Mechanisms of oxidative degradation of carbohydrates during oxygen delignification. II. Reaction of photochemically generated hydroxyl radicals with methyl beta-cellobioside

Reactions involving methyl beta -cellobioside acid several oxygen species w ere used to investigate cleavage of glycosidic linkages in cellulose by rea ction with photochemical hydroxyl radicals. The intent is not to reproduce delignification conditions, but rather to study the specific behavior of ca rbohydrate models toward hydroxyl radical. Experiments show that hydroxyl r adicals are responsible for the degradation of glycosidic linkages in methy l beta -cellobioside by substitution reactions displacing cellobiose, D-glu cose, methyl beta -D-glucoside, and methanol. Once the glycosidic linkages are broken, the reducing carbohydrates undergo a series of reactions formin g aldonic acids and lower order aldoses in the same manner as described pre viously.(1).