Organometallic gold(III) (C^S)-cyclometallated complexes as candidates to new drugs against chagas disease.

Chagas disease or American trypanosomiasis remains a serious public health concern with unsatisfactory treatment outcomes. The serious problems with the efficacy and toxicity of the drugs currently used to treat Chagas disease, along with the emergence of resistant strains, have made the development of new chemotherapy strategies a priority. In this work, fourteen (C^S)-cyclometallated gold(III) complexes were evaluated as potential trypanocidal agents. All the tested compounds had better trypanocidal activity against trypomastigotes than the reference drugs, with five complexes presenting an SI above ten for both strains, and two complexes displaying a SI value >200 for the NINOA strain. Among them, complex 6b was identified as a highly selective agent against T. cruzi amastigotes of the NINOA strain. Furthermore, cytotoxicity to mouse macrophage cells is very low for this compound, resulting in a better selectivity index than that of reference drugs Bnz and Nfx. These results suggest the potential of (C^S)-cyclometallated gold (III) complexes as promising antiparasitic drug candidates.