D-Glucose polymers

Nishi et al. [110] used dextran and dextrin as chiral selectors in capillary-zone electrophoresis. Polysaccharides such as dextrins, which are mixtures of linear a-(l,4)-linked D-glucose polymers, and dextrans, which are polymers of D-glucose units linked predominantly by a-(l,6) bonds, have been employed as chiral selectors in the capillary electrophoretic separation of enantiomers. Because these polymers are electrically neutral, the method is applicable to ionic compounds. The enantiomers of basic or cationic drugs such as primaquine were successfully separated under acidic conditions. The effects of molecular mass and polysaccharide concentration on enantioselectivity were investigated. 

Proof of Constitution.—The definitive synthesis of this crystalline trimethylglucose from 2,3-dimethyl-D-glucose served only to confirm the structure, which had already been assigned to the same compound derived by methylation and hydrolysis from natural D-glucose polymers. 

Dextrose Polymers and Their Nitrates. Dextrose (d-glucose) polymers can be obtd by heating dextrose or polysaccharides composed of dextrose units, in the presence of catalysts, such as boric anhydride, or boric acid. The resulting solid products are light in color and have a high 8 wide degree of... 

Heidelberger and Aisenberg240 studied the cross-reaction of the Merck and DuPont polyglucoses with antibodies to pneumococcal C-substance and to type-specific polysaccharides. One of the D-glucose polymers (Merck 52R61I) was separated into a series of fractions on the basis of fractionation with alcohol (isopropyl alcohol and ethanol) and with glacial acetic acid, the most insoluble fraction being called A, and the most soluble, E. The yield, analyses, and reactivity of these fractions with Types IX, XII, XX, and XXII antipneumococcal horse sera are presented in Table VII. 

All bacteria which have been adequately studied have proved to possess polysaccharides, and, in most instances, these are much more complex than the D-glucose polymers which have attracted the lion s share of attention from carbohydrate chemists. More than twenty different monosaccharide units are known to occur in bacterial polysaccharides, and five or more different kinds of unit may be present in the same polymer. Considering that some of the finer structural details of starch and glycogen remain to be elucidated, it is not surprising that little of the structure of the complex heteropolysaccharides has yet been unravelled. There have also been difficulties in preparing sufficient purified material for chemical work and in... 

Syn. Glucose Polymers G. Polydextrosen F polydextroses These artificial low-polymeric carbohydrates are produced by a polycondensation process of - dextrose in the presence of small amounts of - sorbitol and - citric acid under vacuum at high temperatures. Randomly branched chains of D-glucose polymers result with >90% a-1,6 bonds (some sorbitol- and citric acid monoester groups) and minor amounts of D-glucose (<4%), flee sorbitol (<2%), citric acid, - le-voglucosan, - hydroxymethylfurfiiral. m.w. 162-18 000 with an average distribution 88.7%, 162-5000 5%, 5000-10000 1.2%,... 

Polysaccharides are macromolecules which make up a large part of the bulk of the vegetable kingdom. Cellulose and starch are, respectively, the first and second most abundant organic compounds in plants. The former is present in leaves and grasses the latter in fruits, stems, and roots. Because of their abundance in nature and because of contemporary interest in renewable resources, there is a great deal of interest in these compounds. Both cellulose and starch are hydrolyzed by acids to D-glucose, the repeat unit in both polymer chains. 

The main raw material required for the production of viscose is ceUulose (qv), a natural polymer of D-glucose (Fig. 1). The repeating monomer unit is a pair of anhydroglucose units (AGU). CeUulose and starch (qv) are identical but for the way in which the ring oxygen atoms alternate from side to side of the polymer chain (beta linkages) in ceUulose, but remain on the same side (alpha linkages) in starch. 

Dextrose (D-glucose) is by far the most abundant sugar in nature. It occurs either in the monosaccharide form (free state) or in a polymeric form of anhydrodextrose units. As a monosaccharide, dextrose is present in substantial quantities in honey, fmits, and berries. As a polymer, dextrose occurs in starch, cellulose (qv), and glycogen. Sucrose is a disaccharide of dextrose and fmctose. 

This is a very widely available polymer, since it is the main component of the cell walls of all plants. It is a carbohydrate of molecular formula (C5H q05), where n runs to thousands. The cellulose monomer is D-glucose, and the cellulose molecules are built up from this substance, effectively by condensation and removal of the elements of water. 

Glycogen is the major storage carbohydrate in animals, corresponding to starch in plants it is a branched polymer of a-D-glucose. It occurs mainly in liver (up to 6%) and muscle, where it rarely exceeds 1%. However, because of its greater mass, muscle contains about three to four times as much glycogen as does liver (Table 18—1). 

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