V-Acetyl-D-galactosamine

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... 

D-Galactosamine (2-Amino-2-deoxy-D-galactose) and /V-acetyl-D-galactosamine (2-Acetamido-2-deoxy-D-galactose)... 

V-Acetyl-D-galactosamine, 995, 996 V-Acetyl-D-glucosamine, 988 AcetyUde ion, 336, 345—346, 348. See also Sodium acetyUde... 

V-Acetyl-D-galactosamine (D-GalpNAc, AN) OH OH HO NHCOCH3 D-GalNAc is found in mucopolysaccharide such as chondroitin (cartilage) keratan sulfate (cornea) and dermatan sulfate (skin). In 0-glycoproteins, GalNAc provides attachment to serine. 

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). 

T.P. Skelton, L.V, Hooper, V. Srivastava, O. Hindsgaul and J.U. Baenziger, Characterization of a sulfotransferase responsible for the 4-O-sulfation of terminal p-A-acetyl-D-galactosamine on asparagine-linked oligosaccharides of glycoprotein hormones. J. Biol Chem., 1991, 266, 17142-17150. 

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