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Bergh MSS, Bogen IL, Grafinger KE, Huestis MA, Øiestad ÅML. Metabolite markers for three synthetic tryptamines N-ethyl-N-propyltryptamine, 4-hydroxy-N-ethyl-N-propyltryptamine, and 5-methoxy-N-ethyl-N-propyltryptamine. Drug Test Anal 2024. [PMID: 38459837 DOI: 10.1002/dta.3668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 02/08/2024] [Accepted: 02/11/2024] [Indexed: 03/11/2024]
Abstract
N-Ethyl-N-propyltryptamine (EPT), 4-hydroxy-N-ethyl-N-propyltryptamine (4-OH-EPT), and 5-methoxy-N-ethyl-N-propyltryptamine (5-MeO-EPT) are new psychoactive substances classified as tryptamines, sold online. Many tryptamines metabolize rapidly, and identifying the appropriate metabolites to reveal intake is essential. While the metabolism of 4-OH-EPT and 5-MeO-EPT are not previously described, EPT is known to form metabolites by indole ring hydroxylation among others. Based on general knowledge of metabolic patterns, 5-MeO-EPT is also expected to form ring hydroxylated EPT (5-OH-EPT). In the present study, the aim was to characterize the major metabolites of EPT, 4-OH-EPT, and 5-MeO-EPT, to provide markers for substance identification in forensic casework. The tryptamines were incubated with pooled human liver microsomes at 37°C for up to 4 h. The generated metabolites were separated and detected by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry analysis. The major in vitro EPT metabolites were formed by hydroxylation, N-dealkylation, and carbonylation. In comparison, 4-OH-EPT metabolism was dominated by double bond formation, N-dealkylation, hydroxylation, and carbonylation in vitro and hydroxylation or carbonylation combined with double bond loss, carbonylation, N-dealkylation, and hydroxylation in vivo. 5-MeO-EPT was metabolized by O-demethylation, hydroxylation, and N-dealkylation in vitro. The usefulness of the characterized metabolites in forensic casework was demonstrated by identification of unique metabolites for 4-OH-EPT in a human postmortem blood sample with suspected EPT or 4-OH-EPT intoxication.
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Affiliation(s)
- Marianne Skov-Skov Bergh
- Section for Drug Abuse Research, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
| | - Inger Lise Bogen
- Section for Drug Abuse Research, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, The Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Katharina Elisabeth Grafinger
- Institute of Chemistry and Bioanalytics, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
| | - Marilyn A Huestis
- Institute of Emerging Health Professions, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Åse Marit Leere Øiestad
- Section for Forensic Toxicological Analytics, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
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Glatfelter GC, Pottie E, Partilla JS, Sherwood AM, Kaylo K, Pham DNK, Naeem M, Sammeta VR, DeBoer S, Golen JA, Hulley EB, Stove CP, Chadeayne AR, Manke DR, Baumann MH. Structure-Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice. ACS Pharmacol Transl Sci 2022; 5:1181-1196. [PMID: 36407948 PMCID: PMC9667540 DOI: 10.1021/acsptsci.2c00177] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Indexed: 11/06/2022]
Abstract
4-Phosphoryloxy-N,N-dimethyltryptamine (psilocybin) is a naturally occurring tertiary amine found in many mushroom species. Psilocybin is a prodrug for 4-hydroxy-N,N-dimethyltryptamine (psilocin), which induces psychedelic effects via agonist activity at the serotonin (5-HT) 2A receptor (5-HT2A). Several other 4-position ring-substituted tryptamines are present in psilocybin-containing mushrooms, including the secondary amine 4-phosphoryloxy-N-methyltryptamine (baeocystin) and the quaternary ammonium 4-phosphoryloxy-N,N,N-trimethyltryptamine (aeruginascin), but these compounds are not well studied. Here, we investigated the structure-activity relationships for psilocybin, baeocystin, and aeruginascin, as compared to their 4-acetoxy and 4-hydroxy analogues, using in vitro and in vivo methods. Broad receptor screening using radioligand binding assays in transfected cells revealed that secondary and tertiary tryptamines with either 4-acetoxy or 4-hydroxy substitutions display nanomolar affinity for most human 5-HT receptor subtypes tested, including the 5-HT2A and the serotonin 1A receptor (5-HT1A). The same compounds displayed affinity for 5-HT2A and 5-HT1A in mouse brain tissue in vitro and exhibited agonist efficacy in assays examining 5-HT2A-mediated calcium mobilization and β-arrestin 2 recruitment. In mouse experiments, only the tertiary amines psilocin, psilocybin, and 4-acetoxy-N,N-dimethyltryptamine (psilacetin) induced head twitch responses (ED50 0.11-0.29 mg/kg) indicative of psychedelic-like activity. Head twitches were blocked by 5-HT2A antagonist pretreatment, supporting 5-HT2A involvement. Both secondary and tertiary amines decreased body temperature and locomotor activity at higher doses, the effects of which were blocked by 5-HT1A antagonist pretreatment. Across all assays, the pharmacological effects of 4-acetoxy and 4-hydroxy compounds were similar, and these compounds were more potent than their 4-phosphoryloxy counterparts. Importantly, psilacetin appears to be a prodrug for psilocin that displays substantial serotonin receptor activities of its own.
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Affiliation(s)
- Grant C. Glatfelter
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
| | - Eline Pottie
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, 9000 Ghent, Belgium
| | - John S. Partilla
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
| | | | - Kristi Kaylo
- Usona
Institute, Madison, Wisconsin 53711, United States
| | - Duyen N. K. Pham
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Marilyn Naeem
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Vamshikrishna Reddy Sammeta
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Stacie DeBoer
- Department
of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - James A. Golen
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Elliott B. Hulley
- Department
of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Christophe P. Stove
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, 9000 Ghent, Belgium
| | | | - David R. Manke
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Michael H. Baumann
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
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