Synthesis of New 7-Oxycoumarin Derivatives As Potent and Selective Monoamine Oxidase A Inhibitors

New series of 4-methyl and 3,4-dimethyl-7-oxycoumarin derivatives (oxadiazoles, thiadiazoles, triazoles, and thiazolidinones) were designed, synthesized, and evaluated for their monoamine oxidase (MAO) A and B inhibiting effect. All the synthesized compounds showed in vitro high affinity and selectivity toward MAO-A isoenzyme, compared to clorgyline and moclobemide, with Ki values on the picomolar range. Moreover, most of the tested compounds displayed MAO inhibitory effect when tested in vivo. The docking experiments carried out on MAO-A and MAO-B structures proved new information about the enzyme–inhibitor interaction and the potential therapeutic application of 7-oxycoumarin scaffold.