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Janssens LK, Ametovski A, Sparkes E, Boyd R, Lai F, Maloney CJ, Rhook D, Gerona RR, Connolly M, Liu H, Hibbs DE, Cairns EA, Banister SD, Stove CP. Comprehensive Characterization of a Systematic Library of Alkyl and Alicyclic Synthetic Cannabinoids Related to CUMYL-PICA, CUMYL-BUTICA, CUMYL-CBMICA, and CUMYL-PINACA. ACS Chem Neurosci 2023; 14:35-52. [PMID: 36530139 DOI: 10.1021/acschemneuro.2c00408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
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 Gβγ-mediated membrane hyperpolarization. Altered compound characterization was observed when comparing derived potency (EC50) and efficacy (Emax) 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.
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Affiliation(s)
- Liesl K Janssens
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium
| | - Adam Ametovski
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.,School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Eric Sparkes
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.,School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Rochelle Boyd
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.,School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia
| | - Felcia Lai
- School of Pharmacy, The University of Sydney, Sydney, NSW 2006, Australia
| | - Callan J Maloney
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.,School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Dane Rhook
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.,School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Roy R Gerona
- Clinical Toxicology and Environmental Biomonitoring Laboratory, University of California, San Francisco, California 94143, United States
| | | | | | - David E Hibbs
- School of Pharmacy, The University of Sydney, Sydney, NSW 2006, Australia
| | - Elizabeth A Cairns
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.,School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia
| | - Samuel D Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.,School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium
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2
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Sparkes E, Boyd R, Chen S, Markham JW, Luo JL, Foyzun T, Zaman H, Fletcher C, Ellison R, McGregor IS, Santiago MJ, Lai F, Gerona RR, Connor M, Hibbs DE, Cairns EA, Glass M, Ametovski A, Banister SD. Synthesis and pharmacological evaluation of newly detected synthetic cannabinoid receptor agonists AB-4CN-BUTICA, MMB-4CN-BUTINACA, MDMB-4F-BUTICA, MDMB-4F-BUTINACA and their analogs. Front Psychiatry 2022; 13:1010501. [PMID: 36245876 PMCID: PMC9558907 DOI: 10.3389/fpsyt.2022.1010501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) continue to make up a significant portion new psychoactive substances (NPS) detected and seized worldwide. Due to their often potent activation of central cannabinoid receptors in vivo, use of SCRAs can result in severe intoxication, in addition to other adverse health effects. Recent detections of AB-4CN-BUTICA, MMB-4CN-BUTINACA, MDMB-4F-BUTICA and MDMB-4F-BUTINACA mark a continuation in the appearance of SCRAs bearing novel tail substituents. The proactive characterization campaign described here has facilitated the detection of several new SCRAs in toxicological case work. Here we detail the synthesis, characterization, and pharmacological evaluation of recently detected SCRAs, as well as a systematic library of 32 compounds bearing head, tail, and core group combinations likely to appear in future. In vitro radioligand binding assays revealed most compounds showed moderate to high affinity at both CB1 (pK i = < 5 to 8.89 ± 0.09 M) and CB2 (pK i = 5.49 ± 0.03 to 9.92 ± 0.09 M) receptors. In vitro functional evaluation using a fluorescence-based membrane potential assay showed that most compounds were sub-micromolar to sub-nanomolar agonists at CB1 (pEC50 = < 5 to 9.48 ± 0.14 M) and CB2 (pEC50 = 5.92 ± 0.16 to 8.64 ± 0.15 M) receptors. An in silico receptor-ligand docking approach was utilized to rationalize binding trends for CB2 with respect to the tail substituent, and indicated that rigidity in this region (i.e., 4-cyanobutyl) was detrimental to affinity.
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Affiliation(s)
- Eric Sparkes
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Rochelle Boyd
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Shuli Chen
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Jack W. Markham
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, School of Pharmacy, The University of Sydney, Sydney, NSW, Australia
| | - Jia Lin Luo
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Tahira Foyzun
- Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Humayra Zaman
- Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Charlotte Fletcher
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Ross Ellison
- Clinical Toxicology and Environmental Biomonitoring Laboratory, University of California, San Francisco, San Francisco, CA, United States
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | | | - Felcia Lai
- Faculty of Medicine and Health, School of Pharmacy, The University of Sydney, Sydney, NSW, Australia
| | - Roy R. Gerona
- Clinical Toxicology and Environmental Biomonitoring Laboratory, University of California, San Francisco, San Francisco, CA, United States
| | - Mark Connor
- Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - David E. Hibbs
- Faculty of Medicine and Health, School of Pharmacy, The University of Sydney, Sydney, NSW, Australia
| | - Elizabeth A. Cairns
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Adam Ametovski
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Samuel D. Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
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3
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Deventer MH, Van Uytfanghe K, Vinckier IMJ, Reniero F, Guillou C, Stove CP. A new cannabinoid receptor 1 selective agonist evading the 2021 "China ban": ADB-FUBIATA. Drug Test Anal 2022; 14:1639-1644. [PMID: 35570246 DOI: 10.1002/dta.3285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 12/30/2022]
Abstract
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.
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Affiliation(s)
- Marie H Deventer
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Katleen Van Uytfanghe
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | | | - Fabiano Reniero
- European Commission, Joint Research Centre, Directorate F-Health, Consumers and Reference Materials, Ispra, Italy
| | - Claude Guillou
- European Commission, Joint Research Centre, Directorate F-Health, Consumers and Reference Materials, Ispra, Italy
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
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Deventer MH, Van Uytfanghe K, Vinckier IMJ, Reniero F, Guillou C, Stove CP. Cannabinoid receptor activation potential of the next generation, generic ban evading OXIZID synthetic cannabinoid receptor agonists. Drug Test Anal 2022; 14:1565-1575. [PMID: 35560866 DOI: 10.1002/dta.3283] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 11/07/2022]
Abstract
In recent years, several nations have implemented various measures to control the surge of new synthetic cannabinoid receptor agonists (SCRAs) entering the recreational drug market. In July 2021, China put into effect a new generic legislation, banning SCRAs containing one of 7 general core scaffolds. However, this has driven manufacturers towards the synthesis of SCRAs with alternative core structures, exemplified by the recent emergence of "OXIZID SCRAs". Here, using in vitro β-arrestin2 recruitment assays, we report on the CB1 and CB2 potency and efficacy of five members of this new class of SCRAs: BZO-HEXOXIZID, BZO-POXIZID, 5-fluoro BZO-POXIZID, BZO-4en-POXIZID and BZO-CHMOXIZID. All compounds behaved as full agonists at CB1 and partial agonists at CB2 . Potencies ranged from 84.6 - 721 nM at CB1 and 2.21 - 25.9 nM at CB2 . Shortening the n-hexyl tail to a pentyl tail enhanced activity at both receptors. Fluorination of this pentyl analog did not yield a higher receptor activation potential, whereas an unsaturated tail resulted in decreased potency and efficacy at CB1 . The cyclohexyl methyl analog BZO-CHMOXIZID was the most potent compound at both receptors, with EC50 values of 84.6 and 2.21 nM at CB1 and CB2 , respectively. Evaluation of the activity of a seized powder containing BZO-4en-POXIZID suggested a high purity, in line with HPLC-DAD, GC-MS, LC-QTOF-MS and FTIR and NMR analysis. Furthermore, all tested compounds showed a preference for CB2 , except for BZO-POXIZID. Overall, these findings inform public health officials, law enforcement agencies and clinicians on these newly emerging SCRAs.
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Affiliation(s)
- M H Deventer
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - K Van Uytfanghe
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | | | - F Reniero
- European Commission, Joint Research Centre, Directorate F-Health, Consumers and Reference Materials, Ispra, VA, Italy
| | - C Guillou
- European Commission, Joint Research Centre, Directorate F-Health, Consumers and Reference Materials, Ispra, VA, Italy
| | - C P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
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Kevin RC, Mirlohi S, Manning JJ, Boyd R, Cairns EA, Ametovski A, Lai F, Luo JL, Jorgensen W, Ellison R, Gerona RR, Hibbs DE, McGregor IS, Glass M, Connor M, Bladen C, Zamponi GW, Banister SD. Putative Synthetic Cannabinoids MEPIRAPIM, 5F-BEPIRAPIM (NNL-2), and Their Analogues Are T-Type Calcium Channel (Ca V3) Inhibitors. ACS Chem Neurosci 2022; 13:1395-1409. [PMID: 35442021 DOI: 10.1021/acschemneuro.1c00822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) are a large and growing class of new psychoactive substances (NPSs). Two recently identified compounds, MEPIRAPIM and 5F-BEPIRAPIM (NNL-2), have not been confirmed as agonists of either cannabinoid receptor subtype but share structural similarities with both SCRAs and a class of T-type calcium channel (CaV3) inhibitors under development as new treatments for epilepsy and pain. In this study, MEPIRAPIM and 5F-BEPIRAPIM and 10 systematic analogues were synthesized, analytically characterized, and pharmacologically evaluated using in vitro cannabinoid receptor and CaV3 assays. Several compounds showed micromolar affinities for CB1 and/or CB2, with several functioning as low potency agonists of CB1 and CB2 in a membrane potential assay. 5F-BEPIRAPIM and four other derivatives were identified as potential CaV3 inhibitors through a functional calcium flux assay (>70% inhibition), which was further confirmed using whole-cell patch-clamp electrophysiology. Additionally, MEPIRAPIM and 5F-BEPIRAPIM were evaluated in vivo using a cannabimimetic mouse model. Despite detections of MEPIRAPIM and 5F-BEPIRAPIM in the NPS market, only the highest MEPIRAPIM dose (30 mg/kg) elicited a mild hypothermic response in mice, with no hypothermia observed for 5F-BEPIRAPIM, suggesting minimal central CB1 receptor activity.
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Affiliation(s)
- Richard C. Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
- School of Pharmacy, The University of Sydney, NSW 2006, Australia
| | - Somayeh Mirlohi
- Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW 2109, Australia
| | - Jamie J. Manning
- Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand
| | - Rochelle Boyd
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Elizabeth A. Cairns
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
- School of Psychology, The University of Sydney, NSW 2006, Australia
| | - Adam Ametovski
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Felcia Lai
- School of Pharmacy, The University of Sydney, NSW 2006, Australia
| | - Jia Lin Luo
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
- School of Psychology, The University of Sydney, NSW 2006, Australia
| | | | - Ross Ellison
- Clinical Toxicology and Environmental Biomonitoring Laboratory, University of California, San Francisco, California 94143, United States
| | - Roy R. Gerona
- Clinical Toxicology and Environmental Biomonitoring Laboratory, University of California, San Francisco, California 94143, United States
| | - David E. Hibbs
- School of Pharmacy, The University of Sydney, NSW 2006, Australia
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
- School of Psychology, The University of Sydney, NSW 2006, Australia
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand
| | - Mark Connor
- Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW 2109, Australia
| | - Chris Bladen
- Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW 2109, Australia
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Gerald W. Zamponi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Samuel D. Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, NSW 2050, Australia
- School of Chemistry, The University of Sydney, NSW 2006, Australia
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6
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Markham J, Sparkes E, Boyd R, Chen S, Manning JJ, Finlay D, Lai F, McGregor E, Maloney CJ, Gerona RR, Connor M, McGregor IS, Hibbs DE, Glass M, Kevin RC, Banister SD. Defining Steric Requirements at CB 1 and CB 2 Cannabinoid Receptors Using Synthetic Cannabinoid Receptor Agonists 5F-AB-PINACA, 5F-ADB-PINACA, PX-1, PX-2, NNL-1, and Their Analogues. ACS Chem Neurosci 2022; 13:1281-1295. [PMID: 35404067 DOI: 10.1021/acschemneuro.2c00034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) are a diverse class of new psychoactive substances (NPS). They commonly comprise N-alkylated indole, indazole, or 7-azaindole scaffolds with amide-linked pendant amino acid groups. To explore the contribution of the amino acid side chain to the cannabinoid pharmacology of SCRA NPS, a systematic library of side chain-modified SCRAs was prepared based on the recent detections of amino acid derivatives 17 (5F-AB-PINACA), 18 (5F-ADB-PINACA), 15 (PX-1), 19 (PX-2), and 20 (NNL-1). In vitro binding affinities and functional activities at cannabinoid type 1 and 2 receptors (CB1 and CB2, respectively) were determined for all the library members using radioligand competition experiments and a fluorescence-based membrane potential assay. Binding affinities and functional activities varied widely across compounds (Ki = 0.32 to >10 000 nM, EC50 = 0.24-1259 nM), with several clear structure-activity relationships (SARs) emerging. Affinity and potency at CB1 changed as a function of the heterocyclic core (indazole > indole > 7-azaindole) and the pendant amino acid side chain (tert-butyl > iso-propyl > iso-butyl > benzyl > ethyl > methyl > hydrogen). Ensemble docking at CB1 revealed a clear steric basis for observed SAR trends. Interestingly, although 15 (PX-1) and 19 (PX-2) have been detected in recreational drug markets, they failed to induce centrally CB1-mediated effects (e.g., hypothermia) in mice using radiobiotelemetry. Together, these data provide insights regarding structural contributions to the cannabimimetic profiles of 17 (5F-AB-PINACA), 18 (5F-ADB-PINACA), 15 (PX-1), 19 (PX-2), 20 (NNL-1), and other SCRA NPS.
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Affiliation(s)
- Jack Markham
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Eric Sparkes
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Rochelle Boyd
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Shuli Chen
- Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand
| | - Jamie J. Manning
- Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand
| | - David Finlay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand
| | - Felcia Lai
- School of Pharmacy, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Eila McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Psychology, The University of Sydney, Sydney 2005, New South Wales, Australia
| | - Callan J. Maloney
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Roy R. Gerona
- Clinical Toxicology and Environmental Biomonitoring Laboratory, University of California, San Francisco, California 94143, United States
| | - Mark Connor
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney 2109, New South Wales, Australia
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Psychology, The University of Sydney, Sydney 2005, New South Wales, Australia
| | - David E. Hibbs
- School of Pharmacy, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand
| | - Richard C. Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Pharmacy, The University of Sydney, Sydney 2006, New South Wales, Australia
| | - Samuel D. Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney 2050, New South Wales, Australia
- School of Chemistry, The University of Sydney, Sydney 2006, New South Wales, Australia
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