Análise fitoquímica e atividade antioxidante de extratos de capim-annoni-2 (eragrostis plana nees)

Abstract

The capim-annoni-2 (Eragrostis plana Nees) is an invasive exotic Poaceae pasture and allelopathic potential, which was accidentally introduced in Rio Grande do Sulat 1950. This study aimed to determine the potential antioxidant, identify and quantify some chemical compounds present in capim-annoni-2 which may be related to the allelopathic activity. To conduct this study, aerials parts of the capim-annoni-2 were collected in São Gabriel county, RS. After sampling of the material, the plants were dried in estufa 60 ° C for 72 hours, and then were ground in a Willey mill type for further carrying out the analysis. Experiments were performed with methanolic extract an infusion of capim-annoni-2. The quantification of phenols, flavonoids and tannins total was carried by spectrophotometer. The data were subjected to analysis of variance (ANOVA) at 5% level of significance. When differences were detected, means were compared by Tukey test (P <0.05). It was observed a higher extraction by methanol extract when compared to the method of infusion. In the methanol extract, were found: ellagic acid, caffeic acid, chlorogenic acid, gallic acid, rutin, quercetin, epicatechin and catechin, with the highest concentration of ellagic acid and lower concentration of catechin (34.05 mg / g and 8.16 mg / g, respectively). There are already infused in the same compounds with a higher concentration of caffeic acid and lower concentration of quercentina (33.15 mg / g 7.42 mg / g, respectively). It is observed that the behavior of the methanol extract followed the same pattern of ascorbic acid (standard) to the antioxidant activity, showing an increase in antioxidant activity up to a concentration of 70μg/ml, stabilizing after being in 80% of antioxidant activity, approximately. Thus, it is concluded that the use of methanol extract has a greater extraction of chemical compounds from the capim-annoni-2, compared with infusion. The potential antioxidant was better for methanol extract, compared to infusion.