Isolamento e purificação de compostos sesquiterpênicos do óleo essencial das folhas Eugenia uniflora L. e avaliação da atividade antimicrobiana

Abstract

The Myrtaceae family is among the main fruit families in the world, with high economic potential and high nutritional value. The genus Eugenia, belongs to the Myrtaceae family and has several species. This genus has relevant biological importance, such as insecticidal, antibacterial, antiviral and cytotoxic activities. The species Eugenia unifloraL. is native to Brazil, popularly known as pitangueira and Brazilian cherry, distributed in Brazil in the Northeast, Midwest, Southeast and South regions. The species E. uniflora, is a dense tree from 2 to 9 meters high, branched, rounded shape, simple opposite leaves, hermaphrodite flowers (monoecious), white petals, berry-shaped fruit, the final ripening process of the epicarp red. The essential oil of the leaves of E. uniflora has chemical compounds of the sesquiterpene class, synthesized by secondary metabolism. The species has relevance in its biological properties, due to the bioactive compounds, found only in this species. There are few studies in the literature on secondary metabolites isolated from the E. unifloraspecies, as well as little research on biological activities, such as antimicrobial activity. Therefore, the objective of the present work is to isolate, purify and elucidate the major secondary metabolites furanodiene, selina-1,3,7-trein-8-one and oxidoselina-1,3,7-trien-8-one, present in the oil essential oil from the leaves of the species E. uniflora, as well as to evaluate the antimicrobial activity of the aforementioned compounds aiming at the development of new applications and technological products. The chromatographic techniques of Thin Layer Chromatography and Glass Column Chromatography were used to isolate and purify the sesquiterpene compounds. The structural elucidation of the compounds was carried out using the Nuclear Magnetic Resonance technique. The isolated and purified compounds were evaluated for antimicrobial activity, using the broth microdilution technique in 7 microorganisms to determine the Minimum Inhibitory Concentration (MIC). With this work it was possible to obtain the compounds furanodiene, selina-1,3,7(11)-trien-8-one and oxidoselina-1,3,7(11)-trien-8-one from the essential oil of the leaves of E. unifloraand evaluate their antimicrobial activity. The furanodiene compound at 1000 μg/mL did not obtain the MIC, therefore, not reaching the microbicidal and bacteriostatic inhibitory effect. The compound selin-1,3,7(11)-trien-8-one in 1000 μg/mL obtained the MIC for Streptococcus mutuans; for S. aureus obtained the MIC at 500 μg/mL and the Minimum Bactericidal Concentration (MBC) at 1000 μg/mL; for the fungus Candida albicansobtained the MIC at 1000 μg/mL, being a fungistatic concentration. The compound oxidoselin-1,3,7(11)-trien-8-one at 500 μg/mL obtained MIC for S. mutuansand MBC at 1000 μg/mL; for S. aureusobtained MIC at 250 μg/mL and MBC at 500 μg/mL; for Enterococcus faeciumobtained the MIC at 500 μg/mL; for the fungus C. albicansobtained MIC at 250 μg/mL, being fungistatic concentration and obtained Minimum Fungicide Concentration at 500 μg/mL. This work allowed obtaining pure sesquiterpene compounds, in addition to evaluating antimicrobial activity, evidencing the susceptibility of microorganisms by the concentration of compounds, aiming at expanding new bioactive compounds for the development of applications and technological products for clinical treatments..