In Vitro Antiprotozoal Evaluation of Zinc and Copper Complexes Based on Sulfonamides Containing 8-Aminoquinoline Ligands

Luiz      Everson da Silva; Paulo      Teixeira de Sousa Jr.; Eduardo      Nunes Maciel; Rebeca      Korting Nunes; Iriane      Eger; Mario      Steindel; Ricardo      Andrade Rebelo

Abstract

The present paper reports the synthesis and antiprotozoal activity of N-quinolin-8-yl-arylsulfonamides and their copper and zinc complexes. Sulfonamides 2-5 were synthesized by reacting 8-aminoquinoline with several commercial arylsulfonyl chlorides. The corresponding complexes 6-13 were obtained using copper (II) acetate or zinc chloride in methanol. In vitro activity was carried out against promastigote forms of Leishmania braziliensis and L. chagasi, and epimastigote forms of Trypanosoma cruzi. Selected compounds were tested against axenic amastigote forms of L. braziliensis. The new 2,5-dichlorobenzenesulfonamide ligand was found to be inactive under the selected bioassays, however its copper complex 8 was active with the highest selective indexes (SI) against L. braziliensis promastigote and amastigote forms, with IC50 values of 2.59 and 0.35 μM, respectively. Difluorinated copper 10 and zinc 11 complexes were most active against L. braziliensis, with IC50 of 1.11 μM and 1.25 μM, respectively. However, the SI values were about 12 for both compounds. In general, the complexation of sulfonamides increases the antiprotozoal activity, as well as the cytotoxicity on Vero cells. These results confirm the antiprotozoal potential of sulfonamides and metal-based sulfonamides.

Keywords: Quinolinylarylsulfonamides, Quinolinylarylsulfonamide copper and zinc complexes, Leishmanicidal activity, Trypanocidal activity, Cytotoxicity, Antiprotozoal Evaluation, Sulfonamides, Antiprotozoal activity, Copper, Zinc complexes, Difluorinated copper, Quinolinylarylsulfonamide copper, Metal-based sulfonamides, Leishmaniasis, Toxicity, Leishmaniasis therapy, Sterol metabolism, Parasite proteases, Second-line drugs aminosidine, Paromomycin, Amphotericin B, Miltefosine, Sitama quine, Antileishmanial agents, cis-platin, Kinetoplastid parasites, Antiparasitic activity, Biocompatibility, Quinoline-copper complexes, Monohomocyclic system, Leishmanicidal agents, di-F derivatives, Bruker AC-300, Microanalyses, Promastigotes, Cell monolayer, Pharmacomodulations