Optimization of ultrasound-assisted extraction of phenolic compounds from Croton blanchetianus Baill. leaves and chromatographic analysis

Abstract

In the present study, the optimization of the extraction of phenolic compounds from Croton blanchetianus leaves by ultrasound-assisted extraction (UAE) was carried out, evaluating the effect of the variables ethanol concentration in water, solvent-to-solid ratio and extraction time using a Box-Behnken design, and comparing the phytochemical and antioxidant results obtained by the optimized extracts with those of the extracts prepared by conventional extraction methods (infusion and decoction). The results showed that the best extraction conditions were: ethanol concentration of 40.40%, solvent-to-solid ratio of 72.52 mL/g and time of 20.67 min, which resulted in a TPC (total phenolic content) of 154.99 ± 3.96 mg EAG/g ms. The extract obtained under optimized conditions presented values of TPC, total flavonoid content (TFC) and antioxidant activity higher than those of infusion and decoction, confirming that the UAE method was superior to the other extraction methods regarding the recovery of phenolic compounds. Through the chromatographic profiles of the extracts obtained by the different extraction techniques, it was observed the presence of chemical compounds belonging to the classes of phenolic acids, phenylpropanoids and flavonoids. Thus, this initial study of evaluation of the variables that affect the extraction of phenolic compounds from the species C. blanchetianus will serve as a basis for carrying out additional studies with this medicinal species aiming at obtaining preparations enriched with biologically active phenolic compounds.