Sialic Acid in O-Glycosidically Linked Carbohydrate Chains

Several types of 0-glycosidically linked carbohydrate chains occur in glycoproteins. These carbohydrate chains are usually analysed in the form of oligosaccharide-alditols, prepared by alkaline borohydride reductive cleavage (Carlson 1966). The obtained oligosaccharide-alditols have frequently in common  

0-glycosidic mucin type and some reference substances (Van Halbeek et al. 1980, 1981 a, et al. 1981) 

Galp(l-3)[Neu5Aca(2-6)]- [Galp(l-4)GlcNAcp(l-6)]- [Galp(l-4)GlcNAcp(l-6)]- 

This structural element can be extended with sialic acid in different ways  

Further extension of the aforementioned trisaccharide with a NeuSAc residue a(2-6)-linked to GalNAc-ol affords the following tetrasaccharide-alditol  

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