A NEW APPROACH FOR THE CHARACTERIZATION OF POLYSACCHARIDES FROM ALGAE - PRESENCE OF 4 MAIN ACIDIC POLYSACCHARIDES IN 3 SPECIES OF THE CLASS PHAEOPHYCEA

The fractionation of acidic polysaccharides by ion exchange chromatography followed by agarose gel electrophoresis in a special buffer system made of 1,3-diaminopropane has shown that the algae of the class Phaeophycea, order Dictyotales (Dictyota mertensis and Padina gymnospora) and order Fucales (Sargassum vulgare) as well as its floaters contain 4 main acidic polysaccharides. The compounds have a distinct electrophoretic mobility and are eluted at different concentrations of NaCl from the anion exchange resin; The chemical analyses of the compounds indicate that all the 3 algae contain alginic acid, a xylofucan and 2 species of fucans with different sulfate contents. The main findings of these studies were that this class of algae contains 4 main acidic polysaccharides and that they were similar regarding the sugar composition and sulfate content when the 3 algae were compared. The findings that the acidic polysaccharides migrate as single discrete components in electrophoresis suggest that they have defined structures and as a consequence, the sugars and sulfate residues are not randomly present in the polymer chains. These observations lead also to the conclusion that the quantitative differences of the sugars present in the crude polysaccharide mixture of the 3 algae are due to the relative proportions of the 4 acidic polysaccharides.