on the other hand , the serous cell contained neutral and acid glycoproteins with different residues such as alpha-d-mannose , alpha-d-glucose , beta-d-galactose ( 1 -- -- 3 ) -d-n-acetylgalactose , alpha-l-fucose , n-acetyl-alpha-d-galactosamine , n-acetyl-beta ( 1 -- -- 4 ) -d-glucosamine , galactose , alpha-galactose , alpha-n-acetylglucosamine and sialic acid .
C0017718
glucosamine
C0001056
acetylglucosamine