Serotonergic psychedelics are defined as compounds having serotonin 2A receptor (5-HT2AR) activation as an important pharmacological mechanism. These compounds include the phenylalkylamine class, containing substances with e.g. 2C-X structures (phenethylamines) or their N-methoxybenzyl analogues (NBOMes). Besides their abuse potential, psychedelics are increasingly recognized for having therapeutic benefits. However, many psychedelics remain incompletely characterized, even concerning their structure–activity relationships. Here, five positional isomers of 25H-NBOMe, with two methoxy groups on the different positions of the phenyl ring of the phenethylamine moiety, were subjected to split-nanoluciferase assays assessing the in vitro recruitment of cytosolic proteins to the 5-HT2AR. Furthermore, molecular docking at the 5-HT2AR allowed estimation of which residues interact with the specific isomers’ methoxy groups. Although the optimal substitution pattern of N-unsubstituted phenylalkylamines has been extensively studied, this is the first comparative evaluation of the functional effects of the positioning of the methoxy groups in the phenethylamine moiety of NBOMes.

N‐(2‐Methoxybenzyl)‐2,5‐dimethoxyphenethylamines (NBOMes) are synthetic phenethylamine derivatives emerging on the global drug market and reported to be associated with untoward effects in people who use drugs. Its action involves agonism at serotonin 5‐HT2A receptors, affecting cognitive and behavioral processes. However, certain isomers of NBOMes may not show any psychoactive effects. They are not controlled by legislation and can be tested as pharmaceutical drugs. This study deals with the differentiation among positional isomers of 25H‐NBOMe differing in the position of the two methoxy groups in the phenylethyl moiety of the molecule, using chromatography–mass spectrometry methods. The gas chromatography analysis showed that the isothermal mode was more efficient than the usually applied temperature‐programming mode for the separation of the mentioned isomers. Electron ionization mass spectra of 25H‐NBOMe isomers were highly similar, often resulting in a high probability of erroneous identification. However, mass spectra of their trifluoroacetyl or pentafluoropropanoyl derivatives were easily identified as they contained fragments with many significant differences. The proposed analysis using liquid chromatography–tandem mass spectrometry could distinguish the isomers of 25H‐NBOMe without the need for any derivatization.

Emergence of new psychoactive substances, hallucinogenic phenethylamines in particular, in illicit market is a serious threat to human health in global scale. We have detected and identified N-(2-methoxybenzyl)-2-(2,4,6-trimethoxyphenyl)ethanamine (2,4,6-TMPEA-NBOMe), a new compound in NBOMe series. Identification was achieved by means of gas chromatography/mass spectrometry (GC/MS), including high-resolution mass spectrometry with tandem experiments (GC/HRMS and GC/HRMS ), ultra-high performance liquid chromatography/high-resolution mass spectrometry with tandem experiments (UHPLC/HRMS and UHPLC/HRMS ), and H and C nuclear magnetic resonance spectroscopy. The peculiarities of fragmentation of the compound under electron ionization (EI) and collision-induced dissociation were studied. Despite of the empirical rule denying migration of the hydrogen atom in McLafferty rearrangement to the benzene ring with substituents in the both ortho-positions, it easily occurs for 2,4,6-TMPEA-NBOMe in EI conditions. We have noticed that electron-donating substituents, e.g. methoxy groups in the both ortho-positions and para-positions favor the rearrangement. For specially synthesized N-methyl and N-acyl derivatives McLafferty rearrangement is not observed. N-Acyl derivatives demonstrate McLafferty rearrangement, but the charge retains at the alternative fragment involving N-acyl carbonyl group. We have also showed that the hydrogen atoms in 2,4,6-trimethoxybenzene ring may be easily substituted for deuterium or for strong electrophiles like trifluoroacetyl. Analytical characteristics of 2,4,6-TMPEA-NBOMe and of some derivatives thereof which enable their determination in various criminal seizures are given. Copyright © 2016 John Wiley & Sons, Ltd.

Serotonergic psychedelics, substances exerting their pharmacological action through activation of the serotonin 2A receptor (5-HT 2A R), have continuously comprised a substantial fraction of the over 1000 reported New Psychoactive Substances (NPS) so far. Within this category, N-benzyl derived phenethylamines, such as NBOMes and NBFs, have shown to be of particular relevance. As these substances remain incompletely characterized, this study aimed at synthesizing positional isomers of 25H-NBF, with two methoxy groups placed on different positions of the phenyl group of the phenethylamine moiety. These isomers were then functionally characterized in an in vitro bioassay monitoring the recruitment of β-arrestin 2 to the 5-HT 2A R through luminescent readout via the NanoBiT technology. The obtained results provide insight into the optimal substitution pattern of the phenyl group of the phenethylamine moiety of Nbenzyl derived substances, a feature so far mostly explored in the phenethylamines underived at the N-position. In the employed bioassay, the most potent substances were 24H-NBF (EC 50 value of 158 nM), 26H-NBF (397 nM), and 25H-NBF (448 nM), with 23H-NBF, 35H-NBF, and 34H-NBF yielding μM EC 50 values. A similar ranking was obtained for the compounds' efficacy: taking as a reference LSD (lysergic acid diethylamide), 24H-, 26H-, and 25H-NBF had an efficacy of 106−107%, followed by 23H-NBF (96.1%), 34H-NBF (75.2%), and 35H-NBF (58.9%). The stronger activity of 24H-, 25H-, and 26H-NBF emphasizes the important role of the methoxy group at position 2 of the phenethylamine moiety for the in vitro functionality of NBF substances.

Hallucinogenic drugs potently affect brain and behavior and have also recently emerged as potentially promising agents in pharmacotherapy. Complementing laboratory rodents, the zebrafish (Danio rerio) is a powerful animal model organism for screening neuroactive drugs, including hallucinogens. Here, we test a battery of ten novel N-benzyl-2-phenylethylamine (NBPEA) derivatives with the 2,4-and 3,4-dimethoxy substitutions in the phenethylamine moiety and the −OCH 3 , −OCF 3 , −F, −Cl, and −Br substitutions in the ortho position of the phenyl ring of the N-benzyl moiety, assessing their acute behavioral and neurochemical effects in the adult zebrafish. Overall, substitutions in the Overall, substitutions in the N-benzyl moiety modulate locomotion, and substitutions in the phenethylamine moiety alter zebrafish anxiety-like behavior, also affecting the brain serotonin and/or dopamine turnover. The 24H−NBOMe(F) and 34H−NBOMe(F) treatment also reduced zebrafish despair-like behavior. Computational analyses of zebrafish behavioral data by artificial intelligence identified several distinct clusters for these agents, including anxiogenic/hypolocomotor (24H−NBF, 24H− NBOMe, and 34H−NBF), behaviorally inert (34H−NBBr, 34H−NBCl, and 34H−NBOMe), anxiogenic/hallucinogenic-like (24H−NBBr, 24H−NBCl, and 24H−NBOMe(F)), and anxiolytic/hallucinogenic-like (34H−NBOMe(F)) drugs. Our computational analyses also revealed phenotypic similarity of the behavioral activity of some NBPEAs to that of selected conventional serotonergic and antiglutamatergic hallucinogens. In silico functional molecular activity modeling further supported the overlap of the drug targets for NBPEAs tested here and the conventional serotonergic and antiglutamatergic hallucinogens. Overall, these findings suggest potent neuroactive properties of several novel synthetic NBPEAs, detected in a sensitive in vivo vertebrate model system, the zebrafish, raising the possibility of their potential clinical use and abuse.

Essential oils are widely used in aromatherapy, medicine, and food industries due to a wide spectrum of bioactivity. Their antioxidant properties can be considered as markers of therapeutic effect and quality. Constant–current coulometry with electrogenerated titrants has been successfully applied for these purposes for the first time. Fifteen types of essential oils from various plant materials have been studied. Their composition has been identified by gas chromatography with mass-spectrometric detection (GC-MS). The reactivity of individual antioxidants of essential oils towards electrogenerated titrants (bromine and ferricyanide ions) has been estimated. Total antioxidant parameters, in particular total antioxidant capacity (TAC) and ferric reducing power (FRP) based on the reactions of essential oil antioxidants with electrogenerated bromine and ferricyanide ions, respectively, have been evaluated. Positive correlations (r = 0.7051–0.9558) with common antioxidant tests (antioxidant activity by reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and total phenolic content by the Folin–Ciocalteu method) have been obtained. Coulometric approaches overcome the limitations of spectrophotometry and are applicable to a wider range of essential oils.

N-(2-substituted benzyl)-2,5-dimethoxyphenethylamines often cause severe poisonings which has led to their legal prohibition in many countries. At the same time, their positional isomers can be studied as potential therapeutic drugs. In this regard, the search for various approaches to differentiate these isomers is an important practical

Serotonergic hallucinogenic drugs potently affect human brain and behavior, and have recently emerged as potentially promising agents in psychopharmacotherapy. Complementing rodent studies, zebrafish (Danio rerio) is a powerful animal model for screening neuroactive drugs, including serotonergic agents. Here, we test ten different N-Benzyl-2-phenylethylamine (NBPEA) derivatives with the 2,4- and 3,4-dimethoxy substitutions in the phenethylamine moiety and the -OCH3, -OCF3, -F, -Cl and -Br substitutions in the ortho position of phenyl ring of N-benzyl fragment, assessing their behavioral and neurochemical effects in adult zebrafish. Overall, substitutions in N-benzyl fragment primarily affected zebrafish locomotion, and in phenethylamine moiety - anxiety-like behavior, also modulating brain serotonin and/or dopamine turnover. We also identified several behavioral clusters, including anxiogenic/hypolocomotor (24H-NBF, 24H-NBOMe and 34H-NBF), behaviorally inert (34H-NBBr, 34H-NBCl and 34H-NBOMe), anxiogenic/hallucinogenic-like (24H-NBBr, 24H-NBCl and 24H-NBOMe(F)), and anxiolytic/hallucinogenic-like (34H-NBOMe(F)) agents. The 24H-NBOMe(F) and 34H-NBOMe(F) also reduced despair-like behavior in zebrafish. The artificial intelligence-driven phenotyping supports association of multiple compounds with NMDA antagonists and/or MDMA, supporting their potential hallucinogenic-like properties, as well as other valuable psychoactive effects. In silico functional molecular activity modelling also supports existing of similarities between studied NBOMes drugs, MDMA, and ketamine. Functional analysis implicates potential involvement of serotonin release stimulating activity, calcium channel (voltage-sensitive) activity, some serotonin receptors activity and variety of psychiatric and neurologic disorders treatments activities. Overall, we report potent neuroactive properties of several novel synthetic N-benzylphenylethylamines in an in vivo vertebrate model system (zebrafish), raising the possibility of their potential use in clinical practice.