Uronic acids 3-eliminative degradation

The sulfone degradation has been applied to other polysaccharides, in particular to the product obtained from the Pneumococcus type 2 polysaccharide after methylation and uronic acid elimination (see Section IV,2, p. 218).127 Only about one third of the terminal D-glucose residues was eliminated, and an analysis of... 

Further examples of modified Smith degradation, in which the polyalcohol is methylated prior to hydrolysis under mild conditions, uronic acid degradation, and /3-elimination preceded by oxidation have been reported in connection with structural studies on the Klebsiella type 28 (Ref. 182), 57 (Ref. 183), 59 (Ref. 142), and 81 (Ref. 184) capsular polysaccharides. 

This type of enzyme is commonly obtained from bacterial sources like pneumococci, staphylococci, streptococci, Clostridia [29], Flavobacterium, and Proteus vulgaris [30], and has been demonstrated in Treponema pallidum [31]. Bacterial hyaluronidases degrade hyaluronan to a disaccharide containing a A-4,5-unsaturated uronic acid by eliminating 1 mole of water from the uronic acid portion of the repeating unit of hyaluronan [29]. The full mechanism of this type of reaction has been elucidated by Ludowieg et al. [32],... 

Enzyme-catalyzed hydrolysis of polysaccharides containing uronic acids is well established, but, during the past few years, it has become evident that bacterial enzymes may degrade such materials by a process involving eliminations and the production of oligosaccharides containing nonreducing, terminal, 4,5-unsaturated, uronic acid residues. 

ELIMINATIVE DEGRADATION OF CARBOHYDRATES CONTAINING URONIC ACID RESIDUES... 

Kiss, Joseph, 8-Eliminative Degradation of Carbohydrates Containing Uronic Acid Residues, 29, 229-303... 

Details of a number of established chemical methods used in determining various aspects of the fine structures of polysaccharides-for example, the specific degradation of polysaccharides containing uronic acid residues by base-catalysed elimination, the location of acyl substituents, and the distribution of singleunit side-chains of D-galactose in galactomannans by alkaline hydrolysis of 6-deoxy-6-(4-tolylsulphonyl)hexopyranosides -are reported in the latest volume in the series Methods in Carbohydrate Chemistry . 

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