Abstract Phenolic compounds (PC) have presented antioxidant potential as well as antimicrobial action against several bacteria. This study aimed to extract PC from grumixama (Eugenia brasiliensis Lam.) pulp using solid phase extraction (SPE), then quantify the PC by Folin-Ciocalteu assay, and to evaluate the antioxidant activity (AA) from PC by DPPH, ABTS and FRAP methods as well as its antimicrobial activity by plate diffusion assay (PDA) and Minimal Inhibitory Concentration (MIC) assays. Additionally, the centesimal composition of the fruit and its mineral content by Total Reflection X-Ray Fluorescence Spectroscopy were determined. The fruit is a good source of PC which presented a higher contribution on AA from pulp than NPHRC. Calcium was the trace element in highest concentration in the pulp, followed by iron. PC from grumixama inhibited the growth of Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa but not Escherichia coli and Listeria monocytogenes in the PDA. PC showed antimicrobial activity against the five microorganisms tested in the MIC assay, in which S. aureus and B. cereus were the most sensitive. This study highlights the antioxidant and antimicrobial potential of Eugenia brasiliensis Lam. as natural agent in the development of functional foods and nutraceuticals.

Although Quercetin absorbs in the UVA/UVB electromagnetic region, it is limited for applications as a UV filter due to its low lipophilicity and capacity to penetrate the epidermis. In order to overcome this limitation, we synthetized and evaluated the photo protective properties of a derivative obtained from Quercetin. The derivative was prepared by alkylation of Quercetin with iodoethane and characterized by IR and NMR spectroscopy. The in vitro Solar Protection Factor was determined by the Mansur method and the cytotoxicity was evaluated using hepatocellular cell (Hep G2) cells. Finally, Quercetin and the corresponding derivative were incorporated in nanoemulsions. Nanoemulsions with particles sizes between 53 and 73 nm were obtained, and polydispersity indexes were around 0.1, indicating good homogeneity of the nanoemulsion particles. The cell viability study for the Quercetin derivative indicated a very low cytotoxicity profile. The chemical modification of Quercetin resulted in a promising compound with improved properties desirable for skin penetration and incorporation into sunscreen formulations.