Kinetic behaviour of some acetylenic indolalkylamine derivatives and their corresponding parent amines

Different methoxy indolalkylamines based on a common structure, and differing in the side chain attached at the 2 position of the indole ring were studied as MAO A inhibitors. Some are acetylenic derivatives and consequently might behave as "suicide" MAO inhibitors (FA 42, FA 43, FA 45). The rest of compounds are the corresponding parent amines and they might behave as MAO substrates (FA 51, FA 52, FA 53, FA 54). The kinetic behaviour of the parent amines as MAO A and MAO B inhibitors and substrates was determined. In case of acetylenic derivatives, kinetic constants defining the non-covalent adduct formation and the covalent adduct formation were also calculated for the mechanism-based inhibition. These parameters will allow us to establish the correlation with structural features that predetermine one compound to be a good MAO substrate or a good MAO A and MAO B inhibitor.