Isomeric Fluoro-methoxy-phenylalkylamines: a new series of controlled-substance analogues (designer drugs)

Withdrawal from 3-Fluoroethamphetamine induces hyperactivity and depression-like behaviors in male mice

3-Fluoroethamphetamine (3-FEA) belongs to the amphetamine class of stimulant drugs and functions as a releasing agent for the monoamine neurotransmitters norepinephrine, dopamine, and serotonin. 3-FEA acts on the central nervous system and elicits physical and mental side effects, such as euphoria, increased heart rate, and excitement. However, little is known about the withdrawal symptoms and behavioral changes induced by 3-FEA administration. This study aimed to evaluate the short-term consequences of 3-FEA administration (twice a day, 7 days, i.p.; 1 and 10 mg/kg) in C57BL/6J mice (male, 7 weeks old) at three behavioral levels following 1-4 days of withdrawal. The evaluation included (1) withdrawal score, (2) hyperactivity (open field [OF], elevated plus maze [EPM], and cliff avoidance [CA] test), and (3) depression-like behavior (forced-swim test). In the withdrawal score test, withdrawal behavior increased in all 3-FEA groups at 16 and 40 h after withdrawal. In the OF, EPM, and CA tests, the 3-FEA administration group showed significant changes in terms of hyperactivity. In addition, in the forced-swim test, both the 1 mg/kg and 10 mg/kg 3-FEA groups showed increased immobility time. These findings indicate that 3-FEA administration may lead to physical dependence, demonstrated by the withdrawal score increase and significant changes in hyperactivity and depression-like behavior following repeated administration and drug cessation. In conclusion, this study reveals the adverse consequences of 3-FEA administration and highlights the need for awareness raising and regulatory action to control the use of this new psychoactive substance.

Identification and Quantitative Analysis of 2-Fluoromethamphetamine and Its Metabolites in Human Urine

Various synthetic drugs have appeared over the past years across the world, and phenethylamine derivatives are among them; indeed, aromatic fluoro analogs of methamphetamine and amphetamine have been in the illicit drug market since the early 2000s. Although they are currently widely abused across the world, little information is available on their metabolism and toxicology. Recently, we came across an alleged 2-fluoromethamphetamine (2-FMA) drug abuse case. The urine obtained from the alleged abuser was analyzed as part of a criminal investigation. 2-FMA, 2-fluoroamphetamine (2-FAP) and some related compounds were detected by liquid chromatography-tandem mass spectrometry. In forensic science, both an "unchanged" drug and its metabolite(s) need to be detected in urine to verify the illicit drug use. Notably, the detection of 2-FAP, which is a plausible 2-FMA metabolite, is insufficient as evidence of 2-FMA use because 2-FAP is widely available and may be present as such in taken liquids. In this study, we synthesized analytical standards for N-hydroxy 2-FMA (N-OH-2-FMA) and two diastereomers of 2-fluoroephedrine, which are plausible metabolites of 2-FMA. Using these standards, the urine specimen was found to contain N-OH-2FMA and one diastereomer of 2-fluoroephedrine; moreover, the concentrations of these compounds were successfully determined. The results of our study suggest that N-hydroxylation and aliphatic hydroxylation are the characteristic metabolic pathways of 2-FMA compared with that of methamphetamine. This evidence indicates that both N-OH-2-FMA and 2-fluoroephedrine are plausible candidates as analytical targets for drug-use certification in forensic science.

Comprehensive Analysis of Analogues of Amine-Related Psychoactive Substances Using Femtosecond Laser Ionization Mass Spectrometry

Amine-related psychoactive molecules contain N-C_α and C_α-C_β bonds, which easily dissociate to form various fragment ions in electron ionization mass spectrometry (EIMS). Therefore, observing a molecular ion and then determining the molecular weight of the analyte is difficult. In this study, we examined phenethylamine, 3,4-methylenedioxyphenethylamine, tryptamine, N-methylephedrine, and nicotine as well as analogues of amine-related psychoactive substances using EIMS and femtosecond laser ionization mass spectrometry (fs-LIMS) combined with gas chromatography for comprehensive analysis. A molecular ion was clearly observed in fs-LIMS for all of these compounds, which was in contrast to EIMS providing fragment ions dominantly (no molecular ion was observed for N-methylephedrine). This favorable result was obtained by adjusting the laser wavelength to the optimal value for two-photon ionization to minimize the excess energy remaining in the molecular ion. It therefore appears that fs-LIMS is superior to EIMS in terms of observing a molecular ion and would be potentially useful for identifying a variety of amine-related psychoactive substances, some of which are illegal and are of interest in the field of forensic science.

Chiral Serum Pharmacokinetics of 4-Fluoroamphetamine after Controlled Oral Administration: Can (R)/(S) Concentration Ratios Help in Interpreting Forensic Cases?

Over the last two decades, misuse of 4-fluoroamphetamine (4-FA) became an emerging issue in many European countries. Stimulating effects last for 4-6 hours and can impact psychomotor performance. The metabolism of amphetamine-type stimulants is stereoselective and quantification of (R)- and (S)-enantiomers has been suggested for assessing time of use. To date no data on enantioselective pharmacokinetics is available for 4-FA in serum samples. An enantioselective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed using a chiral Phenomenex® Lux 3 μm AMP column. Validation of the method showed satisfactory selectivity, sensitivity, linearity (0.5-250 ng/mL), precision and accuracy. Recreational stimulant users orally ingested two doses (100 mg, n=12, and 150 mg, n=5) of 4-FA. Blood samples were drawn prior to application and over a period of 12 hours after ingestion and analyzed for 4-FA enantiomers. Peak concentrations and corresponding times did not differ significantly between the enantiomers (mean (R)/(S)-ratio at tmax 1.05, 0.85-1.16). With mean 12.9 (8.3-16.1) hours, apparent elimination half-lives (t1/2) were significantly (p < 0.01) longer for (R)-4-FA than for (S)-4-FA (6.0 hours; range 4.4-10.2 hours) and independent of the dose given. Over time, (R)/(S)-concentration-ratios were linearly increasing in all subjects to maximum ratios of 2.00 (1.08-2.77) in the last samples (after 12 hours). The slopes of the (R)/(S)-ratio exhibited marked inter-individual differences (0.023 to 0.157 h-1, mean 0.095 h-1). Ratios higher than 1.60 only appeared earliest after a minimum of 6 hours and therefore suggest the absence of acute drug effects. Different elimination half-lives of enantiomers lead to constantly increasing (R)/(S)-concentration-ratios. Consequently, ratios of 4-FA enantiomers in serum are a promising indicator for assessment of the time of drug consumption.

Separation of positional isomers of nine 2-phenethylamine-derived designer drugs by liquid chromatography-tandem mass spectrometry

The synthesis of positional isomers of designer drugs is a common way of bypassing legal restrictions. For forensic case work, and especially for the legal assessment of cases, there is a need for screening methods capable of the unequivocal identification of positional isomers. The presented liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method facilitates separation of positional isomers of 9 2-phenethylamine-derived designer drugs in different matrices including seized materials, hair, serum, and urine specimens. Chromatographic separation was achieved on a biphenyl phase using gradient elution with a total runtime of 26 minutes. The limit of detection was 25 pg/mg for hair samples and ranged from 0.1 ng/mL to 0.5 ng/mL for serum and from 0.2 ng/mL to 1.2 ng/mL for urine samples. The method proved to be selective and sensitive and showed good chromatographic resolution (R ≥ 1.2). The method was successfully applied to routine case samples.

Fatalities, Cerebral Hemorrhage, and Severe Cardiovascular Toxicity After Exposure to the New Psychoactive Substance 4-Fluoroamphetamine: A Prospective Cohort Study

STUDY OBJECTIVE

We study adverse health effects after use of the new psychoactive substance 4-fluoroamphetamine.

METHODS

All patients who reported 4-fluoroamphetamine exposure and for whom the Dutch Poisons Information Center was consulted by their physician in 2016 were included in a prospective cohort study. The clinical course was investigated through telephone interviews with the physician and/or patient, using standardized questionnaires. 4-Fluoroamphetamine was analyzed in remaining drug material and biological samples with liquid and gas chromatography-mass spectrometry techniques.

RESULTS

We included 45 patients, and follow-up with the physician and/or patient was performed in 33 cases. All patients experienced adverse effects after 4-fluoroamphetamine use. Severe toxicity was reported in 8 patients. In 5 of these patients, 4-fluoroamphetamine exposure was confirmed in biological specimens. Severe toxicity that was reported included 2 fatalities, 4 patients with cerebral hemorrhage (1 fatal), 2 patients with inverted Takotsubo's cardiomyopathy, 1 patient with myocardial infarction, 1 patient with acute heart failure, and an overall high prevalence of pronounced hypertension and tachycardia.

CONCLUSION

Since the introduction of 4-fluoroamphetamine to the Dutch drug market in 2007, its use continues to increase, possibly because users perceive it as "ecstasy light" and thus relatively safe. However, the proportion of patients with severe toxicity after 4-fluoroamphetamine use is relatively large in our study population. Therefore, users should be warned about the risks of 4-fluoroamphetamine.

Pharmacokinetics, pharmacodynamics and toxicology of new psychoactive substances (NPS): 2C-B, 4-fluoroamphetamine and benzofurans

BACKGROUND

Recently, the number of new psychoactive substances (NPS) appearing on the illicit drug market has shown a marked increase. Although many users perceive the risk of using NPS as medium or low, these substances can pose a serious health risk and several NPS have been implicated in drug-related deaths. In Europe, frequently detected NPS are 4-bromo-2,5-dimethoxyphenethylamine (2C-B), 4-fluoroamphetamine (4-FA) and benzofurans (5-(2-aminopropyl)benzofuran (5-APB) or 6-(2-aminopropyl)benzofuran (6-APB)). However, little is known about the health risks of these specific NPS.

METHODS

In this paper, existing literature on the pharmacokinetics and pharmacodynamics of 2C-B, 4-FA and benzofurans (5-APB/6-APB) was reviewed.

RESULTS

Our review showed that the clinical effects of 2C-B, 4-FA and benzofurans (5-APB/6-APB) are comparable with common illicit drugs like amphetamine and 3,4-methylenedioxymethamphetamine (MDMA). Therefore, NPS toxicity can be handled by existing treatment guidelines that are based on clinical effects instead of the specific drug involved. Even so, information on the health risks of these substances is limited to a number of case reports that are complicated by confounders such as analytical difficulties, mislabelling of drugs, concomitant exposures and interindividual differences.

CONCLUSION

To aid in early legislation, data on clinical effects from poisons centres and user fora should be combined with (in vitro) screening methods and collaboration on an (inter)national level is essential. As a result, potentially hazardous NPS could be detected more quickly, thereby protecting public health.

Raising awareness of new psychoactive substances: chemical analysis and in vitro toxicity screening of 'legal high' packages containing synthetic cathinones

The world's status quo on recreational drugs has dramatically changed in recent years due to the rapid emergence of new psychoactive substances (NPS), represented by new narcotic or psychotropic drugs, in pure form or in preparation, which are not controlled by international conventions, but that may pose a public health threat comparable with that posed by substances listed in these conventions. These NPS, also known as 'legal highs' or 'smart drugs', are typically sold via Internet or 'smartshops' as legal alternatives to controlled substances, being announced as 'bath salts' and 'plant feeders' and is often sought after for consumption especially among young people. Although NPS have the biased reputation of being safe, the vast majority has hitherto not been tested and several fatal cases have been reported, namely for synthetic cathinones, with pathological patterns comparable with amphetamines. Additionally, the unprecedented speed of appearance and distribution of the NPS worldwide brings technical difficulties in the development of analytical procedures and risk assessment in real time. In this study, 27 products commercialized as 'plant feeders' were chemically characterized by gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. It was also evaluated, for the first time, the in vitro hepatotoxic effects of individual synthetic cathinones, namely methylone, pentedrone, 4-methylethcathinone (4-MEC) and 3,4-methylenedioxypyrovalerone (MDPV). Two commercial mixtures ('Bloom' and 'Blow') containing mainly cathinone derivatives were also tested, and 3,4-methylenedioxymethamphetamine (MDMA) was used as the reference drug. The study allowed the identification of 19 compounds, showing that synthetic cathinones are the main active compounds present in these products. Qualitative and quantitative variability was found in products sold with the same trade name in matching or different 'smartshops'. In the toxicity studies performed in primary cultured rat hepatocytes, pentedrone and MDPV proved to be the most potent individual agents, with EC50 values of 0.664 and 0.742 mM, respectively, followed by MDMA (EC50 = 0.754 mM). 4-MEC and methylone were the least potent substances, with EC50 values significantly higher (1.29 and 1.18 mM, respectively; p < 0.05 vs. MDMA). 'Bloom' and 'Blow' showed hepatotoxic effects similar to MDMA (EC50 = 0.788 and 0.870 mM, respectively), with cathinones present in these mixtures contributing additively to the overall toxicological effect. Our results show a miscellany of psychoactive compounds present in 'legal high' products with evident hepatotoxic effects. These data contribute to increase the awareness on the real composition of 'legal high' packages and unveil the health risks posed by NPS.

Headspace analysis of new psychoactive substances using a Selective Reagent Ionisation-Time of Flight-Mass Spectrometer

The rapid expansion in the number and use of new psychoactive substances presents a significant analytical challenge because highly sensitive instrumentation capable of detecting a broad range of chemical compounds in real-time with a low rate of false positives is required. A Selective Reagent Ionisation-Time of Flight-Mass Spectrometry (SRI-ToF-MS) instrument is capable of meeting all of these requirements. With its high mass resolution (up to m/Δm of 8000), the application of variations in reduced electric field strength (E/N) and use of different reagent ions, the ambiguity of a nominal (monoisotopic) m/z is reduced and hence the identification of chemicals in a complex chemical environment with a high level of confidence is enabled. In this study we report the use of a SRI-ToF-MS instrument to investigate the reactions of H₃O⁺, O₂⁺, NO⁺ and Kr⁺ with 10 readily available (at the time of purchase) new psychoactive substances, namely 4-fluoroamphetamine, methiopropamine, ethcathinone, 4-methylethcathinone, N-ethylbuphedrone, ethylphenidate, 5-MeO-DALT, dimethocaine, 5-(2-aminopropyl)benzofuran and nitracaine. In particular, the dependence of product ion branching ratios on the reduced electric field strength for all reagent ions was investigated and is reported here. The results reported represent a significant amount of new data which will be of use for the development of drug detection techniques suitable for real world scenarios.

Bath salts, mephedrone, and methylenedioxypyrovalerone as emerging illicit drugs that will need targeted therapeutic intervention

The term "synthetic cathinones" is fairly new, but, although the abuse of synthetic cathinones is a recent problem, research on cathinone analogs dates back >100 years. One structural element cathinone analogs have in common is an α-aminophenone moiety. Introduction of amine and/or aryl substituents affords a large number of agents. Today, >40 synthetic cathinones have been identified on the clandestine market and many have multiple "street names." Many cathinone analogs, although not referred to as such until the late 1970s, were initially prepared as intermediates in the synthesis of ephedrine analogs. The cathinones do not represent a pharmacologically or mechanistically homogeneous class of agents. Currently abused synthetic cathinones are derived from earlier agents and seem to produce their actions primarily via the dopamine, norepinephrine, and/or serotonin transporter; that is, they either release and/or inhibit the reuptake of one or more of these neurotransmitters. The actions of these agents can resemble those of central stimulants such as methamphetamine, cocaine, and/or empathogens such as 1-(3,4-methylenedioxyphenyl)-2-aminopropane (Ecstasy) and/or produce other effects. Side effects are primarily of a neurological and/or cardiovascular nature. The use of the "and/or" term is emphasized because synthetic cathinones represent a broad class of agents that produce a variety of actions; the agents cannot be viewed as being pharmacologically equivalent. Until valid structure-activity relationships are formulated for each behavioral/mechanistic action, individual synthetic cathinones remain to be evaluated on a case-by-case basis. Treatment of synthetic cathinone intoxication requires more "basic science" research. At this time, treatment is mostly palliative.

New cathinone-derived designer drugs 3-bromomethcathinone and 3-fluoromethcathinone: studies on their metabolism in rat urine and human liver microsomes using GC-MS and LC-high-resolution MS and their detectability in urine

3-Bromomethcathinone (3-BMC) and 3-Fluoromethcathinone (3-FMC) are two new designer drugs, which were seized in Israel during 2009 and had also appeared on the illicit drug market in Germany. These two compounds were sold via the Internet as so-called "bath salts" or "plant feeders." The aim of the present study was to identify for the first time the 3-BMC and 3-FMC Phase I and II metabolites in rat urine and human liver microsomes using GC-MS and LC-high-resolution MS (HR-MS) and to test for their detectability by established urine screening approaches using GC-MS or LC-MS. Furthermore, the human cytochrome-P450 (CYP) isoenzymes responsible for the main metabolic steps were studied to highlight possible risks of consumption due to drug-drug interaction or genetic variations. For the first aim, rat urine samples were extracted after and without enzymatic cleavage of conjugates. The metabolites were separated and identified by GC-MS and by LC-HR-MS. The main metabolic steps were N-demethylation, reduction of the keto group to the corresponding alcohol, hydroxylation of the aromatic system and combinations of these steps. The elemental composition of the metabolites identified by GC-MS could be confirmed by LC-HR-MS. Furthermore, corresponding Phase II metabolites were identified using the LC-HR-MS approach. For both compounds, detection in rat urine was possible within the authors' systematic toxicological analysis using both GC-MS and LC-MS(n) after a suspected recreational users dose. Following CYP enzyme kinetic studies, CYP2B6 was the most relevant enzyme for both the N-demethylation of 3-BMC and 3-FMC after in vitro-in vivo extrapolation.

Identification of ten new designer drugs by GC-MS, UPLC-QTOF-MS, and NMR as part of a police investigation of a Danish internet company

The ability of forensic laboratories to detect and identify unknown compounds is highly important since new, non-controlled designer drugs are appearing on the market with increasing frequency. In this study, the combined use of gas chromatography-mass spectrometry (GC-MS) and ultra performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC-QTOF-MS) was used for screening of new unknowns. In one large seizure from a Danish Internet company, ten different drugs were identified. Several of the compounds were seized for the first time in Denmark. The GC-MS and UPLC-QTOF-MS analyses were supplemented by nuclear magnetic resonance (NMR) spectra for the structural elucidation of p-fluoroamphetamine, mephedrone (4-methylmethcathinone), flephedrone (4-fluoromethcathinone), PPP (α-pyrrolidinopropiophenone), MDPV (3,4-methylenedioxypyrovalerone), Bk-MBDB (2-methylamino-1-(3,4-methylenedioxyphenyl)butan-1-one), pFBT (3-(pfluorobenzoyl)-tropane), and JWH-073 (1-butyl-3-(1-naphthoyl)indol), whereas methylone (3,4-methylenedioxymethcathinone) and N-ethylcathinone matched electron impact-mass spectrometry (EI-MS) library spectra and therefore the screenings were considered sufficient. EI-MS spectra and the proposed main fragmentation patterns are presented as well as QTOF-MS exact masses and fragments and NMR chemical shifts. For the β-ketophenylethylamines (mephedrone, flephedrone, PPP, MDPV, Bk-MBDB, methylone, and N-ethylcathinone) some general fragmentation patterns observed in the EI-MS and QTOF-MS spectra are further discussed and compared to other β-ketophenylethylamines.

The analysis of substituted cathinones. Part 1: chemical analysis of 2-, 3- and 4-methylmethcathinone

The ring substituted methyl isomers of methcathinone, 2-, 3- and 4-methylmethcathinone were analysed. The 2- and 3-isomers were synthesized. The 4-methylmethcathinone isomer is also known as mephedrone and has been widely studied. We present GCMS, NMR and IR data for the three isomers. We show that the three isomers can be separated by GCMS and that the IR spectra for the three compounds can be used to distinguish between them. A seized sample was analysed and it was found to contain 4-methylmethcathinone and benzocaine.

Bioanalysis of new designer drugs

Since the late 1990s the illicit drug market has undergone considerable change: along with the traditional drugs of abuse that still dominate, more than 100 psychotropic substances designed to bypass controlled substances legislation have appeared and led to intoxications and fatalities. Starting from the huge class of phenylalkylamines, containing many subgroups, the spectrum of structures has grown from tryptamines, piperazines, phenylcyclohexyl derivates and pyrrolidinophenones to synthetic cannabinoids and the first synthetic cocaine. Due to the small prevalence and high number of unknown substances, the detection of new designer drugs is a challenge for clinical and forensic toxicologists. Standard screening procedures might fail because a recently discovered or yet unknown substance has not been incorporated in the library used. Nevertheless, many metabolism studies, case reports, screening methods and substance-profiling papers concentrating on single compounds have been published. This review provides an overview of the developed bioanalytical and analytical methods, the matrices used, sample-preparation procedures, concentration of analytes in case of intoxication and also gives a résumé of immunoassay experiences. Additionally, six screening methods for biological matrices with a larger spectrum of analytes are described in more detail.

Chemical analysis of four capsules containing the controlled substance analogues 4-methylmethcathinone, 2-fluoromethamphetamine, alpha-phthalimidopropiophenone and N-ethylcathinone

In August 2007, four capsules containing white powders, said to have originated from an Israel-based Internet company "Neorganics", were anonymously delivered to the Royal Adelaide Hospital, South Australia. The capsules were analysed and the active components were identified including 4-methylmethcathinone, 2-fluoromethamphetamine, alpha-phthalimidopropiophenone and N-ethylcathinone, all of which were unlisted within South Australian controlled substance regulations. We examined the relevant scientific literature surrounding these chemicals and present both GCMS and NMR data for 4-methylmethcathinone and alpha-phthalimidopropiophenone, which have previously received little attention. We also present the vapour- and condensed-phase infrared spectra (IR) of 4-methylmethcathinone as these have also not been reported in the literature previously. We discuss the issues surrounding whether these chemicals can be classified as controlled substance analogues and the likely impact this could have on prosecutions of individuals distributing these products.

Fluoromethcathinone, a new substance of abuse

We have identified a new compound in capsules marketed as plant feeders available from internet suppliers. It is apparent from internet forums that these so-called plant feeders are being used as recreational drugs. The material is identified as being 3'-fluoromethcathinone. The compound in the capsule was identified by GC-MS, 1H, (13)C and (19)F NMR as well as FTIR. Other materials identified in the tablet were caffeine and a methylamine salt. The exact position of the fluorine in the fluoromethcathinone was determined by comparison with materials synthesised in our laboratory. Internet-based companies are known to sell 4'-fluoromethcathinone (flephedrone). We present GC-MS data for the three isomers of fluoromethcathinone and their N-acetyl derivatives and provide a rapid method for determining the positional isomers of fluoromethcathinone using FTIR or (19)F NMR.

Discrimination and identification of the six aromatic positional isomers of trimethoxyamphetamine (TMA) by gas chromatography-mass spectrometry (GC-MS)

A reliable and accurate GC-MS method was developed that allows both mass spectrometric and chromatographic discrimination of the six aromatic positional isomers of trimethoxyamphetamine (TMA). Regardless of the trifluoroacetyl (TFA) derivatization, chromatographic separation of all the investigated isomers was achieved by using DB-5 ms capillary columns (30 m x 0.32 mm i.d.), with run times less than 15 min. However, the mass spectra of the nonderivatized TMAs, except 2,4,6-trimethoxyamphetmine (TMA-6), showed insufficient difference for unambiguous discrimination. On the other hand, the mass spectra of the TFA derivatives of the six isomers exhibited fragments with significant intensity differences, which allowed the unequivocal identification of all the aromatic positional isomers investigated in the present study. This GC-MS technique in combination with TFA derivatization, therefore, is a powerful method to discriminate these isomers, especially useful to distinguish the currently controlled 3,4,5-trimethoxyamphetmine (TMA-1) and 2,4,5-trimethoxyamphetmine (TMA-2) from other uncontrolled TMAs.