The demonstration of O-acetylated sialic acids in colonic epithelial glycoproteins

Glycoproteins have been isolated from a 1 M sodium chloride extract of the colonic epithelial cells of man and rat by a combination of Agarose gel and DEAE-cellulose chromatography; The glycoproteins contain O-acetylated or O-esterified sialic acids of at least four types: (a) unsubstituted or possible at position C-9, (b) substituted at C-4 and possibly at C-9, (c) substituted at C-7 and/or C-8, and (d) substituted at C-4 as well as at C-7 and/or C-8.