Human phase-I metabolism of three synthetic cannabinoids bearing a cumyl moiety and a cyclobutyl methyl or norbornyl methyl tail: Cumyl-CBMEGACLONE, Cumyl-NBMEGACLONE, and Cumyl-NBMINACA

Synthetic cannabinoid receptor agonists (SCRAs) continue to show high prevalence on the new psychoactive substances drug market. Around 2019-2020, new SCRAs bearing a cumyl moiety emerged: Cumyl-CBMEGACLONE and Cumyl-NBMEGACLONE, carrying a cyclobutyl methyl (CBM) and a norbornyl methyl moiety (NBM) attached to the γ-carbolinone core. These were followed by Cumyl-NBMINACA, the indazole carboxamide analog of Cumyl-NBMEGACLONE. The study aimed at evaluating the human phase-I metabolism of these compounds and at identifying suitable urinary markers to prove their consumption. After enzymatic hydrolysis, 14 authentic urine samples (eight for Cumyl-CBMEGACLONE, four for Cumyl-NBMEGACLONE, and two for Cumyl-NBMINACA) were analyzed by liquid chromatography-quadrupole time-of-flight mass spectrometry. Results were compared with in vitro metabolites generated by pooled human liver microsomes incubation. Fifteen human phase-I metabolites were identified for Cumyl-CBMEGACLONE, nine for Cumyl-NBMEGACLONE, and thirteen for Cumyl-NBMINACA. The main in vivo metabolites were built by monohydroxylation, dihydroxylation, or trihydroxylation. The following urinary biomarkers are suggested for detecting the consumption of the investigated SCRAs: products of monohydroxylation at the CBM and at the core for Cumyl-CBMEGACLONE; two products of monohydroxylation at the norbonyl methyl tail for Cumyl-NBMEGACLONE; and metabolites built by dihydroxylation at the NBM substructure and by an additional hydroxylation at the cumyl moiety for Cumyl-NBMINACA.

"Spice"-related deaths in and around Munich, Germany: A retrospective look at the role of synthetic cannabinoid receptor agonists in our post-mortem cases over a seven-year period (2014-2020)

Synthetic cannabinoid receptor agonists (SCRAs, "Spice") are a diverse group of recreational drugs, with their structural and pharmacological variability still evolving. Forensic toxicologists often rely on previous reports to assess their role in intoxication cases. This work provides detailed information on the "Spice"-related fatalities around Munich, Germany, from 2014 to 2020. All cases underwent an autopsy. Pharmaceutical and illicit drugs were detected and quantified in post-mortem peripheral blood or liver by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on circumstantial evidence, only those cases for which a prior consumption was suspected underwent additional analyses for SCRAs and other new psychoactive substances in post-mortem blood, liver or antemortem specimens. Drug concentrations, pathological findings at autopsy and case histories were considered to assess and rank the SCRAs' involvement in each death. Concentration ranges for the individual substances in blood were defined and their distribution patterns over the investigated period were determined and correlated with their legal status and local police seizures. We identified 41 different SCRAs among 98 fatalities. 91.8% were male, at a median age of 36 years. SCRAs played a causative role in 51%, contributory role in 26%, and an insignificant role in 23% of cases. In correlation with local police seizures and legal status, 5F-ADB was the most prevalent in our cases, followed by 5F-MDMB-PICA and AB-CHMINACA. Cumyl-CBMICA and 5F-MDMB-P7AICA were among the least frequently detected SCRAs. "Spice"-related fatalities and SCRAs' causative role have significantly decreased among our cases since the German New Psychoactive Substances Act.

Comprehensive Characterization of a Systematic Library of Alkyl and Alicyclic Synthetic Cannabinoids Related to CUMYL-PICA, CUMYL-BUTICA, CUMYL-CBMICA, and CUMYL-PINACA

Over 200 synthetic cannabinoid receptor agonists (SCRAs) have been identified as new psychoactive substances. Effective monitoring and characterization of SCRAs are hindered by the rapid pace of structural evolution. Ahead of possible appearance on the illicit drug market, new SCRAs were synthesized to complete a systematic library of cumyl-indole- (e.g., CUMYL-CPrMICA, CUMYL-CPMICA) and cumyl-indazole-carboxamides (e.g., CUMYL-CPrMINACA, CUMYL-CPMINACA), encompassing butyl, pentyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, and cyclohexylmethyl tails. Comprehensive pharmacological characterization was performed with three assay formats, monitoring the recruitment of either wild-type or C-terminally truncated (βarr2d366) β-arrestin2 to the activated cannabinoid 1 receptor (CB₁) or monitoring G_βγ-mediated membrane hyperpolarization. Altered compound characterization was observed when comparing derived potency (EC₅₀) and efficacy (E_max) values from both assays monitoring the same or a different signaling event, whereas ranges and ranking orders were similar. Structure-activity relationships (SAR) were assessed in threefold, resulting in the identification of the pendant tail as a critical pharmacophore, with the optimal chain length for CB₁ activation approximating an n-pentyl (e.g., cyclopentylmethyl or cyclohexylmethyl tail). The activity of the SCRAs encompassing cyclic tails decreased with decreasing number of carbons forming the cyclic moiety, with CUMYL-CPrMICA showing the least CB₁ activity in all assay formats. The SARs were rationalized via molecular docking, demonstrating the importance of the optimal steric contribution of the hydrophobic tail. While SAR conclusions remained largely unchanged, the differential compound characterization by both similar and different assay designs emphasizes the importance of detailing specific assay characteristics to allow adequate interpretation of potencies and efficacies.

Effect of new legislation in Germany on prevalence and harm of synthetic cannabinoids

CONTEXT

New psychoactive substances (NPS) have become an ongoing threat to public health. To prevent the emergence and spread of NPS, a new German law, the 'NpSG' took effect in November 2016. This study presents an overview of analytically confirmed synthetic cannabinoid (SC) intoxications from January 2015 to December 2018. In order to demonstrate effects of the NpSG, the results of 23 month before and 25 month after the introduction of the law were compared.

METHODS

Within the scope of a prospective observational study blood and urine samples were collected from emergency patients with suspected NPS intoxication. Comprehensive drug analyses were performed by LC-MS/MS analysis.

RESULTS

In the period considered, 138 patients were included. Within these, SC intake was verified in 65 patients (73%) in the period before the law change, and in 30 patients (61%) after. The median age increased significantly from 19.5 to 26 years. Seizures and admission to the ICU were reported significantly less frequently (seizures 29% versus 6.7%, p = 0.0283; ICU admission 42% versus 13%, p = 0.0089). 34 different SCs were detected, including four SCs (Cumyl-PEGACLONE, 5 F-MDMB-P7AICA, EG-018, 5 F-Cumyl-P7AICA) not covered by the NpSG at the time of detection. In the first period the most prevalent SC was MDMB-CHMICA (n = 24). 5 F-ADB was the most prevalent SC overall, detected in 7 patients (11%) in the first, and in 24 patients (80%) in the second period.

CONCLUSION

The number of SC intoxications decreased overall after the implementation of the NpSG. The shift in the detected SCs can be considered a direct effect of the NpSG but unfortunately the market supply does not appear to have been reduced. Although changes in the age distribution and in the severity of intoxications may be seen as secondary effects of the law, the main objectives of the new law to prevent the emergence and spread of further chemical variations of known scheduled drugs, have apparently not been achieved from the perspective of this study.

Synthetic Cannabinoid-Related Deaths in England, 2012-2019

Aim: To identify drug-related death trends associated with synthetic cannabinoid receptor agonists (SCRAs) reported to the National Programme on Substance Abuse Deaths (NPSAD) from England. Design: Case reports from NPSAD (England) where a SCRA was detected in post-mortem tissue(s) and/or implicated in the death were extracted, analyzed, and compared against non-SCRA-related deaths that occurred over the same time period (2012-2019). Findings: One hundred sixty-five death SCRA-related reports were extracted, with 18 different SCRAs detected. Following the first death in 2012, a subsequent sharp increase in reporting is evident. Acute SCRA use was the underlying cause of death in the majority of cases (75.8%) with cardiorespiratory complications the most frequently cited underlying physiological cause (13.4%). SCRA users were predominantly found dead (68.6%), with a large proportion of those witnessed becoming unresponsive described as suddenly collapsing (81.6%). Psychoactive polydrug use was detected in 90.3% of cases, with alcohol the most commonly co-detected (50.3%), followed by opioids (42.2%), benzodiazepines/Z-drugs (32.1%), stimulants (32.1%, [28.5% cocaine]), and cannabis (24.8%). Compared to all non-SCRA-related NPSAD deaths occurring over the same time period, SCRA-related decedents were more predominantly male (90.3% vs. 72.0%; p<0.01), and lived in more deprived areas (p<0.01). While a comparatively significant proportion of decedents were homeless (19.4% vs. 4.1%), living in a hostel (13.3% vs. 2.3%) or in prison (4.9% vs. 0.2%) at time of death (all p<0.01), the greatest majority of SCRA-related decedents were living in private residential accommodations (57.6%). Conclusions: This is the largest dataset regarding SCRA-related mortalities reported to date. Reporting of SCRA-related deaths in England have increased considerably, with polydrug use a specific concern. Lack of effective deterrents to SCRA use under current UK legislation, compounded by limited knowledge regarding the physiological impacts of SCRA consumption and their interaction with other co-administered substances are contributory factors to the occurrence of SCRA-related mortalities in an increasingly deprived demographic.

The Novel Psychoactive Substance Cumyl-CH-MEGACLONE: Human Phase-I Metabolism, Basic Pharmacological Characterization and Comparison to Other Synthetic Cannabinoid Receptor Agonists with a γ-Carboline-1-One Core

Synthetic cannabinoids (SC) remain one of the largest groups of new psychoactive substances on the European drug market. In December 2018, Cumyl-CH-MEGACLONE, a novel SC based on a γ-carboline-1-one core structure, was firstly identified in Hungary and later also other European countries. This work aims to reveal the pharmacological characteristics and phase-I metabolism of Cumyl-CH-MEGACLONE and compare the data to its analogs Cumyl-PEGACLONE and 5F-Cumyl-PEGACLONE. The purified substance was characterized by means of gas chromatography-mass spectrometry (GC-MS), liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QToF-MS), attenuated total reflection infrared spectroscopy (ATR-FTIR) and nuclear magnetic resonance spectroscopy. Phase-I metabolites were identified by LC-QToF-MS analysis combined with a scheduled precursor ion list of authentic urine samples and confirmed by comparison with metabolites built in vitro by pooled human liver microsome assays. Pharmacological data were obtained in a competitive ligand binding assay and a receptor activation assay at the human cannabinoid receptor 1 (hCB1). The structure of 5-cyclohexylmethyl-2-(2-phenylpropan-2-yl)-2,5-dihydro-1H-pyrido[4,3-b]indol-1-one (semisystematic name: Cumyl-CH-MEGACLONE) was identified in a herbal blend as the main active ingredient. Investigation of phase-I biotransformation of Cumyl-CH-MEGACLONE led to three monohydroxylated metabolites (M08, M10 and M13) as reliable urinary markers for proof of consumption. At the hCB1, Cumyl-CH-MEGACLONE shows high binding affinity with Ki = 1.01 nM (2.5-fold higher than JWH-018), an EC50 of 1.22 nM and high efficacy with EMAX = 143.4% above constitutive activity of the receptor (1.13-fold higher than JWH-018). Comparison to the analogs 5F-Cumyl-PEGACLONE and Cumyl-PEGACLONE (both are hCB1 full agonists carrying a 5-fluoropentyl or pentyl chain instead of the cyclohexylmethyl moiety) suggests that Cumyl-CH-MEGACLONE is more likely to resemble the pharmacologic profile of the latter one.

Emergence of Cumyl-PEGACLONE-related fatalities in the Northern Territory of Australia

Suspected unnatural or unexpected deaths in the Northern Territory of Australia are reportable to the coroner, and investigation of such cases typically includes a post-mortem examination with comprehensive toxicological screening. An autopsy case series of five Cumyl-PEGACLONE-related fatalities over a recent eighteen-month period is presented. Databases of the Northern Territory coroner's office and the Royal Darwin Hospital Forensic Pathology Unit were searched to identify deaths related to synthetic cannabis use between July 1, 2018 and December 31, 2020. Toxicological analysis was performed at Forensic Science South Australia using a combination of liquid chromatography, gas chromatography and mass spectrometry. Cumyl-PEGACLONE, a synthetic cannabinoid receptor agonist (SCRA) with a gamma-carbolinone core, was detected in five cases (range in post-mortem blood 0.73-3.0 μg/L). Concurrent alcohol use and underlying cardiovascular disease were considered relevant factors in most cases. Toxicological Significance Scoring was carefully considered in all five cases, and in four cases, the presence of Cumyl-PEGACLONE was considered to be highly significant (TSS = 3). Synthetic cannabis use has not previously been identified in Northern Territory drug trends, and only one fatality related to the use of gamma-carbolines was identified in a recent Australia-wide study on synthetic cannabinoid-related fatalities. Deaths related to Cumyl-PEGACLONE use are emerging in the Northern Territory of Australia; this has public health implications. Although the exact mechanism(s) of death related to Cumyl-PEGACLONE are not fully established, this additional descriptive case series reaffirm an association with underlying cardiovascular disease, and suggest that concurrent use with alcohol may be relevant.

Post-Mortem Toxicology: A Systematic Review of Death Cases Involving Synthetic Cannabinoid Receptor Agonists

BACKGROUND

Synthetic cannabinoid receptor agonists (SCRAs) have become the largest group of new psychoactive substances monitored by the European Union Early Warning System. Despite the wide diffusion on the market, data regarding effects, toxicities, and mechanisms as well as toxic/lethal doses are still scarce.

METHODS

A comprehensive literature search for articles published up to January 2019 was performed in multiple electronic databases. Only cases of death in which toxicological analyses revealed the presence of SCRAs in blood or urine and at least an external examination was performed, including those occurred in emergency departments, were included.

RESULTS

Of 380 studies identified, 354 were excluded, while 8 additional manuscripts were included through the screening of relevant references cited in the selected articles. A total number of 34 manuscripts (8 case series and 26 case reports) were included.

CONCLUSIONS

Typical toxic ranges for SCRAs have not been so far identified, and the results of toxicological analyses should be interpreted with caution. In death cases involving SCRAs, a thorough post-mortem examination is a prerequisite to assess the role of the substance use in the deceased and to identify a probable mechanism of death. Even after a comprehensive analysis of clinical, circumstantial, toxicological, and autoptic data, the cause and manner of death remain unclear in some cases.

Interpol review of toxicology 2016-2019

This review paper covers the forensic-relevant literature in toxicology from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20.Papers%202019.pdf.

Quantification of Herbal Mixtures Containing Cumyl-PEGACLONE-Is Inhomogeneity Still an Issue?

Synthetic cannabinoid receptor agonizts (SCRAs), also known as synthetic cannabinoids, are mostly consumed in the form of herbal mixtures available in online shops. These herbal mixtures are produced by soaking dried, crushed plant material in a solution of SCRAs or by spraying the solution on the plant material. Inhomogeneity in the distribution of the active ingredient can occur during the production process and pose a serious health risk for consumers of these drugs. In the present study 20 herbal mixtures containing Cumyl-PEGACLONE, one of the most prevalent SCRAs in Germany in 2017, were quantitatively analyzed by high-performance liquid chromatography with diode array detection (HPLC-DAD) after an initial screening by gas chromatography mass spectrometry. All investigated herbal mixtures were purchased in online shops during a systematic product monitoring carried out in the frame of the EU project "SPICE Profiling". The complete content of the packages was divided into aliquots without homogenization and extracted three times with methanol under ultrasonication. The combined extracts of each aliquot were filtered and quantified with a fully validated HPLC-DAD method using a 7-point calibration curve (1-50 μg/mL). The Cumyl-PEGACLONE content in the analyzed material ranged from 8.6 to 146 mg/g (median 29.4 mg/g, mean 38.5 mg/g). The intrapackage concentration variability was mostly below 10% RSD. Analyzed concentrations roughly correlated with product advisory (e.g., "strong") on the websites, if available. Aliquots at the bottom of a package generally tended to show higher levels of Cumyl-PEGACLONE than the upper aliquots. Packages of the same brand with different date of order did not always show the same mean concentrations. Compared to former studies, the SCRA concentrations are generally lower and the risk of extreme variation of intrapackage SCRA contents seems to have dropped.

Adding more "spice" to the pot: A review of the chemistry and pharmacology of newly emerging heterocyclic synthetic cannabinoid receptor agonists

Synthetic cannabinoid receptor agonists (SCRAs) first appeared on the international recreational drug market in the early 2000s in the form of SCRA-containing herbal blends. Due to the cannabimimetic effects associated with the consumption of SCRAs, they have acquired an ill-informed reputation for being cheap, safe, and legal alternatives to illicit cannabis. Possessing high potency and affinity for the human cannabinoid receptor subtype-1 (CB₁ ) and -2 (CB₂ ), it is now understood that the recreational use of SCRAs can have severe adverse health consequences. The major public health problem arising from SCRA use has pressed legislators around the world to employ various control strategies to curb their recreational use. To circumvent legislative control measures, SCRA manufacturers have created a wide range of SCRA analogs that contain, more recently, previously unencountered azaindole, γ-carbolinone, or carbazole heterocyclic scaffolds. At present, little information is available regarding the chemical syntheses of these newly emerging classes of SCRA, from a clandestine perspective. When compared with previous generations of indole- and indazole-type SCRAs, current research suggests that many of these heterocyclic SCRA analogs maintain high affinity and efficacy at both CB₁ and CB₂ but largely evade legislative control. This review highlights the importance of continued research in the field of SCRA chemistry and pharmacology, as recreational SCRA use remains a global public health issue and represents a serious control challenge for law enforcement agencies.

Four cases of death involving the novel synthetic cannabinoid 5F-Cumyl-PEGACLONE

Purpose

Cumyl-PEGACLONE was the first synthetic cannabinoid (SC) with a γ-carbolinone core structure detected in forensic casework and, since then, it has dominated the German SC-market. Here the first four cases of death involving its fluorinated analog, 5F-Cumyl-PEGACLONE, a recently emerged γ-carbolinone derived SC, are reported.

Methods

Complete postmortem examinations were performed. Postmortem samples were screened by immunoassay, gas chromatography mass spectrometry (GC–MS) or liquid chromatography tandem mass spectrometry. For quantification of SCs, the standard addition method was employed. Herbal blends were analyzed by GC–MS. In each case of death, the Toxicological Significance Score (TSS) was assigned to the compound.

Results

5F-Cumyl-PEGACLONE was identified at concentrations ranging 0.09–0.45 ng/mL in postmortem femoral blood. In case 1, signs of hypothermia and kidney bleedings were noted. Despite a possible tolerance due to long term SC use, a TSS of 3 was assigned. In case 2, an acute heroin intoxication occurred and a contributory role (TSS = 1) of 5F-Cumyl-PEGACLONE was suggested. In case 3, a prisoner was found dead. GC–MS analysis of herbal blends, retrieved in his cell together with paraphernalia, confirmed the presence of 5F-Cumyl-PEGACLONE and a causative role was deemed probable (TSS = 2). In case 4, the aspiration of gastric content due to a SC-induced coma was observed (TSS = 3).

Conclusions

5F-Cumyl-PEGACLONE is an emerging and extremely potent SC which raises serious public health concerns. A comprehensive analysis of circumstantial, clinical, and postmortem findings, as well as an in-depth toxicological analysis is necessary for a valid interpretation and for the assessment of the toxicological significance.