Resumen

COSTA, José G. M. da et al. Chemical composition and evaluation of the antibacterial activity and toxicity of the essential oil of Croton zehntneri (variety estragol). Rev. bras. farmacogn. [online]. 2008, vol.18, n.4, pp. 583-586. ISSN 0102-695X.  http://dx.doi.org/10.1590/S0102-695X2008000400015.

Observing that bacteria resistant to antimicrobials represent a challenge in the treatment of infections, it is notorious the need of finding new substances with antimicrobial features to be used in the fight against these microorganisms. This work relates the evaluation of the antibacterial activity, toxicity and identification of the chemical components of the essential oil of Croton zehntneri (variety estragol), plant used in the popular medicine as tranquilizer and appetite stimulant. The antimicrobial activity and minimum inhibitory concentration (MIC) were determined by the method of diffusion in discs. The evaluation of the toxicity was held through brine shrimp test with results considered active (LC₅₀ < 100 µg/mL). The essential oil of leaves presented antibacterial activity with all the bacteria tested except with Salmonlla typhimurium, being the best result with the Shigella flexneri with MIC of 50 µg/mL. The analysis of the chemical composition was obtained by gas chromatography coupled to mass spectrometry (GC/MS) and permitted to identify a total of 97.4 % of the components, with major presence of estragol (76.8%). The presence of the latter drives us to studies with other bacteria, as the estragol was previously reported as being responsible for antibacterial activities.

Palabras llave : Croton zehntneri; Euphorbiaceae; Estragol; Essential oil; Antibacterial activity; Toxicity; MIC.