PRODUCTION AND PHYTOCHEMICAL CHARACTERIZATION OF GREEN-SYNTHESIZED IRON NANOPARTICLES USING A STANDARDIZED EXTRACT OF Euterpe edulis Mart. FRUITS

Euterpe edulis Mart. is a palm tree native to the Atlantic Forest known as “palmito-juçara”. Its fruits contain high concentrations of anthocyanins, natural pigments belonging to the flavonoid class. These compounds exhibit antioxidant potential and they are associated with anti-inflammatory, cardioprotective, and anticancer effects. Despite its biotechnological potential, the predatory exploitation of the species for palm heart extraction causes significant ecological impacts, as the removal of its single stem results in plant’s death. In this context, green synthesis of iron nanoparticles (FeNPs) using a standardized extract from E. edulis fruits emerges as a sustainable approach for the development of biotechnological applications, representing an economic alternative for local communities and contributing to the valorization and preservation of the species. The aim of this study was to develop iron nanoparticles (FeNPs) through green synthesis technique using the standardized extract of E. edulis fruits (EPEe), as well as to perform phytochemical characterization by quantifying the total phenolic and flavonoid contents in EPEe at different concentrations and FeNPs. EPEe was provided by the Atina – Ativos Naturais (partner company). The green synthesis of FeNPs was evaluated using UV-Vis extinction spectroscopy, varying concentrations of EPEe and FeSO₄, pHs, temperature, and reaction time to determine the optimal synthesis conditions. The total phenolic and flavonoid contents of EPEe and FeNPs were determined using Folin-Ciocalteu and AlCl₃ complexation assays. The best spectral profile characterized by the smallest baseline area and highest absorbance intensity, resulted from the solution prepared under the conditions of 4 mg/mL EPEe, 0.02 mol/L FeSO₄ at pH 7 and 30°C for 60 minutes. The total phenolic content of EPEe was concentration-dependent, exhibiting 74.85, 117.81, and 206.70 µg gallic acid equivalent (GAE)/g of sample at 1, 2, and 4 mg/mL, respectively, while the FeNPs presented 155.22 µg GAE/g of sample. Regarding total flavonoids, the FeNPs exhibited 749.87 µg rutin equivalent (RE)/g of sample, which was higher than the values observed for EPEe at 1, 2, and 4 mg/mL, corresponding to 117.20, 202.53, and 386.20 µg RE/g of sample, respectively. Green synthesis technique using EPEe proved to be promising for FeNPs formation, and the differences observed in phenolic and flavonoid contents may be related to the contribution of these compounds in the reduction of iron ions. The results reinforce the biotechnological potential of E. edulis fruits and provide a basis for future studies on the applications of FeNPs synthesized from EPEe, contributing to the valorization and sustainable utilization of the species.

Acknowledgements: São Paulo Research Foundation (FAPESP), Process number: 2023/04247-2.