Cladia aggregata (lichen) from Brazilian Northeast: Chemical Characterization and Antimicrobial Activity

摘要

The chemical composition and antimicrobial activity of the Cladia aggregata (Sw.) Nyl. were evaluated. Barbatic acid, depside obtained from C. aggregata, was spectroscopically analyzed and tested, as well as organic extracts. The extracts and purified substance were tested against four Staphylococcus aureus multi-resistant strains. The structure of barbatic acid was confirmed through NMR (H-1; C-13) and elemental (R) analysis. Biochromatographic assays showed action of this compound, along with other substances contained in organic extracts, suggesting a synergic action, MIC assays placed barbatic acid in the same level of inhibition to other studied lichen substances.