N-Acetyl-o-galactosamine

More reproducible results are obtained with amounts of 5 to 20 pg for N-acetyl-D-glu-cosamine and amino-sugars, and 10 to 50 pg for N-acetyl-O-galactosamine. 

Roth, J., Wang, Y., Eckhardt, A.E., and Hill, R.L. Subccllular localization of the UDP-N-acetyl-D-galactosamine polypeptide N-acetylgalactosaminyltransferase-mediated O-glycosyla-tion reaction in the submaxillary gland. Proc. Natl. Acad. Sci. USA 91 8935-8939, 1994. 

Nitroglycals65 are excellent Michael-type acceptors,66 where O-, N-, S-, C- and P-nucleophiles can be used as donors.67 An application of this kind of reaction was reported by Schmidt et al. for a new synthesis of 2-deoxy-2-nitro-D-galactose nucleoside 86 and of /V-acetyl-D-galactosamine nucleoside 88, based on addition reactions to 3,4,6-tri-0-benzyl-2-nitro-D-galactal 85 (Scheme 28).68... 

Tsuruta O, Shinohara G, Yuasa H et al (1997) UDP-N-acetyl-5-thio-galactosamine is a substrate of lactose synthase. Bioorg Med Chem Lett 7 2523-2526... 

Add (pick) saccharide residues from the list of aldoses (hexoses in al-dopyranose form, pentoses in aldofuranose form, and tetraoses in open-chain form), ketoses (hexoses in ketofuranose form, pentoses and tetraose in open-chain form), derivatives (glucosamine, galactosamine, N-acetylnuraminic acid, N-acetyl muramic acid, inositol, 2-deoxyribose, rhamnose, fucose, and apiose), and blocking groups (H, NH2, =0, COO—, methyl, lactyl, O-methyl, iV-methyl, O-acetyl, iV-acetyl, phosphoric acid, sulfate, iV-sulfonic acid) to build polysaccharides. 

Chondroitin is an unbranched heteropolymer consisting of repeating disaccharides of D-glucuronic acid and / /-acetyl D-galactosamine — [D-glucuronic acid-p(l— 3)-/V-aeetyl D-galaetosamine-p(l— 4)]n —. The galactosamine residue may be O-sulfated at either C-4 (chondroitin-4-sulfate or chondroitin sulfate A) or C-6 (chondroitin-6-sulfate or chondroitin sulfate C). 

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