mechanical and thermal nociception), core temperature, breath rate and motor performance (stepping activity) have been assessed in CD-1 male mice. The present results pointed out that both substances deeply alter sensorimotor responses, nociceptive threshold, core temperature, breath rate and motor activity in mice. Noteworthy, pretreatment with the selective 5-HT2A receptors antagonist MDL100907 (0.1 mg/kg) at least partially prevented sensorimotor disruption, antinociception and hypothermic effects. Conversely, the respiratory and motor impairment was not prevented. Thus, it states the relevance of serotoninergic 5-HT2A mechanisms on pharmaco-toxicological effects induced by SCs.

Potential neonatal toxicity of new psychoactive substances

Cannabis, cocaine, 3,4-methylenedioxymethamphetamine, and lysergic acid diethylamide are psychoactive substances with a significant increase in consumption during the 21st century due to their popularity in medicinal and recreational use. New psychoactive substances (NPSs) mimic established psychoactive substances. NPSs are known as being natural and safe to consumers; however, they are neither natural nor safe, causing severe adverse reactions, including seizures, nephrotoxicity, and sometimes death. Synthetic cannabinoids, synthetic cathinones, phenethylamines, and piperazines are all examples of NPSs. As of January 2020, nearly 1000 NPSs have become documented. Due to their low cost, ease of availability, and difficulty of detection, misuse of NPSs has become a familiar and growing problem, especially in adolescents and young adults in the past decade. The use of NPSs is associated with higher risks of unplanned sexual intercourse and pregnancy. As many as 4 in 100 women seeking treatment for substance abuse are pregnant or nursing. Animal studies and human clinical case reports have shown that exposure to certain NPSs during lactation periods has toxic effects on neonates, increasing various risks, including brain damage. Nevertheless, neonatal toxicity effects of NPSs are usually unrecognized and overlooked by healthcare professionals. In this review article, we introduce and discuss the potential neonatal toxicity of NPSs, emphasizing synthetic cannabinoids. Utilizing the established prediction models, we identify synthetic cannabinoids and their highly accumulative metabolites in breast milk.

Advances in urinary biomarker research of synthetic cannabinoids

New psychoactive substances (NPS) are chemical compounds designed to mimic the action of existing illicit recreational drugs. Synthetic cannabinoids (SCs) are a subclass of NPS which bind to the cannabinoid receptors, CB1 and CB2, and mimic the action of cannabis. SCs have dominated recent NPS seizure reports worldwide. While urine is the most common matrix for drug-of-abuse testing, SCs undergo extensive Phase I and Phase II metabolism, resulting in almost undetectable parent compounds in urine samples. Therefore, the major urinary metabolites of SCs are usually investigated as surrogate biomarkers to identify their consumption. Since seized urine samples after consuming novel SCs may be unavailable in a timely manner, human hepatocytes, human liver microsomes and human transporter overexpressed cell lines are physiologically-relevant in vitro systems for performing metabolite identification, metabolic stability, reaction phenotyping and transporter experiments to establish the disposition of SC and its metabolites. Coupling these in vitro experiments with in vivo verification using limited authentic urine samples, such a two-pronged approach has proven to be effective in establishing urinary metabolites as biomarkers for rapidly emerging SCs.

New Psychoactive Substances: Major Groups, Laboratory Testing Challenges, Public Health Concerns, and Community-Based Solutions

Across communities worldwide, various new psychoactive substances (NPSs) continue to emerge, which worsens the challenges to global mental health, drug rules, and public health risks, as well as combats their usage. Specifically, the vast number of NPSs that are currently available, coupled with the rate at which new ones emerge worldwide, increasingly challenges both forensic and clinical testing strategies. The well-established NPS detection techniques include immunoassays, colorimetric tests, mass spectrometric techniques, chromatographic techniques, and hyphenated types. Nonetheless, mitigating drug abuse and NPS usage is achievable through extensive community-based initiatives, with increased focus on harm reduction. Clinically validated and reliable testing of NPS from human samples, along with community-driven solution, such as harm reduction, will be of great importance, especially in combating their prevalence and the use of other illicit synthetic substances. There is a need for continued literature synthesis to reiterate the importance of NPS, given the continuous emergence of illicit substances in the recent years. All these are discussed in this overview, as we performed another look into NPS, from differentiating the major groups and identifying with laboratory testing challenges to community-based initiatives.

Phase I-metabolism studies of the synthetic cannabinoids PX-1 and PX-2 using three different in vitro models

PURPOSE

Synthetic cannabinoids (SCs), highly metabolized substances, are rarely found unmodified in urine samples. Urine screening relies on SC metabolite detection, requiring metabolism knowledge. Metabolism data can be acquired via in vitro assays, e.g., human hepatocytes, pooled human liver microsomes (pHLM), cytochrome P450 isoforms and a fungal model; or in vivo by screening, e.g., authentic human samples or rat urine. This work describes the comprehensive study of PX-1 and PX-2 in vitro metabolism using three in vitro models. 5F-APP-PICA (PX-1) and 5F-APP-PINACA (PX-2) were studied as they share structural similarity with AM-2201, THJ-2201 and 5F-AB-PINACA, the metabolism of which was described in the literature.

METHODS

For SC incubation, pHLM, cytochrome P450 isoenzymes and the fungal model Cunninghamella elegans LENDNER (C. elegans) were used. PX-1 and PX-2 in vitro metabolites were revealed comprehensively by liquid chromatography-high-resolution mass spectrometry measurements.

RESULTS

In total, 30 metabolites for PX 1 and 15 for PX-2 were detected. The main metabolites for PX-1 and PX-2 were the amide hydrolyzed metabolites, along with an indole monohydroxylated (for PX-1) and a defluorinated pentyl-monohydroxylated metabolite (for PX-2).

CONCLUSIONS

CYP isoforms along with fungal incubation results were in good agreement to those obtained with pHLM incubation. CYP2E1 was responsible for many of the metabolic pathways; particularly for PX-1. This study shows that all three in vitro assays are suitable for predicting metabolic pathways of synthetic cannabinoids. To establish completeness of the PX-1 and PX-2 metabolic pathways, it is not only recommended but also necessary to use different assays.

Pharmacokinetic Approach to Combat the Synthetic Cannabinoid PB-22

Synthetic cannabinoids are part of a group of drugs called new psychoactive substances. Most of these cannabinoids are unregulated, and there are no therapeutic treatments for their addictive properties or reversing a potential overdose. Vaccination and catalytic antibodies strategies were investigated to assess their ability to blunt the psychoactive properties of the cannabinoid PB-22. To complement these antibody concentric investigations, we also disclose the discovery of the enzymatic degradation of this cannabinoid. Serum factors including albumin and carboxylesterase were found to catalyze the hydrolysis of PB-22. Affinity, kinetics, animal behavior, and biodistribution studies were utilized to evaluate the efficiency of these pharmacokinetic approaches. Our findings suggest simple antibody binding as the most efficacious means for altering PB-22's effect on the brain. Catalytic approaches only translated to esterases being capable of PB-22's degradation with a catalytic antibody approach providing no proclivity for PB-22's hydrolysis. Pharmacokinetic approaches provide a powerful strategy for treating substance abuse disorders and overdose for drugs where no therapeutic is available.

Synthetic cannabinoid receptor agonists and their human metabolites in sewage water: Stability assessment and identification of transformation products

Since their first appearance in 2008, synthetic cannabinoid receptor agonists (SCRAs) remain the most popular new psychoactive substances (NPS) in the EU. Following consumption, these drugs and their metabolites are urinary excreted and enter the sewage system enabling the application of wastewater-based epidemiology (WBE). Knowing the fate of target analytes in sewage water is essential for successful application of WBE. This study investigates the stability of several chemically diverse SCRAs and selected human metabolites under sewage conditions utilizing a combination of liquid chromatography-tandem mass spectrometry and high-resolution mass spectrometry (HRMS). Target analytes included SCRAs with indole (5F-PB-22, PB-22 pentanoic acid), indazole (AMB-FUBINACA, 5F-ADB, 5F-ADB dimethylbutanoic acid), carbazole (MDMB-CHMCZCA, EG-018), and γ-carboline (Cumyl-PeGaClone) chemical core structures representing most of the basic core structures that have occurred up to now. Stability tests were performed using wastewater effluent containing 5% activated sludge as inoculum to monitor degradation processes and formation of transformation products (TPs). The majority of investigated SCRAs, excluding the selected human metabolites, was recalcitrant to microbial degradation in sewage systems over a period of 29 days. Their stability was rather controlled by physico-chemical processes like sorption and hydrolysis. Considering a typical hydraulic in-sewer retention time of 24 h, the concentration of AMB-FUBINACA decreased by 90% thus representing the most unstable SCRA investigated in this study. Among the 10 newly identified TPs, three could be considered as relevant markers and should be included into future WBE studies to gain further insight into use and prevalence of SCRAs on the drug market.

Comparison of in vitro and in vivo models for the elucidation of metabolic patterns of 7-azaindole-derived synthetic cannabinoids exemplified using cumyl-5F-P7AICA

Due to the dynamic market involving synthetic cannabinoids (SCs), the determination of analytical targets is challenging in clinical and forensic toxicology. SCs usually undergo extensive metabolism, and therefore their main metabolites must be identified for the detection in biological matrices, particularly in urine. Controlled human studies are usually not possible for ethical reasons; thus, alternative models must be used. The aim of this work was to predict the in vitro and in vivo metabolic patterns of 7-azaindole-derived SCs using 1-(5-fluoropentyl)-N-(2-phenylpropan-2-yl)-1H-pyrollo[2,3-b]pyridin-3-carboxamide (cumyl-5F-P7AICA) as an example. Different in vitro (pooled human liver S9 fraction, pooled human liver microsomes, and pig liver microsomes) and in vivo (rat and pig) systems were compared. Monooxygenase isoenzymes responsible for the most abundant phase I steps, namely oxidative defluorination (OF) followed by carboxylation, monohydroxylation, and ketone formation, were identified. In both in vivo models, OF/carboxylation and N-dealkylation/monohydroxylation/sulfation could be detected. Regarding pHS9 and pig urine, monohydroxylation/sulfation or glucuronidation was also abundant. Furthermore, the parent compound could still be detected in all models. Initial monooxygenase activity screening revealed the involvement of CYP2C19, CYP3A4, and CYP3A5. Therefore, in addition to the parent compound, the OF/carboxylated and monohydroxylated (and sulfated or glucuronidated) metabolites can be recommended as urinary targets. In comparison to literature, the pig model predicts best the human metabolic pattern of cumyl-5F-P7AICA. Furthermore, the pig model should be suitable to mirror the time-dependent excretion pattern of parent compounds and metabolites.

Synthetic Cannabinoids JWH-122 and THJ-2201 Disrupt Endocannabinoid-Regulated Mitochondrial Function and Activate Apoptotic Pathways as a Primary Mechanism of In Vitro Nephrotoxicity at In Vivo Relevant Concentrations

The widespread recreational use of synthetic cannabinoids (SCBs) represents a major public health issue, as reports of intoxications and deaths following SCB use rapidly mount up. Specifically, a direct link between SCB use and acute kidney injury (AKI) has been established, although the pathophysiologic mechanisms remain undefined. Here we assessed the in vitro nephrotoxicity of 3 commonly detected and structurally distinct SCBs-AB-FUBINACA, JWH-122, and THJ-2201-in human proximal tubule cells (HK-2), to ascertain potential similarities and/or differences regarding their nephrotoxicity signatures. We showed that 2 of the 3 SCBs tested, namely JWH-122 and THJ-2201, at in vivo relevant concentrations (1 nM-1 μM), triggered apoptotic cell death pathways, mainly through a shared mechanism involving the deregulation of mitochondrial function (ie, with mitochondrial membrane hyperpolarization and increased intracellular ATP levels), as the primary molecular signature of nephrotoxicity mechanism. Noteworthy, no SCB affected cell viability (MTT reduction, lactate dehydrogenase release, Neutral Red inclusion). Use of the cannabinoid receptor (CBR) antagonists SR141716A and SR144528, as well as HEK293T cells, which do not express CBRs, confirmed the involvement of these receptors in SCB-mediated mitochondrial membrane hyperpolarization but not on other events, suggesting an off-target action regulating SCB-induced kidney cell death. Our results further strengthen the relevance of the endocannabinoid system in maintaining mitochondrial function in kidney cells, as we demonstrate that HK-2 incubation with CBR antagonists or inhibitors of endocannabinoid biosynthesis (ie, methyl arachydonyl fluorophosphonate, tetrahydrolipstatin) alone produced deleterious effects similar to those now reported for SCBs. Overall, SCB-induced nephrotoxicity seems to be mainly regulated at the mitochondrial level, but the specific mechanisms involved require further clarification.

Novel halogenated synthetic cannabinoids impair sensorimotor functions in mice

JWH-018-Cl, JWH-018-Br and AM-2201 (JWH-018 halogenated-derivatives; JWH-018-R compounds) are synthetic cannabinoid agonists illegally marketed as "Spice", "K2", "herbal blend" and research chemicals for their cannabis-like psychoactive effects. In rodents, JWH-018 and its halogenated derivatives reproduce the typical effects of Δ⁹-tetrahydrocannabinol (Δ⁹-THC), i.e. hypothermia, analgesia, hypolocomotion and akinesia. Yet, the effects of JWH-018-R compounds on sensorimotor functions are still unknown. This study was designed to investigate the effect of an acute intraperitoneal (i.p.) administration of JWH-018-R compounds (0.01-6 mg/kg) on sensorimotor functions in mice and to compare them to those caused by the reference compound JWH-018 and Δ⁹-THC. A well validated battery of behavioral tests was used to investigate the effects of these synthetic cannabinoids on the visual, auditory and tactile responses in mice, while the pre-pulse inhibition (PPI) test was used to investigate their effect on sensorimotor gating. The effect of the synthetic cannabinoids on spontaneous locomotion was also measured by a video tracking analysis to assess potential cannabinoid-induced motor impairment. Results showed that, similarly to JWH-018, systemic administration of JWH-018-R compounds inhibits sensorimotor and PPI responses at lower doses (0.01-0.1 mg/kg) and reduced spontaneous locomotion at intermediate/high doses (1-6 mg/kg). All effects were prevented by the administration of the selective cannabinoid CB₁ receptor antagonist/inverse agonist AM-251 thus confirming a CB₁ receptor-mediated action. Finding that lower doses of JWH-018-R compounds selectively impair sensorimotor and PPI responses without affecting locomotion should be carefully considered to better understand the potential danger that halogenated-derivatives of JWH-018 may pose to public health, with particular reference to decreased performance in driving and hazardous works.

Identification of synthetic cannabinoids that were seized, consumed, or associated with deaths in Kuwait in 2018 using GC-MS and LC-MS-MS analysis

Synthetic cannabinoids are gaining much popularity worldwide. Although the death rate associated with their use is rising, these drugs are the largest and fastest growing class of novel psychoactive substances. Despite increased concerns regarding adverse effects stemming from the use of synthetic cannabinoids, there is no published data on the subject for the Gulf region or Kuwait, specifically. The current study investigates the diversity of synthetic cannabinoids in Kuwait in 2018. In total, 434 cases from the Narcotics and Psychotropic Laboratory, 70 cases from the Toxicology Laboratory, and six cases from the Forensic Medicine Department were reviewed and analyzed. Numerous synthetic cannabinoid types were identified using GC-MS and LC-MS-MS. The majority of synthetic cannabinoids were members of the indazole-3-carboxamide or indole-3-carboxamide families. Members from the indazole-3-carboxamide family identified in Kuwait were 5F-ADB, FUB-AMB, ADB-FUBINACA, AB-FUBINACA, 5F-ADB-PINACA, 5F-AKB-48, 5Cl-AKB-48, MDMB-FUBINACA, 5F-AB-PINACA, APINACA, and AB-PINACA whereas MDMB-CHMICA, 5F-MDMB-PICA, ADB-BICA, and MMB-CHMICA belonged to the indole-3-carboxamide family. In addition, members of other families were identified, including CBL2201 and UR-144, which belonged to indole-3-carboxylate and cyclopropylindole families, respectively. The most common synthetic cannabinoids were 5F-ADB, FUB-AMB, and 5Cl-AKB-48. Various mixes of two, three, or four types of synthetic cannabinoids were identified, and mixtures of synthetic cannabinoids with other illicit drugs were also present. Our findings show that in Kuwait, the most common mix of synthetic cannabinoids is FUB-AMB with 5F-ADB. These two types were mixed, either together or individually, with methamphetamine, tramadol, heroin, ^Δ9THC, and ketamine. Most importantly, our results reveal the synthetic cannabinoid types that were associated with six reported deaths.

Identification and Quantification of 5-Fluoro ADB and the 5-Fluoro ADB Ester Hydrolysis Metabolite in Postmortem Blood Samples by LC–MS/MS

5-Fluoro ADB, also known as 5-fluoro MDMB-PINACA, is a potent synthetic cannabinoid that is an agonist to the human cannabinoid CB1 and CB2 receptors. Adverse physiological and psychological effects that have resulted in hospitalization and/or death have been associated with 5-Fluoro ADB use. In addition, analytical confirmation of 5-Fluoro ADB use has been reported in both forensic human performance toxicology and postmortem cases. An analytical method for the identification and quantification of 5-fluoro ADB and the 5-fluoro ADB ester hydrolysis metabolite in human blood samples by liquid chromatography–tandem mass spectrometry was created and validated. The linear range of this assay was determined to be 0.01–10 ng/mL for 5-fluoro ADB and 10–500 ng/mL for the 5-fluoro ADB ester hydrolysis metabolite. The method met both precision and accuracy requirements. Endogenous and exogenous interferences were not observed. Ion suppression exceeding 25% was observed for 5-fluoro ADB. However, additional experiments were performed to ensure that the observed suppression did not affect other method validation parameters such as limit of detection and accuracy. Blood samples from 36 postmortem cases were analyzed utilizing this methodology. The average blood concentration of 5-fluoro ADB was 0.29 ng/mL in central blood specimens and 0.05 ng/mL in peripheral blood specimens. The average blood concentration of the 5-fluoro ADB ester hydrolysis metabolite was 49 ng/mL in central blood specimens and 21 ng/mL in peripheral blood specimens. A serum sample was also analyzed and had a serum concentration of 0.12 ng/mL for 5-fluoro ADB and 42 ng/mL for the 5-fluoro ADB ester hydrolysis metabolite. As the concentration of the 5-fluoro ADB ester hydrolysis metabolite was found at a greater concentration than that of 5-fluoro ADB, this metabolite may be a useful marker to monitor in an attempt to confirm 5-fluoro ADB use in toxicological investigations.

Functional effects of synthetic cannabinoids versus Δ9 -THC in mice on body temperature, nociceptive threshold, anxiety, cognition, locomotor/exploratory parameters and depression

Synthetic cannabinoids are psychoactive substances designed to mimic the euphorigenic effects of the natural cannabis. Novel unregulated compounds appear once older compounds become illegal. It has been previously reported that synthetic cannabinoids are different than Δ⁹ -tetrahydrocannabinol (Δ⁹ -THC) as they have chemical structures unrelated to Δ⁹ -THC, different metabolism and, often, greater toxicity. This study aimed to investigate the effects of three novel synthetic cannabinoids and pure Δ⁹ -THC on body temperature, nociceptive threshold, anxiety, memory function, locomotor and exploratory parameters, and depression. We performed a battery of behavioural and motor tests starting 50 minutes post i.p. injection of each drug to adult ICR mice. The synthetic cannabinoids that were used are AB-FUBINACA, AB-CHMINACA and PB-22. All synthetic cannabinoids and Δ⁹ -THC caused hypothermia, but only Δ⁹ -THC induced a clear antinociceptive effect. All synthetic cannabinoids and Δ⁹ -THC caused decreased anxiety levels, spatial memory deficits and decreased exploratory behaviour as measured in the elevated plus maze, Y-maze and staircase paradigm, respectively. However, all synthetic cannabinoids but not Δ⁹ -THC demonstrated decreased locomotor activity in the staircase test. Moreover, only AB-FUBINACA and Δ⁹ -THC affected the gait balance and grip strength of the mice as was assessed by the latency time to fall from a rod. In the forced swimming test, PB-22 caused elevated depression-like behaviour while AB-FUBINACA induced a reversed effect. These results suggest varied effects among different synthetic cannabinoids and Δ⁹ -THC. Further studies are needed to characterize the overall effects and differences between these synthetic cannabinoids and Δ⁹ -THC.

New Synthetic Cannabinoids Metabolism and Strategies to Best Identify Optimal Marker Metabolites

Synthetic cannabinoids (SCs) were initially developed as pharmacological tools to probe the endocannabinoid system and as novel pharmacotherapies, but are now highly abused. This is a serious public health and social problem throughout the world and it is highly challenging to identify which SC was consumed by the drug abusers, a necessary step to tie adverse health effects to the new drug's toxicity. Two intrinsic properties complicate SC identification, their often rapid and extensive metabolism, and their generally high potency relative to the natural psychoactive Δ9-tetrahydrocannabinol in cannabis. Additional challenges are the lack of reference standards for the major urinary metabolites needed for forensic verification, and the sometimes differing illicit and licit status and, in some cases, identical metabolites produced by closely related SC pairs, i.e., JWH-018/AM-2201, THJ-018/THJ-2201, and BB-22/MDMB-CHMICA/ADB-CHMICA. We review current SC prevalence, establish the necessity for SC metabolism investigation and contrast the advantages and disadvantages of multiple metabolic approaches. The human hepatocyte incubation model for determining a new SC's metabolism is highly recommended after comparison to human liver microsomes incubation, in silico prediction, rat in vivo, zebrafish, and fungus Cunninghamella elegans models. We evaluate SC metabolic patterns, and devise a practical strategy to select optimal urinary marker metabolites for SCs. New SCs are incubated first with human hepatocytes and major metabolites are then identified by high-resolution mass spectrometry. Although initially difficult to obtain, authentic human urine samples following the specified SC exposure are hydrolyzed and analyzed by high-resolution mass spectrometry to verify identified major metabolites. Since some SCs produce the same major urinary metabolites, documentation of the specific SC consumed may require identification of the SC parent itself in either blood or oral fluid. An encouraging trend is the recent reduction in the number of new SC introduced per year. With global collaboration and communication, we can improve education of the public about the toxicity of new SC and our response to their introduction.

Metabolic profiling of synthetic cannabinoid 5F-ADB by human liver microsome incubations and urine samples using high-resolution mass spectrometry

5F-ADB (methyl 2-{[1-(5-fluoropentyl)-1H-indazole-3-carbonyl] amino}-3,3-dimethylbutanoate) is a frequently abused new synthetic cannabinoid that has been sold since at least the end of 2014 on the drug market and has been classified as an illicit drug in most European countries, as well as Turkey, Japan, and the United States. In this study, the in vitro metabolism of 5F-ADB was investigated by using pooled human liver microsomes (HLMs) assay and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). 5F-ADB (5 μmol/L) was incubated with HLMs for up to 3 hours, and the metabolites were identified using LC-HRMS and software-assisted data mining. The in vivo metabolism was investigated by the analysis of 30 authentic urine samples and was compared to the data received from the in vitro metabolism study. Less than 3.3% of the 5F-ADB parent compound remained after 1 hour of incubation, and no parent drug was detected after 3 hours. We identified 20 metabolites formed via ester hydrolysis, N-dealkylation, oxidative defluorination, hydroxylation, dehydrogenation, further oxidation to N-pentanoic acid and glucuronidation or a combination of these reactions in vitro. In 12 urine samples (n = 30), 5F-ADB was detected as the parent drug. Three of the identified main metabolites 5F-ADB carboxylic acid (M20), monohydroxypentyl-5F-ADB (M17), and carboxypentyl ADB carboxylic acid (M8) were suggested as suitable urinary markers. The screening of 8235 authentic urine samples for identified 5F-ADB metabolites in vitro resulted in 3135 cases of confirmed 5F-ADB consumption (38%).

Cytotoxicity of new psychoactive substances and other drugs of abuse studied in human HepG2 cells using an adopted high content screening assay

New psychoactive substances (NPS) are still an emerging issue in clinical and forensic toxicology. Information about their cytotoxic potential is limited or even unavailable before distribution and thus their intake can be of high risk for consumers. The aim of the presented study was to develop a strategy to identify cytotoxic potential of NPS based on a high content screening assay (HCSA) using HepG2 cell line and four fluorescent dyes, namely Hoechst33342, TMRM, CAL-520, and TOTO-3. The HCSA was optimized to work without an automated analyzer by using the model compounds fluvastatin, paracetamol, propranolol, and simvastatin. The following parameters were monitored: stained nuclei as a measure for cell count as well as nuclear size and nuclear intensity (all Hoechst33342), mitochondrial membrane potential (TMRM), cytosolic calcium level (CAL-520), and plasma membrane integrity (TOTO-3). The present study showed strong cytotoxic potential for the NPS 5F-PB-22 and MDAI, moderate effects for MDMA, MDPV, methylone, cathinone, 4-MEC, and mephedrone, and no toxic effects for methamphetamine. To assess the metabolic suitability of HepG2 cells under the chosen conditions, cell culture supernatants were analyzed by liquid chromatography-high resolution-tandem mass spectrometry. Metabolites were merely detected for lipophilic drugs such as 5F-PB-22 and MDPV and in addition with a much lower abundance in comparison to the parent compound but the study only allowed a qualitative look for metabolites and the used liver cell line might not ideal when considering metabolism.

Suspect and non-target screening workflows to investigate the in vitro and in vivo metabolism of the synthetic cannabinoid 5Cl-THJ-018

The use of synthetic cannabinoids causes similar effects as Δ⁹ -tetrahydrocannabinol and long-term (ab)use can lead to health hazards and fatal intoxications. As most investigated synthetic cannabinoids undergo extensive biotransformation, almost no parent compound can be detected in urine, which hampers forensic investigations. Limited information about the biotransformation products of new synthetic cannabinoids makes the detection of these drugs in various biological matrices challenging. This study aimed to identify the main in vitro biotransformation pathways of 5Cl-THJ-018 and to compare these findings with an authentic urine sample of a 5Cl-THJ-018 user. The synthetic cannabinoid was incubated with pooled human liver microsomes and cytosol to simulate phase I and phase II biotransformations. Resulting extracts were analyzed with liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Three different data analysis workflows were applied to identify biotransformation products. A suspect screening workflow used an in-house database built from literature data and in silico biotransformation predictions. Two non-target screening workflows used a commercially available software and an open-source software for mass spectrometry data processing. A total of 23 in vitro biotransformation products were identified, with hydroxylation, oxidative dechlorination, and dihydrodiol formation pathways as the main phase I reactions. Additionally, five glucuronidated and three sulfated phase II conjugates were identified. The predominant in vivo pathway was through oxidative dechlorination and in total six metabolites of 5Cl-THJ-018 were identified. Biotransformation products both in vitro and in vivo were successfully identified using complementary suspect and non-target screening workflows.

Human phase I metabolism of the novel synthetic cannabinoid 5F-CUMYL-PEGACLONE

PURPOSE

5F-CUMYL-PEGACLONE is a recently emerged γ-carbolinone derived synthetic cannabinoid. The present study aimed to identify phase I metabolites to reliably prove consumption of the substance by urine analysis and to differentiate from the uptake of the non-fluorinated analog CUMYL-PEGACLONE.

METHODS

For metabolite characterization, phase I metabolites were analyzed by liquid chromatography-high resolution mass spectrometry after incubation with pooled human liver microsomes. Reliability of the biomarkers was evaluated by analysis of human urine samples (n = 20) by liquid chromatography-triple quadrupole tandem mass spectrometry. Sample preparation included β-glucuronidase treatment followed by liquid-liquid extraction.

RESULTS

In total, 15 metabolites were detected in vivo and characterized. Metabolic reactions were primarily observed at the γ-carbolinone core and the 5-fluoropentyl chain, and included N-dealkylation, hydroxylation, hydrolytic defluorination, formation of a dihydrodiol, oxidation to the pentanoic acid metabolite and formation of the propionic acid metabolite. Six of these metabolites were identical with phase I metabolites of CUMYL-PEGACLONE, which must be considered for interpretation of analytical findings in urine samples.

CONCLUSIONS

5F-CUMYL-PEGACLONE was subject to extensive metabolism in humans. The propionic acid metabolite was the most abundant metabolite in all urine samples and should be targeted when maximum sensitivity is needed (e.g., drug abstinence control). However, this metabolite also occurs in the biotransformation of the non-fluorinated analog and is, therefore, not a compound-specific marker. For differentiation, a metabolite hydroxylated at the γ-carbolinone core showed to be the most reliable marker and should be used as an additional target analyte.

Synthetic cannabinoids in biological specimens: a review of current analytical methods and sample preparation techniques

Synthetic cannabinoids are a new class of chemical drugs capable of modifying human behavior. These products do not contain cannabis, but produce similar effects after consumption. The fact that they are easily accessed, and are many times considered to be harmless, justifies their widespread use among young people. This fact, together with the difficulty in their detection by routine drug tests, makes it extremely important to develop new procedures able to detect and monitor their consumption. The aim of this work is to perform a critical review regarding the human biological samples that can be used for the determination of synthetic cannabinoids, paying special attention to analytical methods and sample preparation techniques. The reviewed articles deal with the determination of synthetic cannabinoids in the context of forensic and toxicological analysis.

Screening, quantification, and confirmation of synthetic cannabinoid metabolites in urine by UHPLC-QTOF-MS

Synthetic cannabinoids are one of the most significant groups within the category new psychoactive substances (NPS) and in recent years new compounds have continuously been introduced to the market of recreational drugs. A sensitive and quantitative screening method in urine with metabolites of frequently seized compounds in Norway (AB‐FUBINACA, AB‐PINACA, AB‐CHMINACA, AM‐2201, AKB48, 5F‐AKB48, BB‐22, JWH‐018, JWH‐073, JWH‐081, JWH‐122, JWH‐203, JWH‐250, PB‐22, 5F‐PB‐22, RCS‐4, THJ‐2201, and UR‐144) using ultra‐high pressure liquid chromatography–quadrupole time of flight–mass spectrometry (UHPLC–QTOF–MS) has been developed. The samples were treated with ß‐glucuronidase prior to extraction and solid‐phase extraction was used. Liquid handling was automated using a robot. Chromatographic separation was achieved using a C18‐column and a gradient of water and acetonitrile, both with 0.1% formic acid. Each sample was initially screened for identification and quantification followed by a second injection for confirmation. The concentrations by which the compounds could be confirmed varied between 0.1 and 12 ng/mL. Overall the validation showed that the method fulfilled the set criteria and requirements for matrix effect, extraction recovery, linearity, precision, accuracy, specificity, and stability. One thousand urine samples from subjects in drug withdrawal programs were analyzed using the presented method. The metabolite AB‐FUBINACA M3, hydroxylated metabolite of 5F‐AKB48, hydroxylated metabolite of AKB48, AKB48 N‐pentanoic acid, 5F‐PB‐22 3‐carboxyindole, BB‐22 3‐carboxyindole, JWH‐018 N‐(5‐hydroxypentyl), JWH‐018 N‐pentanoic acid, and JWH‐073 N‐butanoic acid were quantified and confirmed in 2.3% of the samples. The method was proven to be sensitive, selective and robust for routine use for the investigated metabolites.

Synthetic cannabinoids: Variety is definitely not the spice of life

Although the past few years have seen a significant increase in the use of synthetic cannabinoids, very few fatalities have been reported whereby synthetic cannabinoids have contributed or were solely responsible for the death of an individual. We report a rapid death of an individual following ingestion of 5 F-PB-22 and 5 F-AKB-48. Case information and autopsy findings are presented. Post-mortem blood samples were obtained and 5 F-PB-22 and 5 F-AKB-48 were detected along with 311 mg/100 ml alcohol. The cause of death was certified as the effects of a combination of alcohol and synthetic cannabinoids (5 F-PB-22 and 5 F-AKB-48).

Synthetic cannabinoids are substrates and inhibitors of multiple drug-metabolizing enzymes

Synthetic cannabinoids, a new class of psychoactive substances, are potent agonists of cannabinoid receptors, which mimic the psychoactive effects of the principal psychoactive component of cannabis, ∆9-tetrahydrocannabinol. Despite governmental scheduling as illicit drugs, new synthetic cannabinoids are being produced. The abuse of synthetic cannabinoids with several drugs containing different chemical groups has resulted in large numbers of poisonings. This has increased the urgency for forensic and public health laboratories to identify the metabolites of synthetic cannabinoids and apply this knowledge to the development of analytical methods and for toxicity prediction. It is necessary to determine whether synthetic cannabinoids are involved in drug-metabolizing enzyme-mediated drug-drug interactions. This review describes the metabolic pathways of 13 prevalent synthetic cannabinoids and various drug-metabolizing enzymes responsible for their metabolism, including cytochrome P450 (CYP), UDP-glucuronosyltransferases (UGTs), and carboxylesterases. The inhibitory effects of synthetic cannabinoids on CYP and UGT activities are also reviewed to predict the potential of synthetic cannabinoids for drug-drug interactions. The drug-metabolizing enzymes responsible for metabolism of synthetic cannabinoids should be characterized and the effects of synthetic cannabinoids on CYP and UGT activities should be determined to predict the pharmacokinetics of synthetic cannabinoids and synthetic cannabinoid-induced drug-drug interactions in the clinic.

Phase I metabolism of the carbazole-derived synthetic cannabinoids EG-018, EG-2201, and MDMB-CHMCZCA and detection in human urine samples

Synthetic cannabinoids (SCs) are a structurally diverse class of new psychoactive substances. Most SCs used for recreational purposes are based on indole or indazole core structures. EG-018 (naphthalen-1-yl(9-pentyl-9H-carbazol-3-yl)methanone), EG-2201 ((9-(5-fluoropentyl)-9H-carbazol-3-yl)(naphthalen-1-yl)methanone), and MDMB-CHMCZCA (methyl 2-(9-(cyclohexylmethyl)-9H-carbazole-3-carboxamido)-3,3-dimethylbutanoate) are 3 representatives of a structural subclass of SCs, characterized by a carbazole core system. In vitro and in vivo phase I metabolism studies were conducted to identify the most suitable metabolites for the detection of these substances in urine screening. Detection and characterization of metabolites were performed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (LC-ESI-QToF-MS). Eleven in vivo metabolites were detected in urine samples positive for metabolites of EG-018 (n = 8). A hydroxypentyl metabolite, most probably the 4-hydroxypentyl isomer, and an N-dealkylated metabolite mono-hydroxylated at the carbazole core system were most abundant. In vitro studies of EG-018 and EG-2201 indicated that oxidative defluorination of the 5-fluoropentyl side chain of EG-2201 as well as dealkylation led to common metabolites with EG-018. This has to be taken into account for interpretation of analytical findings. A differentiation between EG-018 and EG-2201 (n = 1) uptake is possible by the detection of compound-specific in vivo phase I metabolites evaluated in this study. Out of 30 metabolites detected in urine samples of MDMB-CHMCZCA users (n = 20), a metabolite mono-hydroxylated at the cyclohexyl methyl tail is considered the most suitable compound-specific consumption marker while a biotransformation product of mono-hydroxylation in combination with hydrolysis of the terminal methyl ester function provides best sensitivity due to its high abundance.

Metabolism of the synthetic cannabinoids AMB-CHMICA and 5C-AKB48 in pooled human hepatocytes and rat hepatocytes analyzed by UHPLC-(IMS)-HR-MSE

The main analytical targets of synthetic cannabinoids are often metabolites. With the high number of new psychoactive substances entering the market, suitable workflows are needed for analytical target identification in biological samples. The aims of this study were to identify the main metabolites of the synthetic cannabinoids, AMB-CHMICA and 5C-AKB48, using an in silico-assisted workflow with analytical data acquired using ultra-high-performance liquid chromatography-(ion mobility spectroscopy)-high resolution-mass spectrometry in data-independent acquisition mode (UHPLC-(IMS)-HR-MS^E). The metabolites were identified after incubation with rat and pooled human hepatocytes using UHPLC-HR-MS^E, followed by UHPLC-IMS-HR-MS^E. Metabolites of AMB-CHMICA and 5C-AKB48 were predicted with Meteor (Lhasa Ltd) and imported to the UNIFI software (Waters). The predicted metabolites were assigned to analytical components supported by the UNIFI in silico fragmentation tool. The main metabolic pathway of AMB-CHMICA was O-demethylation and hydroxylation of the methylhexyl moiety. For 5C-AKB48, the main metabolic pathways were hydroxylation(s) of the adamantyl moiety and oxidative dechlorination with subsequent oxidation to the ω-COOH. The matrix components in the metabolite spectra were reduced with IMS, which improved the accuracy of the spectral interpretation; however, this left fewer fragment ions for assigning sites of metabolism. Meteor was able to predict the majority of the metabolites, with the most notable exception being the oxidative dechlorination and, consequently, all metabolites that underwent that transformation pathway. Oxidative dechlorination of ω-chloroalkanes in humans has not been previously reported in the literature. The postulated metabolites can be used for screening of biological samples, with four-dimensional identification based on retention time, collision cross section, precursor ion, and fragment ions.

Human Toxicity Caused by Indole and Indazole Carboxylate Synthetic Cannabinoid Receptor Agonists: From Horizon Scanning to Notification

BACKGROUND

The emergence of novel psychoactive substances (NPS), particularly synthetic cannabinoid receptor agonists (SCRA), has involved hundreds of potentially harmful chemicals in a highly dynamic international market challenging users', clinicians', and regulators' understanding of what circulating substances are causing harm. We describe a toxicovigilance system for NPS that predicted the UK emergence and identified the clinical toxicity caused by novel indole and indazole carboxylate SCRA.

METHODS

To assist early accurate identification, we synthesized 5 examples of commercially unavailable indole and indazole carboxylate SCRA (FUB-NPB-22, 5F-NPB-22, 5F-SDB-005, FUB-PB-22, NM-2201). We analyzed plasma and urine samples from 160 patients presenting to emergency departments with severe toxicity after suspected NPS use during 2015 to 2016 for these and other NPS using data-independent LC-MS/MS.

RESULTS

We successfully synthesized 5 carboxylate SCRAs using established synthetic and analytical chemistry methodologies. We identified at least 1 SCRA in samples from 49 patients, including an indole or indazole carboxylate SCRA in 17 (35%), specifically 5F-PB-22 (14%), FUB PB-22 (6%), BB-22 (2%), 5F NPB-22 (20%), FUB NPB-22 (2%), and 5F-SDB-005 (4%). In these 17 patients, there was analytical evidence of other substances in 16. Clinical features included agitation and aggression (82%), reduced consciousness (76%), acidosis (47%), hallucinations and paranoid features (41%), tachycardia (35%), hypertension (29%), raised creatine kinase (24%), and seizures (12%).

CONCLUSIONS

This toxicovigilance system predicted the emergence of misuse of indole and indazole carboxylate SCRA, documented associated clinical harms, and notified relevant agencies. Toxicity appears consistent with other SCRA, including mental state disturbances and reduced consciousness.

The Chemistry and Pharmacology of Synthetic Cannabinoid Receptor Agonist New Psychoactive Substances: Evolution

Synthetic cannabinoid receptor agonists (SCRAs) are the largest and most structurally diverse class of new psychoactive substances (NPS). Although the earliest SCRA NPS were simply repurposed from historical academic manuscripts or pharmaceutical patents describing cannabinoid ligands, recent examples bear hallmarks of rational design. SCRA NPS manufacturers have applied traditional medicinal chemistry strategies (such as molecular hybridization, bioisosteric replacement, and scaffold hopping) to existing cannabinoid templates in order to generate new molecules that circumvent structure-based legislation. Most SCRAs potently activate cannabinoid type 1 and type 2 receptors (CB₁ and CB₂, respectively), with the former contributing to the psychoactivity of these substances. SCRAs are generally more toxic than the Δ⁹-tetrahydrocannabinol (Δ⁹-THC) found in cannabis, and this may be due to ligand bias, metabolism, or off-target activity. This chapter will chart the evolution of recently identified SCRA NPS chemotypes, as well as their putative manufacturing by-products and thermolytic degradants, and describe structure-activity relationships within each class.

In vitro metabolism of the synthetic cannabinoids CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA and CUMYL-4CN-B7AICA

Synthetic cannabinoid consumption trends underlie fast changes and provide several challenges to clinical and forensic toxicologists. Due to their extensive metabolism, parent compounds are hardly detectable in urine. Therefore, knowledge of the metabolism of synthetic cannabinoids is essential to allow their detection in biological matrices. The aim of the present study was the elucidation of the metabolism of CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA, and CUMYL-4CN-B7AICA with a focus on the analytical and interpretational differentiation of the compounds. Microsomal assay mixtures containing co-substrates, 10 μg/mL substrate and 1 mg/mL pooled human liver microsomes were incubated for 1 hour at 37°C. Investigation of the metabolites was performed on a Thermo Fischer Ultimate 3000 UHPLC system coupled to a Sciex 6600 QTOF System. Hydroxylation was observed to be a major biotransformation step for all 5 cumyl-derivatives, followed by dihydroxylation. For CUMYL-PINACA, a major metabolic pathway was hydroxylation at the pentyl moiety, followed by a second hydroxylation at that pentyl moiety or oxidation to ketone. A major metabolic pathway for the compounds containing a nitrile function was nitrile hydrolysis followed by carboxylation and further hydroxylation. For the fluorinated compounds, oxidative defluorination and carboxylation were abundant metabolic steps. Some of the metabolic transformations lead to structurally identical metabolites, which should not be used as marker for the intake of a particular parent compound. In addition, several constitutional isomers containing either an indazole or azaindole core structure were detected, which should be differentiated by retention time rather than by their mass spectra alone.

Kinetic and metabolic profiles of synthetic cannabinoids NNEI and MN-18

In 2014 and 2015, synthetic cannabinoid receptor agonists NNEI (N-1-naphthalenyl-1-pentyl-1H-indole-3-carboxamide) and MN-18 (N-1-naphthalenyl-1-pentyl-1H-indazole-3-carboxamide) were detected in recreationally used and abused products in multiple countries, and were implicated in episodes of poisoning and toxicity. Despite this, the pharmacokinetic profiles of NNEI and MN-18 have not been characterized. In the present study NNEI and MN-18 were incubated in rat and human liver microsomes and hepatocytes, to estimate kinetic parameters and to identify potential metabolic pathways, respectively. These parameters and pathways were then examined in vivo, via analysis of blood and urine samples from catheterized male rats following intraperitoneal (3 mg/kg) administration of NNEI and MN-18. Both NNEI and MN-18 were rapidly cleared by rat and human liver microsomes, and underwent a range of oxidative transformations during incubation with rat and human hepatocytes. Several unique metabolites were identified for the forensic identification of NNEI and MN-18 intake. Interestingly, NNEI underwent a greater number of biotransformations (20 NNEI metabolites versus 10 MN-18 metabolites), yet parent MN-18 was eliminated at a faster rate than NNEI in vivo. Additionally, in vivo elimination was more rapid than in vitro estimates. These data highlight that even closely related synthetic cannabinoids can possess markedly distinct pharmacokinetic profiles, which can vary substantially between in vitro and in vivo models.

Human Hepatocyte Metabolism of Novel Synthetic Cannabinoids MN-18 and Its 5-Fluoro Analog 5F-MN-18

BACKGROUND

In 2014, 2 novel synthetic cannabinoids, MN-18 and its 5-fluoro analog, 5F-MN-18, were first identified in an ongoing survey of novel psychoactive substances in Japan. In vitro pharmacological assays revealed that MN-18 and 5F-MN-18 displayed high binding affinities to human CB₁ and CB₂ receptors, with K_i being 1.65-3.86 nmol/L. MN-18 and 5F-MN-18 were scheduled in Japan and some other countries in 2014. Despite increasing prevalence, no human metabolism data are currently available, making it challenging for forensic laboratories to confirm intake of MN-18 or 5F-MN-18.

METHODS

We incubated 10 μmol/L of MN-18 and 5F-MN-18 in human hepatocytes for 3 h and analyzed the samples on a TripleTOF 5600⁺ high-resolution mass spectrometer to identify appropriate marker metabolites. Data were acquired via full scan and information-dependent acquisition-triggered product ion scans with mass defect filter.

RESULTS

In total, 13 MN-18 metabolites were detected, with the top 3 abundant metabolites being 1-pentyl-1H-indazole-3-carboxylic acid, pentyl-carbonylated MN-18, and naphthalene-hydroxylated MN-18. For 5F-MN-18, 20 metabolites were observed, with the top 3 abundant metabolites being 5'-OH-MN-18, MN-18 pentanoic acid, and 1-(5-fluoropentyl)-1H-indazole-3-carboxylic acid.

CONCLUSIONS

We have characterized MN-18 and 5F-MN-18 metabolism with human hepatocytes and high-resolution mass spectrometry, and we recommend characteristic major metabolites for clinical and forensic laboratories to identify MN-18 and 5F-MN-18 intake and link observed adverse events to these novel synthetic cannabinoids.

In Vitro Metabolite Profiling of ADB-FUBINACA, A New Synthetic Cannabinoid

Metabolite profiling of novel psychoactive substances (NPS) is critical for documenting drug consumption. N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indazole-3-carboxamide (ADB-FUBINACA) is an emerging synthetic cannabinoid whose toxicological and metabolic data are currently unavailable. We aimed to determine optimal markers for identifying ADB-FUBINACA intake. Metabolic stability was evaluated with human liver microsome incubations. Metabolites were identified after 1 and 3 h incubation with pooled human hepatocytes, liquid chromatography- high resolution mass spectrometry in positive-ion mode (5600+ TripleTOF®, Sciex) and several data mining approaches (MetabolitePilot™, Sciex). Metabolite separation was achieved on an Ultra Biphenyl column (Restek®); full-scan TOF-MS and information-dependent acquisition MS/MS data were acquired. ADB-FUBINACA microsomal half-life was 39.7 min, with a predicted hepatic clearance of 9.0 mL/min/kg and a 0.5 extraction ratio (intermediate-clearance drug). Twenty-three metabolites were identified. Major metabolic pathways were alkyl and indazole hydroxylation, terminal amide hydrolysis, subsequent glucuronide conjugations, and dehydrogenation. We recommend ADB-FUBINACA hydroxyalkyl, hydroxydehydroalkyl and hydroxylindazole metabolites as ADB-FUBINACA intake markers. N-dealkylated metabolites are not specific ADB-FUBINACA metabolites and should not be used as definitive markers of consumption. This is the first ADB-FUBINACA in vitro metabolism study; in vivo experiments enabling pharmacokinetic and pharmacodynamics studies or urine from authentic clinical/forensic cases are needed to confirm our results.

Motor vehicle collisions caused by the 'super-strength' synthetic cannabinoids, MAM-2201, 5F-PB-22, 5F-AB-PINACA, 5F-AMB and 5F-ADB in Japan experienced from 2012 to 2014

From 2012 to 2014 in Japan, 214 cases of motor vehicle collisions were attributed to the use of illegal drugs. In 93 out of 96 investigated cases, the causative agents were a variety of synthetic cannabinoids (SCs). These SCs can be classified into three groups according to the lineage of the chemical structures: (1) naphthoyl indoles, such as MAM-2201, (2) quinolinyl ester indoles, such as 5F-PB-22, and (3) indazole carboxamides, such as 5F-AB-PINACA, 5F-AMB, and 5F-ADB. These SCs became available sequentially with increasing cannabinoid CB₁ agonist potencies and reached a nationwide outbreak in the summer of 2014. They caused acute intoxication with impaired consciousness, anterograde amnesia (impaired memory), catalepsy with muscle rigidity, tachycardia, and vomiting or drooling soon after smoking. Drivers who had abused one of these SCs might unexpectedly experience the acute intoxication that caused uncontrolled driving. These SCs were generally difficult to detect from body fluid samples. It is thought that the highly lipophilic SCs disappear from the blood via rapid degradation by liver enzymes and selective accumulation into adipose tissues. Thus, much effort should be directed to the development of fast and sensitive chemical detection of the drug usage.

Detection of the recently emerged synthetic cannabinoid 5F-MDMB-PICA in 'legal high' products and human urine samples

Indole or indazole-based synthetic cannabinoids (SCs) bearing substituents derived from valine or tert-leucine are frequently abused new psychoactive substances (NPS). The emergence of 5F-MDMB-PICA (methyl N-{[1-(5-fluoropentyl)-1H-indol-3-yl]carbonyl}-3-methylvalinate) on the German drug market is a further example of a substance synthesized in the context of scientific research being misused by clandestine laboratories by adding it to 'legal high' products. In this work, we present the detection of 5F-MDMB-PICA in several legal high products by gas chromatography-mass spectrometry (GC-MS) analysis. To detect characteristic metabolites suitable for a proof of 5F-MDMB-PICA consumption by urine analysis, pooled human liver microsome (pHLM) assays were performed and evaluated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) techniques to generate reference spectra of the in vitro phase I metabolites. The in vivo phase I metabolism was investigated by the analysis of more than 20 authentic human urine specimens and compared to the data received from the pHLM assay. Biotransformation of the 5-fluoropentyl side chain and hydrolysis of the terminal methyl ester bond are main phase I biotransformation steps. Two of the identified main metabolites formed by methyl ester hydrolysis or mono-hydroxylation at the indole ring system were evaluated as suitable urinary biomarkers and discussed regarding the interpretation of analytical findings. Exemplary analysis of one urine sample for 5F-MDMB-PICA phase II metabolites showed that two of the main phase I metabolites are subject to extensive glucuronidation prior to renal excretion. Therefore, conjugate cleavage is reasonable for enhancing sensitivity. Commercially available immunochemical pre-tests for urine proved to be unsuitable for the detection of 5F-MDMB-PICA consumption. Copyright © 2017 John Wiley & Sons, Ltd.