Structure elucidation of the novel synthetic cannabinoid Cumyl-tosyl-indazole-3-carboxamide (Cumyl-TsINACA) found in illicit products in Germany

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.

EMCDDA framework and practical guidance for naming synthetic cannabinoids

Synthetic cannabinoids (SCs), often sold as "legal" replacements for cannabis, are the largest group of new psychoactive substances monitored by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). Currently, close to 240 structurally heterogeneous SCs are monitored through the European Union (EU) Early Warning System, and attributing consistent, informative, and user-friendly names to SCs has been a challenge in the past. Over time, several naming conventions have been employed with the aim of making SCs more easily recognizable by non-chemists, including regulators. To achieve this, the names assigned need to contain detailed information on the structural features present in the substance. This work provides a theoretical framework and a practical hands-on guideline for consistent naming of SCs, which is easy to understand and can be applied by the forensic community, researchers, clinical practitioners, and policy-makers. The proposed framework builds on the established letter code system for molecular building blocks (core, linker, linked group, and tail) implemented by the EMCDDA in 2013 and has been expanded to incorporate additional structural features through substitution. The scope of the issue of attributing semi-systematic code names is illustrated, and earlier approaches used for naming SCs are discussed. The concepts and rules of the EMCDDA framework are described through a flowchart that provides a basis for naming new SCs, a graphical overview of the chemical diversity of SCs, and a detailed list of the SCs identified in the EU by the Early Warning System of the EMCDDA for reference.

A new synthetic cathinone: 3,4-EtPV or 3,4-Pr-PipVP? An unsuccessful attempt to circumvent the German legislation on new psychoactive substances

Synthetic cathinones comprise psychostimulants with desired effects like euphoria, increased vigilance, appetite suppression, and-mainly depending on certain structural features-entactogenic properties. 3,4-EtPV (1-(bicyclo[4.2.0]octa-1,3,5-trien-3-yl)-2-(pyrrolidin-1-yl)pentan-1-one) was first mentioned in an online drug forum in September 2021, where its imminent synthesis was announced. The goal was to produce a legal alternative to the phenylethylamines already banned by the German NpSG. In February and June 2022, two samples labeled with the name and molecular structure of 3,4-EtPV were analyzed. The molecular structure of the obviously mislabeled compound was elucidated and comprehensively characterized within the ADEBAR project. The synthetic cathinone identified differed from the declared 3,4-EtPV by a 3,4-propylene bridge instead of a 3,4-ethylene bridge and a piperidine ring instead of a pyrrolidine ring. The short name 3,4-Pr-PipVP (3,4-propylene-2-(1-piperidinyl)valerophenone) was suggested as a semisystematic name in collaboration with the European Monitoring Centre for Drugs and Drug Addiction. Herein, the results of the analyses are discussed and will enable forensic laboratories to update their databases quickly and identify 3,4-Pr-PipVP confidently. 3,4-Pr-PipVP is already scheduled under the German NpSG. This study highlights that there are ongoing efforts to deliberately circumvent generic definitions given, for example, in the German NpSG and that (unintentional?) mislabeling can be an issue. The end user purchasing substances online can never be sure that the material actually supplied will be the one ordered, and he might receive an illicit drug instead of an uncontrolled one. Furthermore, the purity is always unknown, creating health risks due to unexpected effects and potencies.

Identification of the synthetic cannabinoid-type new psychoactive substance, CH-PIACA, in seized material

Synthetic cannabinoids (SCs) remain the largest class of new psychoactive substances (NPS), and while the number of NPS that are reported to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) for the first time each year declines, the number of newly reported SCs still exceeds other NPS classes. This decline can be seen as a result of legislative changes by different jurisdictions which have sometimes transitioned to a more generalized approach when controlling substances by defining common structural scaffolds rather than explicit structures. While the consequences of such legislative changes have been expected over the years, the introduction of so‐called “class‐wide” bans puts further pressure on clandestine laboratories to synthesize compounds which are out of the scope of the legislation, and thus, these compounds are initially harder to detect and/or identify in the absence of analytical data. Recently, a SC with an indole‐3‐acetamide core‐linker scaffold, AD‐18 (i.e., ADB‐FUBIATA or ADB‐FUBIACA), was reported for the first time in China in 2021. Here, an additional cannabinoid with the indole‐3‐acetamide scaffold, N‐cyclohexyl‐2‐(1‐pentyl‐1H‐indol‐3‐yl)acetamide (CH‐PIACA), is reported which was identified for the first time in a seized material in Denmark. Structural characterization was performed using gas chromatography–mass spectrometry (GC–MS), liquid chromatography‐high‐resolution mass spectrometry (LC‐HRMS), and nuclear magnetic resonance (NMR) spectroscopy.

The ADEBAR project - European and international provision of analytical data from structure elucidation and analytical characterization of NPS

Novel substances for which none or limited analytical data are available constitute a challenge for police and customs forensic laboratories. The time-consuming process of structural elucidation and acquisition of analytical data has been centralized in the ADEBAR project in Germany, co-funded since 2017 by the EU's Internal Security Fund. The project aims to comprehensively characterize substances relevant for forensic-toxicological casework within the analytical competence network. The analytical datasets are distributed digitally through European and (inter-) national channels. Additionally, pharmacological evaluation allows for estimating in vivo potency and potential harm required as scientific evidence for legislative amendments. The ADEBAR project contributes to the availability of analytical data on new substances relevant to the daily work of police and customs laboratories. Since the inception of the ADEBAR project, 549 samples have been registered, and 302 substance reports notified to the EMCDDA, including numerous spectrometric and spectroscopic data. In addition, 3619 mass spectra have been accumulated in ADEBAR mass spectra databases. A central institution for the structure elucidation and acquisition of valid, high-quality analytical data for police and customs forensic laboratories and forensic medicine institutes is important in the future because there does not seem to be an end to the dynamic of novel NPS appearing on the drug market.