Extração assistida por ultrassom para obtenção de compostos antioxidantes a partir das folhas de Echinodorus macrophyllus

Abstract

Medicinal plants have aroused great interest due to the presence of compounds with therapeutic properties in their composition. The “Chapéu de couro” (Echinodorus macrophyllus) is a medicinal plant commonly found in Brazil and its popular uses range from the treatment of infections to diseases such as rheumatism. Thus, the objective of this work was to evaluate the extraction process of Echinodorus macrophyllus leaves, observing the influence of factors such as temperature, solvent, ultrasound power and solute/solvent ratio on the final yield, phenolic compounds content and antioxidant activity, as well as in squalene content and antimicrobial activity. It was observed that the ultrasound-assisted extraction technique presented several advantages, mainly due to the reduction in extraction time. The best extraction yield obtained was 10.93% at a temperature of 40°C, ultrasound power of 525 W and a solute/solvent ratio of 30 mL per gram. As for antioxidant activity, the best extract was obtained under conditions of temperature at 40°C, ultrasound power at 525 W and solute/solvent ratio of 10mL per gram, presenting 52.95 mg EAG 100g-1 extract and concentration of 0.555 mg mL-1 required to inhibit the DPPH radical by 50%. All extracts had the chemical compound squalene in their chemical composition. The antimicrobial analysis showed that the extracts showed weak potential against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa strains.