Combining versatility with cost-effectiveness: Determination of both free and bound sialic acids, N-acetylneuraminic and N-glycolylneuraminic in unprocessed bovine milk

[Extract] Sialic acids are a group of nine‑carbon monosaccharides structurally
derived from neuraminic acid, also known as 5-amino-3,5-dideoxy-Dglycero-D-galactonon-2-ulosonic
acid (a 9‑carbon monosaccharaide
containing a keto group at position C2 (ketononose)). The two most
common sialic acids are N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic
acid (Neu5Gc). Sialic acids naturally reside on the
surface of most eukaryotic cells and soluble proteins, and can exist in
the free or bound form, in the second case typically bound to the
terminal end of glycoproteins and glycolipid oligosaccharides. The
human biological pathways are able to synthesise Neu5Ac, and although
Neu5Gc has been found in cases of certain cancers or severe
inflammatory diseases, it cannot be endogenously synthesised due to an
evolutionarily acquired gene mutation