Chemical Characterization, Antioxidant Capacity and Antimicrobial Potential of Essential Oil from the Leaves of Baccharis oreophila Malme.

This is the first time that composition, antimicrobial potential and antioxidant ability of essential oil from the leaves of Baccharis oreophila are reported. Essential oil was obtained by hydrodistillation and analyzed by GC/MS. Antimicrobial potential was evaluated by diffusion disk and broth microdilution methods. ABTS^.+ , DPPH^. and FRAP methods were employed for antioxidant activity evaluation. Essential oil yield was 0.47 %. Sixty-five compounds were identified, representing 88.53 % of the total essential oil, which showed to be rich in oxygenated (37.88 %) and hydrocarbons sesquiterpenes (34.84 %). The main constituents were khusimone (16.37 %) and spathulenol (16.12 %). Antimicrobial activity was verified against S. aureus (10.33±0.5 mm, MIC: 1250 μg mL^-1 ) and C. albicans (8.66±0.5 mm, MIC: >2500 μg mL^.1 ). Antioxidant ability was evidenced by FRAP (4.09 μmol FeSO₄ E mL^-1 ), ABTS^.+ (1.45 μmol TE mL^-1 ) and DPPH^. (1.04 μmol TE mL^-1 ) scavenging capacity. Results showed that this essential oil has interesting biological potential, encouraging further investigations especially in relation to action mechanisms of antimicrobial and antioxidant activity.