AVALIAÇÃO FITOQUÍMICA E DA ATIVIDADE ANTIOXIDANTE E ANTIMICROBIANA DE CASCAS DO CAULE DE Synadenium grantii Hook. f. (Euphorbiaceae)

Abstract

The Synadenium grantii specie is a shrub that reaches between 3 and 5 meters high, native of tropical Africa, producing of toxic latex. It is known in Brazil as janauba, tiborna or leitosinha and its latex is popularly used as remedy for reducing warts, treatment of cancer, gastric and inflammatory diseases. From its latex and aerial parts, some terpenes, anthocyanins, glycoproteins as lectin and serine proteases were already isolated. Biological studies report antitumor, antiparasitic, anti-haemostatic and anti-ulcer activities. The current study aimed to isolate and indentify bioactive compounds, as well as to identify the antioxidant and antimicrobial potential of the crude stem bark extract of S. grantii and its fractions. The chemical study was performed with the chloroform fraction, obtained from the crude stem bark extract (CE) using column and thin layer chromatographic techniques what enabled to isolate three triterpenes: eufol, and for the first time from this specie friedelin and 3 friedelinol. The compounds were identified by NMR and IR spectrometry and compared with literature data. With HPLC technique it was detected the presence of flavonoids in the CE, result that was reinforced with the quantification of total phenolics, by Folin-Ciocalteaumethod, for both CE and its fractions. It was observed that this specie is source of antioxidant compounds, due to the pronounced CE action for both chemical (ABTS+•, DPPH•, O2, HOCl) and enzymatic (MPO) in vitro systems, as well as ex vivo system (free radical induced haemolysis) indicating potential not only to neutralize, but for reduce formation of free radicals, as protect cells (erythrocytes) of free radicals deleterious action. In addition, an antimicrobial study was performed using disc-diffusion and MIC methods with the following microorganisms: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa,Enterococcus faecalis and Candida albicans. The last one exhibited sensibility to CE in both disc-diffusion and MIC (312 μg/mL).