Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the essential oils from Aubl., L. e Kunth.

The objective of this study was to determine the chemical profile and to evaluate the antibacterial activity of the essential oils of species and modulation of the antibiotic activity, using the microdilution method to determine the minimum inhibitory concentration. The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4-α-ol (31.38%), spathulenol (25.92%), and germacrene B (21.53%) as major constituents of the essential oils of , , respectively. The essential oils analyzed in this study did not present a clinically relevant activity against standard and multiresistant . However, in the case of multiresistant , there was a significant activity, corroborating with reports in the literature, where Gram-positive bacteria are more susceptible to antimicrobial activity. The essential oils modulated the effect of the antibiotics norfloxacin and gentamicin, having on the latter greater modulating effect; however, for erythromycin, no statistically significant effect was observed. In conclusion, the results obtained in this study demonstrated that the essential oils of the analyzed species present an inhibitory effect against and modulate antibiotic activity, most of which presents synergistic activity.