Bioisosteric analogs of MDMA: Improving the pharmacological profile?

3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') is re-emerging in clinical settings as a candidate for the treatment of specific neuropsychiatric disorders (e.g. post-traumatic stress disorder) in combination with psychotherapy. MDMA is a psychoactive drug, typically regarded as an empathogen or entactogen, which leads to transporter-mediated monoamine release. Despite its therapeutic potential, MDMA can induce dose-, individual-, and context-dependent untoward effects outside safe settings. In this study, we investigated whether three new methylenedioxy bioisosteres of MDMA improve its off-target profile. In vitro methods included radiotracer assays, transporter electrophysiology, bioluminescence resonance energy transfer and fluorescence-based assays, pooled human liver microsome/S9 fraction incubations, metabolic stability studies, isozyme mapping, and liquid chromatography coupled to high-resolution mass spectrometry. In silico methods included molecular docking. Compared with MDMA, all three MDMA bioisosteres (ODMA, TDMA, and SeDMA) showed similar pharmacological activity at human serotonin, dopamine, and norepinephrine transporters (hSERT, hDAT, and hNET, respectively) but decreased agonist activity at 5-HT2A/2B/2C receptors. Regarding their hepatic metabolism, they differed from MDMA, with N-demethylation being the only metabolic route shared, and without forming phase II metabolites. In addition, TDMA showed an enhanced intrinsic clearance in comparison to its congeners. Additional screening for their interaction with human organic cation transporters (hOCTs) and plasma membrane monoamine transporter (hPMAT) revealed a weaker interaction of the MDMA analogs with hOCT1, hOCT2, and hPMAT. Our findings suggest that these new MDMA bioisosteres might constitute appealing therapeutic alternatives to MDMA, sparing the primary pharmacological activity at hSERT, hDAT, and hNET, but displaying a reduced activity at 5-HT2A/2B/2C receptors and alternative hepatic metabolism. Whether these MDMA bioisosteres may pose lower risk alternatives to the clinically re-emerging MDMA warrants further studies.

Analytical characterization of bioactive N-benzyl-substituted phenethylamines and 5-methoxytryptamines.

RATIONALE: Substances based on the N-(2-methoxybenzyl)phenethylamine template ('NBOMe' derivatives) play an important role in medicinal research but some of these derivatives have also appeared as 'research chemicals' for recreational use which has attracted attention worldwide. A major challenge associated with newly emerging substances includes the lack of analytical data and the ability to correctly identify positional isomers. METHODS: Six N-benzylphenethylamines based on the 2,5-dimethoxy-4-iodophenethylamine structure ('25I') and twelve substituted N-benzyl-5-methoxytryptamines ('5MT') have been prepared and extensively characterized. Techniques used for characterization were gas chromatography/ion trap mass spectrometry in electron and chemical ionization mode, liquid chromatography/diode array detection (DAD), infrared spectroscopy, electrospray high mass accuracy quadrupole time-of-flight tandem mass spectrometry, and triple quadrupole tandem mass spectrometry. RESULTS: The characterization of 18 'NBOMe' compounds provided a comprehensive collection of chromatographic and spectral data. Four groups of three positional isomers, i.e. 25I-NB2OMe, 25I-NB3OMe, 25I-NB4OMe, 25I-NB2B, 25I-NB3B, 25I-NB4B and their 5-methoxytryptamine counterparts, were included and assessed for ability to obtain differentiation. Six meta-substituted N-benzyl derivatives of 5-methoxytryptamine (CF3, F, CH3, Cl, I, SCH3) were also studied. CONCLUSIONS: The implementation of mass spectral techniques was helpful for the differentiation between isomers, for example, when considering the difference in a number of ion ratios. This was considered beneficial in cases where chromatographic separation was only partially achieved under liquid chromatography (LC) conditions. The use of LC/DAD analysis was also found to be valuable for this particular purpose, which confirmed the integrative value of complementary techniques used in areas related to forensic toxicology.

Benzofuran analogues of amphetamine and methamphetamine: studies on the metabolism and toxicological analysis of 5-APB and 5-MAPB in urine and plasma using GC-MS and LC-(HR)-MS(n) techniques.

5-APB (5-(2-aminopropyl)benzofuran) and its N-methyl derivative 5-MAPB (N-methyl-5-(2-aminopropyl)benzofuran) are analogues of amphetamine and methamphetamine, respectively, and belong to the so-called novel psychoactive substances (NPS). They were consumed as stimulants or entactogens with euphoric and empathogenic effects. Being controlled in some countries, both compounds should be covered by drug testing in clinical and forensic toxicology. Therefore, metabolism studies have been performed by working up rat urine samples after a high single dose of the corresponding NPS with solid-phase extraction without and after enzymatic conjugates cleavage. The phase I metabolites were separated and identified after acetylation by GC-MS and/or LC-HR-MS(n) and the phase II metabolites by LC-HR-MS(n). The main metabolite of 5-APB was 3-carboxymethyl-4-hydroxy amphetamine and the main metabolites of 5-MAPB were 5-APB (N-demethyl metabolite) and 3-carboxymethyl-4-hydroxy methamphetamine. The cytochrome P450 (CYP) isoenzymes involved in the 5-MAPB N-demethylation were CYP1A2, CYP2B6, CYP2C19, and CYP2D6, and according to the kinetic parameters, CYP2B6 was responsible for the main part of the total CYP-dependent clearance. An intake of a common users' dose of 5-APB or 5-MAPB could be confirmed in rat urine using the authors' GC-MS and the LC-MS(n) standard urine screening approaches with the corresponding parent drugs as major target. In authentic human urine samples after ingestion of unknown doses of 5-MAPB, both metabolites could also be detected besides the parent drug. The plasma concentrations determined in six clinical cases ranged from 5 to 124 µg/L for 5-MAPB and from 1 to 38 µg/L for its N-demethyl metabolite 5-APB.

Metabolic fate, mass spectral fragmentation, detectability, and differentiation in urine of the benzofuran designer drugs 6-APB and 6-MAPB in comparison to their 5-isomers using GC-MS and LC-(HR)-MS(n) techniques.

The number of so-called new psychoactive substances (NPS) is still increasing by modification of the chemical structure of known (scheduled) drugs. As analogues of amphetamines, 2-aminopropyl-benzofurans were sold. They were consumed because of their euphoric and empathogenic effects. After the 5-(2-aminopropyl)benzofurans, the 6-(2-aminopropyl)benzofuran isomers appeared. Thus, the question arose whether the metabolic fate, the mass spectral fragmentation, and the detectability in urine are comparable or different and how an intake can be differentiated. In the present study, 6-(2-aminopropyl)benzofuran (6-APB) and its N-methyl derivative 6-MAPB (N-methyl-6-(2-aminopropyl)benzofuran) were investigated to answer these questions. The metabolites of both drugs were identified in rat urine and human liver preparations using GC-MS and/or liquid chromatography-high resolution-mass spectrometry (LC-HR-MS(n)). Besides the parent drug, the main metabolite of 6-APB was 4-carboxymethyl-3-hydroxy amphetamine and the main metabolites of 6-MAPB were 6-APB (N-demethyl metabolite) and 4-carboxymethyl-3-hydroxy methamphetamine. The cytochrome P450 (CYP) isoenzymes involved in the 6-MAPB N-demethylation were CYP1A2, CYP2D6, and CYP3A4. An intake of a common users' dose of 6-APB or 6-MAPB could be confirmed in rat urine using the authors' GC-MS and the LC-MS(n) standard urine screening approaches with the corresponding parent drugs as major target allowing their differentiation. Furthermore, a differentiation of 6-APB and 6-MAPB in urine from their positional isomers 5-APB and 5-MAPB was successfully performed after solid phase extraction and heptafluorobutyrylation by GC-MS via their retention times.

GC-MS and LC-(high-resolution)-MS(n) studies on the metabolic fate and detectability of camfetamine in rat urine.

Camfetamine (N-methyl-3-phenyl-norbornan-2-amine; CFA) belongs as amphetamine-type stimulant to the so-called new psychoactive substances. CFA is an analogue of fencamfamine, an appetite suppressant developed in the 1960s. The described effects of CFA are slight stimulation and increased vigilance and the side effects are tachycardia, paranoia, and sleeplessness. The aims of the presented work were to study the metabolic fate and the detectability of CFA in urine and to elucidate which cytochrome-P450 (CYP) isoenzymes are involved in the main metabolic steps. For metabolism studies, rat urine samples were isolated by solid-phase extraction without and after enzymatic cleavage of conjugates. The phase I metabolites were separated and identified after/without acetylation by gas chromatography-mass spectrometry (GC-MS) and/or liquid chromatography-high resolution-linear ion trap mass spectrometry (LC-HR-MS(n)), respectively, and the phase II metabolites by LC-HR-MS(n). From the identified metabolites, the following main metabolic pathways were deduced: N-demethylation, aromatic mono or bis-hydroxylation followed by methylation of one hydroxy group, hydroxylation of the norbornane ring, combination of these steps, and glucuronidation and/or sulfation of the hydroxy metabolites. The N-demethylation was catalyzed by CYP2B6, CYP2C19, CYP2D6, and CYP3A4, the aromatic hydroxylation by CYP2C19 and CYP2D6, and the aliphatic hydroxylation was catalyzed by CYP1A2, CYP2B6, CYP2C19, and CYP3A4. Finally, the intake of a common user's dose of CFA could be confirmed in rat urine using the authors' GC-MS and the LC-MS(n) standard urine screening approaches via CFA and several metabolites, with the hydroxy-aryl CFA and the corresponding glucuronide being the most abundant.

Studies on the metabolism and the detectability of 4-methyl-amphetamine and its isomers 2-methyl-amphetamine and 3-methyl-amphetamine in rat urine using GC-MS and LC-(high-resolution)-MSn.

4-Methyl-amphetamine (1-(4-methylphenyl)propane-2-amine; 4-MA) and its isomers 2-methyl-amphetamine (2-MA) and 3-methyl-amphetamine (3-MA) belong to the group of amphetamine-type stimulants and of new psychoactive substances. Several studies showed similar potencies in releasing noradrenalin and dopamine, but higher potencies in releasing serotonin than amphetamine. In March 2013, the EU Council decided on an EU-wide control based on the European Monitoring Centre for Drugs and Drug Addiction risk assessment report documenting that 4-MA was sold as amphetamine on the illicit market and detected in several fatal cases. Therefore, 4-MA and its isomers should be covered by drug testing in clinical and forensic toxicology. The aims of the presented work were to study the metabolism and detectability of each isomer in urine samples. For metabolism studies, rat urine samples were isolated by solid-phase extraction without and after enzymatic cleavage of conjugates. The phase I metabolites were separated and identified after acetylation by gas chromatography-mass spectrometry (GC-MS) and/or liquid chromatography-high resolution-linear ion trap mass spectrometry (LC-HR-MS(n)) and the phase II metabolites by LC-HR-MS(n). From the identified phase I and II metabolites, the following main metabolic pathways were deduced: aromatic hydroxylation, hydroxylation of the phenylmethyl group followed by oxidation to the corresponding carboxylic acid, hydroxylation of the side chain, and glucuronidation and/or sulfation of the hydroxy and carboxy groups. CYP2D6 was involved in the aromatic hydroxylation. Finally, the intake of a commonly used dose of the MAs could be confirmed in rat urine using the authors' GC-MS and the LC-MS(n) standard urine screening approaches. Differentiation of the isomers to confirm the intake of a specific isomer was possible with an additional workup in rat urine.

Identification of N-pyrrolidino protonitazene in powders sold as heroin and associated with overdose clusters in Dublin and Cork, Ireland.

Synthetic opioids have been associated globally with adverse effects in drug users. The nitazene group of drugs is a relatively new addition to the synthetic opioid class emerging in Europe in 2019. Some nitazenes have been shown to be more potent than fentanyl. Overdose clusters in heroin users in Dublin (57 cases) and Cork (20 cases), Ireland, in November and December 2023, respectively, prompted a rapid response from a number of Irish laboratories to identify the substance(s) of concern. Light brown (tan) powders were obtained from cases associated with overdoses, and the results from these analyses by collaboration of four laboratories are reported here. The samples were found to contain N-pyrrolidino protonitazene (protonitazepyne), caffeine, paracetamol, benzoic acid and mannitol.

Analytical and behavioral characterization of 1-hexanoyl-LSD (1H-LSD).

The development of lysergic acid diethylamide (LSD) derivatives and analogs continues to inform the design of novel receptor probes and potentially new medicines. On the other hand, a number of newly developed LSD derivatives have also emerged as recreational drugs, leading to reports of their detection in some countries. One position in the ergoline scaffold of LSD that is frequently targeted is the N1-position; numerous N1-alkylcarbonyl LSD derivatives have been reported where the acyl chain is attached to the indole nitrogen, for example, in the form of linear n-alkane substituents, which represent higher homologs of the prototypical 1-acetyl-N,N-diethyllysergamide (1A-LSD, ALD-52). In this study, 1-hexanoyl-LSD (1H-LSD, SYN-L-027), a novel N1-acyl LSD derivative, was characterized analytically using standard techniques, followed by evaluation of its in vivo behavioral effects using the mouse head-twitch response (HTR) assay in C57BL/6J mice. 1H-LSD induced the HTR, with a median effective dose (ED50) of 192.4 µg/kg (equivalent to 387 nmol/kg), making it roughly equipotent to ALD-52 when tested previously under similar conditions. Similar to other N1-acylated analogs, 1H-LSD is anticipated to by hydrolyzed to LSD in vivo and acts as a prodrug. It is currently unknown whether 1H-LSD has appeared as on the research chemical market or is being used recreationally.

Analytical and behavioral characterization of N-ethyl-N-isopropyllysergamide (EIPLA), an isomer of N6 -ethylnorlysergic acid N,N-diethylamide (ETH-LAD).

Preclinical investigations have shown that N-ethyl-N-isopropyllysergamide (EIPLA) exhibits lysergic acid diethylamide (LSD)-like properties, which suggests that it might show psychoactive effects in humans. EIPLA is also an isomer of N6 -ethylnorlysergic acid N,N-diethylamide (ETH-LAD), a lysergamide known to produce psychedelic effects in humans that emerged as a research chemical. EIPLA was subjected to analysis by various forms of mass spectrometry, chromatography (GC, LC), nuclear magnetic resonance (NMR) spectroscopy, and GC condensed-phase infrared spectroscopy. The most straightforward differentiation between EIPLA and ETH-LAD included the evaluation of mass spectral features that reflected the structural differences (EIPLA: N6 -methyl and N-ethyl-N-isopropylamide group; ETH-LAD: N6 -ethyl and N,N-diethylamide group). Proton NMR analysis of blotter extracts suggested that EIPLA was detected as the base instead of a salt, and two blotter extracts suspected to contain EIPLA revealed the detection of 96.9 ± 0.5 µg (RSD: 0.6%) and 85.8 ± 2.8 µg base equivalents based on LC-MS analysis. The in vivo activity of EIPLA was evaluated using the mouse head-twitch response (HTR) assay. Similar to LSD and other serotonergic psychedelics, EIPLA induced the HTR (ED50 = 234.6 nmol/kg), which was about half the potency of LSD (ED50 = 132.8 nmol/kg). These findings are consistent with the results of previous studies demonstrating that EIPLA can mimic the effects of known psychedelic drugs in rodent behavioral models. The dissemination of analytical data for EIPLA was deemed justifiable to aid future forensic and clinical investigations.

Analytical and behavioral characterization of 1-dodecanoyl-LSD (1DD-LSD).

1-Acetyl-N,N-diethyllysergamide (1A-LSD, ALD-52) was first synthesized in the 1950s and found to produce psychedelic effects similar to those of LSD. Evidence suggests that ALD-52 serves as a prodrug in vivo and hydrolysis to LSD is likely responsible for its activity. Extension of the N1-alkylcarbonyl chain gives rise to novel lysergamides, which spurred further investigations into their structure-activity relationships. At the same time, ALD-52 and numerous homologues have emerged as recreational drugs ("research chemicals") that are available from online vendors. In the present study, 1-dodecanoyl-LSD (1DD-LSD), a novel N1-acylated LSD derivative, was subjected to analytical characterization and was also tested in the mouse head-twitch response (HTR) assay to assess whether it produces LSD-like effects in vivo. When tested in C57BL/6J mice, 1DD-LSD induced the HTR with a median effective dose (ED50) of 2.17 mg/kg, which was equivalent to 3.60 µmol/kg. Under similar experimental conditions, LSD has 27-fold higher potency than 1DD-LSD in the HTR assay. Previous work has shown that other homologues such as ALD-52 and 1-propanoyl-LSD also have considerably higher potency than 1DD-LSD in mice, which suggests that hydrolysis of the 1-dodecanoyl moiety may be comparatively less efficient in vivo. Further investigations are warranted to determine whether the increased lipophilicity of 1DD-LSD causes it to be sequestered in fat, thereby reducing its exposure to enzymatic hydrolysis in plasma and tissues. Further clinical studies are also required to assess its activity in humans and to test the prediction that it could potentially serve as a long-acting prodrug for LSD.

Bioisosteric analogs of MDMA with improved pharmacological profile.

3,4-Methylenedioxymethamphetamine (MDMA, ' ecstasy' ) is re-emerging in clinical settings as a candidate for the treatment of specific psychiatric disorders (e.g. post-traumatic stress disorder) in combination with psychotherapy. MDMA is a psychoactive drug, typically regarded as an empathogen or entactogen, which leads to transporter-mediated monoamine release. Despite its therapeutic potential, MDMA can induce dose-, individual-, and context-dependent untoward effects outside safe settings. In this study, we investigated whether three new methylenedioxy bioisosteres of MDMA improve its off-target profile. In vitro methods included radiotracer assays, transporter electrophysiology, bioluminescence resonance energy transfer and fluorescence-based assays, pooled human liver microsome/S9 fraction incubation with isozyme mapping, and liquid chromatography coupled to high-resolution mass spectrometry. In silico methods included molecular docking. Compared with MDMA, all three MDMA bioisosteres (ODMA, TDMA, and SeDMA) showed similar pharmacological activity at human serotonin and dopamine transporters (hSERT and hDAT, respectively) but decreased activity at 5-HT 2A/2B/2C receptors. Regarding their hepatic metabolism, they differed from MDMA, with N -demethylation being the only metabolic route shared, and without forming phase II metabolites. Additional screening for their interaction with human organic cation transporters (hOCTs) and plasma membrane transporter (hPMAT) revealed a weaker interaction of the MDMA analogs with hOCT1, hOCT2, and hPMAT. Our findings suggest that these new MDMA analogs might constitute appealing therapeutic alternatives to MDMA, sparing the primary pharmacological activity at hSERT and hDAT, but displaying a reduced activity at 5-HT 2A/2B/2C receptors and reduced hepatic metabolism. Whether these MDMA bioisosteres may pose lower risk alternatives to the clinically re-emerging MDMA warrants further studies.

2-methiopropamine, a thiophene analogue of methamphetamine: studies on its metabolism and detectability in the rat and human using GC-MS and LC-(HR)-MS techniques.

2-Methiopropamine [1-(thiophen-2-yl)-2-methylaminopropane, 2-MPA], a thiophene analogue of methamphetamine, is available from online vendors selling "research chemicals." The first samples were seized by the German police in 2011. As it is a recreational stimulant, its inclusion in routine drug screening protocols should be required. The aims of this study were to identify the phase I and II metabolites of 2-MPA in rat and human urine and to identify the human cytochrome-P450 (CYP) isoenzymes involved in its phase I metabolism. In addition, the detectability of 2-MPA in urine samples using the authors' well-established gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-linear ion trap-mass spectrometry (LC-MS(n)) screening protocols was also evaluated. The metabolites were isolated from rat and human urine samples by solid-phase extraction without or following enzymatic cleavage of conjugates. The phase I metabolites, following acetylation, were separated and identified by GC-MS and/or liquid chromatography-high-resolution linear ion trap mass spectrometry (LC-HR-MS(n)) and the phase II metabolites by LC-HR-MS(n). The following major metabolic pathways were proposed: N-demethylation, hydroxylation at the side chain and at the thiophene ring, and combination of these transformations followed by glucuronidation and/or sulfation. CYP1A2, CYP2C19, CYP2D6, and CYP3A4 were identified as the major phase I metabolizing enzymes. They were also involved in the N-demethylation of the analogue methamphetamine and CYP2C19, CYP2D6, and CYP3A4 in its ring hydroxylation. Following the administration of a typical user's dose, 2-MPA and its metabolites were identified in rat urine using the authors' GC-MS and the LC-MS(n) screening approaches. Ingestion of 2-MPA could also be detected by both protocols in an authentic human urine sample.

Tentative Identification of Etazene (Etodesnitazene) Metabolites in Rat Serum and Urine by Gas Chromatography-Mass Spectrometry and Accurate Mass Liquid Chromatography-Mass Spectrometry.

2-Benzylbenzimidazole derivatives comprise a small but forensically significant group of synthetic opioids. In humans, the metabolism of some members of this group is extensive, with little or none of the parent compound remaining. The recent detection of the 2-benzylbenzimidazole derivative, etazene (etodesnitazene), in products seized in Russia required the detection of its metabolites in biofluids for forensic toxicology purposes. Using gas chromatography--mass spectrometry (GC-MS) and high resolution accurate mass (HRAM) liquid chromatography-mass spectrometry (LC-MS), eight etazene metabolites were found in the urine and serum of rats. These were tentatively identified as products of N-deethylation, O-deethylation, hydroxylation or N-oxidation of benzimidazole moiety and combinations of these processes. The parent substance and its O-deethylated metabolite prevailed in rat serum, while in urine, the level of etazene was low compared to N,O-deethylated and N-deethylated with hydroxylation metabolites. Glucuronidated, sulfonated and glutathionated forms were not found. Taking into account reports on the study of the metabolism of other 2-benzylbenzimidazole derivatives in humans, it may be concluded that the mono-deethylated and mono-hydroxylated metabolites are suitable as target analytes in urine.

In vitro metabolic fate of the synthetic cannabinoid receptor agonists (quinolin-8-yl 4-methyl-3-(morpholine-4-sulfonyl)benzoate [QMMSB]) and (quinolin-8-yl 4-methyl-3-((propan-2-yl)sulfamoyl)benzoate [QMiPSB]) including isozyme mapping and carboxylesterases activity testing.

The synthetic cannabinoid receptor agonists (SCRAs) (quinolin-8-yl 4-methyl-3-(morpholine-4-sulfonyl)benzoate [QMMSB]) and (quinolin-8-yl 4-methyl-3-((propan-2-yl)sulfamoyl)benzoate [QMiPSB], also known as SGT-46) are based on the structure of quinolin-8-yl 4-methyl-3-(piperidine-1-sulfonyl)benzoate (QMPSB) that has been identified on seized plant material in 2011. In clinical toxicology, knowledge of the metabolic fate is important for their identification in biosamples. Therefore, the aim of this study was the identification of in vitro Phase I and II metabolites of QMMSB and QMiPSB in pooled human liver S9 fraction (pHLS9) incubations for use as screening targets. In addition, the involvement of human monooxygenases and human carboxylesterases (hCES) was examined. Analyses were performed by liquid chromatography coupled with high-resolution tandem mass spectrometry. Ester hydrolysis was found to be an important step in the Phase I metabolism of both SCRAs, with the carboxylic acid product being found only in negative ionization mode. Monohydroxy and N-dealkyl metabolites of the ester hydrolysis products were detected as well as glucuronides. CYP2C8, CYP2C9, CYP3A4, and CYP3A5 were involved in hydroxylation. Whereas enzymatic ester hydrolysis of QMiPSB was mainly catalyzed by hCES1 isoforms, nonenzymatic ester hydrolysis was also observed. The results suggest that ester hydrolysis products of QMMSB and QMiPSB and their glucuronides are suitable targets for toxicological screenings. The additional use of the negative ionization mode is recommended to increase detectability of analytes. Different cytochrome P450 (CYP) isozymes were involved in the metabolism; thus, the probability of drug-drug interactions due to CYP inhibition can be assessed as low.

Analytical profile of the lysergamide 1cP-AL-LAD and detection of impurities.

The development of novel lysergamides continues to occur, based on both the needs of psychedelic medicine and commercial interest in new recreational substances. The present study continues the authors' research on novel lysergamides and describes the analytical profile of 1-cyclopropanoyl-AL-LAD (IUPAC name: 1-(cyclopropanecarbonyl)-N,N-diethyl-6-(prop-2-en-1-yl)-9,10-didehydroergoline-8ß-carboxamide; 1cP-AL-LAD), using various chromatographic, mass spectrometric, and spectroscopic methods. Analysis of a powdered sample of 1cP-AL-LAD, obtained from an online vendor, by high performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry in full scan/AutoMS/MS mode revealed the detection of 17 impurities based on high-resolution tandem mass spectral data; tentative determination of their identity was based on mass spectral grounds alone, though detection of AL-LAD and 1P-AL-LAD was confirmed using available reference standards. Other tentative compound identifications included 1-acetyl-AL-LAD and several other substances potentially reflecting oxidation of the N6 -allyl group as well as other positions on the ergoline ring system. These data may assist those interested in the chemistry of lysergamides. Finally, 1cP-AL-LAD was also detected in samples of "blotters" sold online for recreational use.

The analysis of amphetamine-like cathinone derivatives using positive electrospray ionization with in-source collision-induced dissociation.

RATIONALE: Amphetamine-like cathinone derivatives have become popular as recreational drugs over the past several years but their identification for forensic purposes is made difficult as they undergo extensive fragmentation under commonly used electron ionization (EI) conditions to afford ambiguous mass spectra. To overcome this, the feasibility of using positive electrospray ionization (ESI) with in-source collision-induced dissociation (CID) to produce distinguishable product ion mass spectra was examined. METHODS: A set of six homologous cathinone derivatives was analyzed using an LTQ/Orbitrap™ high-resolution mass spectrometer to establish if there are any commonalities or uniqueness in their mass spectra. These compounds and a number of other cathinone derivatives were also analyzed on a single quadrupole mass spectrometer to establish the feasibility of using in-source CID for their identification in forensic drug samples. RESULTS: The ESI product ion mass spectra of the [M + H](+) ions of six model compounds were found to be readily interpretable and product ion formation pathways are presented. The use of such mass spectral data in the analysis of forensic drug samples facilitated the discrimination of closely related cathinone derivatives that were difficult to distinguish using conventional gas chromatography/electron ionization mass spectrometry. A product ion mass spectral library of 22 commonly encountered cathinone derivatives was also developed. CONCLUSIONS: It has been shown that the product ion ESI mass spectra of cathinone derivatives are readily interpretable and are useful for the identification of this drug group in forensic samples.

An unusual detection of 2-amino-3-(2-chlorobenzoyl)-5-ethylthiophene and 2-methylamino-5-chlorobenzophenone in illicit yellow etizolam tablets marked "5617" seized in the Republic of Ireland.

Benzodiazepines are a class of compounds used clinically to treat a variety of conditions including anxiety and insomnia. Their potential for abuse has led to a surge in their availability on the illegal drugs market. End users often rely on markings on illicit tablets to identify their contents. However, falsified tablets mimicking genuine pharmaceutical preparations often contain ingredients that differ from what people believe they are taking. The absence of any quality control of the content, purity, or strength of fake tablets can result in adverse effects or even fatal outcomes. In recent years, drug seizures involving illicit round yellow tablets marked "5" on one side and "5617" below a scoreline on the reverse have been submitted to Forensic Science Ireland (FSI) by An Garda Síochána (Irish Police) from throughout the Republic of Ireland. These findings relate to 26 different seizures; the cumulative tablet total seized was in excess of 20,000, and the total number of tablets of this description analyzed at FSI was 141. Irish users assume that the active ingredient present was diazepam. The qualitative analytical results for these tablets are reported. All tablets were found to contain 2-methylamino-5-chlorobenzophenone. In addition, the tablets contained either 2-amino-3-(2-chlorobenzoyl)-5-ethylthiophene or etizolam or both. The constituents were present in varying relative amounts in visually similar tablets. Neither 2-amino-5-chlorobenzophenone nor 2-amino-3-(2-chlorobenzoyl)-5-ethylthiophene had previously been found in tablets analyzed at FSI.

Detection of ADB-BUTINACA Metabolites in Human Urine, Blood, Kidney and Liver.

The N-butyl indazole derivative, N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-butyl-1H-indazole-3-carboxamide (ADB-BUTINACA or ADB-BINACA), currently a drug of abuse in Russia, is reported to have a cannabinoid receptor potency and efficacy almost three times higher than JWH-018. ADB-BUTINACA was detected in blood from patients with suspected drug intoxications, as well as in blood, kidney and liver samples collected during postmortem investigations. Using liquid chromatography-time-of-flight-mass spectrometry, a number of ADB-BUTINACA metabolites were tentatively identified in urine samples. These include products of mono- and dihydroxylation, hydroxylation of the N-butyl side chain and dehydrogenation, formation of a dihydrodiol, hydrolysis of the terminal amide group, N-dealkylation of the indazole and a combination of these reactions. The dihydrodiol was found to be the predominant metabolite, with its chromatographic peak area exceeding those of other metabolites by almost an order of magnitude. For the routine analysis of blood, liver and kidney samples, the dihydrodiol and monohydroxylated metabolites along with the parent compound are recommended as target analytes. The same metabolites in free and glucuronidated forms are also recommended for analytical confirmation in urine samples.

Return of the lysergamides. Part VII: Analytical and behavioural characterization of 1-valeroyl-d-lysergic acid diethylamide (1V-LSD).

The psychopharmacological properties of the psychedelic drug lysergic acid diethylamide (LSD) have attracted the interest of several generations of scientists. While further explorations involving novel LSD-type compounds are needed to assess their potential as medicinal drugs, the emergence of novel derivatives as recreational drugs has also been observed. 1-Valeroyl-LSD (also known as 1-valeryl-LSD, 1-pentanoyl-LSD, 1V-LSD, or "Valerie") is a new N1 -acylated LSD derivative that recently appeared on the online market, and it could be viewed as a higher homolog of ALD-52, 1P-LSD, and 1B-LSD. The present study included the analytical characterization and involved various methods of mass spectrometry (MS), gas and liquid chromatography (GC and LC), nuclear magnetic resonance (NMR) spectroscopy, GC-solid-state infrared (GC-sIR) analysis, and Raman spectroscopy. The in vivo activity of 1V-LSD was assessed using the mouse head-twitch response (HTR), a 5-HT2A -mediated head movement that serves as a behavioral proxy in rodents for human hallucinogenic effects. Similar to LSD and other psychedelic drugs, the HTR induced by 1V-LSD was dose dependent, and the median effective dose for 1V-LSD was 373 nmol/kg, which was about a third of the potency of LSD (ED50  = 132.8 nmol/kg). Lysergamides containing the N1 -substituent typically act as weak partial agonists at the 5-HT2A receptor and are believed to serve as prodrugs for LSD. 1V-LSD is also likely to be hydrolyzed to LSD and serve as a prodrug, but studies to assess the biotransformation and receptor pharmacology of 1V-LSD should be performed to fully elucidate its mechanism of action.

Analytical profile, in vitro metabolism and behavioral properties of the lysergamide 1P-AL-LAD.

Lysergic acid diethylamide (LSD) is known to induce powerful psychoactive effects in humans, which cemented its status as an important tool for clinical research. A range of analogues and derivatives has been investigated over the years, including those classified as new psychoactive substances. This study presents the characterization of the novel lysergamide N,N-diethyl-1-propanoyl-6-(prop-2-en-1-yl)-9,10-didehydroergoline-8ß-carboxamide (1P-AL-LAD) using various mass spectrometric, gas- and liquid chromatographic and spectroscopic methods. In vitro metabolism studies using pooled human liver microsomes (pHLM) confirmed that 1P-AL-LAD converted to AL-LAD as the most abundant metabolite consistent with the hypothesis that 1P-AL-LAD may act as a prodrug. Fourteen metabolites were detected in total; metabolic reactions included hydroxylation of the core lysergamide ring structure or the N6 -allyl group, formation of dihydrodiol metabolites, N-dealkylation, N1 -deacylation, dehydrogenation, and combinations thereof. The in vivo behavioral activity of 1P-AL-LAD was evaluated using the mouse head twitch response (HTR), a 5-HT2A -mediated head movement that serves as a behavioral proxy in rodents for human hallucinogenic effects. 1P-AL-LAD induced a dose-dependent increase in HTR counts with an inverted U-shaped dose-response function, similar to lysergic acid diethylamide (LSD), psilocybin, and other psychedelics. Following intraperitoneal injection, the median effective dose (ED50 ) for 1P-AL-LAD was 491 nmol/kg, making it almost three times less potent than AL-LAD (174.9 nmol/kg). Previous studies have shown that N1 -substitution disrupts the ability of lysergamides to activate the 5-HT2A receptor; based on the in vitro metabolism data, 1P-AL-LAD may induce the HTR because it acts as a prodrug and is metabolized to AL-LAD after administration to mice.