Glycosidic bonds alkaline hydrolysis

The main processes occuring in the alkaline degradation of cellulose are the so called degradation of cellulose from the reducing end of the molecule and the alkaline hydrolysis of glycosidic bonds. The former process is observed almost exclusively at temperatures up to 150°C. 

Peeling. Peeling is the term applied to the stepwise depolymerization of polysaccharides from the reducing end groups under alkaline conditions. In conjunction with the formation of new end groups by alkaline hydrolysis of glycosidic bonds, the degradation of the polysaccharides can be extensive. 

To extract these pentoses there are different processes based on the nature of chemical bonds targeted acid-catalyzed hydrolysis of the glycosidic bond, hot alkaline hydrolysis of ester bonds between chains, or hydrolysis with biological catalysts. 

The N-glycosidic bonds of nucleosides are usually highly stable in neutral and alkaline media and prone to acid hydrolysis. Purine derivative hydrolysis is then much faster than that of pyrimidine derivatives (Table 8.5.1). 

In the absence of oxygen, cellulose is highly resistant to alkali. Oxidized cellulose, however, is far less resistant to alkaline hydrolysis as formation of C = 0 groups adjacent to the glycosidic bond greatly weakens it. Celluloses that have been oxidized, either with oxygen or more specific oxidizers such as periodate, are known as oxycelluloses leading to the destruction of the material. 

---