Análise fitoquímica e atividades farmacológicas da espécie Vachellia farnesiana (L.) Wight & Arn. [sin.Acacia farnesiana (L.) Wild.]

Abstract

Natural products are the basis for the development of a large number of drugs, and the growing interest in studies of drugs from natural products is due to the failure of pharmaceutical drugs. The species Vachellia farnesiana (sin. Acacia farnesiana) belongs to the Fabaceae family (Leguminosae), the third largest angiosperma family with 751 genera and 19500 species. Among the secondary metabolites already identified in Acacia species are terpenoids, phytosterols, saponins, flavonoids and tannins. Thus, the main objective of this work was the study of the phytochemical profile and evaluation of the toxicity, antioxidant activity and total flavonoid content of ethanolic leaf extracts (ELE and ELESoxhlet) and stem (ESE) of Acacia farnesina, collected in the region of the Parnaiba-Pi Delta. Analysis of the phytochemical profile by thin-layer chromatography (TLC) indicated the presence of terpenoid compounds, sugars, flavonoids and coumarins. Phytochemical tests indicated the presence of constituents of the flavonoid, free steroid, coumarin and alkaloid classes. The ELE (DL50 = 8,3 mg mL-1) and ESE (DL50 = 21 mg mL-1) were not toxic to Artemia salina. Although the total flavonoid content found in the ELE was higher (71,85 ER/g extract) than that obtained for ESE (21,65 ER/g extract), the percentage of antioxidant activity, using the DPPH radical, of ESE was higher (approximately 90% to 625 µg mL-1), comparable to the Trolox® standard. This is due to the majority presence of glycosylated or monohydroxylated flavonoids in the ELE, since these compounds confer low antioxidant potential on the extract.This is the first report of the phytochemical profile of the ESE of V. Farnesiana, which contributes to the chemotaxonomic knowledge of this species.