Essential oils are highly demanded substances worldwide. They can be used without modification due to their different chemical and biological properties or as natural sources of chemical compounds. The limit in the use of these metabolites is their low yield. In the present investigation, the essential oil of fruits from Dacryodes peruviana collected in the Ecuadorian Amazon was extracted and studied. The essential oil was released from the plant matrix and isolated by hydrodistillation. The yields obtained were 4.8 ± 0.2% and 11.3 ± 0.2% for fresh and dried fruits, respectively, one of the highest yields on record to date. Twenty-five chemical compounds were identified by GC/MS and GC/FID techniques. The principal constituent was α-phellandrene, with 50.32 ± 3.32%. The antimicrobial activity of the oil was assayed against five Gram negative bacteria, two Gram positive bacteria and two fungi. The essential oil exerted a moderate activity against Staphylococcus aureus. The repellent activity of the oil was assayed against mosquitoes (Diptera: Culicidae); the samples with 3%, 2% and 1% essential oil were class 4, and the sample with 0.5% showed to be class 3. The essential oil showed a weak antioxidant activity through the DPPH and ABTS methods.

The chemical composition, antifungal and antibacterial activity of essential oils isolated by hydrodistillation from the aerial parts of Chromolaena laevigata (Asteraceae) growing wild in Ecuador, were evaluated. The chemical composition was analyzed by Gas chromatography/Mass spectrometry (GC-MS) and GC/Flame ionization detector (GC/FID). Twenty-five volatile components were identify in essential oils, corresponding to 96.13 % of the total oils. Essential oils was rich in laevigatin (46.84 %), germacrene D (15. 38 %), viridiflorol (11.37 %), bicyclogermacrene (4.14 %), limonene (4.94 %) and α-pinene (2.85 %). The antibacterial and antifungal activities were studied by the broth microdilution method. The antibacterial activity was tested against Gram-negative bacterial strains [Pseudomonas aeruginosa (ATCC 27853), Klebsiella pneumoniae (ATCC 9997), Proteus vulgaris (ATCC 8427), Escherichia coli (ATCC 25922) and Salmonella typhimurium (LT2)] and Gram-positive bacterial strains [Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 25923)] and antifungal activity was determined against Trichophyton rubrum (ATCC 28188) and Trichophyton mentagrophytes (ATCC 28185). The essential oil from C. laevigata exhibited activity against Trichophyton rubrum (ATCC 28188) and Trichophyton mentagrophytes (ATCC 28185).