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This study evaluated the antimicrobial, antioxidant and toxicity activity of essential oils (EOs) of Hymenaea courbaril L. var. courbaril bark and Syzygium cumini (L.) Skeels leaves. The EOs were extracted by hydrodistillation and chemically characterized by gas chromatography coupled to mass spectrometry (GC/MS). The ABTS and DPPH assay were used to evaluate antioxidant activity. For the toxicity assay, lethality was evaluated against Artemia salina Leach. For the antimicrobial assay, the method of Disc Diffusion and Dilution in Broth was applied to obtain the minimum inhibitory concentration and minimum bactericidal. The major constituent of the EO of H. courbaril was ß-ocimene (23.33%) and the EO of S. cumini was isocaryophyllene (18.01%). Both OE showed relevant antioxidant activity and low toxicity against Artemia salina. The EOs showed bactericidal activity against E. coli, S. aureus, P. aeruginosa, Salmonella sp., B. cereus and P. mirabilis. The results obtained are encouraged by the potential use of the OE's studied in the control and fight of pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

Bixa orellana L. is widely used as a dye, and other properties are still little studied, especially in relation to leaves. This article evaluates how drying B. orellana L. influences the properties of essential oils (EOs) extracted from their leaves. The collected plant material was submitted to convective air-drying oven at temperatures of 35, 45 and 55 °C. Chemical profiles were determined by Gas Chromatography-Mass Spectrometry (GC-MS). Mathematical models were applied to represent the drying process and statistical analysis performed using Statistica 10 software. The EO's were obtained through the hydrodistillation technique with verification of physicochemical properties and antimicrobial activity by the Disc Diffusion Method. For the toxicity test, the bioassay was applied to Artemia salina. Through the results obtained it was possible to determine that the mathematical model of Verma was the one that best fitted the experimental data. Significant differences in the properties of EO's were observed. The temperature of 45 °C allowed obtaining the best EO yield, still presenting the most efficient antimicrobial activity. This study states through the activities analyzed that the drying temperature influences the physicochemical and biological properties of the EO's, thus requiring studies such as this one that evaluate the best mathematical model to predict drying as well as the specific temperatures that influence the properties of the product obtained. [ABSTRACT FROM AUTHOR]