Poly-D-glucoses

Some antigens, such as type 3 pneumococcal polysaccharide, EPS and other polymeric substances such as dextrans (poly-D-glucose) and levan (poly-D-fructose) can induce antibody synthesis without the assistance of TH cells. These are known as T-independent (Ti) antigens. Only one class of immunoglobulin (IgM) is synthesized and there is a weak memory response. 

Dextrans are bacterial and yeast polysaccharides made up of (a 1—>6)-linked poly-D-glucose all have (al—>3) branches, and some also have (al—>2) or (al—>4) branches. Dental plaque, formed by bacteria growing on the surface of teeth, is rich in dextrans. Synthetic dextrans are used in several commercial products (for example, Sephadex) that serve in the fractionation of proteins by size-exclusion chromatography (see Fig. 3-18b). The dextrans in these products are chemically cross-linked to form insoluble materials of various porosities, admitting macromolecules of various sizes. 

Penidllium luteum Zukal. A neutral polysaccharide, luteose, is produced by the mild alkaline hydrolysis of the malonyl residues from luteic acid, a metabolic product of this mould. Luteose was shown to be a poly-D-glucose in which the hexose units were joined by /3-1,6-glycosidic... 

Poly(D-glucose) Fractional precipitation Water/methanol Lowering temp. 2164... 

Other compounds identified in caramels are di-D-fructose and poly(glycosyl) dianhydrides (DFAs). DFAs were found in caramels prepared from D-fructose, D-glucose, and sucrose. The analysis was done after derivatization as TMS (per-0-trimethylsilyl) derivatives or as TMS-oxime (per-O-trimethylsilyl oxime) by... 

This enzyme oxidizes a- and P-anomers of D-glucose to the same extent and shows excellent stability and sensitivity about twice that for the methods with immobilized glucose oxidase. In this approach, pyranose oxidase is immobilized on tresylate-poly(vinylalcohol) beads and packed into a stainless column and peroxidase is immobilized on tresylate-hydrophylic vinyl polymer beads and packed into a transparent FITE tube that is used as the CL flow cell. The H202... 

An almost complete separation of D-glucose from D-ribose on the poly(acrylamide) gel Bio-Gel P-2, with water as the eluant, has been reported by John and coworkers.81 A water-jacketed column (127 X 1.5 cm) at a temperature of 65° and gel of very fine particle-size (400 mesh) were used. Only under such conditions, where resolution is optimal, does good separation of monosaccharides by gel chromatography become possible. 

They heated a solution of D-glucose with a phenolsulfonic acid resin at 70° for 72 hours. A complex mixture of oligo- and poly-saccharides was formed, from which gentiobiose was isolated. Laminaribiose was produced by the action of a cation-exchange resin on D-glucose.142... 

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