Bioprospecção para atividade antiplasmódica de extratos vegetais de espécies da mata atlântica selecionadas por critério etológico, identificação de produtos naturais de extratos ativos por UPLC-DAD-ESI-MS/MS e estudo fitoquímico biomonitorado de Xylopia sericea A. ST. Hill (Annonaceae)

Abstract

The use of plant species for treatment of malaria is old practice, and the isolation of compound quinine a framework for the study of natural products antimalarials. Since the high incidence of malaria in endemic countries such as Brazil, and the increasing resistance of Plasmodium to the drugs currently in use, the discovery of new molecules antiplasmódicas is highly relevant. The use of ethological criteria for the selection of new plant species was used in order to identify different species that are not part of ethnopharmacological known arsenal against malaria. The combination of different chromatography techniques to separate chemical analysis methods was an important tool for the isolation and / or identification of natural products. In this way, screening of various plant extracts derived from species selected via ethological criteria, followed by fractionation of those active in vitro extracts against the resistant strain W2 Plasmodium falciparum has allowed the discovery of 8 different extracts, among the 36 analyzed, which showed antiplasmodial activity. Identification via UPLC-DAD-ESI-MS/MS in the ethanol extract of Alchornea glandulosa and Miconia latecrenata showed the presence of flavonoids and hydrolysable tannin while the ethanol extract of Psychotria suterella was identified alkaloid -carboline and indole. From the extracts dichloromethane and ethanol from leaves of Xylopia sericea were identified and isolated a flavanone (dihydroquecetin-3O-rhamnoside) Collection 1 is a diterpene kaurenic (7-oxo-ent-Kaur-16-en-19-oic acid) and three aporphine alkaloids (liriodenine, O-metilmoschatoline and anonaine) and the liriodenine presented high antiplasmodial activity (IC50 6.1 ± 0.1 µg/mL, CC50 > 1000.0 µg/mL, SI > 164.47), possibly being the promoter activity observed of extracts and other fractions of X. sericea Collection 2. The results prove the validity the ethological criteria for the selection of plant species in research antiplasmodial activity, since it allowed the identification of native plant species of the Atlantic Forest, as well as extracts, fractions and substances active against the P. falciparum.