In vitro phase I metabolism of three phenethylamines 25D‐NBOMe, 25E‐NBOMe and 25N‐NBOMe using microsomal and microbial models

The metabolism of three hallucinogenic phenethylamines—25D-NBOMe, 25E-NBOMe, and 25N-NBOMe—was investigated using pooled human liver microsomes (pHLM) and the fungus Cunninghamella elegans. In pHLM, 36, 26, and 24 phase I metabolites were identified for 25D-NBOMe, 25E-NBOMe, and 25N-NBOMe, respectively; in C. elegans, 14, 11, and 9 metabolites were found. Major biotransformation steps included oxidative deamination, N-dealkylation, O-demethylation, hydroxylation, and oxidation of alcohols. Unique metabolites included N-oxide and hydroxylamine derivatives, reported for the first time for NBOMe compounds. C. elegans produced all main biotransformation steps observed in human microsomes, suggesting its potential as a model for studying new psychoactive substances.

Study at a glance

Abstract

) receptors and show hallucinogenic effects. The present study investigated the metabolism of 25D-NBOMe, 25E-NBOMe, and 25N-NBOMe using the microsomal model of pooled human liver microsomes (pHLM) and the microbial model of the fungi Cunninghamella elegans (C. elegans). Identification of metabolites was performed using liquid chromatography-high resolution-tandem mass spectrometry (LC-HR-MS/MS) with a quadrupole time-of-flight (QqToF) instrument. In total, 36 25D-NBOMe phase I metabolites, 26 25E-NBOMe phase I metabolites and 24 25N-NBOMe phase I metabolites were detected and identified in pHLM. Furthermore, 14 metabolites of 25D-NBOMe, 11 25E-NBOMe metabolites, and nine 25N-NBOMe metabolites could be found in C. elegans. The main biotransformation steps observed were oxidative deamination, oxidative N-dealkylation also in combination with hydroxylation, oxidative O-demethylation possibly combined with hydroxylation, oxidation of secondary alcohols, mono- and dihydroxylation, oxidation of primary alcohols, and carboxylation of primary alcohols. Additionally, oxidative di-O-demethylation for 25E-NBOMe and reduction of the aromatic nitro group and N-acetylation of the primary aromatic amine for 25N-NBOMe took place. The resulting 25N-NBOMe metabolites were unique for NBOMe compounds. For all NBOMes investigated, the corresponding 2,5-dimethoxyphenethylamine (2C-X) metabolite was detected. This study reports for the first time 25X-NBOMe N-oxide metabolites and hydroxylamine metabolites, which were identified for 25D-NBOMe and 25N-NBOMe and all three investigated NBOMes, respectively. C. elegans was capable of generating all main biotransformation steps observed in pHLM and might therefore be an interesting model for further studies of new psychoactive substances (NPS) metabolism.