D-Galactopyranose residues

The trideuteriomethyl group at 0-3 in the D-galactopyranose residue was located by mass spectrometry (m.s.), and its position demonstrated that it derived from a chain residue, substituted at this position this was an important piece of evidence in determining the... 

As to the whole molecule of agar, Jones and Peat28 proposed that it is a linear polysaccharide, esterified with sulfuric acid, the unit chain of which consists of approximately nine D-galactopyranose residues combined by 1 —> 3 glycosidic unions. This unit chain or repeating unit is terminated... 

Galactans are unbranched out chains of D-galactopyranose residues bound through P(l->4) glycosidic bonds. 

Acacia gum A mixture of structurally related polysaccharides, the main one is based on P-D-galactopyranose residues Natural plant exudates solutions are stable at pH 2-7 and display relatively low viscosity Emulsifying or suspending agents, adhesive and binders (in tablets)... 

Keratan sulfate consists of the disaccharide, iV-acetyl-lactosamine, linked /3-(1 3) to the D-galactopyranose residue of the next iV-acetyl-lactosamine unit. Keratan sulfate is the most heterogeneous of the glycosaminoglycans, with variable sulfate content linked to C-4 or C-6 of the D-galactop)Tanose residue in lactosamine, and small amounts of L-fucose (6-deoxy-L-galactose), D-mannose, and iV-acetyl-neuraminic acid residues [93] (also see Sects. 10.2 and O 14 on the occurrence of iV-acetyl-D-neuraminic acid and L-fucose in other systems). Keratan sulfate is found in the cornea, on the surfaces of erythrocytes, in cartilage, and in bone. 

Much of the information on acid hydrolysis of polysaccharides is in the form of unpublished, empirical observations, although inferences (such as, that during the acid hydrolysis of guaran, the D-galactopyranose residues are readily removed, whereas D-mannose is set free somewhat more slowly ") may be found in the literature. 

Enzymic sulfation, with 3 -0-phosphonoadenylyl sulfate, of the 3-hydroxyl group of the D-galactopyranose residue of the cerebrosides obtained led to the sulfatides.58,59... 

It was concluded that the arabinogalactan is a highly branched polymer, containing a framework of (1— 3)-linked /3-D-galactopyranose residues,... 

The noncellulosic fraction of SB hull polysaccharides consists mainly of xylose and mannose. The acidic polysaccharides that can be extracted from SB hulls in sequential extractions steps (acidic polysaccharides 1-V) are all very similar in structure with interior chains made up of D-galacturonic acid and L-rhamnopyranose residues. These interior acidic chains are associated with side chains consisting of neutral sugars, including L-arabinose and chains of 1 4 linked P-D-galactopyranose residues. In addition, 2-O-P-D-gal-D-xyl and 2-O-a-L-fuc-D-xyl residues also may be present (Aspinall et al., 1966). Although the acidic polysaccharide fractions I—V are similar structurally, upon hydrolysis they may yield different monosaccharide concentrations. For example, acidic polysaccharide III contains 76% uronic acids, whereas fractions IV and V contained approximately 45% uronic acids. Hydrolysis of the acidic polysac-... 

An efficient one-pot procedure for removal of 4,6-O-ethylidene groups from D-galactopyranose residues in hetero-oligosaccharides has been described, involving acetolysis, followed by hydrolysis and acetylation. ... 

The macrolide anitbiotics quartromicins Al, A2, and A3, obtained from Amylolatopsis orientalis contain two a-D-galactopyranose residues separately attached as 0-glycosides to a 32-membered carbon ring. ... 

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