Biosynthesis of Monosaccharide Components, and Their Activation for Polymeric-Chain Formation

Biosynthesis of Monosaccharide Components, and Their Activation for Polymeric-Chain Formation 

A great diversity of monosaccharide structures is a characteristic feature of bacterial polysaccharide chains, especially of O-specific chains of lipopolysaccharides from Gram-negative bacteria. Several surveys of monosaccharide components of bacterial polysaccharides have been published.95 98 

In this Section, deoxy sugars, aminodeoxy sugars, and glycuronic acids are treated as modification products of simple aldoses that are classified here according to the structure of their formal, carbohydrate precursors. 

Transition from the D-gluco to the D-galacto configuration occurs through enzymic epimerization at C-4 of the hexosyl group in glycosyl nucleotides. Such reactions were observed for UDP-Glc,14,102-104 UDP-GlcNAc,44,105-107 

Epimerization at C-2 of UDP-GlcNAc, leading to the UDP derivative of 2-acetamido-2-deoxy-D-mannose, was also observed115 118 the monosaccharide was identified as a constituent of several capsular polysaccharides from Streptococcus pneumonia119-122 and Neisseria meningitidis group A (Ref. 123), the teichuronic acid of Bacillus cereus,124 and the O-specific 

---