Preparo e caracterização de tinturas das folhas de chá verde [Camellia sinensis (L.) O. Kuntze] Theaceae / Preparation and characterization of Theaceae green tea [Camellia sinensis (L.) O. Kuntze] leaf tinctures

Tinturas preparadas com as folhas de Camellia sinensis (chá verde), foram caracterizadas visando a obtenção de extratos enriquecidos em polifenóis. As tinturas foram obtidas por meio de maceração estática da droga pulverizada, com diferentes misturas de 60, 70, 80 e 94,5% de etanol em água. Em seguida foram filtradas e, após 8 dias de extração, realizaram-se as analises: organoléptica, pH, densidade, determinação do resíduo seco, perfil cromatográfico por camada delgada, e teor de polifenóis. Os resultados demonstraram que o solvente (mistura hidroalcoólica a 60 ou 70%) extraiu a maior quantidade de constituintes químicos do chá verde; também foi o mais seletivo ao extrair, especificamente os polifenóis. Estes dados sugerem que a utilização de álcool etílico a 60 ou 70% conduz à obtenção de tinturas mais ricas em polifenóis, a partir das folhas do chá verde (C. sinensis).

In this work, we prepared and characterized Camellia sinensis leaf tinctures aiming to obtain a polyphenol-enriched extract. The tinctures were prepared through the static maceration process of the powdered drug, at different mixtures 60, 70, 80 and 94.5% of ethanol in water. The tinctures were filtered, and after 8 days of extraction, submitted to organoleptic analysis, determination of pH, density analysis, dry residue analysis, thin layer chromatographic profile and polyphenol percentage analysis. The results showed that the 60 or 70% alcohol-water mixture has the best extraction of the constituents of green tea and it was more selective to extract, specifically, the polyphenols of the plant. These data suggest the use of 60 or 70% ethanol to carry out polyphenol-enriched tinctures from green tea leaves (C. sinensis).

Does native bromeliads represent important breeding sites for Aedes aegypti (L.) (Diptera: Culicidae) in urbanized areas?

This study evaluates the importance of native bromeliads growing on rocky outcrops interspersed with urbanized areas as breeding sites for the Aedes aegypti (L.) in Vitória, state of Espírito Santo, Brazil. Oviposition traps were installed in backyards of houses in two separate zones. In the first zone houses were up to 50 m away from the rocky outcrops, while in the second zone they were at least at 200 m from the rocky outcrops. Aedes aegypti was significantly more abundant in the latter zone. The finding was that rocky outcrops with native bromeliads, even with the greater availability of potential breeding sites, do not play an important role as breeding sites for A. aegypti. This conclusion supports the hypothesis that the macrobiota of native bromeliads plays an important role in the natural control of A. aegypti. Besides, the interspecific competition between species of mosquitoes and the attractiveness of bromeliads could also be important factors.