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Markus R Meyer

34 papers in the library · 768 citations · publishing 2009-2026

Papers

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Correction to "Next-Generation MDMA Analogue SDMA: Pharmacological and Metabolic Insights".

ACS Chem Neurosci March 4, 2026 Nina Kastner, Núria Nadal‐gratacós, Selina Hemmer et al. correction

Correction 1: Table 1.The analyses were conducted using the correct data, and all results, interpretations, and conclusions in the paper remain fully accurate.The issue is limited to the presentation of values in the table.Correction 2: p 4733, second paragraph, 1 st sentence.Thigmotaxis was evaluated to assess potential anxiety-like effects induced by the compounds.When comparing the tested...

In vivo and in vitro toxicokinetics including metabolism, isozyme mapping, and monoamine oxidase inhibition of three (2-aminopropyl)benzo[b]thiophene (APBT) psychedelics.

Toxicology March 1, 2026 Lea Wagmann, Simon D. Brandt, Pierce V. Kavanagh et al.

3-(2-Aminopropyl)benzo[b]thiophene (3-APBT), 5-APBT, and 6-APBT are recently identified psychedelics and entactogens that activate serotonin 2 receptor subtypes and lead to a head-twitch response in mice. The present study characterized their toxicokinetics, metabolism, and monoamine oxidase (MAO) inhibition using liquid chromatography-high-resolution tandem mass spectrometry. Metabolites were...

Toxicometabolomics Characterization of Two N1-Sulfonated Dimethyltryptamine Derivatives in Zebrafish Larvae and Human Liver S9 Fractions Using Liquid Chromatography-High-Resolution Mass Spectrometry.

Metabolites February 14, 2026 Prajwal Punnamraju, Sascha K. Manier, Selina Hemmer et al.

Introduction: The availability of toxicokinetic data is critical for detecting and monitoring the intake of psychoactive substances. Timely characterization of novel psychoactive substances (NPS) is particularly important to assess their abuse potential and inform public health responses. Methods: Toxicometabolomics offers a powerful approach to characterize xenobiotic metabolism through...

Next-Generation MDMA Analogue SDMA: Pharmacological and Metabolic Insights

ACS Chemical Neuroscience December 2, 2025 Nina Kastner, Núria Nadal‐gratacós, Selina Hemmer et al.

3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy, shows promise in treating depression and post-traumatic stress disorder (PTSD), resulting in breakthrough status. However, concerns regarding MDMA's abuse potential and cytotoxicity have sparked interest in developing safer analogues with similar therapeutic benefits. This study investigated the pharmacological properties of...

Studies on the Stability and Microbial Biotransformation of Five Deschloroketamine Derivatives as Prerequisite for Wastewater-Based Epidemiology Screening.

Drug Testing and Analysis August 1, 2025 Fabian Frankenfeld, Lea Wagmann, Markus R Meyer 2 citations

Wastewater (WW)-based epidemiology (WBE) is a powerful tool for screening and surveillance of drugs (of abuse) or new psychoactive substances (NPSs) in larger population. Since the drug market changes frequently, it is crucial for WBE to define screening and surveillance biomarkers considering drug metabolism and (microbial) stability. The aims of the presented work were first to identify...

Metabolic fate of drugs of abuse and new psychoactive substances: A pilot study on a novel workflow using a zebrafish embryo model combined with human microdosing.

British Journal of Clinical Pharmacology June 16, 2025 Wellenberg K Simon, Tanja M Gampfer, Wagmann Lea et al. 1 citation

The aim of this study was to develop a novel workflow to identify human urine biomarkers for drugs of abuse and new psychoactive substances. Metabolites of amphetamine, cocaine, LSD, MDMA, methamphetamine, THC, MDMB-CHMICA, and MDPPP were first identified in a zebrafish embryo (ZE) metabolism study followed by comparison to most abundant human metabolites in literature. Finally, metabolites...

Bioisosteric analogs of MDMA: Improving the pharmacological profile?

Journal of Neurochemistry September 1, 2024 Ana Sofia Alberto-Silva, Selina Hemmer, Hailey A. Bock et al. 10 citations

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...

Metabolism and cytotoxicity studies of the two hallucinogens 1cP-LSD and 4-AcO-DET in human liver and zebrafish larvae models using LC-HRMS/MS and a high-content screening assay.

Journal of Pharmaceutical and Biomedical Analysis August 1, 2024 Tanja M Gampfer, Victoria Schütz, Philip Schippers et al. 11 citations

The continuous emergence of new psychoactive substances (NPS) attracted a great deal of attention within recent years. Lately, the two hallucinogenic NPS 1cP-LSD and 4-AcO-DET have appeared on the global market. Knowledge about their metabolism to identify potential metabolic targets for analysis and their cytotoxic properties is lacking. The aim of this work was thus to study their in vitro...

In Vivo and In Vitro Metabolic Fate and Urinary Detectability of Five Deschloroketamine Derivatives Studied by Means of Hyphenated Mass Spectrometry.

Metabolites May 8, 2024 Fabian Frankenfeld, Lea Wagmann, Anush Abelian et al. 3 citations

Ketamine derivatives such as deschloroketamine and deschloro-N-ethyl-ketamine show dissociative and psychoactive properties and their abuse as new psychoactive substances (NPSs) has been reported. Though some information is available on the biotransformation of dissociative NPSs, data on deschloro-N-cyclopropyl-ketamine deschloro-N-isopropyl-ketamine and deschloro-N-propyl-ketamine concerning...

Bioisosteric analogs of MDMA with improved pharmacological profile.

bioRxiv : the preprint server for biology April 11, 2024 Ana Sofia Alberto-Silva, Selina Hemmer, Hailey A. Bock et al. preprint

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...

Can the Intake of a Synthetic Tryptamine be Detected Only by Blood Plasma Analysis? A Clinical Toxicology Case Involving 4-HO-MET

Journal of Analytical Toxicology June 3, 2021 Lea Wagmann, Sascha K. Manier, Markus R Meyer 11 citations

Tryptamines represent a group of hallucinogenic new psychoactive substances with increasing prevalence. Unfortunately, only limited data concerning their toxicology and bioanalysis are available as tryptamines are not included in routine screening procedures in many laboratories. In order to expand the current knowledge, we report a non-fatal clinical toxicology case involving the synthetic...

Pharmacological and biotransformation studies of 1-acyl-substituted derivatives of -lysergic acid diethylamide (LSD)

Neuropharmacology November 19, 2019 Adam L. Halberstadt, Muhammad Chatha, Adam K. Klein et al. 37 citations

The ergoline d-lysergic acid diethylamide (LSD) is one of the most potent psychedelic drugs. 1-Acetyl-LSD (ALD-52), a derivative of LSD containing an acetyl group on the indole nitrogen, also produces psychedelic effects in humans and has about the same potency as LSD. Recently, several other 1-acyl-substitued LSD derivatives, including 1-propanoyl-LSD (1P-LSD) and 1-butanoyl-LSD (1B-LSD), have...

Phenethylamine-derived new psychoactive substances 2C-E-FLY, 2C-EF-FLY, and 2C-T-7-FLY: Investigations on their metabolic fate including isoenzyme activities and their toxicological detectability in urine screenings.

Drug Testing and Analysis October 1, 2019 Lea Wagmann, Nora Hempel, Lilian H. J. Richter et al. 20 citations

Psychoactive substances of the 2C-series are phenethylamine-based designer drugs that can induce psychostimulant and hallucinogenic effects. The so-called 2C-FLY series contains rigidified methoxy groups integrated in a 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran core. The aim of the presented work was to investigate the in vivo and in vitro metabolic fate including isoenzyme activities and...

In vitro metabolic fate of nine LSD-based new psychoactive substances and their analytical detectability in different urinary screening procedures

Analytical and Bioanalytical Chemistry July 19, 2019 Lea Wagmann, Lilian H. J. Richter, Tobias Kehl et al.

The market of new psychoactive substances (NPS) is characterized by a high turnover and thus provides several challenges for analytical toxicology. The analysis of urine samples often requires detailed knowledge about metabolism given that parent compounds either may be present only in small amounts or may not even be excreted. Hence, knowledge of the metabolism of NPS is a prerequisite for the...

Interactions of phenethylamine-derived psychoactive substances of the 2C-series with human monoamine oxidases.

Drug Testing and Analysis February 1, 2019 Lea Wagmann, Simon D. Brandt, Alexander Stratford et al. 26 citations

Psychoactive substances of the 2C-series (2Cs) are phenethylamine-derived designer drugs that can induce psychostimulant and hallucinogenic effects. Chemically, the classic 2Cs contain two methoxy groups in positions 2 and 5 of the phenyl ring, whereas substances of the so-called FLY series contain rigidified methoxy groups integrated in a 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran core. One...

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

Talanta October 1, 2018 Achim T. Caspar, Markus R Meyer, Folker Westphal et al. 17 citations

Among the emerging new psychoactive substances (NPS), compounds carrying an N-ortho-methoxybenzyl substituent, the so-called NBOMes, represented a highly potent group of new hallucinogens. Recently, 3,4-dimethoxyamphetamine (3,4-DMA)-NBOMe and 4-methylmethamphetamine (4-MMA)-NBOMe occurred, but no data on their pharmacokinetics were available. According to other NBOMes, they are expected to be...

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

Toxicology Letters March 15, 2018 Achim T. Caspar, Markus R Meyer, Hans H Maurer

A huge number of new chemical derivatives of known drugs of abuse, so-called new psychoactive substances (NPS), are sold and consumed without prior preclinical and clinical testing. For assessing the elimination behaviors, determination of the kinetic constants Km and Vmax of the cytochrome P450 (CYP) isoforms involved in the hepatic metabolism of NPS could help to predict their contributions...

Metabolism of the tryptamine-derived new psychoactive substances 5-MeO-2-Me-DALT, 5-MeO-2-Me-ALCHT, and 5-MeO-2-Me-DIPT and their detectability in urine studied by GC-MS, LC-MSn , and LC-HR-MS/MS.

Drug Testing and Analysis 2018 Achim T. Caspar, Jonas B Gaab, Julian A Michely et al. 33 citations

Many N,N-dialkylated tryptamines show psychoactive properties and were encountered as new psychoactive substances. The aims of the presented work were to study the phase I and II metabolism and the detectability in standard urine screening approaches (SUSA) of 5-methoxy-2-methyl-N,N-diallyltryptamine (5-MeO-2-Me-DALT), 5-methoxy-2-methyl-N-allyl-N-cyclohexyltryptamine (5-MeO-2-Me-ALCHT), and...

In vitro monoamine oxidase inhibition potential of alpha-methyltryptamine analog new psychoactive substances for assessing possible toxic risks.

Toxicology Letters April 15, 2017 Lea Wagmann, Simon D. Brandt, Pierce V. Kavanagh et al.

Tryptamines have emerged as new psychoactive substances (NPS), which are distributed and consumed recreationally without preclinical studies or safety tests. Within the alpha-methylated tryptamines, some of the psychoactive effects of the prototypical alpha-methyltryptamine (AMT) have been described decades ago and a contributing factor of its acute toxicity appears to involve the inhibition of...

Biotransformation and detectability of the new psychoactive substances N,N-diallyltryptamine (DALT) derivatives 5-fluoro-DALT, 7-methyl-DALT, and 5,6-methylenedioxy-DALT in urine using GC-MS, LC-MSn, and LC-HR-MS/MS.

Analytical and Bioanalytical Chemistry February 1, 2017 Julian A Michely, Simon D. Brandt, Markus R Meyer et al. 23 citations

Derivatives of N,N-diallyltryptamine (DALT) can be classified as new psychoactive substances. Biotransformation and detectability of 5-fluoro-DALT (5-F-DALT), 7-methyl-DALT (7-Me-DALT), and 5,6-methylenedioxy-DALT (5,6-MD-DALT) are described here. Their metabolites detected in rat urine and pooled human liver microsomes were identified by liquid chromatography (LC)-high resolution (HR)-tandem...

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

Drug Testing and Analysis 2017 Simon D. Brandt, Pierce V. Kavanagh, Geraldine Dowling et al. 16 citations

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...

Metabolic fate and detectability of the new psychoactive substances 2-(4-bromo-2,5-dimethoxyphenyl)- N- [(2-methoxyphenyl)methyl]ethanamine (25B-NBOMe) and 2-(4-chloro-2,5-dimethoxyphenyl)- N- [(2-methoxyphenyl)methyl]ethanamine (25C-NBOMe) in human and rat urine by GC–MS, LC–MS n , and LC–HR–MS/MS approaches

Journal of Pharmaceutical and Biomedical Analysis November 27, 2016 Achim T. Caspar, Simon D. Brandt, Andreas E. Stoever et al. 43 citations

25B-NBOMe and 25C-NBOMe are potent 5-HT2A receptor agonists that have been associated with inducing hallucinogenic effects in drug users and severe intoxications. This paper describes the identification of their metabolites in rat and human urine by liquid chromatography (LC)-high resolution (HR)-MS/MS, the comparison of metabolite formation in vitro and in vivo and in different species, the...

Screening for illicit drugs in pooled human urine and urinated soil samples and studies on the stability of urinary excretion products of cocaine, MDMA, and MDEA in wastewater by hyphenated mass spectrometry techniques

Drug Testing and Analysis February 17, 2016 Marie Mardal, Juliet Kinyua, Pedram Ramin et al. 31 citations

Monitoring population drug use through wastewater‐based epidemiology (WBE) is a useful method to quantitatively follow trends and estimate total drug consumption in communities. Concentrations of drug biomarkers might be low in wastewater due to dilution; and therefore analysis of pooled urine (PU) is useful to detect consumed drugs and identify targets of illicit drugs use. The aims of the...

Metabolism of the new psychoactive substances N,N-diallyltryptamine (DALT) and 5-methoxy-DALT and their detectability in urine by GC-MS, LC-MSn, and LC-HR-MS-MS.

Analytical and Bioanalytical Chemistry October 1, 2015 Julian A Michely, Andreas G. Helfer, Simon D. Brandt et al. 49 citations

N,N-Diallyltryptamine (DALT) and 5-methoxy-DALT (5-MeO-DALT) are synthetic tryptamine derivatives commonly referred to as so-called new psychoactive substances (NPS). They have psychoactive effects that may be similar to those of other tryptamine derivatives. The objectives of this work were to study the metabolic fate and detectability, in urine, of DALT and 5-MeO-DALT. For metabolism studies,...

Studies on the metabolism and toxicological detection of the new psychoactive designer drug 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25I-NBOMe) in human and rat urine using GC-MS, LC-MSn, and LC-HR-MS/MS

Analytical and Bioanalytical Chemistry June 24, 2015 Achim T. Caspar, Andreas G. Helfer, Julian A Michely et al. 69 citations

25I-NBOMe, a new psychoactive substance, is a potent 5-HT2A receptor agonist with strong hallucinogenic potential. Recently, it was involved in several fatal and non-fatal intoxication cases. The aim of the present work was to study its phase I and II metabolism and its detectability in urine screening approaches. After application of 25I-NBOMe to male Wistar rats, urine was collected over 24...