Glucosamine, biosynthesis structure

Figure 48-9. Structure of heparin. The polymer section illustrates structural features typical of heparin however, the sequence of variously substituted repeating disaccharide units has been arbitrarily selected. In addition, non-O-sulfated or 3-0-sulfated glucosamine residues may also occur. (Modified, redrawn, and reproduced, with permission, from Lindahl U et al Structure and biosynthesis of heparin-like polysaccharides. Fed Proc 1977 36 19.)...

Lucka, L. Krause, M. Danker, K. Reutter, W. Horstkorte, R. Primary structure and expression analysis of human UDP-N-acetyl-glucosamine-2-epimerase/N-acetylmannosamine kinase, the bifimctional enzyme in neuraminic acid biosynthesis. FEBS Lett., 454, 341-344 (1999)... 

From this result, it was confirmed that 3-amino-5-hydroxybenzoic acid was the direct biosynthetic precursor of the w-CyN unit of porfiromycin. Because of its chemical structure, it might be thought that tryptophan could be involved in the biosynthesis of the mitomycins, like those alkaloids possessing an indole nucleus, whereas in fact the mitomycins were biosynthesized from an m-CyN unit and a D-glucosamine moiety. 

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