Tentative identification of in vitro metabolites of O‐acetylpsilocin (psilacetin, 4‐AcO‐DMT) by UHPLC‐Q‐Orbitrap MS

4-Acetoxy-N,N-dimethyltryptamine (4-AcO-DMT, psilacetin) is a synthetic psychedelic that may act as a precursor to psilocin, but its metabolism was poorly understood. Incubating 4-AcO-DMT with pooled human liver microsomes produced 15 metabolites: 12 from phase I and 3 from phase II reactions. Transformations included hydrolysis, hydroxylation, N-demethylation, oxidation, and glucuronic acid conjugation. The hydrolysis product was the most abundant. For forensic detection of 4-AcO-DMT use, the beta-hydroxylation metabolite (M2-1) is recommended as a biomarker. These findings may help predict in vivo metabolism and assist drug testing.

Study at a glance

Abstract

Abstract 4‐Acetoxy‐ N , N ‐dimethyltryptamine (4‐AcO‐DMT, psilacetin, O ‐acetylpsilocin) is a synthetic tryptamine with psychedelic properties. Psilacetin may also act as precursor drug of psilocin, similar to psilocybin, but little is known about its metabolism. In this study, the phase I and phase II in vitro metabolism of 4‐AcO‐DMT was investigated with pooled human liver microsomes, and the reaction mixture was analyzed using liquid chromatography‐quadrupole/electrostatic field orbitrap mass spectrometry. Fifteen metabolites were formed after incubation of pooled human liver microsomes with 4‐AcO‐DMT (12 phase I metabolites and 3 phase II metabolites). The proposed metabolite structures were based on accurate mass analysis and MS/MS fragmentation patterns. The biotransformations included hydrolysis, hydroxylation, N ‐demethylation, oxidation, and conjugation with glucuronic acid. The hydrolysis metabolite was the most abundant compound. For the development of new methods for the identification of 4‐AcO‐DMT consumption, the beta‐hydroxylation metabolite of 4‐AcO‐DMT (M2‐1) is recommended as a biomarker. The data reported in this work might be applicable to metabolic transformation of 4‐AcO‐DMT in vivo and also forensically helpful.