Identificação de potenciais antimaláricos a partir de compostos de coordenação com ligantes de produtos naturais

Abstract

The species of Vismia spp. They are common in the Amazon region and popularly used by traditional people to treat malaria, as well as many diseases that affect the skin. Considering the occurrence of pathology in pathology, this study sought to identify and characterize chemical compounds from hydroethanolic extracts and of different polarities, from the fruits of species from the region of Vismia cayennensis and Vismia guianensis, in addition to evaluating the antioxidant potential against ABTS+ and DPPH•, quantify the phenolic content of extracts from the fruits of these species and analyze against plasmodial strains. From identified flavonoids, standards were acquired that were used as ligands in copper coordination compounds, which were also evaluated for antioxidant and antimalarial activity. Chemical identification was carried out using mass spectrometry and Nuclear Magnetic Resonance techniques, and the determination of antioxidant activity was carried out using Trolox as a standard. In the antimalarial analysis, strains D10 (resistant to chloroquine) and W2 (sensitive to chloroquine) were used. The study made it possible to identify anthraquinones such as Ferruginin C and flavonoids such as Catechin and Quercetin, these compounds with phenolic characteristics were used as ligands to coordinate copper. The extracts showed good effectiveness against the tested free radicals DPPH and ABTS. The hydroalcoholic extracts of both species showed significant scavenging capacity against the two free radicals. The extract from V. guianensis (1412.1±7.7 µM ET) was more effective against DPPH than the extract from the species of V. cayennensis (916.6±29.5µM ET). The same observation in determining the restriction of the ABTS radical (EVC: 3001.5 ± 74.24 5µM ET; EVG: 3129 ± 7.075µM ET), with the inhibitory concentration for this specific radical being much more expressive when compared to the other extracts organic. All extracts, at a concentration of 20µg/ml, were active against strains of P. falciparum, with the hexane extract of V. guianensis being more expressive for strain D10 (106.62%) and the hydroethanolic extract of Vismia cayenensis being the highest percentage for strain W2 ( 98.55. The metal complexes also demonstrated high antimalarial effectiveness, with the copper-quercetin sample (100.29%) being much more effective than quercetin in its free form (60.91%). Metals, such as copper, can be a good alternative for treating the disease.