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    Aplicação de extratores verdes para obtenção de flavonoides da própolis vermelha
    (Universidade Federal de São Paulo (UNIFESP), 2020-06-25) Santos, Cintia Maria dos [UNIFESP]; Rosso, Veridiana Vera de [UNIFESP]; Universidade Federal de São Paulo
    Red propolis has been widely studied in recent years, mainly by their flavonoids, which are responsible for most of their biological actions. Red propolis was recently discovered in Brazil and it is derived from the species Dalbergia ecastophyllum, from the Leguminaceae family. There are some studies that have shown antiparasitic, antioxidant and anti-tumor activity of this natural product. In general, the main solvent used in the extraction of bioactive propolis is ethanol, however, in some regions of the world the consumption of this type of extract is not allowed for religious reasons, therefore, the objective of this work was to develop a new method for extraction of flavonoids from red propolis using ionic liquids (ILs) and / or eutectic solvents (SEs), in order to obtain a high performance extract in terms of flavonoids and antioxidant activity. For that, an experimental design (CCDR 23) and the response-surface methodology were used as a strategy to establish the best parameters for the obtation of an extract rich in flavonoids. Initially, four ILs were tested in this work: 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]), 1-hexyl-3-methylimidazolium chloride ([C6mim]Cl), 1-butyl-3- chloride methylimidazolium ([C4mim]Cl) and 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]), in addition to three eutectic solvents: Choline chloride - glycerol (CH-GLY), choline chloride - butanediol (CH- BUT) and choline chloride - levulinic acid (CH-LEV). For the extracts obtation, 0.5 g of red propolis were mixed with the solvents in a solid-liquid ratio of 1: 3 and subjected to extraction in 80% amplitude ultrasound equipment (equivalent to 400W of power) for 5 minutes, followed by centrifugation at 4700 rpm for 15 minutes. An ethanolic extract (70 and 95% v: v) was prepared using the same experimental conditions to compare yields. The quantification of the total flavonoids present in the extracts was performed using the method of Zhishen, Mengcheng and Jianming (1999) and the results expressed in rutin equivalent (RuE.g-1). The extract obtained with the IL [C6mim]Cl in 10: 1 concentration (p:v) presented the best better performance, with 581.06 mg RuE.g-1, so it was selected for CCDR 23, considering the responses: flavonoid yield and antioxidant activity. In the response surface methodology, the following variables were evaluated: extraction time (Tmin), number of extractions and probe power (W). In this way, four extractions with [C6min]Cl, under the operational conditions set at 3.3 minutes and 300W were able to extract 394.39 ± 36,30 mg RuE.g-1 of total flavonoids and generate 7595.77 ± 5.48 mg TE.g-1 of dry biomass of antioxidant activity. Then, the antimicrobial evaluation of the optimized extract of red propolis, which showed the growth inhibition of Staphylococcus aureus and Salmonella enteritidis. In this way, the work contributed to the production of extracts, alcohol-free, of high performance in terms of flavonoids and antioxidant activity in comparison with conventional solvents.