Estudo fitoquímico dos extratos metanólicos de flores e folhas de Macrolobium acaciifolium e algumas avaliações biológicas dos seus extratos

Abstract

Many species of plants and trees have not yet been studied and require and chemical biological data for verification of its constituents and activities, seeking the discovery of new molecules and ways of using them in health benefits. The Amazon contains many species not studied and Macrolobium acaciifolium is one of them, which is a tree of the Caesalpinioidea (Fabaceae) subfamily and is present not only in the Amazon, but in other states of Brazil, as well as Central and South American countries. The objective of this work was to study chemically the secondary metabolites of M.acaciifolium and to test the antioxidant, toxic and antibacterial potential of this extracts. Hexanic and methanolic extracts were obtained by cold maceration with the aid of ultrasound and its potential antioxidants were evaluated by the DPPH radical and the Fe3+/Phenantroline complex, as well as toxic tests against Artemia salina and some strains of bacteria. The phytochemical study of the methanolic extract of the flowers allowed the isolation of the flavonoid kaempferol-3-O-rutinoside and of the methanolic extract of the leaves to apigenin, luteolin-3’-O-α-L-rhamnoside and luteolin-4’-O-α-L-rhamnoside. The assays performed indicated that the leaves' methanolic extract has a high antioxidant potential and the leaf hexanic and methanolic extracts of the branches have high bacteriostatic potentials, but all were nontoxic against Artemia salina. Luteolin-4’-O-α-L-rhamnoside is not reported in the literature consulted and its presence, together with the flavonoids isolated, suggest the antioxidant potential of the leaf methanolic extract.