[Isolation and structural studies of glucans from Phytophthora parasitica]

Several polysaccharides have been isolated from the cell walls of Phytophthora parasitica, a phytopathogenic fungus of carnation. The crude polysaccharides were fractionated by successive chromatographies on DEAE-cellulose, Sephadex G-25, concanavalin-A-Sepharose and Sephadex G-200 columns. The neutral polysaccharides consist of a mixture of beta(1----3, 1----6)-D-glucans whose relative molecular masses varied from 9000 to about 200 000. All these polysaccharides have a main chain of beta(1----3)-linked D-glucose residues. They differ by the presence of 1----6 branched chains consisting of D-glucose and D-Glc-(1----3)-D-Glc, for the lowest molecular mass polysaccharides or D-Glc-(1----3)-D-Glc-(1---3)-D-Glc for the highest molecular mass polysaccharides.