Disaccharides cellobiose

Die Umlagerung X->XI verlauft relativ langsam, und daher sind die 1,4-Disaccharide Cellobiose rmd Lactose erwartungsgemaB nicht so empfindlich gegen Alkali wie die entsprechenden 1-3-Disaccharide Laminaribiose und 3-yS-Galaktosido-glucose (127), (136). 

The highly polymerised compound cellulose is broken down into its octa-acetyl disaccharide cellobiose by acetolysis (Franchimont, Skraup, Ost). The bioses belong to the important group of glucosides. 

Disaccharides cellobiose and cellobiulose, (gentiobiose, isomaltose, kojibiose, laminarabiose, leucrose, melibiose, nigerose, palatinose, sophorose, trehalose, turanose, and xylobiose), lactose and lactulose, maltose and maltulose ... 

Conformational Anafysis of a Disaccharide (Cellobiose) mth the Molecular Mechanics Program (MM2)... 

The hydrolysis of cellulose, a polysaccharide, sometimes yields the disaccharide cellobiose. When cellobiose, a reducing sugar, is hydrolyzed, two glucose molecules result. Unlike maltose, which we describe in the preceding section, the linkage involves the (3 anomer of the left glucose (see Figure 16-24). 

Evans has suggested that the reducing half of the disaccharide cellobiose (LXXXIX) is degraded in such a manner that it does not form lactic acid. The reaction was formulated as follows. 

The disaccharide cellobiose could also be considered the repeating unit of cellulose, but the DP value is measured by the number of glucose units in the macromolecule. This number varies from about 200 for purified cellulose, which suffers some... 

C. beijerinckii (formerly C. acetohutylicum) NCIMB 8052 prefers glucose as substrate but also ferments glucitol, galactose, and the disaccharides cellobiose, lactose, maltose, and sucrose [25]. C. beijerinckii NCIMB 8052 is a grampositive, rod-shaped, obligately anaerobic, mesophylic bacterium and possesses peritrichous flagella. 

For that purpose, disaccharides (cellobiose, lactose, etc.) having a reducing end group, are introduced, in the presence of a reductant, on chitosan in the open-chain form (Yalpani and Hall 1984). These derivatives are water soluble. Fibers made of chitin and chitosan are useful as absorbable structures and wound-dressing materials (Nakajima et al. 1984, Muzzarelli 1997, Ravi Kumar 1999). 

OH Partial hydrolysis of cellulose (Section 22.13C) gives the disaccharide cellobiose (C12H22O11) (Fig. 22.11). Cellobiose resembles maltose in every respect except one the configuration of its glycosidic linkage. 

Cellulose an unbranched plant polysaccharide, M, 300,000-500,000, consisting of pi,4-linked glucose units. C. is enzymatically hydrolysed to the disaccharide cellobiose. It can be hydrolysed to D-glucose by treatment with concentrated acids, such as 40% HCl or 60-70 % H2SO4 at high temperature. This process, called saccharification of wood, is used to produce fermentable sugar from wood. 

The enthalpies of dilution at 25°C of binary and tertiary aqueous solutions containing the isomeric disaccharides cellobiose, maltose, and trehalose, were investigated, and an empirical relationship between saccharide solvation and solute solute interactions was deduced. The thermochemical properties of aqueous solutions of small carbohydrates as glasses and rubbers at sub-zero temperatures have been measured by differential scanning calorimetry (DSC), and the thermodynamic properties of alcohols and monosaccharides in aqueous biuret solution at 25 C have been determined by flow microcalorimetry. By use of DTG... 

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