The new drug phenomenon

Identification of in vitro and in vivo human metabolites of the new psychoactive substance nitracaine by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

The purpose of this work was to investigate the in vitro metabolism of nitracaine, a new psychoactive substance, using human liver microsome incubations, to evaluate the cytochrome P450 (CYP) enzyme isoforms responsible for the phase-I metabolism and to compare the information from the in vitro experiments with data resulting from an authentic user's urine sample. Accurate mass spectra of metabolites were obtained using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) and were used in the structural identification of metabolites. Two major and three minor phase-I metabolites were identified from the in vitro experiments. The observed phase-I metabolites were formed through N-deethylation, N,N-deethylation, N-hydroxylation, and de-esterification, with CYP2B6 and CYP2C19 being the main enzymes catalyzing their formation. One glucuronidated product was identified in the phase-II metabolism experiments. All of these metabolites are reported for the first time in this study except the N-deethylation product. All the in vitro metabolites except the minor N,N-deethylation product were also present in the human urine sample, thus demonstrating the reliability of the in vitro experiments in the prediction of the in vivo metabolism of nitracaine. In addition to the metabolites, three transformation products (p-nitrobenzoic acid, p-aminobenzoic acid, and 3-(diethylamino)-2,2-dimethylpropan-1-ol) were identified, as well as several glucuronides and glutamine derived of them.

The 2-alkyl-2H-indazole regioisomers of synthetic cannabinoids AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA are possible manufacturing impurities with cannabimimetic activities

Indazole-derived synthetic cannabinoids (SCs) featuring an alkyl substituent at the 1-position and l-valinamide at the 3-carboxamide position (e.g., AB-CHMINACA) have been identified by forensic chemists around the world, and are associated with serious adverse health effects. Regioisomerism is possible for indazole SCs, with the 2-alkyl-2H-indazole regioisomer of AB-CHMINACA recently identified in SC products in Japan. It is unknown whether this regiosiomer represents a manufacturing impurity arising as a synthetic byproduct, or was intentionally synthesized as a cannabimimetic agent. This study reports the synthesis, analytical characterization, and pharmacological evaluation of commonly encountered indazole SCs AB-CHMINACA, AB-FUBINACA, AB-PINACA, 5F-AB-PINACA and their corresponding 2-alkyl-2H-indazole regioisomers. Both regioisomers of each SC were prepared from a common precursor, and the physical properties, ¹H and ¹³C nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry, and ultraviolet-visible spectroscopy of all SC compounds are described. Additionally, AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA were found to act as high potency agonists at CB₁ (EC₅₀ = 2.1-11.6 nM) and CB₂ (EC₅₀ = 5.6-21.1 nM) receptors in fluorometric assays, while the corresponding 2-alkyl-2H-indazole regioisomers demonstrated low potency (micromolar) agonist activities at both receptors. Taken together, these data suggest that 2-alkyl-2H-indazole regioisomers of AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA are likely to be encountered by forensic chemists and toxicologists as the result of improper purification during the clandestine synthesis of 1-alkyl-1H-indazole regioisomers, and can be distinguished by differences in gas chromatography-mass spectrometry fragmentation pattern.

Analytical characterization of N,N-diallyltryptamine (DALT) and 16 ring-substituted derivatives

Many N,N-dialkylated tryptamines show psychoactive properties in humans and the number of derivatives involved in multidisciplinary areas of research has grown over the last few decades. Whereas some derivatives form the basis of a range of medicinal products, others are predominantly encountered as recreational drugs, and in some cases, the areas of therapeutic and recreational use can overlap. In recent years, 5-methoxy-N,N-diallyltryptamine (5-MeO-DALT) has appeared as a new psychoactive substance (NPS) and 'research chemical' whereas 4-acetoxy-DALT and the ring-unsubstituted DALT have only been detected very recently. Strategies pursued in the authors' laboratories included the preparation and biological evaluation of previously unreported N,N-diallyltryptamines (DALTs). This report describes the analytical characterization of 17 DALTs. Fifteen DALTs were prepared by a microwave-accelerated Speeter and Anthony procedure following established procedures developed previously in the authors' laboratories. In addition to DALT, the substances included in this study were 2-phenyl-, 4-acetoxy-, 4-hydroxy-, 4,5-ethylenedioxy-, 5-methyl-, 5-methoxy-, 5-methoxy-2-methyl-, 5-ethoxy-, 5-fluoro-, 5-fluoro-2-methyl-, 5-chloro-, 5-bromo-, 5,6-methylenedioxy-, 6-fluoro-, 7-methyl, and 7-ethyl-DALT, respectively. The DALTs were characterized by nuclear magnetic resonance spectroscopy (NMR), gas chromatography (GC) quadrupole and ion trap (EI/CI) mass spectrometry (MS), low and high mass accuracy MS/MS, photodiode array detection, and GC solid-state infrared analysis, respectively. A comprehensive collection of spectral data was obtained that are provided to research communities who face the challenge of encountering newly emerging substances where analytical data are not available. These data are also relevant to researchers who might wish to explore the clinical and non-clinical uses of these substances. Copyright © 2016 John Wiley & Sons, Ltd.

A scoping review of home-produced heroin and amphetamine-type stimulant substitutes: implications for prevention, treatment, and policy

Several home-produced substances such as krokodil and boltushka are prevalent in many Eastern European countries. Anecdotal reports of its use have been circulating in Germany and Norway; however, this has not been confirmed. Its use has also been reported by the media in the USA, although only one confirmed report of its use exists. Home-produced drugs are associated with high levels of morbidity and a number of complex health issues such as the spread of blood borne viruses, gangrene, and internal organ damage. The high incidence of HIV rates amongst people who inject home-produced substances is a public health concern. The resulting physical health consequences of injecting these crude substances are very severe in comparison to heroin or amphetamine acquired in black markets. Due to this fact and the increased mortality associated with these substances, professionals in the area of prevention, treatment, and policy development need to be cognisant of the presentation, harms, and the dangers associated with home-produced substances globally. This scoping review aimed to examine existing literature on the subject of home-produced heroin and amphetamine-type stimulant substitutes. The review discussed the many implications such research may have in the areas of policy and practice. Data were gathered through the use of qualitative secondary resources such as journal articles, reports, reviews, case studies, and media reports. The home production of these substances relies on the utilisation of precursor drugs such as less potent stimulants, tranquillizers, analgesics, and sedatives or natural plant ingredients. The Internet underpins the facilitation of this practice as recipes, and diverted pharmaceutical sales are available widely online, and currently, ease of access to the Internet is evident worldwide. This review highlights the necessity of prevention, education, and also harm reduction related to home-produced drugs and also recommends consistent monitoring of online drug fora, online drug marketplaces, and unregulated pharmacies.

Oral fluid drug analysis in the age of new psychoactive substances

Oral fluid has become an important matrix for drugs of abuse analysis. These days the applicability is challenged by the fact that an increasing number of new psychoactive drugs are coming on the market. Synthetic cannabinoids and synthetic cathinones have been the main drug classes, but the diversity is increasing and other drugs like piperazines, phenethylamines, tryptamines, designer opioids and designer benzodiazepines are becoming more prevalent. Many of the substances are very potent, and low doses ingested will lead to low concentrations in biological media, including oral fluid. This review will highlight the phenomenon of new psychoactive substances and review methods for oral fluid drug testing analysis using on-site tests, immunoassays and chromatographic methods.

Drug testing in Europe: monitoring results of the Trans European Drug Information (TEDI) project

Drug testing is a harm reduction strategy that has been adopted by certain countries in Europe. Drug users are able to hand in their drugs voluntarily for chemical analysis of composition and dose. Drug users will be alerted about dangerous test results by the drug testing systems directly and through warning campaigns. An international collaborative effort was launched to combine data of drug testing systems, called the Trans European Drug Information (TEDI) project. Drug testing systems of Spain, Switzerland, Belgium, Austria, Portugal, and the Netherlands participated in this project. This study presents results of some of the main illicit drugs encountered: cocaine, ecstasy and amphetamine and also comments on new psychoactive substances (NPS) detected between 2008 and 2013. A total of 45 859 different drug samples were analyzed by TEDI. The drug markets of the distinct European areas showed similarities, but also some interesting differences. For instance, purity of cocaine and amphetamine powders was generally low in Austria, whilst high in Spain and the Netherlands. And the market for ecstasy showed a contrast: whereas in the Netherlands and Switzerland there was predominantly a market for ecstasy tablets, in Portugal and Spain MDMA (3,4-methylenedioxymethamphetamine) crystals were much more prevalent. Also, some NPS appearing in ecstasy seemed more specific for one country than another. In general, prevalence of NPS clearly increased between 2008 and 2013. Drug testing can be used to generate a global picture of drug markets and provides information about the pharmacological contents of drugs for the population at risk. Copyright © 2016 John Wiley & Sons, Ltd.

Systematic analytical characterization of new psychoactive substances: A case study

New psychoactive substances (NPS) are synthesized compounds that are not usually covered by European and/or international laws. With a slight alteration in the chemical structure of existing illegal substances registered in the European Union (EU), these NPS circumvent existing controls and are thus referred to as "legal highs". They are becoming increasingly available and can easily be purchased through both the internet and other means (smart shops). Thus, it is essential that the identification of NPS keeps up with this rapidly evolving market. In this case study, the Belgian Customs authorities apprehended a parcel, originating from China, containing two samples, declared as being "white pigments". For routine identification, the Belgian Customs Laboratory first analysed both samples by gas-chromatography mass-spectrometry and Fourier-Transform Infrared spectroscopy. The information obtained by these techniques is essential and can give an indication of the chemical structure of an unknown substance but not the complete identification of its structure. To bridge this gap, scientific and technical support is ensured by the Joint Research Centre (JRC) to the European Commission Directorate General for Taxation and Customs Unions (DG TAXUD) and the Customs Laboratory European Network (CLEN) through an Administrative Arrangement for fast recognition of NPS and identification of unknown chemicals. The samples were sent to the JRC for a complete characterization using advanced techniques and chemoinformatic tools. The aim of this study was also to encourage the development of a science-based policy driven approach on NPS. These samples were fully characterized and identified as 5F-AMB and PX-3 using (1)H and (13)C nuclear magnetic resonance (NMR), high-resolution tandem mass-spectrometry (HR-MS/MS) and Raman spectroscopy. A chemoinformatic platform was used to manage, unify analytical data from multiple techniques and instruments, and combine it with chemical and structural information.

Test purchase, synthesis and characterization of 3-fluorophenmetrazine (3-FPM) and differentiation from its ortho- and para-substituted isomers

The knowledge captured in patent and scientific research literature stimulates new ideas and fosters new drug development efforts. Manufacturers and entrepreneurs dedicated to the sale of 'research chemicals' and/or new psychoactive substances (NPS) also make use of access to information to identify, prepare, and launch a range of new substances. One of the most recent compounds to appear on the NPS market is the phenmetrazine analog 3-fluorophenmetrazine (3-FPM) which represents one of many phenylmorpholines designed to explore treatment options in areas such as obesity and drug dependence. The anorectic drug analogs phenmetrazine and phendimetrazine, used as prescription medicines before they were withdrawn, feature amphetamine-like properties associated with monoamine release. Available data on 3-FPM suggest that the effects might show mechanistic overlaps. This study describes the synthesis and extensive analytical characterization of 3-FPM and its differentiation from synthesized ortho- and para- substituted isomers, 2-FPM and 4-FPM, respectively. This study was triggered by the purchase of five powdered samples advertised as 3-FPM by five different Internet vendors based in the United Kingdom. The analytical data obtained for the vendor samples were consistent with the synthesized 3-FPM standard and differentiation between all three isomers was possible. The presence of positional isomers and the absence of suitable reference material can cause difficulties in the day-to-day operation of forensic work and given the rate at which many of the newly emerging NPS appear on the market, a comprehensive approach is needed when attempting to decipher the identity of NPS arriving onto the drug market. Copyright © 2016 John Wiley & Sons, Ltd.

In vitro characterization of potential CYP- and UGT-derived metabolites of the psychoactive drug 25B-NBOMe using LC-high resolution MS

One of the main challenges posed by the emergence of new psychoactive substances is their identification in human biological samples. Trying to detect the parent drug could lead to false-negative results when the delay between consumption and sampling has been too long. The identification of their metabolites could then improve their detection window in biological matrices. Oxidative metabolism by cytochromes P450 and glucuronidation are two major detoxification pathways in humans. In order to characterize possible CYP- and UGT-dependent metabolites of the 2-(4-bromo-2,5-dimethoxy-phenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25B-NBOMe), a synthetic psychoactive drug, analyses of human liver microsome (HLM) incubates were performed using an ultra-high performance liquid chromatography system coupled with a quadrupole-time of flight mass spectrometry detector (UHPLC-Q-TOF/MS). On-line analyses were performed using a Waters OASIS HLB column (30 x 2.1 mm, 20 µm) for the automatic sample loading and a Waters ACQUITY HSS C18 column (150 x 2 mm, 1.8 µm) for the chromatographic separation. Twenty-one metabolites, consisting of 12 CYP-derived and 9 UGT-derived metabolites, were identified. O-Desmethyl metabolites were the most abundant compounds after the phase I process, which appears to be in accordance with data from previously published NBOMe-intoxication case reports. Although other important metabolic transformations, such as sulfation, acetylation, methylation or glutathione conjugation, were not studied and artefactual metabolites might have been produced during the HLM incubation process, the record of all the metabolite MS spectra in our library should enable us to characterize relevant metabolites of 25B-NBOMe and allow us to detect 25B-MBOMe users.

In vitro Phase I and Phase II metabolism of α-pyrrolidinovalerophenone (α-PVP), methylenedioxypyrovalerone (MDPV) and methedrone by human liver microsomes and human liver cytosol

The aim of the present study was to identify the in vitro Phase I and Phase II metabolites of three new psychoactive substances: α-pyrrolidinovalerophenone (α-PVP), methylenedioxypyrovalerone (MDPV), and methedrone, using human liver microsomes and human liver cytosol. Accurate-mass spectra of metabolites were obtained using liquid chromatography-quadrupole time-of-flight mass spectrometry. Six Phase I metabolites of α-PVP were identified, which were formed involving reduction, hydroxylation, and pyrrolidine ring opening reactions. The lactam compound was the major metabolite observed for α-PVP. Two glucuronidated metabolites of α-PVP, not reported in previous in vitro studies, were further identified. MDPV was transformed into 10 Phase I metabolites involving reduction, hydroxylation, and loss of the pyrrolidine ring. Also, six glucuronidated and two sulphated metabolites were detected. The major metabolite of MDPV was the catechol metabolite. Methedrone was transformed into five Phase I metabolites, involving N- and O-demethylation, hydroxylation, and reduction of the ketone group. Three metabolites of methedrone are reported for the first time. In addition, the contribution of individual human CYP enzymes in the formation of the detected metabolites was investigated.

4,4'-DMAR: chemistry, pharmacology and toxicology of a new synthetic stimulant of abuse

In recent years, the spread of new psychoactive substances has dramatically increased in term of availability of both number of compounds and chemical families. In November 2012, 4,4'-Dimethylaminorex (4,4'-DMAR), a novel synthetic stimulant, was first detected in the Netherlands. Between June 2013 and June 2014, thirty-one deaths associated with the consumption of this new drug have been registered across Europe. In this MiniReview, we have summarized the chemical, pharmacological and toxicological information about this new legal high.

Test purchase, synthesis, and characterization of 2-methoxydiphenidine (MXP) and differentiation from its meta- and para-substituted isomers

The structurally diverse nature of the 1,2-diphenylethylamine template provides access to a range of substances for drug discovery work but some have attracted attention as 'research chemicals'. The most recent examples include diphenidine, i.e. 1-(1,2-diphenylethyl)piperidine and 2-methoxydiphenidine, i.e. 1-[1-(2-methoxyphenyl)-2-phenylethyl]piperidine (MXP, methoxyphenidine, 2-MXP) that have been associated with uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist activity. Analytical challenges encountered during chemical analysis include the presence of positional isomers. Three powdered samples suspected to contain 2-MXP were obtained from three Internet retailers in the United Kingdom and subjected to analytical characterization by gas chromatography (GC) and high performance liquid chromatography (HPLC) coupled to various forms of mass spectrometry (MS). Nuclear magnetic resonance spectroscopy, infrared spectroscopy and thin layer chromatography were also employed. This was supported by the synthesis of all three isomers (2-, 3- and 4-MXP) by two different synthetic routes. The analytical data obtained for the three purchased samples were consistent with the synthesized 2-MXP standard and the differentiation between the isomers was possible. Distinct stability differences were observed for all three isomers during in-source collision-induced dissociation of the protonated molecule when employing detection under HPLC selected-ion monitoring detection, which added to the ability to differentiate between them. Furthermore, the analysis of a 2-MXP tablet by matrix assisted inlet ionization Orbitrap mass spectrometry confirmed that it was possible to detect the protonated molecule of 2-MXP directly from the tablet surface following addition of 3-nitrobenzonitrile as the matrix.

Identification and characterization of an imidazolium by-product formed during the synthesis of 4-methylmethcathinone (mephedrone)

4-Methylmethcathinone (2-methylamino-1-(4-methylphenyl)propan-1-one, mephedrone) is a psychoactive substance that has been associated with recreational use worldwide. Analytical data related to mephedrone are abundantly available but the characterization of by-products obtained during organic synthesis remains to be explored. This study presents the identification of a 1,2,3,5-tetramethyl-4-(4-methylphenyl)-1H-imidazol-3-ium salt (TMMPI), which was formed during the synthesis of mephedrone. When diethyl ether was added to the crude reaction product, solid material precipitated from the solution. Analytical characterization of TMMPI employed a range of analytical techniques including chromatographic analysis in combination with various mass spectrometric detection methods, nuclear magnetic resonance spectroscopy, and crystal structure analysis. Additional confirmation was obtained from organic synthesis of the imidazolium by-product. When TMMPI was subjected to analysis by gas chromatography-mass spectrometry (GC-MS), isomerization and degradation into two distinct compounds were observed, which pointed towards thermal instability under GC conditions. A liquid chromatography-mass spectrometry (LC-MS) based investigation into a micro-scale synthesis of mephedrone and three additional analogues revealed that the corresponding TMMPI analogue was formed. Interestingly, storage of mephedrone freebase in a number of organic solvents also gave rise to TMMPI and it appeared that its formation during storage was significantly reduced in the absence of air. The present study aimed to support clandestine forensic investigations by employing analytical strategies that are applicable to manufacturing sites. The imidazolium salts will most likely be found amongst the waste products of any clandestine lab site under investigation rather than with the desired product.

Baths salts, spice, and related designer drugs: the science behind the headlines

The abuse of synthetic psychoactive substances known as "designer drugs," or "new psychoactive substances" (NPS), is increasing at an alarming rate. NPS are purchased as alternatives to traditional illicit drugs of abuse and are manufactured to circumvent laws regulating the sale and use of controlled substances. Synthetic cathinones (i.e., "bath salts") and synthetic cannabinoids (i.e., "spice") are two types of NPS that have received substantial media attention. Although low recreational doses of bath salts or spice compounds can produce desirable effects, high doses or chronic exposure often leads to dangerous medical consequences, including psychosis, violent behaviors, tachycardia, hyperthermia, and even death. Despite the popularity of NPS, there is a paucity of scientific data about these drugs. Here we provide a brief up-to-date review describing the mechanisms of action and neurobiological effects of synthetic cathinones and cannabinoids.

Isolation and structural determination of non-racemic tertiary cathinone derivatives

In this paper the dynamic resolution of racemic tertiary cathinones is demonstrated through co-crystallization with enantiopure aromatic tartaric acids.

Synthesis, characterization, and monoamine transporter activity of the new psychoactive substance 3',4'-methylenedioxy-4-methylaminorex (MDMAR)

The recent occurrence of deaths associated with the psychostimulant cis-4,4'-dimethylaminorex (4,4'-DMAR) in Europe indicated the presence of a newly emerged psychoactive substance on the market. Subsequently, the existence of 3,4-methylenedioxy-4-methylaminorex (MDMAR) has come to the authors' attention and this study describes the synthesis of cis- and trans-MDMAR followed by extensive characterization by chromatographic, spectroscopic, mass spectrometric platforms and crystal structure analysis. MDMAR obtained from an online vendor was subsequently identified as predominantly the cis-isomer (90%). Exposure of the cis-isomer to the mobile phase conditions (acetonitrile/water 1:1 with 0.1% formic acid) employed for high performance liquid chromatography analysis showed an artificially induced conversion to the trans-isomer, which was not observed when characterized by gas chromatography. Monoamine release activities of both MDMAR isomers were compared with the non-selective monoamine releasing agent (+)-3,4-methylenedioxymethamphetamine (MDMA) as a standard reference compound. For additional comparison, both cis- and trans-4,4'-DMAR, were assessed under identical conditions. cis-MDMAR, trans-MDMAR, cis-4,4'-DMAR and trans-4,4'-DMAR were more potent than MDMA in their ability to function as efficacious substrate-type releasers at the dopamine (DAT) and norepinephrine (NET) transporters in rat brain tissue. While cis-4,4'-DMAR, cis-MDMAR and trans-MDMAR were fully efficacious releasing agents at the serotonin transporter (SERT), trans-4,4'-DMAR acted as a fully efficacious uptake blocker. Currently, little information is available about the presence of MDMAR on the market but the high potency of ring-substituted methylaminorex analogues at all three monoamine transporters investigated here might be relevant when assessing the potential for serious side-effects after high dose exposure.