Atividade antimalárica in vitro e composição química de Machaerium ferox (Benth.) Ducke (Fabaceae)

Abstract

In Oriximiná, Pará, a municipality with a high rate of malaria, traditional groups such as remnant peoples from quilombos were able to experience and learn about useful plants against the disease and its symptoms. Machaerium ferox is native from Amazon and used by traditional communities as an herbal medicine to treat diseases. The present work aimed to study the chemical composition and evaluate the in vitro antiplasmodic activity of the extracts of the M. ferox species against the K1 (chloroquine resistant) strain of Plasmodium falciparum. Eight extracts obtained from the stem of the M. ferox species were evaluated. The extract that obtained the best result, considering yield and antiplasmodic activity was the acetone extract. Acetone extract had a minimum inhibitory concentration (IC50) of 21.3 μg/mL (14.1 – 32.4 μg/mL), being considered partially active. The acetone extract was subjected to liquid-liquid extraction and fractionation using column chromatography (CC). From the F.ACoET fraction, 200 subfractions were obtained, divided into 8 fractions according to their chromatographic profiles visualized on CCD. The first fraction gathered (37.1 mg) showed a good purity level and was submitted to NMR analysis (1D and 2D). The analysis of the substance led to the conclusion that it was the flavonoid epicatechin. From the F.CHCl3 fraction, 152 subfractions were obtained, divided into 5 fractions. The second fraction gathered (4.7 mg) showed a good level of purity and was submitted to NMR analysis (1D and 2D). According to the analysis, it was concluded that the substance is a pentacyclic triterpene, but it was not possible to identify the substance by comparing it with literature data. This is the first report of the presence of epicatechin in the species M. ferox.