Avaliação da atividade antioxidante do extrato metanólico e das frações apolares e polares de Quassia amara L. (Simaroubaceae)

Abstract

The Quassia amara L. is a native plant of northern Brazil, belonging to the family of Simaroubaceae. In folk medicine is widely used for combating gastrointestinal disorders, headaches, and malaria. This is due to the presence of bioactive compounds, such as antioxidants. The ingestion of these supplements, or foods containing antioxidants reduce oxidative damage caused by free radicals in the body, however the use of synthetic antioxidants in high doses, give deleterious effects to the organism, such as degenerative and cardiovascular diseases. Consequently, the natural products have gained prominence as valuable for the development of new active principles sources, allowing progress in the discovery of biomolecules with potential applications in many areas of industry, especially in the food. Therefore, the present study was to evaluate the antioxidant activity (AA) of the methanol extract of Quassia amara (EMQa) and its hexane fractions (FHQa), ethyl acetate (FAcQa), and methanol (FMQa), obtained by fractionation Liquid-liquid through the determination of the content of phenolic compounds in the DPPH yield (expressed in IC50, and Trolox) of reduced iron power (FRAP) and ABTS, In addition to the evaluation of AA samples characterization was performed by infrared and identified phenolic compounds by high performance liquid chromatography (HPLC). It is observed that had a greater FAcQa sequestration radicals as ABTS, DPPH and expressed as trolox and high phenolic content. The EMQa also obtained similar values and presents the lowest inhibition coefficient (IC50 = 15,42 μg.mL-1) thus higher antioxidant activity. Probably due to the synergism between the various phenolic compounds present in the crude extract. The FHQa had the lowest AA results. The characterization of the samples confirmed the high phenolic content, as well as HPLC allow for the identification of some phenolic compounds like gallic acid and coumaric acid. It can be concluded that the fractionation was efficient, because the compounds suitably were separated according to their polarity and extraction of compounds which showed the best AA was more polar solvents, and the Quassia amara can be considered a replacement option of synthetic antioxidants widely used in the pharmaceutical and food industry.