Analytical characterization of three hallucinogenicN-(2-methoxy)benzyl derivatives of the 2C-series of phenethylamine drugs

Applications of MALDI mass spectrometry in forensic science

Forensic chemistry literature has grown exponentially, with many analytical techniques being used to provide valuable information to help solve criminal cases. Among them, matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS), particularly MALDI MS imaging (MALDI MSI), has shown much potential in forensic applications. Due to its high specificity, MALDI MSI can analyze a wide variety of compounds in complex samples without extensive sample preparation, providing chemical profiles and spatial distributions of given analyte(s). This review introduces MALDI MS(I) to forensic scientists with a focus on its basic principles and the applications of MALDI MS(I) to the analysis of fingerprints, drugs of abuse, and their metabolites in hair, medicine samples, animal tissues, and inks in documents.

25X-NBOMe compounds - chemistry, pharmacology and toxicology. A comprehensive review

Recently, a growing number of reports have indicated a positive effect of hallucinogenic-based therapies in different neuropsychiatric disorders. However, hallucinogens belonging to the group of new psychoactive substances (NPS) may produce high toxicity. NPS, due to their multi-receptors affinity, are extremely dangerous for the human body and mental health. An example of hallucinogens that have been lately responsible for many severe intoxications and deaths are 25X-NBOMes - N-(2-methoxybenzyl)-2,5-dimethoxy-4-substituted phenethylamines, synthetic compounds with strong hallucinogenic properties. 25X-NBOMes exhibit a high binding affinity to serotonin receptors but also to dopamine, adrenergic and histamine receptors. Apart from their influence on perception, many case reports point out systemic and neurological poisoning with these compounds. In humans, the most frequent side effects are tachycardia, anxiety, hypertension and seizures. Moreover, preclinical studies confirm that 25X-NBOMes cause developmental impairments, cytotoxicity, cardiovascular toxicity and changes in behavior of animals. Metabolism of NBOMes seems to be very complex and involves many metabolic pathways. This fact may explain the observed high toxicity. In addition, many analytical methods have been applied in order to identify these compounds and their metabolites. The presented review summarized the current knowledge about 25X-NBOMes, especially in the context of toxicity.

4-EA-NBOMe, an amphetamine derivative, alters glutamatergic synaptic transmission through 5-HT1A receptors on cortical neurons from SpragueDawley rat and pyramidal neurons from C57BL/6 mouse

New psychoactive substances (NPSs) are compounds designed to mimic illegal recreational drugs. In particular, there are difficulties in legal restrictions because there is no fast NPS detection method to suppress the initial spread of NPS with criminal records; thus, they expose the public to serious health threats, including toxicity and dependence. However, the effects of NPSs on the brain and the related cellular mechanisms are well unknown. One of the recently emerging drugs is 4-ethylamphetamine-NBOMe (4-EA-NBOMe), a member of the 2 C phenylalanine family with a similar structure to methamphetamine (methA). In this study, we tested the effect of methA analogs on the glutamatergic synaptic transmission on primary cultured cortical neurons of SpragueDawley (SD) rats and C57BL/6 mice, and also layer 2/3 pyramidal neurons of the medial prefrontal cortex (mPFC) of C57BL/6 mice. We found that acute treatment with 4-EA-NBOMe inhibits spontaneous excitatory postsynaptic currents (EPSCs) and that withdrawal after chronic inhibition by 4-EA-NBOMe augments glutamatergic synaptic transmission. These modifications of synaptic responses are mediated by 5-HT_1A receptors. These findings suggest that 4-EA-NBOMe directly affects the central nervous system by changing the efficacy of glutamatergic synaptic transmission.

Potential of chromatography and mass spectrometry for the differentiation of three series of positional isomers of 2-(dimethoxyphenyl)-N-(2-halogenobenzyl)ethanamines

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 task, the solution of which would guarantee from identification errors during laboratory analysis. In this paper, the possibilities of differentiation of isomers varying in the position of two methoxy groups in the phenylethyl part of the molecule are considered on the example of compounds of NBF, NBCl and NBBr series by chromatography-mass spectrometry methods. Gas or liquid reverse-phase chromatography in the proposed chromatographic separation modes has demonstrated their ability to resolve this problem reliably. Data on retention indices of isomeric compounds and their derivatives can serve as an additional identification criterion for gas chromatography-mass spectrometry (GC-MS) analysis. Differentiation of NBF and NBCl isomers using electron ionization (EI) mass spectra is feasible only if both the spectrum of the compound and its N-trifluoroacetyl derivative are registered; differentiation of NBBr positional isomers under these conditions does not require obtaining the derivatives. Using electrospray ion source, the compounds can easily be differentiated based on the distinctive features of their collision induced dissociation (CID) spectra recorded at low energy values, which also does not require the synthesis of derivatives. The data presented in current paper will be useful for analysis in laboratories providing the determination of narcotic drugs.

Discrimination of phenethylamine regioisomers and structural analogues by Raman spectroscopy

In this study, the Raman spectra of 21 phenethylamines were obtained using far-red excitation (785 nm). The distinguishing ability of Raman for phenethylamines, especially for phenethylamine regioisomers and structural analogues, was investigated. Here, the evaluation of a cross section of Raman spectra demonstrated that all types of phenethylamines were distinguishable, even for certain structural analogues with high spectrum similarity. Raman exhibited high distinguishing ability for phenethylamine regioisomers that differ in the substitution position of halogen, methoxy, alkyl, or other substituted groups; as well as for structural analogues containing different groups, such as furanyl, 2,3-dihydrofuranyl, halogen, and alkyl substituted at the same position. The Raman spectra for homologues with differences in only a methyl group were found to be highly similar; however, their spectra demonstrated small but detectable differences. Four analogue mixtures and 59 seized samples were also analyzed to study the practical use of the Raman method in forensic field. 95% of the seized samples were correctly identified, which significantly validated the ability of Raman method in identifying the correct isomers. Accordingly, this study provides a non-destructive, high-throughput and minimal sample preparation technique for the discrimination of phenethylamines.

Development and validation of a color spot test method for the presumptive detection of 25-NBOMe compounds

The great increase of new psychoactive substances over the past decade has substantially transformed the illicit drug industry to an ever-changing dynamic market. 25-NBOMe compounds are just one of these new substance groups that pose a public health risk in many countries around the world. These highly potent, hallucinogenic phenethylamines have previously been sold as "legal highs" or "synthetic LSD" and the necessity to rapidly identify their presence is crucial. While there are many laboratory-based analytical methods capable of identifying these compounds, the lack of presumptive test methods indicates the need for a specific and timely test that could be used in the field. Herein we outline the developed chemical spot test that can selectively identify the presence of 25-NBOMe compounds and related analogs through the reaction with a substituted benzoquinone reagent under basic conditions. This test method has been comprehensively validated showing a high level of selectivity, specificity, and precision with only two other illicit substances producing similar positive results as 25-NBOMe and few false-negative results seen. The working limit of detection was determined to be 225 μg and there was no cross-reactivity from potential adulterants of significance. This test has also been shown to work directly with blotter papers containing 25-NBOMe compounds, indicating no interference from this common matrix and the ability to differentiate these compounds from LSD. This method shows a high potential to be translated to a field compatible test that is simple, rapid, and selective for 25-NBOMe compounds.

Structure fragmentation studies of ring-substituted N-trifluoroacetyl-N-benzylphenethylamines related to the NBOMe drugs

RATIONALE

The halogenated derivatives of N-(2-methoxy)benzyl-2,5-dimethoxyphenethylamine (25-NBOMe) such as the 4-bromo analogue (25B-NBOMe) represent a new class of hallucinogenic or psychedelic drugs. The purpose of this study was to determine the role of the electron-donating groups (halogen and dimethoxy) in the pathway of decomposition for the distonic molecular radical cation in the electron ionization mass spectrometry (EI-MS) process of the trifluoroacetamide (TFA) derivatives.

METHODS

The systematic removal of substituents from the 4-halogenated 2,5-dimethoxyphenethylamine portion of the N-dimethoxybenzyl NBOMe analogues allowed an evaluation of structural effects on the formation of major fragment ions in the EI-MS of the TFA derivatives. All six regioisomeric dimethoxybenzyl-substituted analogues (2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-dimethoxy) for the four series of phenethyl aromatic ring substitution patterns were prepared, derivatized and analyzed via gas chromatography coupled with EI-MS.

RESULTS

The analogues yield two unique radical cation fragments from the decomposition of the common distonic molecular radical cation. The substituted phenylethene radical cation (m/z 164) is the base peak or second most abundant ion in all six TFA-2,5-dimethoxyphenethylamine isomers. The dimethoxybenzyltrifloroacetamide radical cation (m/z 263) is the base peak or second most abundant ion in the 2- and 3-monomethoxyphenethylamine isomers. However, the 2- and 3-methoxyphenylethene radical cation (m/z 134) is among the five most abundant ions for each of these twelve isomers. Only one isomer in the phenethylamine series yields the corresponding unsubstituted phenylethene radical cation at m/z 104.

CONCLUSIONS

The decomposition of the hydrogen-rearranged distonic molecular radical cation favors formation of the dimethoxybenzyltrifloroacetamide (m/z 263) species for the less electron-rich phenethyl aromatic rings. The addition of electron-donating groups to the aromatic ring of the phenethyl group as in the NBOMe-type molecules shifts the decomposition of the common distonic molecular radical cation to favor the formation of the electron-rich substituted phenylethene radical cation.

Clinical value of analytical testing in patients presenting with new psychoactive substances intoxication

New psychoactive substances (NPS) have emerged worldwide in recent years, posing a threat to public health and a challenge to drug policy. NPS are usually derivatives or analogues of classical recreational drugs designed to imitate their effects while circumventing regulations. This article provides an overview of benefits and limitations of analytical screening in managing patients presenting with acute NPS toxicity. NPS typically cannot be analytically identified with the usual immunoassay tests. To detect NPS using an immunoassay, antibodies specifically binding to the new structures would have to be developed, which is complicated by the rapid change of the NPS market. Activity-based assays could circumvent this problem since no prior knowledge on the substance structure is necessary. However, classical recreational drugs activating the same receptors could lead to false positive results. Liquid or gas chromatography coupled with mass spectrometry is a valuable NPS analysis tool, but its costs (e.g. equipment), run time (results usually within hours vs minutes in case of immunoasssays) and the need for specialized personnel hinder its use in clinical setting, while factors such as lack of reference standards can pose further limitations. Although supportive measures are sufficient in most cases for adequate patient management, the detection and identification of NPS can contribute significantly to public health and safety in cases of e.g. cluster intoxications and outbreaks, and to the investigation of these novel compounds' properties. However, this requires not only availability of the necessary equipment and personnel, but also collaboration between clinicians, authorities and laboratories.

MS-Based Molecular Networking of Designer Drugs as an Approach for the Detection of Unknown Derivatives for Forensic and Doping Applications: A Case of NBOMe Derivatives

The NBOMe family is a group of new psychoactive substances (NPSs). In this study, the fragmentation patterns of NBOMe derivatives were analyzed using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). The MS/MS spectral data was used to establish a molecular networking map for NBOMe derivatives. The fragmentation patterns of nine NBOMe derivatives were interpreted on the basis of their product ion spectral data. NBOMe derivatives generally showed similar product ion spectral patterns; among them, the halogen-substituted methoxybenzyl ethanamine type derivatives showed a characteristic product ion of a radical cation. Molecular network analysis of the MS/MS data revealed that all NBOMe derivatives formed one integrated networking cluster that discriminated them from other types of NPSs. NBOMe derivatives were spiked into human urine and identified by connection to the NBOMe database network. Furthermore, the NBOMe compounds that were not registered in the database were also recognized as an NBOMe-related substance by molecular networking. These results demonstrate the potential of using molecular networking-based screening methods for designer drugs, and the proposed method would be useful in forensic or doping analysis.

Clinical and Toxicological Profile of NBOMes: A Systematic Review

BACKGROUND

NBOMes are a new class of potent hallucinogens widely present in illicit drugs. Little is known about this class of drugs, regarding its detection and clinical manifestations of intoxication.

OBJECTIVE

This study aims to enhance care involving NBOMes by reviewing the literature on their clinical manifestations and laboratorydetection.

METHODS

A systematic review was performed on the clinical manifestations and laboratory tests of NBOMEs ingestion. Embase, Pubmed, PsycINFO, and Cochrane databases were employed in this analysis.

RESULTS

Forty-five articles met the inclusion criteria out of the 2814 nonduplicated studies on the theme. Seventy case reports of intoxication were found in the analyzed articles (64.3% were men and 11.4% were women, mean age of 22.5). The technique most employed for NBOMes identification was chromatography of blood, urine, and oral fluids. Moreover, the studies identified 13 chemical structures differentfrom the NBOMes on their toxicological analyses.According to these studies, most of these drugs were ingested orally-nasal use was the second preferred administration route, followed by intravenous administration.

CONCLUSION

Better identification of the clinicalmanifestations and laboratory profile of NBOMes is crucial to the recognition of intoxication as well as to its effective treatment.

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

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.

Analysis of Fragmentation Pathways of New-Type Synthetic Cannabinoids Using Electrospray Ionization

Recently, dozens of new psychoactive substances have appeared on the European drug market every year. The most abundant group of these compounds is synthetic cannabinoids. In the first few years of the "legal highs" phenomenon, JWH (John W. Huffman) compounds were especially popular among drug users. However, the group of synthetic cannabinoids is constantly expanding, as new compounds are created by replacing known structural elements with different chemical groups. The problem with the identification of novel substances in forensic laboratories results from the structural similarity of the compounds and the rapid introduction of newer designer drugs on the black market. In this study, the fragmentation patterns of 29 new-type synthetic cannabinoids using electrospray ionization were investigated. The analysis was performed using quadrupole time-of-flight mass spectrometry. Based on measurements carried out under various conditions, the way of fragmentation of the tested compounds that were divided into groups due to their chemical structure was established. The study showed that the bond between the carbon atom of the carbonyl group and the ring or NH group attached to the ring was mainly cleaved. This mechanism was adequate for the fragmentation of first-generation synthetic cannabinoids. This paper presents characteristic ions formed by synthetic cannabinoids (i.e., ions originating from an indole/indazole ring and an adamanyl/naphthalene/quinoline ring) using electrospray ionization. Knowledge of these specific fragments can be used in forensic laboratories to determine the structure of novel compounds from the group of synthetic cannabinoids. Graphical Abstract ᅟ.

Nano liquid chromatography-high-resolution mass spectrometry for the identification of metabolites of the two new psychoactive substances N-(ortho-methoxybenzyl)-3,4-dimethoxyamphetamine and N-(ortho-methoxybenzyl)-4-methylmethamphetamine

Among the emerging new psychoactive substances (NPS), compounds carrying an N-ortho-methoxybenzyl substituent, the so-called NBOMes, represented a highly potent group of new hallucinogens. Recently, 3,4-dimethoxyamphetamine (3,4-DMA)-NBOMe and 4-methylmethamphetamine (4-MMA)-NBOMe occurred, but no data on their pharmacokinetics were available. According to other NBOMes, they are expected to be extensively metabolized. For detection and identification of their phase I and II metabolites, nano liquid chromatography coupled to high resolution tandem mass spectrometry (nanoLC-HRMS/MS) was used. Rat urine was prepared by simple dilution and incubation mixtures with pooled human liver S9 fraction by precipitation. Furthermore, the results concerning detectability using the new nanoLC approach were compared to those obtained by conventional ultra-high performance LC (UHPLC). In addition, the detectability of the compounds by standard urine screening approaches (SUSAs) routinely used by the authors with UHPLC-HRMS/MS, LC-MSⁿ, and GC-MS was tested. Both NBOMes were extensively metabolized mainly by O-demethylation and conjugation with glucuronic acid (3,4-DMA-NBOMe) or oxidation of the tolyl group to the corresponding carboxylic acid (4-MMA-NBOMe). The developed nanoLC-HRMS/MS approach was successfully applied for identification of 38 3,4-DMA-NBOMe metabolites and 33 4-MMA-NBOMe metabolites confirming its detection power. Furthermore, the solvent saving nanoLC system showed comparable results to the UHPLC-HRMS/MS approach. In addition, an intake of an estimated low common user's dose of the compounds was detectable by all SUSAs only via their metabolites. Suggested targets for urine screening procedures were O-demethyl- and O,O-bis-demethyl-3,4-DMA-NBOMe and their glucuronides and carboxy-4-MMA-NBOMe and its glucuronide and N-demethyl-carboxy-4-MMA-NBOMe.

Human cytochrome P450 kinetic studies on six N-2-methoxybenzyl (NBOMe)-derived new psychoactive substances using the substrate depletion approach

A huge number of new chemical derivatives of known drugs of abuse, so-called new psychoactive substances (NPS), are sold and consumed without prior preclinical and clinical testing. For assessing the elimination behaviors, determination of the kinetic constants K_m and V_max of the cytochrome P450 (CYP) isoforms involved in the hepatic metabolism of NPS could help to predict their contributions to hepatic clearance, drug-drug interactions and polymorphisms. Therefore, the aims of the present study were to determine the K_m and V_max values for CYP isoforms using the substrate depletion approach for the six N-2-methoxybenzyl (NBOMe)-derived NPS 25B-NBOMe, 25C-NBOMe, 25I-NBOMe, 3,4-DMA-NBOMe, 4-EA-NBOMe, and 4-MMA-NBOMe. Furthermore, the contributions of each CYP isozyme to the hepatic net clearance were elucidated using the relative activity factor approach. Several CYPs including CYP1A2, CYP2B6, CYP2C19, CYP2D6, and CYP3A4 were identified to be involved in the metabolism of the investigated compounds. The determined K_m values ranged from 0.010 μM (CYP2D6, 4-MMA-NBOMe) to 13 μM (CYP2B6, 4-EA-NBOMe). All NBOMes were good substrates of CYP2C19 and CYP2D6 resulting in very low K_m values in the nanomolar range. The main contributors to hepatic net clearance were CYP2D6 for 25B-NBOMe (69%), 25C-NBOMe (83%), 25I-NBOMe (61%), 3,4-DMA-NBOMe (89%) as well as for 4-EA-NBOMe (62%) and CYP2C19 for 4-MMA-NBOMe (64%). As more than one isoform was involved in the particular steps, the risk of harm associated with drug-drug interactions might be considered low. However, in cases where substances with high contributions from polymorphically expressed CYP2C19 and CYP2D6 are encountered, inter-individual variations in metabolism and excretion cannot be excluded.

Analytical Validation of a Portable Mass Spectrometer Featuring Interchangeable, Ambient Ionization Sources for High Throughput Forensic Evidence Screening

Forensic evidentiary backlogs are indicative of the growing need for cost-effective, high-throughput instrumental methods. One such emerging technology that shows high promise in meeting this demand while also allowing on-site forensic investigation is portable mass spectrometric (MS) instrumentation, particularly that which enables the coupling to ambient ionization techniques. While the benefits of rapid, on-site screening of contraband can be anticipated, the inherent legal implications of field-collected data necessitates that the analytical performance of technology employed be commensurate with accepted techniques. To this end, comprehensive analytical validation studies are required before broad incorporation by forensic practitioners can be considered, and are the focus of this work. Pertinent performance characteristics such as throughput, selectivity, accuracy/precision, method robustness, and ruggedness have been investigated. Reliability in the form of false positive/negative response rates is also assessed, examining the effect of variables such as user training and experience level. To provide flexibility toward broad chemical evidence analysis, a suite of rapidly-interchangeable ion sources has been developed and characterized through the analysis of common illicit chemicals and emerging threats like substituted phenethylamines. Graphical Abstract ᅟ.

Pharmacology and Toxicology of N-Benzylphenethylamine ("NBOMe") Hallucinogens

Serotonergic hallucinogens induce profound changes in perception and cognition. The characteristic effects of hallucinogens are mediated by 5-HT2A receptor activation. One class of hallucinogens are 2,5-dimethoxy-substituted phenethylamines, such as the so-called 2C-X compounds 2,5-dimethoxy-4-bromophenethylamine (2C-B) and 2,5-dimethoxy-4-iodophenethylamine (2C-I). Addition of an N-benzyl group to phenethylamine hallucinogens produces a marked increase in 5-HT2A-binding affinity and hallucinogenic potency. N-benzylphenethylamines ("NBOMes") such as N-(2-methoxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBOMe) show subnanomolar affinity for the 5-HT2A receptor and are reportedly highly potent in humans. Several NBOMEs have been available from online vendors since 2010, resulting in numerous cases of toxicity and multiple fatalities. This chapter reviews the structure-activity relationships, behavioral pharmacology, metabolism, and toxicity of members of the NBOMe hallucinogen class. Based on a review of 51 cases of NBOMe toxicity reported in the literature, it appears that rhabdomyolysis is a relatively common complication of severe NBOMe toxicity, an effect that may be linked to NBOMe-induced seizures, hyperthermia, and vasoconstriction.

Mass spectrometric properties of N-(2-methoxybenzyl)-2-(2,4,6-trimethoxyphenyl)ethanamine (2,4,6-TMPEA-NBOMe), a new representative of designer drugs of NBOMe series and derivatives thereof

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/HRMS² ), ultra-high performance liquid chromatography/high-resolution mass spectrometry with tandem experiments (UHPLC/HRMS and UHPLC/HRMS² ), and ¹ H and ¹³ 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.

Fatal Intoxications with 25B-NBOMe and 25I-NBOMe in Indiana During 2014

Over the last few years, NBOMe substances have been used either as a legal alternative to lysergic acid diethylamide (LSD) or sold surreptitiously as LSD to unknown users. These NBOMe substances have been detected in blotter papers, powders, capsules and liquids. We report the deaths of two teenage male subjects that were related to 25B-NBOMe and 25I-NBOMe in Indiana during 2014. Samples were extracted via a solvent protein precipitation with acetonitrile and analyzed via ultra-performance liquid chromatography with tandem mass spectrometry. For these two cases, we describe the NBOMe instrumental analysis, toxicological results for postmortem heart blood and urine specimens and the relevant case history and pathological findings at autopsy. In the first case, 25B-NBOMe was detected in postmortem heart blood at 1.59 ng/mL; in the second case, 25I-NBOMe was detected in postmortem heart blood at 19.8 ng/mL. We also review relevant published casework from clinical toxicology and postmortem toxicology in which analytically confirmed 25B-NBOMe and 25I-NBOMe were determined to be causative agents in intoxications or deaths.

Analysis of 25I-NBOMe, 25B-NBOMe, 25C-NBOMe and Other Dimethoxyphenyl-N-[(2-Methoxyphenyl) Methyl]Ethanamine Derivatives on Blotter Paper

In recent years, N-methoxybenzyl-methoxyphenylethylamine (NBOMe) derivatives, a class of designer hallucinogenic drugs, have become popular drugs of abuse. These drugs have been the cause of severe intoxications and even deaths. They act as 5-HT2A receptors agonists and have been reported to produce serotonin-like syndrome with bizarre behavior, severe agitation and seizures persisting for as long as 3 days. The most commonly reported derivatives are 25I-NBOMe, 25B-NBOMe and 25C-NBOMe, respectively 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl) methyl]ethanamine, N-(2-methoxybenzyl)-2,5-dimethoxy-4-bromophenethylamine and N-(2-methoxybenzyl)-2,5-dimethoxy-4-chlorophenethylamine. Like many low dose hallucinogenic drugs these compounds are often sold on blotter paper. Three different types of commercially available blotter papers reported to contain NBOMe derivatives were obtained. These blotter papers were screened using Direct Analysis in Real Time AccuTOF(TM) mass spectrometry followed by confirmation and quantification by high-performance liquid chromatography triple quadrapole mass spectrometry. The major drug present on each of the three blotter products was different, 25I-NBOMe, 25C-NBOMe or 25B-NBOMe. The blotter papers were also found to have minute amounts of two or three NBOMe derivative impurities of 25H-NBOMe, 25I-NBOMe, 25C-NBOMe, 25B-NBOMe and/or 25D-NBOMe.

Receptor interaction profiles of novel N-2-methoxybenzyl (NBOMe) derivatives of 2,5-dimethoxy-substituted phenethylamines (2C drugs)

BACKGROUND

N-2-methoxybenzyl-phenethylamines (NBOMe drugs) are newly used psychoactive substances with poorly defined pharmacological properties. The aim of the present study was to characterize the receptor binding profiles of a series of NBOMe drugs compared with their 2,5-dimethoxy-phenethylamine analogs (2C drugs) and lysergic acid diethylamide (LSD) in vitro.

METHODS

We investigated the binding affinities of 2C drugs (2C-B, 2C-C, 2C-D, 2C-E, 2C-H, 2C-I, 2C-N, 2C-P, 2C-T-2, 2C-T-4, 2C-T-7, and mescaline), their NBOMe analogs, and LSD at monoamine receptors and determined functional 5-hydroxytryptamine-2A (5-HT2A) and 5-HT2B receptor activation. Binding at and the inhibition of monoamine uptake transporters were also determined. Human cells that were transfected with the respective human receptors or transporters were used (with the exception of trace amine-associated receptor-1 [TAAR1], in which rat/mouse receptors were used).

RESULTS

All of the compounds potently interacted with serotonergic 5-HT2A, 5-HT2B, 5-HT2C receptors and rat TAAR1 (most Ki and EC50: <1 μM). The N-2-methoxybenzyl substitution of 2C drugs increased the binding affinity at serotonergic 5-HT2A, 5-HT2C, adrenergic α1, dopaminergic D1-3, and histaminergic H1 receptors and monoamine transporters but reduced binding to 5-HT1A receptors and TAAR1. As a result, NBOMe drugs were very potent 5-HT2A receptor agonists (EC50: 0.04-0.5 μM) with high 5-HT2A/5-HT1A selectivity and affinity for adrenergic α1 receptors (Ki: 0.3-0.9 μM) and TAAR1 (Ki: 0.06-2.2 μM), similar to LSD, but not dopaminergic D1-3 receptors (most Ki:>1 μM), unlike LSD.

CONCLUSION

The binding profile of NBOMe drugs predicts strong hallucinogenic effects, similar to LSD, but possibly more stimulant properties because of α1 receptor interactions.

Characterization of the designer drug bk-2C-B (2-amino-1-(bromo-dimethoxyphenyl)ethan-1-one) by gas chromatography/mass spectrometry without and with derivatization with 2,2,2-trichloroethyl chloroformate, liquid chromatography/high-resolution mass spectrometry, and nuclear magnetic resonance

RATIONALE

We describe the analytical characterization of the designer drug bk-2C-B, a cathinone derivative, contained in a seized tablet, in the absence of an analytical standard.

METHODS

The analytical techniques employed include gas chromatography/mass spectrometry (GC/MS), without and with derivatization with 2,2,2-trichloroethyl chloroformate, liquid chromatography/high-resolution-MS (LC/HRMS) with an Orbitrap® analyzer, and nuclear magnetic resonance (NMR). LC/HRMS measurements consisted of accurate mass measurements of MH(+) ionic species under full scan conditions; comparison of experimental and calculated MH(+) isotopic patterns; examination of the isotopic fine structure (IFS) of the M+1, M+2, M+3 isotopic peaks relative to the monoisotopic M+0 peak; study of MH(+) collision-induced dissociation (CID) product ions obtained in fragmentation experiments.

RESULTS

GC/MS analysis gave highly informative EI mass spectra, particularly after the derivatization of bk-2C-B with 2,2,2-trichloroethyl chloroformate. The application of LC/HRMS, allowing for accurate mass measurements at 100,000 resolving power, greatly enhanced analytical capabilities in structural characterization of this new designer drug. HRMS allowed us to obtain the accurate mass measurements of bk-2C-B MH(+) ionic species, with a mass accuracy of 2.19 ppm; fully superimposable experimental and calculated MH(+) isotopic patterns, with RIA1 and RIA2 values <4%; the IFS of the M+1, M+2, M+3 isotopic peaks relative to the monoisotopic M+0 peak completely in accordance with theoretical values. These findings enabled us to obtain the elemental composition formula of the seized drug. Furthermore, characteristic MH(+) CID product ions enabled the characterization of the bk-2C-B molecular structure. The presence of (79)Br and (81)Br isotopes in the substance molecule produced a characteristic isotopic pattern in most MS spectra. Lastly, NMR spectra allowed us to obtain useful information about the position of substituents in the designer drug.

CONCLUSIONS

The combination of all the analytical techniques employed allowed the characterization of the seized psychoactive substance, in spite of the lack of a reference standard.

Toxicities associated with NBOMe ingestion-a novel class of potent hallucinogens: a review of the literature

BACKGROUND

A new class of synthetic hallucinogens called NBOMe has emerged as drugs of abuse.

OBJECTIVE

Our aim was to conduct a systematic review of published reports of toxicities associated with NBOMe ingestion.

METHODS

We searched PubMed for relevant English-language citations that described adverse effects from analytically confirmed human NBOMe ingestion. Demographic and clinical data were extracted.

RESULTS

A total of 10 citations met the criteria for inclusion, representing 20 individual patients. 25I-NBOMe was the most common analogue identified, followed by 25B-NBOMe and 25C-NBOMe. Fatalities were reported in 3 (15%) cases. Of all the patients, 7 (35%) were discharged after a period of observation, whereas 8 (40.0%) required admission to an intensive care unit. The most common adverse effects were agitation (85.0%), tachycardia (85.0%), and hypertension (65.0%). Seizures were reported in 8 (40.0%) patients. The most common abnormalities reported on laboratory tests were elevated level of creatinine kinase (45.0%), leukocytosis (25.0%), and hyperglycemia (20.0%).

CONCLUSION

NBOMe ingestion is associated with severe adverse effects. Clinicians need to have a high index of suspicion for NBOMe ingestion in patients reporting the recent use of hallucinogens.

The NBOMe hallucinogenic drug series: Patterns of use, characteristics of users and self-reported effects in a large international sample

The NBOMe compounds are a novel series of hallucinogenic drugs that are potent agonists of the 5-HT2A receptor, have a short history of human consumption and are available to buy online, in most countries. In this study, we sought to investigate the patterns of use, characteristics of users and self-reported effects. A cross-sectional anonymous online survey exploring the patterns of drug use was conducted in 2012 (n = 22,289), including questions about the use of 25B-NBOMe, 25C-NBOMe, and 25I-NBOMe and comparison drugs. We found that 2.6% of respondents (n = 582) reported having ever tried one of the three NBOMe drugs and that at 2.0%, 25I-NBOMe was the most popular (n = 442). Almost all (93.5%) respondents whose last new drug tried was a NBOMe drug, tried it in 2012, and 81.2% of this group administered the drug orally or sublingually/buccally. Subjective effects were similar to comparison serotonergic hallucinogens, though higher 'negative effects while high' and greater 'value for money' were reported. The most common (41.7%) drug source was via a website. The NBOMe drugs have emerged recently, are frequently bought using the internet and have similar effects to other hallucinogenic drugs; however, they may pose larger risks, due to the limited knowledge about them, their relatively low price and availability via the internet.

High-performance liquid chromatography with tandem mass spectrometry for the determination of nine hallucinogenic 25-NBOMe designer drugs in urine specimens

We present a high-performance liquid chromatography triple quadrupole mass spectrometry (HPLC-MS-MS) method for the identification and quantification of nine serotonin 5-HT2A receptor agonist hallucinogenic substances from a new class of N-methoxybenzyl derivatives of methoxyphenylethylamine (NBOMe) designer drugs in human urine: 25H-NBOMe, 2CC-NBOMe, 25I-NBF, 25D-NBOMe, 25B-NBOMe, 2CT-NBOMe, 25I-NBMD, 25G-NBOMe and 25I-NBOMe. This assay was developed for the Virginia Commonwealth University Clinical and Forensic Toxicology laboratory to screen emergency department specimens in response to an outbreak of N-benzyl-phenethylamine derivative abuse and overdose cases in Virginia. The NBOMe derivatives were rapidly extracted from the urine specimens by use of FASt™ solid-phase extraction columns. Assay performance was determined as recommended for validation by the Scientific Working Group for Forensic Toxicology (SWGTOX) for linearity, lower limit of quantification, lower limit of detection, accuracy/bias, precision, dilution integrity, carryover, selectivity, absolute recovery, ion suppression and stability. Linearity was verified to be from 1 to 100 ng/mL for each of the nine analytes. The bias determined for the NBOMe derivatives was 86-116% with a <14% coefficient of variation over the linear range of the assay. Four different NBOMe derivatives were detected using the presented method in patient urine specimens.

Structural elucidation and identification of a new derivative of phenethylamine using quadrupole time-of-flight mass spectrometry

RATIONALE

In recent years, the phenomenon of uncontrolled distribution of new psychoactive substances that were marketed without prior toxicological studies has been observed. Because many designer drugs are related in chemical structure, the potential for misidentifying them is an important problem. It is therefore essential to develop an analytical procedure for unequivocal elucidation of the structures of these compounds. The issue has been discussed in the context of 25I-NBMD [2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2,3-methylenedioxyphenyl)methyl]ethanamine], a psychoactive substance first discovered on the drug market in 2012.

METHODS

The substance was extracted from blotter papers with methanol. Separation was achieved via liquid chromatography. Analysis was conducted by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOFMS). Identification of the psychoactive component was supported by electron impact gas chromatography/mass spectrometry (GC/EI-MS).

RESULTS

The high accuracy of the LC/ESI-QTOFMS method allowed the molecular mass of the investigated substance (M(exp) = 441.0438 Da; mass error, ∆m = 0.2 ppm) and the formulae of ions formed during fragmentation to be determined. The main ions were recorded at m/z = 135.0440, 290.9876 and 305.9981. Structures of the obtained ions were elucidated in the tandem mass spectrometry (MS/MS) experiments by comparing them to mass spectra of previously detected derivatives of phenethylamine.

CONCLUSIONS

The performed study indicated the potential for using LC/QTOFMS method to identify new designer drugs. This technique can be used supplementary to standard GC/MS. Prior knowledge of the fragmentation mechanisms of phenethylamines allowed to predict the mass spectra of the novel substance--25I-NBMD.

Effects of the hallucinogen 2,5-dimethoxy-4-iodophenethylamine (2C-I) and superpotent N-benzyl derivatives on the head twitch response

N-benzyl substitution markedly enhances the affinity of phenethylamine hallucinogens at the 5-HT(2A) receptor. N-benzyl substituted derivatives of 2,5-dimethoxy-4-iodophenethylamine (2C-I), such as N-(2-methoxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBOMe) and N-(2,3-methylenedioxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBMD), have appeared recently as designer drugs, but have not been characterized behaviorally. The head twitch response (HTR) is induced by 5-HT(2A) receptor activation in rats and mice, and is widely used as a behavioral proxy for hallucinogen effects in humans. Nevertheless, it is not clear whether phenethylamine hallucinogens reliably provoke this behavior. Hence, we investigated whether 2C-I, 25I-NBOMe and 25I-NBMD induce head twitches in C57BL/6J mice. The HTR was assessed using a head-mounted magnet and a magnetometer coil. 2C-I (1-10 mg/kg SC), 25I-NBOMe (0.1-1 mg/kg SC), and 25I-NBMD (1-10 mg/kg SC) induced the HTR. 25I-NBOMe displayed 14-fold higher potency than 2C-I, and the selective 5-HT(2A) antagonist M100,907 completely blocked the HTR induced by all three compounds. These findings show that phenethylamine hallucinogens induce the HTR by activating 5-HT(2A) receptors. Our results demonstrate that 25I-NBOMe is a highly potent derivative of 2C-I, confirming previous in vitro findings that N-benzyl substitution increases 5-HT(2A) affinity. Given the high potency and ease of synthesis of N-benzylphenethylamines, it is likely that the recreational use of these hallucinogens will become more widespread in the future.