New 1,3-thiazole derivatives and their biological and ultrastructural effects on Trypanosoma cruzi

Abstract In previous studies, the compound 3-(bromopropiophenone) thiosemicarbazone was described as a potent anti- Trypanosoma cruzi and cruzain inhibitor. In view to optimize this activity, 1,3-thiazole core was used as building-block strategy to access new lead generation of anti T . cruzi agents. In this way a series of thiazole derivatives were synthesized and most of these derivatives exhibited antiparasitic activity similar to benznidazole (Bzd). Among them, compounds ( 1c ) and ( 1g ) presented better selective index (SI) than Bzd. In addition, compounds showed inhibitory activity against the cruzain protease. As observed by electron microscopy, compound ( 1c ) treatment caused irreversible and specific morphological changes on ultrastructure organization of T . cruzi , demonstrating that this class of compounds is killing parasites.