Disaccharide 1—>4-link

C-Disaccharides.5 These disaccharides linked by a CH2 group can be prepared by an extension of the Giese reaction. Thus the radical generated from a glycosyl... 

Polysaccharides You may have seen large carbohydrate polymers referred to as complex carbohydrates in nutritional references. Another name for a complex carbohydrate is polysaccharide, which is a polymer of simple sugars that contains 12 or more monomer units. The same type of bond that joins two monosaccharides in a disaccharide links them together in a polysaccharide. Pasta is a good source of polysaccharides. The pasta shown in Figure 24-10b contains large amounts of starch, a polysaccharide from plants. 

Exogenous maltosyl bovine serum albumine at two concentrations. MBSA (Sigma Chemical lot 98F8120) is prepared from bovine albumin and maltose coupled via reductive amination.8 One mole of albumin contains 14 moles of disaccharide linked to lysine residues. The sugar content represents 5% of the molecule. The MBSA molecular weight and p/ are 71 kDa and 4, respectively. It was used without further purification. 

Considerable interest continues to be shown in disaccharides linked by carbon... 

In addition to oligomers obtained from the amino-acid (114), two other reports have described the synthesis of disaccharides linked through amide bonds. Hexosaminides (e.g. benzyl 2-amino-2-deoxy-a-D-glucopyranoside) have been condensed directly, or in the presence of DCC, with hexuronic acid derivatives (e.g. l,2 3,4-di-0-isopropylidene-a-D-galactopyranosyluronic acid) to give the corresponding A -acylamino derivatives [e.g. (128)], and a similar... 

Maltose (Section 25.14) A disaccharide obtained from starch in which two glucose units are joined by an a(l,4)-glyco-sidic link. 

FIGURE 6.20 A disaccharide of galactose and glucose is covalently linked to the 5-hydroxyl group of hydroxylysines in collagen by the combined action of the enzymes galactosyl transferase and glucosyl transferase. 

Disaccharides contain a glycosidic acelal bond between the anomeric carbon of one sugar and an -OH group at any position on the other sugar. A glycosidic bond between Cl of the first sugar and the -OH at C4 of the second sugar is particularly common. Such a bond is called a 1—>4 link. 

Disaccharide (Section 25.8) A carbohydrate formed by linking two simple sugars through an acetal bond. 

Disaccharide, 997-999 1—>4 link in, 997-998 synthesis of, 1002 Dispersion forces, 62 alkanes and, 92 Disrotatory motion. 1183 Distortionless enhancement by... 

In 1967, Heidelberger, Stacey et al. reported the purification, some structural features, and the chemical modification of the capsular polysaccharide from Pneumococcus Type I. Difficulties of direct hydrolysis of the polysaccharide were overcome and it was possible to identify some of the fragments in the hy-drolyzate. At least six products resulted from nitrous acid deamination. Two were disaccharides, which were identified, and sequences of linked sugar units were proposed. As modification of the polysaccharide decreased the amounts of antibody precipitated by anti-pneumococcal Type I sera, the importance of the unmodified structural features in contributing to the specificity of the polysaccharide was indicated. 

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