oxidative stress. Here, we describe the synthesis and the activity of new containing bioactive-heterocycles analogues of naftifine as potential T. cruzi membrane sterolbiosynthesisinhibitors. Benzimidazole 1,3-dioxides (11 and 13) and quinoxaline 1,4-dioxides (22 and 23) displayed excellent parasite/mammal selectivity indexes. Analysis of the free sterols from parasite incubated with the compounds