Optimized Enzymatic Synthesis of Hesperidin Fatty Acid Esters in a Two-Phase System Containing Ionic Liquid

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Response surface methodology (RSM) based on a five-level, three-variable central composite design (CCD) was employed for modeling and optimizing the conversion yield of the enzymatic acylation of hesperidin with decanoic acid using immobilized Candida antarctica lipase B (CALB) in a two-phase system containing [bmim]BF(4). The three variables studied (molar ratio of hesperidin to decanoic acid, [bmim]BF(4)/acetone ratio and lipase concentration) significantly affected the conversion yield of acylated hesperidin derivative. Verification experiments confirmed the validity of the predicted model. The lipase showed higher conversion degree in a two-phase system using [bmim] BF4 and acetone compared to that in pure acetone. Under the optimal reaction conditions carried out in a single-step biocatalytic process when the water content was kept lower than 200 ppm, the maximum acylation yield was 53.6%.16871717182Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [09/09224-3

Enantioselective behavior of lipases from Aspergillus niger immobilized in different supports

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Considering the extraordinary microbial diversity and importance of fungi as enzyme producers, the search for new biocatalysts with special characteristics and possible applications in biocatalysis is of great interest. Here, we report the performance in the resolution of racemic ibuprofen of a native enantioselective lipase from Aspergillus niger, free and immobilized in five types of support (Accurel EP-100, Amberlite MB-1, Celite, Montmorillonite K10 and Silica gel). Amberlite MB-1 was found to be the best support, with a conversion of 38.2%, enantiomeric excess of 50.7% and enantiomeric ratio (E value) of 19 in 72 h of reaction. After a thorough optimization of several parameters, the E value of the immobilized Aspergillus niger lipase was increased (E = 23) in a shorter reaction period (48 h) at 35A degrees C. Moreover, the immobilized Aspergillus niger lipase maintained an esterification activity of at least 80% after 8 months of storage at 4A degrees C and could be reused at least six times.367949954Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Sao Francisco (USF)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Immobilization of glucosyltransferase from Erwinia sp using two different techniques

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Two different techniques of glucosyltransferase immobilization were studied for the conversion of sucrose into isomaltulose. The optimum conditions for immobilization of Erwinia sp. glucosyltransferase onto Celite 545, determined using response surface methodology, was pH 4.0 and 170 U of glucosyltransferase/g of Celite 545. Using this conditions more than 60% conversion of sucrose into isomaltulose can be obtained. The immobilization of glucosyltransferase was also studied by its entrapment in microcapsules of low-methoxyl pectin and fat (butter and oleic acid). The non-lyophilized microcapsules of pectin, containing the enzyme and fat, showed higher glucosyltransferase activity, compared with lyophilized microcapsules containing enzyme plus fat, and also lyophilized microcapsules containing enzyme without fat addition. The non-lyophilized microcapsules of pectin containing the glucosyltransferase and fat, converted 30% of sucrose into isomaltulose in the first batch. However the conversion decreased to 5% at the 10th batch, indicating inactivation of the enzyme. (C) 2012 Elsevier B.V. All rights reserved.1583137143Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Enhancement of the antioxidant activity of orange and lime juices by flavonoid enzymatic de-glycosylation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Pure flavonoid glycosides and those present in orange (Citrus sinensis) and lime (Citrus latifolia) juices were structurally modified by enzymatic de-glycosylation to obtain functional derivatives with higher antioxidant activity. The enzymatic reactions were carried out using commercial rhamnosidases (hesperidinase and naringinase) and beta-D-glucosidase. An experimental design and statistical tools for the data analysis were employed for each enzyme to evaluate the independent variables (pH and temperature) that significantly affected the enzyme activity (dependent variable), and the antioxidant activity was evaluated before and after bioconversion using DPPH center dot and FRAP assays. Aliquots of controls and enzyme-treated samples were taken at different times and analyzed by UPLC-MS. The antioxidant activity of both treated juices was higher than that of the untreated juices, confirming that the bioconversion reaction conditions used were efficient and produced an increment in the antioxidant activity. After the 4 h-hesperidinase reaction 60% of the hesperidin was converted into hesperetin in the orange juice. The antioxidant capacities of the glycosylated standards were also increased by the enzyme treatment. The results presented herein are a step forward in the use of alpha-L-rhamnosidases to produce functional beverages by way of de-glycosylation reactions of their flavonoid glycosides. (C) 2013 Elsevier Ltd. All rights reserved.521308314Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES