This study had analyzed the antibacterial, antifungal and trypanocidal activity of the essential oils from Cinnamodendron dinisii Schwacke (Canellaceae) and Siparuna guianensis Aublet (Siparunaceae). The essential oils were obtained from fresh leaves by hydrodistillation, using a modified Clevenger apparatus. Chemical analysis by gas-liquid chromatography coupled to mass spectrometry (GC-MS) showed that these essential oils are rich in monoterpene and sesquiterpene hydrocarbons. Activity against the pathogenic bacteria Escherichia coli , Listeria monocytogenes , Pseudomonas aeruginosa , Salmonella choleraesuis and Staphylococcus aureus was evaluated with the agar cavity diffusion method, while activity on the filamentous fungi Aspergillus flavus , Aspergillus niger , Aspergillus carbonarius and Penicillium commune was evaluated by the disk diffusion technique. Trypanocidal activity was tested against Trypanosoma cruzi epimastigotes, using the Tetrazolium salt (MTT) colorimetric assay. Both essential oils exhibited low inhibitory effect towards bacteria, showing high MIC values (125–500 μg mL −1 ), with Gram positive bacteria being more susceptible. Better inhibitory effect was obtained for the evaluated fungi, with lower MIC values (7.81–250 μg mL −1 ), being A. flavus the most susceptible species. Both essential oils presented low trypanocidal activity, with IC 50 /24 h values of 209.30 μg mL −1 for S. guianensis and 282.93 μg mL −1 for C. dinisii . Thus, the high values observed for the MIC of evaluated bacteria and for IC 50 /24 h of T. cruzi , suggest that the essential oils have a low inhibitory activity against these microorganisms. In addition, the low MIC values observed for the tested fungi species indicate good inhibitory activity on these microorganisms’s growth.

The application of the film improved post-harvest quality of raspberry, since the addition of essential oils of citrus films promoted to the inhibitory effect of fungi and bacteria growth after 15 days of storage, without changing quality parameters. © 2016 Society of Chemical Industry.

The essential oils from Mentha viridis L. and Mentha pulegium L. were characterized by gas chromatography coupled to mass spectrometry (GC-MS). These oils were obtained by hydrodistillation and presented linalool (40.70%), carvone (13.52%) and α-terpinene (8.56%) as the principal constituents in the essential oil from Mentha viridis L. Pulegone (50.01%), menthol (31.90%) and menthone (16.56%) were the principal constituents in the essential oil from Mentha pulegium L. These essential oils (in concentrations ranging from 3.91 to 500 μL·mL −1 ) showed satisfactory activities against Escherichia coli, Listeria monocytogenes, Salmonella choleraesuis and Staphylococcus aureus. The antioxidant activities with 2-deoxyribose and phosphomolybdenum and the reducing power (in concentrations ranging from 0.78 to 1000 μL·mL −1 ) were determined. The antioxidant activity was observed for the two oils evaluated by the phosphomolybdenum and 2-deoxyribose methods, whereas the essential oil from M. viridis presented low antioxidant activity in the reducing power assay.

This work describes the chemical composition of the essential oils extracted from fresh leaves of Lippia origanoides Kunth. and Mentha spicata L. and their antioxidant and insecticidal activities. The essential oils were extracted by steam distillation using a modified Clevenger apparatus and subsequently analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. The antioxidant activities were determined by the β-carotene-linoleic acid method and by sequestration of the 2,2-diphenyl-1-picryl-hidrazila radical. The concentrations of the essential oils and the synthetic standard, butylated hydroxyltoluene, were 25, 50, 100, 150, 200, 250, 300 and 500 µg mL −1 . Insecticidal activity was analyzed by non-preference with choice and no choice against the aphid Myzus persicae Sulzer. Gas chromatography analysis of the essential oil from Lippia origanoides Kunth. revealed carvacrol (41.51%), p-cymene (18.36%), γ-terpinene (17.03%) and thymol (4.86%) as major constituents, and the essential oil from Mentha spicata L. contained piperitona (81.18%), piperitenone (14.57%) and limonene (1.47%) as the principal components. The essential oils and the standard exhibited dose-dependent antioxidant activities at the concentrations tested. The essential oils were shown to be potential agents in the integrated management of the aphid Myzus persicae Sulzer.

The extraction of essential oils was performed by using the technique of hydrodistillation modified Clevenger apparatus, identification and quantification of the constituents was achieved by Gas Chromatography coupled to Mass Spectrometry, and Gas Chromatography equipped with a flame ionization detector. Assessment of allelopathic activity was evaluated with the use of the method that assesses the direct contact of essential oils on germination and vigor of lettuce seeds. The major constituents that characterize the essential oil from the flowers of Callistemon viminalis were 1, 8-cineole, α-pinene and limonene at concentrations of 66.9%, 16.0% and 10.0%, respectively. The essential oil presented allelopathic activity at intensities that varied proportionately to the concentration of the essential oil, with a reduction in the percentage of germination and the germination speed index (GSI) of lettuce seeds and in the dry mass and length of shoots and roots of lettuce seedlings.