Determinação de atividade antioxidante, compostos fenólicos totais e teor de resveratrol em cinco cultivares brasileiras de Arachis hypogaea L. com a utilização de duas metodologias extrativas

Abstract

Peanut A. hypogaea L. is the fourth most consumed oleaginous in the world and its seeds are high energetic, with high amounts of lipides, proteins, vitamins and carbohidrates. Several pharmacological activities have been observed in extracts of roots, leaves and seeds, especially an antioxidant activity. In this work, the comparison between two extraction methodologies (by maceration and microwave assisted extraction) for the extraction of antioxidant compounds, including resveratrol, was studied. We also carried out a comparison between extracts from different organs of Brazilian cultivars (IAC 886, IAC Caiapó, Tatu ST IAC, IAC 8112 and IAC 99-1) for antioxidant activity by DPPH, the content of phenolic compounds by Folin-Ciocalteu and the resveratrol content by HPLC. Finally, we established tissue culture protocols for seed explants, aiming at the production of in vitro plant material for future measurement of compounds of interest in the view of possible modulation of in vitro conditions. The best conditions for the extraction of antioxidant from A. hypogaea compounds by maceration were 80% of ethanol in water as a solvent, trituration by mortar and pestle, 50 mL solvent/g dry plant, 120 minutes of incubation and two stages of extraction. The best conditions for the extraction of resveratrol assisted by micro-wave were the use of 37 mL of solvent for each gram of dry plant, with 1200 rpm of agitation for 15 minutes, with 37oC. In general, root extracts and assisted by microwave showed higher antioxidant activity (until 92,36 ± 2,71%), phenolic (untill 54,15 ± 1,39 mg AGE/g extract) and resveratrol content (untill 1,614 ± 0,356 mg/g extract). Among the studied cultivars, IAC Tatu and IAC 99-1 showed the best results. In tissue culture, shoots and friable calli were obtained from cotiledons, embryonic axis and embryonic leaflet cultured in media supplemented with BAP and picloram, respectively.