Banca de QUALIFICAÇÃO: CYNTHIA HAYNARA FERREIRA DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : CYNTHIA HAYNARA FERREIRA DA SILVA
DATA : 16/09/2019
HORA: 09:00
LOCAL: Sala Carl Von Dietrich
TÍTULO:

Evaluation of synergic antioxidant activity of ascorbic acid and fucoidans from brown algae Dictyota mertensii: purification of fucoidan with better antioxidant activity.

PALAVRAS-CHAVES:

Fucan; brown seaweed; synergic antioxidants; sulfated polysaccharides

PÁGINAS: 86
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
SUBÁREA: Química de Macromoléculas
RESUMO:

Seaweed are organisms that have several organic compounds with bioactive functions, and among these are sulfated polysaccharides (SP). The brown seaweed SP (fucans and fucoidans) have several activities, including antioxidant activity, which may be enhanced by the presence of other antioxidants.Here, SP from Dictyota mertensii were mixed with ascorbic acid (AA) and their synergistic effect as antioxidant agents was evaluated. The algal SP were obtained after its proteolysis. Subsequently, they were fractionated by differential acetone precipitation, which led to obtaining 6 fractions (F0.3; F0.5; F0.7; F1.0; F1.5; F2.1).Chemical analysis, infrared spectroscopy, agarose gel electrophoresis showed that all fractions are rich in fucoidans, with low contamination by proteins and phenolic compounds.Analysis of antioxidant potential showed that all fractions increased antioxidant potential in the presence of AA. However, in a hydrogen peroxide oxidative stress cell model using dog renal epithelial cells (MDCK), only F0.3, F0.5 and F0.7 prevented the MDCK cells from hydrogen peroxide oxidative stress.Based on the data, F0.7 was chosen for fucoidan purification. The analysis showed that F0.7 is composed of three main PS populations, and after ion exchange chromatography, ultracentrifugation, and gel filtration chromatography (HPLC) it is possible to purify one fucoidan molecule from the other PS.

MEMBROS DA BANCA:
Externa à Instituição - KAROLINE RACHEL TEODOSIO DE MELO - FAMENE
Interno - 3060683 - LEONARDO THIAGO DUARTE BARRETO NOBRE
Presidente - 2962496 - RAFAEL BARROS GOMES DA CAMARA