Chemical, antioxidant, and antimicrobial evaluation of essential oils and an anatomical study of the aerial parts from Baccharis species (Asteraceae).

The aim of this study was to evaluate the chemical, antioxidant, and antimicrobial activity of the essential oils as well as the anatomy of the aerial parts from Baccharis aracatubaensis, Baccharis burchellii, and Baccharis organensis owing to the therapeutic potential of Baccharis. The volatile constituents were analyzed using GC-MS, the antioxidant activity was evaluated by oxygen radical absorbance capacity (ORACFL) and DPPH assays, and the antimicrobial activity by a microdilution technique. Of the 56 compounds identified, only 7 (β-caryophyllene, ɣ-muurolene, bicyclogermacrene, β-germacrene, spathulenol, τ-muurolol, and α-cadinol) were common in the three specimens studied. Of these, ɣ-muurolene was found abundantly in B. aracatubaensis, while bicyclogermacrene was abundant in B. burchellii and B. organensis. The essential oils exhibited antioxidant activity in the ORACFL (>500.0 μmol TE g-1) and DPPH assays. However, they did not exhibit any antimicrobial activity. Secretory ducts and flagelliform glandular trichomes were observed in the anatomical study of all the Baccharis species studied.