Structural Feature of Uronate—Sugar Conjugates, and the General Pathways for Degradation

Common Structural Feature of Uronate-Sugar Conjugates, AND THE General Pathways for Degradation 

The common structural feature of all of the aforementioned natural polysaccharides is the hexopyranuronate linked 4-O-glycosidically to a sugar residue, as in 1. The position of the glycosidic linkage on the 4-hy- 

Similar linkage of furanoid sugars, as in 2, has, thus far, not been found in Nature, Such a linkage system can, however, be obtained by selective 

A similar procedure is the alkali-catalyzed degradation of the 3-O-sub-stituted pentofuranuronate conjugates. This reaction also gives a structurally similar product, namely, the 3,4-unsaturated, 3-deoxypento-furanuronate derivative 6. 

The detection or quantitative determination of these characteristic, enolacetal sugars (often involving complex reaction-mixtures) has proved to be easy, for example, by measurement of the u.v. absorption (Xmax 220-240 nm). 

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