5‐(2‐Aminopropyl)indole (5‐IT): a psychoactive substance used for recreational purposes is an inhibitor of human monoamine oxidase (MAO)
Drug Testing and Analysis September 20, 2013 Tomás Herraiz, Simon D. Brandt 25 citations
5-(2-Aminopropyl)indole (5-IT), a psychoactive compound linked to fatal and non-fatal intoxications in Europe, was tested for its effect on human monoamine oxidase (MAO) enzymes. Using kynuramine as a substrate, 5-IT selectively, competitively, and reversibly inhibited MAO-A with an IC50 of 1.6 μM and a Ki of 0.25 μM, while showing no inhibition of MAO-B up to 500 μM. Compared to established inhibitors, 5-IT was less potent than clorgyline (IC50 16 nM) and harmaline (20 nM) but more potent than toloxatone (6.7 μM) and moclobemide (>500 μM). This MAO-A inhibition suggests 5-IT may contribute to serotonergic toxicity, though further research is needed.