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). © 2020 Informa UK Limited, trading as Taylor & Francis Group.