Yield, composition and biological activities of Eugenia uniflora L. essential oil according to seasonality

ABSTRACT The aim of this study was to verify the seasonal influence on the Eugenia uniflora essential oils. The collections were carried out in October 2017 and March, May and August 2018. The extraction of the essential oils was performed by hydrodistillation and their composition was determined by gas chromatography. The yield of the essential oils was lower in winter (1.04% m/m). The composition of the essential oils in the different seasons did not change in relation to their compounds, differing only in their amounts. Germacrone was identified as the main compound, having a higher percentage in spring (48.05%) and summer (45.00%). Antioxidant activity (DPPH) may have been influenced by the higher percentages of germacrone, with better inhibitory concentration values (IC50) in summer (0.62 mg/mL), followed by spring (0.98 mg/mL). The E. uniflora essential oils tested have moderate to weak antibacterial activity and were more efficient against Escherichia coli.