Antitrypanosomal and antileishmanial activities of novel N-alkyl-(1-phenylsubstituted-β-carboline)-3-carboxamides

A series of 1-phenylsubstituted β-carbolines containing an N-butylcarboxamide group at C-3 of β-carboline nucleus were synthesized and evaluated in vitro against epimastigote form of Trypanosoma cruzi and promastigote form of Leishmania amazonensis. Among all compounds tested, two derivatives (2b and 2d) presented potent activity against both parasites. The most active derivative 2b showed also the higher selectivity index ratio (SI) for L. amazonensis (SI = 2,084). The effect of other N-alkylcarboxamide groups at C-3, such as pyrrolidyl, N-cyclohexil and N-benzylcarboxamide on T. cruzi and L. amazonensis activity was also evaluated. Our results pointed the synthesized β-carboline-3-carboxamide derivatives as potential compounds for new drugs for Chagas’ disease and leishmaniasis’ treatment.