This work evaluated the antioxidant, antimicrobial and cytotoxic activities of Myracrodruon urundeuva methanolic extract (MuBME) and identified its major phenolic compounds. The extract showed activity against all tested microorganisms (MIC: 0.39 to 3.13 mg/mL), and was able to enhance the erythromycin activity against some clinically isolatedStaphylococcus aureus strains: fractional inhibitory concentration indices (ΣFIC) < 1. MuBME also showed a high antioxidant activity with 81.34 ± 0.2% of ascorbic acid activity (in phosphomolybdenum assay) and inhibited H₂O₂ and DPPH radical (IC₅₀ of 0.038 and 0.0033 mg/mL, respectively). The phenolic and flavanoid content were 37.0 ± 0.47 mg/g gallic acid equivalents (GAE) and 43.88 ± 6.55 quercertin equivalents (QE)/mg, respectively. Additionally, we tested the cytotoxicity and observed IC₅₀ of 1.94 (human erythrocytes) and 1.57 (Vero cells) mg/mL, much higher than the concentrations required for the biological responses tested. Gallic acid, protocatechuic acid, chlorogenic acid, catechuic acid and fumaric acid were detected by Ultra-fast liquid chromatography (UFLC) analysis and they are possible active compounds. Our results showed that M. urundeuvabark exhibits antimicrobial and antioxidant properties with application in pharmaceutical, food and cosmetics industries.

Key words: Caatinga, Myracrodruon urundeuva, antimicrobial, antioxidants, non-hemolytic compounds.