DEPLOYMERIZATION OF POLYSACCHARIDES BY ACTIVE OXYGEN SPECIES DERIVED FROM A XANTHINE OXIDASE SYSTEM

Depolymerization of isolated plant polysaccharides by active forms of oxygen produced by the action of xanthine oxidase was measured by viscosity changes. With the use of enzymes, specific inhibitors, quenchers and scavengers of active oxygen species we found that the two forms responsible for the depolymerizations are hydroxyl radical and singlet oxygen. Both of those active forms are produced by the interaction of superoxide ion with hydrogen peroxide, the latter two being produced by xanthine oxidase.