Serotonin 2A Receptor (5-HT2AR) Activation by 25H-NBOMe Positional Isomers: In Vitro Functional Evaluation and Molecular Docking

Introduction

Serotonergic psychedelics produce their effects largely through activation of the serotonin 2A receptor (5-HT2AR). This chemical family includes diverse scaffolds (ergolines, tryptamines, phenylalkylamines) and both longstanding psychedelics and newer psychoactive substances. Within the phenylalkylamine subgroup, N-benzyl derivatives of 2C-X compounds (NBOMes) have high potency and have been incompletely characterised with respect to structure–activity relationships, despite recent availability of 5-HT2AR structural data that hint at different binding modes for distinct ligands. Pottie and colleagues set out to examine how the positional arrangement of two methoxy groups on the phenethylamine ring of 25H-NBOMe affects functional activation of 5-HT2AR. They compared five positional isomers of 25H-NBOMe using cell-based recruitment assays that monitor cytosolic protein association with the activated receptor, complemented these assays with molecular docking into an adapted cryo-EM 5-HT2AR structure, and aimed to link specific methoxy positions to differential receptor interactions and activation profiles. This is presented as the first direct comparative functional study of methoxy positional isomerism in NBOMes while retaining the N-methoxybenzyl substituent.