Síntese de glicosídeos de eugenol e análogos e avaliação da atividade antibacteriana in vitro e em embalagens ativas

Abstract

The composition of food promotes microorganisms growth, which suggests that conservation techniques are needed to extend its useful life. Essential oils as well as its components separately, have shown promising alternatives to synthetic preservatives replacement for the natural ones due to its vast properties. Therefore, it becomes interesting to optimize the effect of these compounds and evaluation of its applicability as additives in food. In order to improve the quality of packaging and provide advancement in their role in a society that seeks increasingly consumption of healthy, safe and less harmful to the environment, packaging has undergone changes and it appeared that we called active packaging. Active packages are those that interact with food in order to provide some property to this, besides the protective function. Six acetylated and deacetylated glycosides were synthesized from eugenol, isoeugenol and dihydroeugenol present in the essential oil of clove. All glycosides were characterized by IR and NMR. The synthesized compounds and their aglycones were evaluated for the minimal inhibitory and bactericidal concentration (MIC and MBC) against the spoilage food bacteria Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella Enteritidis through the microdilution in broth technique, using 96 wells polystyrene plates. All deacetylated glycosides were about two times more active than aglycones source, and the peracetylated glycosides were, in most cases, equipotent to aglycones. The results revealed that the acetylated glycoside of dihydroeugenol proved to be the most active compound in comparison to the other ones, facing the bacteria tested, with a 0.37% MIC and MBC v/v for E. coli and 0.18% v/v for others bacteria. Deacetylated diidroeugenol glycoside and diidroeugenol were used as additives in production of active packaging, which were evaluated for activity against the same bacteria. The results show that the film produced with the addition of glycoside was significantly more effective in inhibiting the growth of all bacteria evaluated than film produced with the addition of diidroeugenol, confirming the increased activity of synthesized glycoside.