A new series of 3-phenylcoumarins as potent and selective MAO-B inhibitors.

6-Methyl-3-phenylcoumarins 3-6 were designed, synthesized and evaluated as monoamine oxidase A and B (MAO-A and MAO-B) inhibitors. The synthesis of these new compounds (resveratrol-coumarin hybrids) was carried out with good yield by a Perkin reaction, from the 5-methylsalicylaldehyde and the corresponding phenylacetic acid. They show high selectivity to the MAO-B isoenzyme, with IC(50) values in the nanomolar range. Compound 5 is the most active compound and is several times more potent and selective than the reference compound, R-(-)-deprenyl.