Substituted Xanthones as Selective and Reversible Monoamine Oxidase A (MAO-A) Inhibitors

Abstract
L,3-Dihydroxy-2-methylxanthone (XI), its 4-chloro and 4-bromo derivatives (X1-C1 and Xl-Br), and 1 ,3-dihydroxy-4-methylxanthone were investigated for their inhibition activities toward MAO. A hyperbolic function was derived to fit the data and to calculate IC50 values. The compounds proved to be reversible and selective inhibitors of MAO-A, with XI displaying the highest activity (IC50 = 3.7 µM).