Otimização de método para extração de compostos fenólicos das folhas de Myrocarpus frondosus

Abstract

The Myrocarpus frondosus is known for its anti-inflammatory and wound-healing properties. Due to its various health benefits, indigenous peoples have long utilized this tree. Some studies indicate antioxidant activity in its bark; however, there is limited research on its leaves. For this reason, this study developed an optimization method for extracting phenolic compounds from the tree's leaves. A 2² factorial design was conducted, with the dependent variables being the total phenolic content (TPC) using the Folin-Ciocalteu reagent, the DPPH radical scavenging method, the ABTS radical scavenging method, and the ferric reducing antioxidant power (FRAP). The independent variables were the solvent ratio (ethanol: water) and the extraction time using an ultrasound bath. The antioxidant activity measured by these methods showed variation: TPC ranged from 52.59 to 249.06 mg GAE L-1, DPPH radical ranged from 63.79 to 104.86 μmol Trolox L-1, ABTS radical ranged from 372.67 to 2219.33 μmol Trolox L-1, and FRAP ranged from 464.71 to 4302.14 μmol Fe²⁺/L. Based on the experimental design and response surface analysis, it was concluded that for TPC, ABTS, and FRAP, the significant factor was the ethanol concentration, with optimal ratios being (10:90 v.v-1) for TPC and ABTS, and (90:10 v.v-1) for FRAP. The extraction time was not significant for these three methods. In contrast, for DPPH analysis, both extraction time and its interaction with ethanol were significant. High-performance liquid chromatography (HPLC) injections of hydroalcoholic extracts from Myrocarpus frondosus with the highest and lowest antioxidant compound extraction efficiencies were performed to identify these compounds.