Synthetic Reducing Disaccharide

On oxidation of the phenylosotriazole derivative of the disaccharide with sodium periodate, three moles of periodate are consumed with the formation of one mole each of formic acid and formaldehyde per mole of the phenylosotriazole derivative. If the D-glucose in the u-glucopyrano-syl-L-arabinose phenylosotriazole were attached to carbon atom 4 of the L-arabinose derivative, oxidation of this compound with sodium periodate would require two moles of periodate and would liberate one mole of 

On methylation of the disaccharide with dimethyl sulfate and sodium hydroxide a hexamethyl ether of the carbohydrate was obtained. When this fully methylated derivative (VII) was hydrolyzed with acid, 2,3,4,6-tetramethyl-D-glucose (VIII) and dimethyl-L-arabinose (IX) were produced. Since position 3 in the L-arabinose component of VI was shown to be occupied in glycosidic linkage with D-glucose, the dimethyl-L-arabinose could be either the 2,5- or 2,4-dimethyl derivative (IX), 

If this acid were the 2,5-dimethyI-L-arabonic acid, it would possess a pair of adjacent hydroxyls (on positions 3 and 4) which on oxidation with 

A more direct confirmation that the dimethyl-L-arabinose possesses a pyranose configuration was obtained from the study of the rate with which its lactone derivative is hydrolyzed to the corresponding open chain acid.8 

When the dimethyl-L-arabonolactone was dissolved in water, it was found to be almost completely hydrolyzed within four hours. This was indicated by a change of its rotation from [a]D +60° to +24°. A con- 

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Aldonic acids (e.g. melibionic and gentiobionic acids) derived from reducing disaccharides have been coupled to the amino-groups of proteins with the aid of a water-soluble carbodi-imide/ The immunochemical properties of some of the synthetic glycoproteins were assessed using plant agglutinins and antibodies raised towards the conjugates. 

In connection with synthetic studies of fragments of the O-antigens of the polysaccharide of Shigella flexneri three pentasaccharides were made based on the tetramer p-D-GlcNAc-(1 2)-a-L-Rha-(1 2)-a-L-Rha-(l- 3)-L-Rha with modifications as follows a-D-Glc substituted at 0-4 of the terminal Rha unit, the same substituent at the 0-3 of the central Rha unit, and a-D-Glc attached at 0-3 of the terminal Rha and also, at the non-reducing end, the disaccharide moiety inverted in a-L-Rha-(l->3)-p-D-GlcNAc-(l- 2)-a-L-Rha-(l- 2)-[a-D-Glc-(l- 3)]-L-Rha. ... 

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