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  2. Neurochemical pharmacology of psychoactive substituted N-benzylphenethylamines: High potency agonists at 5-HT2A receptors

Neurochemical pharmacology of psychoactive substituted N-benzylphenethylamines: High potency agonists at 5-HT2A receptors

  • Biochem Pharmacol. 2018 Dec:158:27-34. doi: 10.1016/j.bcp.2018.09.024.
Amy J Eshleman 1 Katherine M Wolfrum 2 John F Reed 2 Sunyoung O Kim 2 Robert A Johnson 2 Aaron Janowsky 3
Affiliations

Affiliations

  • 1 Research Service, VA Portland Health Care System, Portland, OR 97239, United States; Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, United States. Electronic address: eshleman@ohsu.edu.
  • 2 Research Service, VA Portland Health Care System, Portland, OR 97239, United States.
  • 3 Research Service, VA Portland Health Care System, Portland, OR 97239, United States; Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, United States; Department of Psychiatry, Oregon Health and Science University, Portland, OR 97239, United States; The Methamphetamine Abuse Research Center, Oregon Health and Science University, Portland, OR 97239, United States.
Abstract

The use of new psychoactive substituted 2,5-dimethoxy-N-benzylphenethylamines is associated with abuse and toxicity in the United States and elsewhere and their pharmacology is not well known. This study compares the mechanisms of action of 2-(2,5-dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe), 2-(4-ethyl-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25E-NBOMe), 2-(2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25H-NBOMe), 2-(((4-iodo-2,5-dimethoxyphenethyl)amino)methyl)phenol (25I-NBOH); and 2-(2,5-dimethoxy-4-nitrophenyl)-N-(2-methoxybenzyl)ethanamine) (25N-NBOMe) with hallucinogens and stimulants. Mammalian cells heterologously expressing 5-HT1A, 5-HT2A, 5-HT2B or 5-HT2C receptors, or dopamine, serotonin or norepinephrine transporters (DAT, SERT and NET, respectively) were used to assess drug affinities at radioligand binding sites. Potencies and efficacies were determined using [35S]GTPγS binding assays (5-HT1A), inositol-phosphate accumulation assays (5-HT2A, 5-HT2B and 5-HT2C), and uptake and release assays (transporters). The substituted phenethylamines were very low potency and low efficacy agonists at the 5-HT1A receptor. 25D-NBOMe, 25E-NBOMe, 25H-NBOMe, 25I-NBOH and 25N-NBOMe had very high affinity for, and full efficacy at, 5-HT2A and 5-HT2C receptors. In the 5-HT2A receptor functional assay, 25D-NBOMe, 25E-NBOMe, 25I-NBOH and 25N-NBOMe had subnanomolar to low nanomolar potencies similar to (+)lysergic acid diethylamide (LSD) while 25H-NBOMe had lower potency, similar to serotonin. At the 5-HT2C receptor, four had very high potencies, similar to LSD and serotonin, while 25H-NBOMe had lower potency. At the 5-HT2B receptor, the compounds had lower affinity, potency and efficacy compared to 5-HT2A or 5-HT2C. The phenethylamines had low to mid micromolar affinities and potencies at the transporters. These results demonstrate that these -NBOMe and -NBOH substituted phenethylamines have a biochemical pharmacology consistent with hallucinogenic activity, with little psychostimulant activity.

Keywords

2-(((4-Iodo-2,5-dimethoxyphenethyl)amino)methyl)phenol (25I-NBOH) (PubChem CID: 10001761); 2-(2,5-Dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe) (PubChem CID: 118536027); 2-(2,5-Dimethoxy-4-nitrophenyl)-N-(2-methoxybenzyl)ethanamine) (25N-NBOMe) (PubChem CID: 118536028); 2-(2,5-Dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25H-NBOMe) (PubChem CID: 121230760); 2-(4-Ethyl-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25E-NBOMe) (PubChem CID: 121230757); Drug abuse; Lysergic acid diethylamide (LSD); NBOMe; Serotonin receptor; Substituted phenethylamine.

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