Caracterização química e atividades biológicas dos óleos essenciais das folhas de Eugenia spp. (myrtaceae) ocorrentes na Amazônia de terra firme

Abstract

The genus Eugenia (Myrtacaeae) has more than 500 species distributed in the Neotropics, occurring in the main Brazilian biomes, especially in the Amazon, in which the Forest Reserve Adolpho Ducke (RFAD) in Manaus a representative sample of Amazonian terra firme forest where has identified 28 species of Eugenia. The chemistry of the genus reveals a composition rich in flavonoids / glycosides, hydrolyzable tannins, coumarins, anthocyanins, monoterpenes / sesquiterpenes and triterpenes / steroids. However, chemical and biological studies of Eugenia spp. occurring in the Amazon biome are still scarce. In this context, this work aimed to chemical characterization and biological activity of essential oils from leaves of seven species of Eugenia magna, E. ramosii, E. feijoi, E. lisbonii, E. pseudopsidium, E. marleneae e E.adenocalyx, obtained by hydrodistillation and analyzed by gas chromatography with ionization detectors in flames (GC-FID) and mass spectrometer (GC-MS). The seven species were compared to determine the similarity and difference between their volatile chemical compositions by PCA and HCA. Essential oils have been tested bactericides by Agar disk diffusion method containing microorganisms: Escherichia coli, Klebsiella pneumoniae, Burkholderia cepacia, Streptococcus pneumoniae, Enterococcus faecalis and Staphylococcus aureus resistant to methicillin. The results for the essential oils of these tests showed antimicrobial activity for both Gram-positive bacteria as Gram-negative. In addition, we evaluated the susceptibility of strains of human breast tumor cells (MCF-7), human colon (HCT116), human melanoma (SKMEL-19), human ovarian (ES-2), adenocarcinoma (ACP02) and Normal MRC-5 (human fibroblast) compared to essential oils employing Alamar-blue test. All samples exhibit cytotoxic activity in normal cells (MRC-5, IC50 between 33.21 to 38.38 μg.mL-1) and tumor cell lines (MCF-7 and HCT-116, ES- 2, ACP02, IC50 ≤ 30μg.mL-1 concentration value set by the National Cancer Institute. The chemical composition of the essential oils showed predominance of sesquiterpene compounds, the components with higher levels were caryophyllene oxide for Eugenia magna, E. ramosii, β- elemene to E. feijoi, E-caryophyllene for E. lisbonii, E. pseudopsidium, E. marleneae and E. adenocalyx. Common chemical constituents of essential oils were all α-copaene, β-elemene, Ecaryophyllene, α-humulene, allo aromadendrene, β-bisabolene, caryophyllene oxide and humulene II oxide.