N-acetylgalactosamine is an amino sugar derivative of galactose.
N-acetylgalactosamine, or n-acetyl-α-D-galactosamine, alpha-GalNAc; TN saccharide; alpha-GalpNAc; GalNAc-alpha; n-acetyl-α-d-galactosamine; or N-acetyl-alpha-D-galactosamine, is an amino sugar derivative of galactose. In humans, it is the terminal carbohydrate of the blood group A antigen.