Effects of the extraction method and chromatographic separation solvent in the antioxidant activity of different species of "espinheira-santa".

Bioactivity of "espinheira-santa" leaves can be evaluated through solvent purification processes. Species of the same genus may contain different compounds, which may be separated by conventional chromatography using different solvents. The extraction process also influences the contents of these compounds. In order to optimize the above process research is required on variables such as solvents, temperature and extraction time. The objective of this work was to evaluate the antioxidant activity (ABTS, DPPH and FRAP) of extracts and purified fractions from leaves of Maytenus ilicifolia and M. aquafolium. Percolation at 28 °C for 7 days, and ultrasound at 50, 60 and 70 °C for 15 min were the extraction methods tested. Open column chromatography (silica gel) was used in the fractionation of extracts, and hexane, chloroform and methanol were the elution solvents used. The evaluation methods of the antioxidant activity were DPPH, FRAP and ABTS. Plant species showed no significant differences between methods for DPPH, but the fractions obtained with chromatography had significant differences, the crude ethanolic extract (CEE) and the methanolic been in general superior. "espinheira-santa" is a plant with antioxidant potential, but the extraction methods are not optimal. Still, it can be said that the separation by chromatography provided a better visualization of the nature of the components of that plant that best stood out in relation to the antioxidant activity.