Essential Oils of Five Species: Investigations on the Chemical Composition and Biological Activities.

This paper provides a comparative account of the essential oil chemical composition and biological activities of five Brazilian species of (Asteraceae), namely , , , , and . The chemical compositions of three species (, , and ) are reported for the first time. Analyses by GC/MS showed notable differences in the essential oil compositions of the five species. α-Pinene was observed in the highest concentration (24.50%) in . Other major compounds included α-bisabolol (23.63%) in , spathulenol (24.74%) and kongol (22.22%) in , β-pinene (18.33%) and limonene (18.77%) in , and β-pinene (15.24%), limonene (14.33%), and spathulenol (13.15%) in . In vitro analyses for antimalarial, antitrypanosomal, and insecticidal activities were conducted for all of the species. and showed good antitrypanosomal activities; showed insecticidal activities in fumigation bioassay against bed bugs; and , , and exhibited moderate antimalarial activities. and showed cytotoxicity. The leaves and stems of all five species showed glandular trichomes and ducts as secretory structures. DNA barcoding successfully determined the main DNA sequences of the investigated species and enabled authenticating them.