Tables of Oligosaccharides

Contents of oligosaccharides of defatted meals are given in Table 6. Sucrose, rafflnose, and stachyose are the principal sugars present. The polysaccharide ... 

Table 6. Oligosaccharide Contents of Defatted Oilseed Meals, % ...

Numerous lectins have been purified and are commercially available three plant lectins that have been widely used experimentally are listed in Table 47-7. Among many uses, lectins have been employed to purify specific glycoproteins, as tools for probing the glycoprotein profiles of cell surfaces, and as reagents for generating mutant cells deficient in certain enzymes involved in the biosynthesis of oligosaccharide chains. 

Fig. 2.—Conformations of oligosaccharides having the angles shown in Table IX for minimum-energy conformations predicted by the HSEA algorithm for use as building units in molecular modeling. The molecules are shown without the anomeric hydroxyl group.

Table I. Oligosaccharides produced on hydrolysis of carob galactomannan by p-mannanases...

Table 5.3 Production of oligosaccharides by metabolic engineered living E. coli cells (see Scheme 5.9 for product formulas).

Scheme 5.9 Examples of oligosaccharides produced by metabolically engineered living E. coli cells (see Table 5.3 for references). Lacto-N-neotetraose (LNnT, 17), globotetraose (18), Le trisaccharide bound on a GicNAc motif (19),...

Table III. Possible Structure of Oligosaccharides Obtained by the Partial Acid Hydrolysis of Rice Bran Arabinogalactoglucuronoxylan...

Studies to elucidate the correlation between the structure of the polymer gels and their blood compatibility were carried out by means of 13C-NMR (for mobility of the PEG chains) and H-NMR and DSC (for the effect of water on their properties). Results are shown in Table 7. By comparing these results with one another, Tanzawa et al. concluded that material surfaces with the highest fraction of water molecules of intermediate mobility exhibit the best blood compatibility. This was supposed to come from a similar mobility of the intermediate water compared to that of oligosaccharides on the outermost surface of the cell... 

Table 4.2.2 Ri values (distance travelled by the substance on the plate) of oligosaccharide standards...

Table XI. Glycosides of Oligosaccharides Containing Simple Aldohexoses. . 211 Table XII. Methyl Glycosides of Oligosaccharides Containing Galactose and...

Table XX. Oligosaccharides Related to Those of Salmonella (Glycosides). . . 222...

Support-bound triacylmethanes (e.g. 2-acetyldimedone) readily react with primary aliphatic amines to yield enamines. These are stable towards weak acids and bases, and can be used as linkers for solid-phase peptide synthesis using either the Boc or Fmoc methodologies, as well as for the solid-phase synthesis of oligosaccharides [456]. Cleavage of these enamines can be achieved by treatment with primary amines or hydrazine (Entries 2 and 3, Table 3.23 see also Section 10.1.10.4). 

Silyl ethers of aliphatic alcohols are inert towards strong bases, oxidants (ozone [81], Dess-Martin periodinane [605], iodonium salts [610,611], sulfur trioxide-pyridine complex [398]), and weak acids (e.g., 1 mol/L HC02H in DCM [605]), but can be selectively cleaved by treatment with HF in pyridine or with TBAF (Table 3.32). Phenols can also be linked to insoluble supports as silyl ethers, but these are less stable than alkyl silyl ethers and can even be cleaved by treatment with acyl halides under basic reaction conditions [595], Silyl ether attachment has been successfully used for the solid-phase synthesis of oligosaccharides [600,601,612,613] and peptides [614]. 

The solid-phase synthesis of oligosaccharides is usually performed using acid-resistant linkers and protective groups, because of the slightly acidic reaction conditions required for glycosylations (Section 16.3). Hydroxyl group protection is conveniently achieved by conversion into carboxylic esters, such as acetates, benzoates, or nitro-benzoates. Support-bound esters of primary or secondary aliphatic alcohols can be cleaved by treatment with alcoholates [97-99] (Table 7.8), with DBU in methanol, with hydrazine in DMF [100] or dioxane [101], or with ethylenediamine [102], provided that a linker resistant towards nucleophiles has been chosen. 

Allyl carbonates can be cleaved by nucleophiles under palladium(O) catalysis. Allyl carbonates have been proposed for side-chain protection of serine and threonine, and their stability under conditions of /VT moc or /V-Boc deprotection has been demonstrated [107]. Prolonged treatment with nucleophiles (e.g., 20% piperidine in DMF, 24 h) can, however, lead to deprotection of Alloc-protected phenols [108,109]. Carbohydrates [110], tyrosine derivatives [107], and other phenols have been protected as allyl ethers, and deprotection could be achieved by palladium-mediated allylic substitution (Entry 9, Table 7.8). 9-Fluorenyl carbonates have been used as protected intermediates for the solid-phase synthesis of oligosaccharides [111]. Deprotection was achieved by treatment with NEt3/DCM (8 2) at room temperature. 

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