Total Phenolic Composition and Antioxidant Activity of Silver Nanoparticles using Aqueous Extract of Chilca Leaves (Baccharis latifolia)

The importance of studying polyphenols as natural antioxidants has encouraged the search for new methods of rapid, simple analysis. The synthesis of silver Nanoparticles (Ag NPs) using plant extracts has been presented as an alternative to determine the presence of polyphenolic compounds. In this study, aqueous extract of chilca (Baccharis latifolia), an endemic plant species from South America known for its medicinal properties, was used. This extract, because of its composition, can convert Ag+ ions to Ag0 in a chemical reduction process. To determine the optimal conditions for microwave-assisted nanoparticle synthesis, factorial experimental designs were used and analyzed with Statgraphics software. Ag NPs characterization was carried out with transmission electron microscopy; synthesized nanoparticles measured 4.86±2.44 nm on average. For the extract and Ag NPs, total polyphenolic content and antioxidant capacity were determined using oxygen radical absorbance capacity and cyclic voltammetry analysis. The method used to prepare both plant extracts and Ag NPs was determined to be fast and reliable. In addition to being a green and economical, this method allows the direct measurement of the plant extract’s total polyphenolic content and antioxidant capacity using analytical techniques that may be potentially applicable in the pharmaceutical industry.