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.
Proscaline and methallylescaline are two phenylethylamine derivatives of the classic hallucinogen mescaline, classified as new psychoactive substances (NPS) not controlled by international drug conventions. Limited toxicity information has hindered their identification. Using high-resolution mass spectrometry with three complementary models—computational prediction, zebrafish (in vivo), and human liver microsomes (in vitro)—the study identified 7 proscaline metabolites and 11 methallylescaline metabolites for the first time. Hydroxylated and N-acetylated products were the major metabolites, enabling their selection as biomarkers for detecting intake of these two NPS over a relatively wide detection window.