SULFATED POLYSACCHARIDES OF BROWN SEAWEED Dictyota mertensii: EVALUATION OF SYNERGIC ANTIOXIDANT EFFECT IN ASSOCIATION WITH ASCORBIC ACID AND PURIFICATION OF A FRACTION.
Fucan; brown seaweed; synergic antioxidants.
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 And was evaluated the antioxidant potential resulting of synergic effect. The algal were collected SP from Potigar coast and submitted to proteolysis and differential acetone fractionation to obtain PS, 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 purification process, and after ion Exchange chromatography, and gel filtration chromatography (HPLC), the analysis showed that F0.7 is composed of three main PS populations.