In vitro characterization of the pyrazole-carrying synthetic cannabinoid receptor agonist 5F-3,5-AB-PFUPPYCA and its structural analogs

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The rapidly evolving synthetic cannabinoid receptor agonist (SCRA) market poses significant challenges for forensic scientists. Since the enactment of a generic ban in China, a variety of new compounds have emerged capable of evading the legislation by carrying new structural features. One recent example of a SCRA with new linker and head moieties is CH‐PIATA (CH‐PIACA, CHX‐PIATA, CHX‐PIACA). CH‐PIATA bears an additional methylene spacer in the linker moiety between the indole core and the traditional carbonyl component of the linker. This study describes detections in 2022 of this new SCRA in the United States, Belgium, and Scottish prisons. CH‐PIATA was detected once in a seized powder by Belgian customs and 12 times in Scottish prisons in infused papers or resin. The metabolites of CH‐PIATA were investigated via in vitro human liver microsome (HLM) incubations and eight metabolites were identified, dominated by oxidative biotransformations. A blood sample from the United States was confirmed to contain a mixture of SCRAs including CH‐PIATA via presence of the parent and at least five of the metabolites identified from HLM incubations. Furthermore, this paper evaluates the intrinsic in vitro cannabinoid 1 and 2 (CB1 and CB2) receptor activation potential of CH‐PIATA reference material and the powder seized by Belgian customs by means of β‐arrestin 2 recruitment assays. Both the reference and the seized powder showed a weak activity at both CB receptors with signs of antagonism found. Based on these results, the expected harm potential of this newly emerging substance remains limited.

Section: Resultssupporting

confidence: 88%

Section: In Vitro Activitymentioning

confidence: 99%

Section: Nuclear Magnetic Resonance Spectroscopy (Nmr)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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In vitro cannabinoid receptor activity, metabolism, and detection in seized samples of CH‐PIATA, a new indole‐3‐acetamide synthetic cannabinoid

Norman,

Deventer,

Dremann

et al. 2023

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“…[21][22][23] Furthermore, substances with a modified linker, such as ADB-FUBIATA, [23][24][25] CH-PIATA, [26][27][28] and CH-FUBIATA, 29 as well as some monocyclic pyrazole SCRAs (e.g., 5F-3,5-AB-PFUPPYCA and 3,5-ADB-4en-PFUP-PYCA), have (re-)emerged on the market. [30][31][32] Recently, two new indazole compounds (ADB-5 0 Br-INACA and MDMB-5 0 Br-INACA) have been detected in Europe, the United Kingdom, and the United States, carrying a bromine at position 5 on the phenyl ring and lacking a tail structure, a structural component that has been consistently present in the most prevalent SCRAs as a part of the head-linker-core-tail building block structure. 8,18,33 Both structural modifications allow these compounds to circumvent the Chinese legislation, as it only covers an indazole core with an unsubstituted phenyl ring, while the pyrazole moiety can only carry a linear or cyclic alkyl group or a heterocyclic functional group in order to be controlled.…”

Section: Introductionmentioning

confidence: 99%

In vitro cannabinoid activity profiling of generic ban‐evading brominated synthetic cannabinoid receptor agonists and their analogs

Deventer,

Persson,

Norman

et al. 2023

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Following the enactment of a generic ban in China in 2021, the synthetic cannabinoid market has been evolving, now encompassing even wider structural diversity. Compounds carrying a brominated core such as ADB‐5′Br‐BUTINACA (ADMB‐B‐5Br‐INACA) and tail‐less analogs, such as ADB‐5′Br‐INACA (ADMB‐5Br‐INACA), MDMB‐5′Br‐INACA, and ADB‐INACA (ADMB‐INACA), have been detected since late 2021. This study investigated the cannabinoid receptor (CB) activation potential of synthesized (S)‐enantiomers of these substances, as well as of two predicted analogs MDMB‐5′Br‐BUTINACA (MDMB‐B‐5Br‐INACA) and ADB‐5′F‐BUTINACA (ADMB‐B‐5F‐INACA), using CB1 and CB2 β‐arrestin 2 recruitment assays and a CB1 intracellular calcium release assay. Surprisingly, the tail‐less (S)‐ADB‐5′Br‐INACA and (S)‐MDMB‐5′Br‐INACA retained CB activity, albeit with a decreased potency compared to their tailed counterparts (S)‐ADB‐5′Br‐BUTINACA and (S)‐MDMB‐5′Br‐BUTINACA, respectively, which were potent and efficacious CB1 agonists. Also, at CB2, tail‐less analogs showed a lower potency but increased efficacy. Removing the bromine substitution ((S)‐ADB‐INACA) resulted in a reduced activity at CB1; however, this effect was less prominent at CB2. Looking at tailed analogs, replacing the bromine with a fluorine substitution ((S)‐ADB‐5′F‐BUTINACA) resulted in an increased potency and efficacy at both receptors. Furthermore, as ADB‐5′Br‐INACA and MDMB‐5′Br‐INACA have been frequently detected together in Scottish prisons, this study also evaluated the CB1 receptor activation potential of different mixtures of their respective reference standards, showing no unexpected cannabimimetic effect of combining both substances. Lastly, two powders seized by Belgian Customs and confirmed to contain ADB‐5′Br‐INACA and MDMB‐5′Br‐INACA, respectively, were assessed for CB activity. Based on the comparison with their reference standards, varying degrees of purity were suspected.

Detection in seized samples, analytical characterization, and in vitro metabolism of the newly emerged 5‐bromo‐indazole‐3‐carboxamide synthetic cannabinoid receptor agonists

Norman,

Webling,

Kyslychenko

et al. 2023

Synthetic cannabinoid receptor agonists (SCRAs) are a diverse class of new psychoactive substances (NPS) and new structural scaffolds have emerged on the recreational drug market since the enactment of Chinese SCRA analog controls in 2021. This study reports the first SCRAs to be detected with a bromide at the 5 position (5′Br) on the phenyl ring of the indazole core and without a tail moiety. ADB‐5′Br‐INACA (ADMB‐5′Br‐INACA) and MDMB‐5′Br‐INACA were detected in seized samples from Scottish prisons, Belgian customs, and US forensic casework. The brominated analog with a tail moiety, ADB‐5′Br‐BUTINACA (ADMB‐5′Br‐BUTINACA), was also detected in Scottish prisons and US forensic casework. The metabolites of these compounds and the predicted compound MDMB‐5′Br‐BUTINACA were identified through incubation with primary human hepatocytes to aid in their toxicological identification. The bromide on the indazole remains intact on metabolites, allowing these compounds to be easily distinguished in toxicological samples from their non‐brominated analogs. Glucuronidation was more common for tail‐less analogs than their butyl tail‐containing counterparts. Forensic toxicologists are advised to update their analytical methods with the characteristic ions for these compounds, as well as their anticipated urinary markers: amide hydrolysis and monoOH at tert‐butyl metabolites (after β‐glucuronidase treatment) for ADB‐5′Br‐INACA; monoOH at tert‐butyl and amide hydrolysis metabolites for ADB‐5′Br‐BUTINACA; and ester hydrolysis metabolites with additional metabolites for MDMB‐5′Br‐INACA and MDMB‐5′Br‐BUTINACA. Toxicologists should remain vigilant to the emergence of new SCRAs with halogenation of the indazole core and tail‐less analogs, which have already started to emerge.