Isolement et étude structurale de glucanes de Phytophthora parasitica

Abstract

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 β(1 →3,1 →6)‐D‐glucans whose relative molecular masses varied from 9000 to about 200000. All these polysaccharides have a main chain of β(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.