Sialic acids of human large bowel mucosa: o-acylated variants in normal and malignant states.

Five sialic acid variants have been demonstrated in normal, 'transitional', and tumour extracts of human large bowel mucosa by thin-layer chromatography. Two-dimensional thin-layer chromatography, with intermediate alkaline hydrolysis, confirmed that the variants were N-acetyl neuraminic acids with additional O-acylation. Cases studied so far show changes in the proportions of these variants in malignancy.