Kopsanone and N-oxide isolated from Aspidosperma macrocarpon Mart. (Apocynaceae) leaves and their MAO-A inhibitory activity.

Aspidosperma macrocarpon Mart., popularly known as 'guatambu' or 'peroba', is found from North American (Mexico) to South American (Argentina) continents and in Brazil. Two indole alkaloids were isolated from leaves of A. macrocarpon, kopsanone (1) and unreported N(4)-oxide-kopsanone (2).