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http://ciatej.repositorioinstitucional.mx/jspui/handle/1023/739| FRUCTOSILACIÓN ENZIMÁTICA DE FLAVONOIDES CON β-FRUCTOSIDASAS DE DIFERENTES FAMILIAS DE GLICÓSIDOS HIDROLASAS | |
| MARIA AZUCENA HERRERA GONZALEZ | |
| Javier Arrizon Gaviño | |
| Acceso Abierto | |
| Atribución-NoComercial-SinDerivadas | |
| "Flavonoids constitute an important source of bioactive molecules. They have some health benefits such as anti-inflammatory, antiviral, anti-tumor and anti-oxidant activities; however most of them show a rather low bioavailability due to their hydrophobic nature. Enzymatic fructosylation is an interesting approach to overcome these limitations. In this thesis work, the focus was to study the capacity for the enzymatic fructosylation of flavonoids using β-fructosidases from the families GH32 and GH68 in order to produce new fructosides that do not exist in nature. Thus, we performed a bibliographic revision of the enzymatic fructosylation of different molecules, in order to chose the reaction conditions for the fructosylation of flavonoids. Next, new β-fructosidases from non-saccharomyces yeast isolated from fermenting must of Mezcal were tested for the enzymatic fructosylation of flavonoids. Consequently, the gene of a new β-fructosidase from Rhodotorula mucilaginosa was cloned and expressed in Pichia pastoris; the produced enzyme was tested for the fructosylation of different class of flavonoids. The results showed that it was possible to fructosylate acceptors other than sucrose in absence of co-solvents and the yields were around 20%. The best yield was obtained in the case of coniferyl alcohol and only the presence of monofructosyl coniferyl alcohol was detected. Thus, it was the first time that the fructosylation of puerarin by a β-fructosidases from non-saccharomyces yeasts was described. Moreover, the enzymatic fructosylation of phlorizin was compared by β-fructosidases from different sources and specificities belonging to GH32 and GH68 families, the new β-fructosidase from R. mucilaginosa, a plant fructosyltransferase (sucrose:sucrose 1-fructosyltransferase) and a levansucrase. The best results were obtained with levansucrase from Gluconacetobacter diazotrophicus (LsdA), which is able to synthetize β-D-fructofuranosyl–(26)-phlorizin as a new substance from phlorizin by enzymatic fructosylation in 79.1 % of conversion in absence of co-solvents. The mono-fructosylated product was 15.9 fold (30.5 g L-1 at 25°C) more soluble in water than the original substrate phlorizin (1.93 g L-1 at 25°C), although exhibited a 1.4-fold reduction in the antioxidant capacity"" | |
| 17-12-2020 | |
| Tesis de doctorado | |
| CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA | |
| Aparece en las colecciones: | DOCTORADO EN CIENCIA Y TECNOLOGÍA |
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| María Azucena Herrera Gonzalez.pdf | 3.74 MB | Adobe PDF | Visualizar/Abrir |