A new cannabinoid receptor 1 selective agonist evading the 2021 “China ban”: ADB‐FUBIATA

• Published in: Drug testing and analysis 2022-09, Vol.14 (9), p.1639-1644
• Main Authors: Deventer, Marie H., Van Uytfanghe, Katleen, Vinckier, Inge M. J., Reniero, Fabiano, Guillou, Claude, Stove, Christophe P.
• Format: Article
• Language: English
• Subjects: ADB‐FUBIATA; bioassay; Cannabinoid Receptor Agonists - chemistry; Cannabinoid Receptor Agonists - pharmacology; CB1 cannabinoid receptor; Chromatography; Luciferases; Mass spectrometry; new psychoactive substances; NMR; Nuclear magnetic resonance; Powders; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Recreational drugs; Scientific imaging; synthetic cannabinoid receptor agonists
• ISSN: 1942-7603; 1942-7611
• DOI: 10.1002/dta.3285

Following the class‐wide ban of synthetic cannabinoid receptor agonists (SCRAs) in China, SCRAs carrying new core and linker structures, aimed at circumventing the recent Chinese generic legislation, have appeared on the recreational drug market. A very recent example is (S)‐2‐(2‐(1‐(4‐fluorobenzyl)‐1H‐indol‐3‐yl)acetamido)‐3,3‐dimethylbutanamide (ADB‐FUBIATA), which is structurally closely related to the potent SCRA ADB‐FUBICA, but carries an additional methylene in the linker region of the molecule. ADB‐FUBIATA has recently been identified in seized materials in China, Russia, the United States, and also Belgium; however, its pharmacological characteristics were unknown. The aim of this study was to evaluate the intrinsic cannabinoid receptor (hCB1 and hCB2) activation potential of this previously unknown substance via two distinct yet similar in vitro β‐arrestin2 recruitment assays, based on the NanoLuc Binary Technology®. At CB1, a potency of 635 nM (EC50) was found, with an efficacy (Emax) of 141% relative to the reference compound CP55,940. On the other hand, ADB‐FUBIATA had almost no activity at CB2, indicative of a clear CB1 selectivity. Interestingly, this activation pattern differs markedly from that observed for ADB‐FUBICA, which was previously found to be potent and efficacious at both cannabinoid receptors. Additionally, the bioassays were applied to a seized powder containing ADB‐FUBIATA, as analytically confirmed by high‐performance liquid chromatography coupled to diode‐array detection (HLPC‐DAD), gas chromatography coupled to mass spectrometry (GC‐MS), liquid chromatography couple to time‐of‐flight mass spectrometry (LC‐QTOF‐MS), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR). The EC50 and Emax values obtained for this powder were very similar to those of the ADB‐FUBIATA analytical standard, suggesting a high purity of the powder, although analytical techniques did reveal that the sample was not entirely pure. Via in vitro CB1 and CB2 activation assays, the cannabinoid activity of the newly identified ADB‐FUBIATA and a seized powder containing this substance was evaluated. While being moderately active at CB1, ADB‐FUBIATA had almost no activity at CB2, indicative of CB1 selectivity. The seized powder was equipotent with the reference standard, suggesting a high purity, as also confirmed via different analytical techniques.