Polysaccharides Glycans

N.A. Eleuthero sides, lignans, coumarins, phenylpropamoids, isofraxin, pectin, triterpenoid saponins, resins, glycans, polysaccharides.99 100 127-128 An adaptogen, tonic, stimulant, protects the immune system. 

C. difficile is also the cause of emerging nosocomial infections that result in abundant morbidity and mortality worldwide. The glycans Polysaccharide I (PSI) and Polysaccharide II (PSII) were recently identified on the bacterial surface, and are promising vaccine candidates to prevent C. difficile infections. PSI 41 and PSII 42 have a phosphorylated hexa- and pentasaccharide repeating unit, respectively (Scheme 14). 

Polysaccharides. Polysaccharides, also called glycans, are the nutrient and stmctural materials of plants. They are a principle part of the carbohydrate portion of the biomass. The most prevalent monomeric carbohydrate is glucose. Common polysaccharides are all polymers of glucose (Pig. 

L-Fucosamine was found as a constituent of Pneumococcus Type V capsular polysaccharide and as a constituent of the mucopolysaccharides (glycosamino-glycans) of certain enteric bacteria A new synthesis was devised to make the amino sugar more available. 

A general term for a polysaccharide (glycan) composed of a single type of monosaccharide residue is obtained by replacing the ending -ose of the sugar name by -an . 

A polysaccharide (glycan) composed entirely of glycuronic acid residues is named byreplacing -icacid by -an . The generic name for this group of polysaccharides is glycuronan . 

When substitution occurs in a polysaccharide (glycan), each type of sub cited in the name at an appropriate position (in alphabetical order). 

Rice bran hemicelluloses reduce thymus atrophy in rats (Takenaka, 1992). Hikino et al. (1988) isolated and purified four glycan fractions from rice bran hemicelluloses and named them as Oryzabrans A, B, C, and D. All these glycans were shown to improve the peripheral utilization of insulin, resulting in significant hypoglycemic activity (Hikino et al., 1988 Hikino and Hayashi, 1989). Several investigations into rice bran polysaccharides and hemicelluloses (Masayoshi et al., 1987) have indicated a strong improvement in the immune... 

Retention of native carbohydrate structure also is important in applications that utilize the conjugated polysaccharide in binding studies with receptors or lectins. In these cases, the carbohydrate should be modified at limited sites, preferentially only at its reducing end. Section 4.6 of this chapter discusses glycan conjugation techniques in greater detail. 

Xylan has the general properties of insolubility in water, solubility in alkaline solutions, ease of acid hydrolysis, high negative optical rotation, and non-reducing action toward Fehling s solution. It can be placed in three general polysaccharide classes (1) pentosan, (2) glycan, and (3) hemicellulose. It is classed as a pentosan because it is principally a polymer of a pentose. It is by far the most abundant pentosan. 

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