Identification of catechin in ethyl acetate phase and determination of redox profile of the Anacardium occidentale L. through electrochemical techniques

Abstract

Anacardium occidentale L., also known how “cajueiro”, is very used for your pharmacological properties, like: anti-inflammatory, healing, anti-glycemic and others. Their curls have been described as rich in phenolic compounds, powerful natural antioxidants. Thus, the objective of this work was to determine the redox profile of the A. occidentale inner bark extract using electrochemical and spectrophotometric techniques through the DPPH radical sequestration reaction. For this, a phytochemical prospection was made in which steroids, phenols, flavones, flavonoids, saponins, tannins and xanthones were detected in the hydroethanolic extract (HEE) and in the ethyl acetate phase (EAP). Total phenolic content in the EAP was also quantified with values of 848.62 ± 78.18 μg mg^-1 ofgallic acid. The DPPH assay showed that the EAP at a concentration of 25μg mL^-1, presents the greater sequestration of free radicals (around 90%) with an CE₅₀ value of 16.13 μg mL^-1 and an AAI value of 2.48, noting the very strong antioxidant potential of the plant. The EAP High Performance Liquid Chromatography analysis showed a similar behavior to the catechin standard, with a major peak eluted at 3 minutes and 30 seconds with a slightly broad base and a UV absorbance spectrum with a maximum absorbance of 274 nm, identifying (+) - catechin, when compared to the 279 nm UV-Visible scanning spectrum obtained with catechin standard. The EAP voltammograms were similar to the (+) - catechin standard, inferring the catechin involvement with A. occidentale redox activity.