SCREENING OF UNSUBSTITUTED CYCLIC-COMPOUNDS AS INHIBITORS OF MONOAMINE OXIDASES

A number of unsubstituted aromatic hydrocarbons, azaheterocycles, oxah eterocycles and cyclic ketones were screened for their inhibitory pote ncy towards monoamine oxidases (MAO; EC 1.4.3.4.) A and B. Fair activi ties (IC50 10-100 mu M) and selectivities were found for, e.g. naphtha lene, anthracene, phenanthrene, isoquinoline and acridine. The most ac tive inhibitors are oxygen-containing compounds (e.g. coumarin, flavon e, dibenzofuran, xanthene, thioxanthone and acridone), with xanthone e merging as a potent (IC50 0.8 mu M) and reversible MAO-A inhibitor. Al l tested inhibitors seem to act in a reversible and time-independent m anner.