Oligosaccharides trisaccharides

Vic G, Scigelova M, Hastings JJ, Howarth OW, Crout DHG. Glycosidase-catalysed synthesis of oligosaccharides trisaccharides with the a-D-gal-(1 3)-D-gal terminus responsible for the hyperacute rejection response in cross-species transplant rejection 34. from pigs to man. Chem. Commun. 1996 12 1473-1474. 

On acetolysis and deacetylation, Leuconostoc mesenteroides NRRL B-1299S dextran gave, amongst other oligosaccharides, trisaccharide 9... 

In addition, the CB glycoside method has been successfully applied to the synthesis of some important oligosaccharides, trisaccharide 89, tetrasaccharide 98, and octaarabinofbranoside 112 as the latent-active glycosylation method, which is a valuable strategy for the rapid assembly of oligosaccharides. 

The trisaccharide raffiaose [512-69-6] which consists of a sucrose molecule with an a-D-galactopyranosyl unit linked 1 — 6 to its D-glucosyl unit, is the second most abundant oligosaccharide and, like sucrose, may be ubiquitous in the plant kingdom. However, it is present in only minor amounts as compared to sucrose. 

Immobilization of A and B blood group oligosaccharide haptens and preparation of immunoadsorbents with specificity to anti-A and anti-B antibodies has been carried out with the use of poly acrylate-coated PG (WPG-PA) [124]. Prespacered A and B-trisaccharide-fl-aminopropylglycosides were used for the synthesis. WPG-PA (1 g) quantitatively binds both haptens (2 pinole) whereas some other activated affinity supports (for example, CNBr-Sepharose 4B) do not. On the other hand, glycidoxypropyl-silica binds prespacered haptens completely but these materials reveal no specific adsorptivity. 

The important advantage of the immunosorbents based on WPG-PA is the fast rate of biospecific interaction between the oligosaccharides and antibodies. For B-trisaccharide-WPG-PA the average sorption time of monoclonal B8 antibodies was 20 times shorter than with B-trisaccharide-Sepharose 4B. The role of the flexible polymeric spacer, therefore, is in this case very pronounced. 

Hen egg-white lysozyme catalyzes the hydrolysis of various oligosaccharides, especially those of bacterial cell walls. The elucidation of the X-ray structure of this enzyme by David Phillips and co-workers (Ref. 1) provided the first glimpse of the structure of an enzyme-active site. The determination of the structure of this enzyme with trisaccharide competitive inhibitors and biochemical studies led to a detailed model for lysozyme and its hexa N-acetyl glucoseamine (hexa-NAG) substrate (Fig. 6.1). These studies identified the C-O bond between the D and E residues of the substrate as the bond which is being specifically cleaved by the enzyme and located the residues Glu 37 and Asp 52 as the major catalytic residues. The initial structural studies led to various proposals of how catalysis might take place. Here we consider these proposals and show how to examine their validity by computer modeling approaches. 

If derivatives are to be named on the basis of the trivial name, the component cited last in the systematic name receives locants with no primes, the preceding component singly-primed locants, etc. However, naming of trisaccharide and higher oligosaccharide derivatives systematically is preferred, to avoid ambiguity. 

Terms designating branches should be enclosed in square brackets. In a branched chain, the longest chain is regarded as the parent. If two chains are of equal length the one with lower Iocants at the branch point is preferred, although some oligosaccharides are traditionally depicted otherwise, such as the blood group A trisaccharide exemplified below. 

Im einzelnen wurden von R. Kuhn, H. H. Baer und A. Gauhe aus dem Oligosaccharid-Gemisch funf Komponenten in reiner Form isoliert. Es handelt sich um ein Trisaccharid, ein Tetrasaccharid, zwei isomere Pentasaccharide und ein Hexasaccharid (140), (143), (145), (146). 

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