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

The fractionation of acidic polysaccharides by ion exchange chromatogr aphy followed by agarose gel electrophoresis in a special buffer syste m made of 1,3-diaminopropane has shown that the algae of the class Pha eophycea, 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 electrop horetic mobility and are eluted at different concentrations of NaCl fr om the anion exchange resin; The chemical analyses of the compounds in dicate that all the 3 algae contain alginic acid, a xylofucan and 2 sp ecies of fucans with different sulfate contents. The main findings of these studies were that this class of algae contains 4 main acidic pol ysaccharides and that they were similar regarding the sugar compositio n and sulfate content when the 3 algae were compared. The findings tha t the acidic polysaccharides migrate as single discrete components in electrophoresis suggest that they have defined structures and as a con sequence, the sugars and sulfate residues are not randomly present in the polymer chains. These observations lead also to the conclusion tha t the quantitative differences of the sugars present in the crude poly saccharide mixture of the 3 algae are due to the relative proportions of the 4 acidic polysaccharides.