Effect of sonication and pressing on recovery of compounds with antioxidant activity from leaves and bark of Byrsonima crassifolia

Abstract

One of the traditional techniques to extract metabolites is maceration with solvents assisted by mechanical-grinding. Recently, ultrasound has been proposed as a factor to improve extraction. However, information about ultrasound times necessary is insufficient. Additionally, the pressing method helps the solids recuperation, abating loss of extract. This work established an efficient extraction methodology of metabolites with antioxidant activity, combining the ultrasound assisting solvent extraction and pressing (UPAE). Leaves and bark of B. crassifolia, dried by forced air, ground and sieved to form a flour, were used to make the UPAE, the results of the yields were compared with a conventional maceration (95% ethanol, 1: 4 p / v, control). The assisted ultrasound time were 5, 20, 40 and 50 min. The separation was carried out by pressing in a glass syringe. Antioxidant activity was determined qualitatively by fine chromatography plates and quantitatively by spectrophotometry DPPH antioxidant assay at 517 nm. The UPAE method increased the total solids extract, without affect the antioxidant activity of compounds in leaves as in bark, since 5 and 20 minutes, respectively. Without a specific identification, it was evidenced that B. crassifolia produces a great variety of antioxidant compounds in both leaves and the bark, that polar as apolar type, which remain unchanged independently of ultrasound assisted time. With this method is possibly make extractions with small amounts of powdered sample (4 g of flour), which would be advisable in studies when the biological material is limited.