Identification and characterization of α-PVT, α-PBT, and their bromothienyl analogs found in illicit drug products

Synthetic Cathinones: Recent Developments, Enantioselectivity Studies and Enantioseparation Methods

New psychoactive substances represent a public health threat since they are not controlled by international conventions, are easily accessible online and are sold as a legal alternative to illicit drugs. Among them, synthetic cathinones are widely abused due to their stimulant and hallucinogenic effects. To circumvent the law, new derivatives are clandestinely synthesized and, therefore, synthetic cathinones keep emerging on the drug market, with their chemical and toxicological properties still unknown. In this review, a literature assessment about synthetic cathinones is presented focusing on the recent developments, which include more than 50 derivatives since 2014. A summary of their toxicokinetic and toxicodynamic properties are also presented. Furthermore, synthetic cathinones are chiral compounds, meaning that they can exist as two enantiomeric forms which may present different biological and toxicological activities. To analyze the enantiomers, the development of enantiomeric resolution methods for synthetic cathinones is crucial. Many methods have been reported over the years that include mostly chromatographic and electromigration techniques, with liquid chromatography using chiral stationary phases being the technique of choice. This review intended to present an overview of enantioselectivity studies and enantioseparation analysis regarding synthetic cathinones, highlighting the relevance of chirality and current trends.

Simple Analytical Strategy for Screening Three Synthetic Cathinones (α-PVT, α-PVP, and MDPV) in Oral Fluids

Synthetic cathinones are analogue compounds of the plant based stimulant cathinone. Its use, abuse, and related consumption complications have steadily increased in the last years. For this reason, there is a need for innovative analytical approaches that enable its rapid screening in biological matrices (e.g., oral fluids). The present work proposes a new analytical methodology by combining bar adsorptive microextraction followed by microliquid desorption and gas chromatography coupled to mass spectrometry (BAµE-µLD/GC-MS) for screening three synthetic cathinones (α-PVP, α-PVT, and MDPV) in oral fluids. The optimization of the BAµE-µLD/GC-MS methodology was successfully applied for the analysis of the target compounds in oral fluids. The results show average recoveries between 43.1 and 52.3% for the three synthetic cathinones. Good selectivity was also noticed. The developed methodology presents itself as an alternative tool to screen these compounds in oral fluids. To the best of our knowledge, this is the first work that combines a microextraction sorption-based technique followed by GC-MS analysis for the screening of synthetic cathinones in oral fluids.

The key role of mass spectrometry in comprehensive research on new psychoactive substances

New psychoactive substances (NPS) are a wide group of compounds that try to mimic the effects produced by the 'classical' illicit drugs, including cannabis (synthetic cannabinoids), cocaine and amphetamines (synthetic cathinones) or heroin (synthetic opioids), and which health effects are still unknown for most of them. Nowadays, more than 700 compounds are being monitored by official organisms, some of which have been recently identified in seizures and/or intoxication cases. Toxicological analysis plays a pivotal role in NPS research. A comprehensive investigation on NPS, from the first identification of a novel substance until its detection in drug users to help in diagnostics and medical treatment, requires the use of a wide variety of instruments and analytical strategies. This paper illustrates the key role of mass spectrometry (MS) along a comprehensive investigation on NPS. The synthetic cannabinoid XLR-11 and the synthetic cathinone 5-PPDi have been chosen as representative substances of the most consumed NPS families. Moreover, both compounds have been investigated at our laboratory in different stages of the three-step strategy considered in this article. The initial identification and characterisation of the compound in consumption products, the first reported metabolic pathway and the development of analytical methodologies for its determination (and/or their metabolites) in different toxicological samples are described. The analytical strategies and MS instruments are briefly discussed to show the reader the possibilities that MS instrumentation offer to analytical scientists. This publication aims to be a starting point for those interested on the NPS research field from an analytical chemistry point of view.

Understanding the pharmacokinetics of synthetic cathinones: Evaluation of the blood-brain barrier permeability of 13 related compounds in rats

Synthetic cathinones are the second most commonly seized new psychoactive substance family in Europe. These compounds have been related to several intoxication cases, including fatalities. Although the pharmacological effects, metabolism, and pharmacokinetics of cathinones have been studied, there is little information about the permeability of these compounds through the blood-brain barrier (BBB). This is an important parameter to understand the behavior and potency of cathinones. In this work, 13 selected cathinones have been analyzed in telencephalon tissue from Sprague-Dawley rats intraperitoneally dosed at 3 mg/kg. Our results revealed a direct relationship between compound polarity and BBB permeability, with higher permeability for the more polar cathinones. The chemical moieties present in the cathinone had an important impact on the BBB permeability, with lengthening of the α-alkyl chain or functionalization of the aromatic ring with alkyl moieties resulting in lower concentration in telencephalon tissue. Our data suggest that transport of cathinones is a carrier-mediated process, similar to cocaine transport across the BBB.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Metabolic profiling of four synthetic stimulants, including the novel indanyl-cathinone 5-PPDi, after human hepatocyte incubation

Synthetic cathinones are new psychoactive substances that represent a health risk worldwide. For most of the 130 reported compounds, information about toxicology and/or metabolism is not available, which hampers their detection (and subsequent medical treatment) in intoxication cases. The principles of forensic analytical chemistry and the use of powerful analytical techniques are indispensable for stablishing the most appropriate biomarkers for these substances. Human metabolic fate of synthetic cathinones can be assessed by the analysis of urine and blood obtained from authentic consumers; however, this type of samples is limited and difficult to access. In this work, the metabolic behaviour of three synthetic cathinones (4-CEC, 4-CPrC and 5-PPDi) and one amphetamine (3-FEA) has been evaluated by incubation with pooled human hepatocytes and metabolite identification has been performed by high-resolution mass spectrometry. This in vitro approach has previously shown its feasibility for obtaining excretory human metabolites. 4-CEC and 3-FEA were not metabolised, and for 4-CPrC only two minor metabolites were obtained. On the contrary, for the recently reported 5-PPDi, twelve phase I metabolites were elucidated. Up to our knowledge, this is the first metabolic study of an indanyl-cathinone. Data reported in this paper will allow the detection of these synthetic stimulants in intoxication cases, and will facilitate future research on the metabolic behaviour of other indanyl-based cathinones.

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In vitro metabolic behaviour of 4-CEC, 4-CPrC, 5-PPDi and 3-FEA has been evaluated.

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Metabolite elucidation has been performed by high-resolution mass spectrometry.

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4-CEC and 3-FEA were not metabolised. Two minor metabolites were obtained for 4-CPrC.

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Twelve phase I metabolites were elucidated for the indanyl-cathinone 5-PPDi.

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Up to our knowledge, this is the first metabolic study of an indanyl-cathinone.

Synthetic cathinones: an evolving class of new psychoactive substances

Synthetic cathinones (SCat) are amphetamine-like psychostimulants that emerged onto drug markets as "legal" alternatives to illicit drugs such as ecstasy, cocaine, and amphetamines. Usually they are sold as "bath salts," "plant food," or "research chemicals," and rapidly gained popularity amongst drugs users due to their potency, low cost, and availability. In addition, internet drug sales have been replacing the old way of supplying drugs of abuse, contributing to their rapid spread. Despite the legislative efforts to control SCat, new derivatives continue to emerge on the recreational drugs market and their abuse still represents a serious public health issue. To date, about 150 SCat have been identified on the clandestine drugs market, which are one of the largest groups of new psychoactive substances (NPS) monitored by the United Nations Office on Drugs and Crime and the European Monitoring Center for Drugs and Drug Addiction. Similar to the classical stimulants, SCat affect the levels of catecholamines in the central nervous system, which results in their psychological, behavioral and toxic effects. Generally, the effects of SCat greatly differ from drug to drug and relatively little information is available about their pharmacology. The present work provides a review on the development of SCat as substances of abuse, current patterns of abuse and their legal status, chemical classification, known mechanisms of action, and their toxicological effects.

Characterization of a recently detected halogenated aminorex derivative: para-fluoro-4-methylaminorex (4'F-4-MAR)

Despite the fact that 33% of the new psychoactive substances seized in 2015 were synthetic cathinones, the number of these derivatives has been decreasing in the last years, probably as a consequence of the unfavourable effects reported by users. Thus, the list of possible cathinone analogues is expected to get shorter, and it is likely that the same moiety changes applied for the preparation of synthetic cathinones will be applied in the near future to other stimulants in the search for favourable alternatives to controlled substances. This is evidenced by the increase in newly reported substances belonging to stimulant classes other than cathinones. One of the possible candidates for a new backbone from which to base new stimulants is aminorex, which is classified as a Schedule I substance by the Drug Enforcement Administration. Three derivatives have been reported until now: 4-methylaminorex or 4-MAR (also categorized as a Schedule I substance), para-methyl-4-methylaminorex (4,4′-DMAR) and 3′,4′-methylenedioxy-4-methylaminorex (MDMAR). Recently, the new halogenated 4-MAR derivative, para-fluoro-4-methylaminorex, characterised in this work (and abbreviated as pF-4-methylaminorex or 4′F-4-MAR) was detected by the Slovenian police. In the present work, 4′F-4-MAR has been characterized by high resolution mass spectrometry and nuclear magnetic resonance in a sample obtained from an anonymous consumer. This research shows that the same modifications applied for the preparation of synthetic cathinones are being used to prepare new stimulants based on the aminorex backbone.

Characterization of a new illicit phosphodiesterase-type-5 inhibitor identified in the softgel shell of a dietary supplement

A new sildenafil analog has been identified in the softgel shell of a dietary supplement. The compound was investigated by UV spectroscopy and high-resolution MS analysis, leading to the proposed structure 1-methyl-5-{5-[2-(4-methylpiperazin-1-yl)acetyl]-2-propoxyphenyl}-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one. A synthetic reference compound with the proposed structure was prepared, and the two sets of analytical data were compared, confirming the structure of the new compound. The compound was named propoxyphenyl noracetildenafil from its structure and similarity with the known compound.

The newest cathinone derivatives as designer drugs: an analytical and toxicological review

PURPOSE

Currently, among new psychoactive substances, cathinone derivatives constitute the biggest group, which are mainly classified into N-alkylated, 3,4-methylenedioxy-N-alkylated, N-pyrrolidinyl, and 3,4-methylenedioxy-N-pyrrolidinyl derivatives. These derivatives are actively being subjected to minor modifications at the alkyl chains or the aromatic ring to create new synthetic cathinones with the goal of circumventing laws. In this review, the new synthetic cathinones that have appeared on the illegal drug market during the period 2014-2017 are highlighted, and their characterization by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry is presented.

METHODS

Various key words were used to conduct an extensive literature search across a number of databases, specifically for synthetic cathinones that emerged between 2014 and 2017.

RESULTS

More than 30 new cathinone derivatives were discovered. The preexisting parental compounds for the new derivatives are also referenced, and their mass spectral data are compiled in a table to facilitate their identification by forensic toxicologists.

CONCLUSIONS

To our knowledge, this is the most current review presenting new synthetic cathinones. Political authorities should take measures to implement and enforce generic scheduling (comprehensive system) laws to control the diversely modified synthetic cathinones. Supplementing the existing databases with new findings can greatly facilitate the efforts of forensic toxicologists.

Intended and unintended use of cathinone mixtures

INTRODUCTION

Cathinones are one of the most popular categories of new psychoactive substances (NPS) consumed. Cathinones have different pharmacological activities and receptor selectivity for monoamine transporters based on their chemical structures. They are incorporated into NPS mixtures and used with other NPS or 'traditional' drugs. Cathinone use represents significant health risks to individuals and is a public health burden.

METHODS

Evidence of poly-NPS use with cathinones, seizure information, and literature analyses results on NPS mixtures was systematically gathered from online database sources, including Google Scholar, Scopus, Bluelight, and Drugs-Forum.

RESULTS AND DISCUSSION

Results highlight the prevalence of NPS with low purity, incorporation of cathinones into NPS mixtures since 2008, and multiple members of the cathinone family being present in individual UK-seized samples. Cathinones were identified as adulterants in NPS marketed as being pure NPS, drugs of abuse, branded products, herbal blends, and products labelled "not for human consumption." Toxicity resulting from cathinone mixtures is unpredictable because key attributes remain largely unknown. Symptoms of intoxication include neuro-psychological, psychiatric, and metabolic symptoms. Proposed treatment includes holistic approaches involving psychosocial, psychiatric and pharmacological interventions.

CONCLUSION

Raising awareness of NPS, education, and training of health care professionals are paramount in reducing harms related to cathinone use.