Oligosaccharide backbones

The Gram-negative cell envelope (Fig. 1.4) is even more complicated essentially, it contains lipoprotein molecules attached covalently to the oligosaccharide backbone and in addition, on its outer side, a layer of lipopolysaccharide (LPS) and protein attached by hydrophobic interactions and divalent metal cations, Ca and Mg. On the inner side is a layer of phospholipid (PL). 

Molinaro, A., De Castro, C., Lanzetta, R., Parrilli, M., Raio, A., Zoina, A. Structural elucidation of a novel core oligosaccharide backbone of the lipopolysaccharide from the new bacterial species Agrobacterium larrymoorei. Carbohydr Res 338 (2003) 2721-2730. 

Fraser-Reid et al. reported the synthesis of the oligosaccharide backbones of two GPI anchors of Trypanosoma brucei and rat brain, which involved highly stereocontrolled glycosylations.H8... 

Elevation of the nonrotated portion of the oligosaccharide backbone and rotated residues above the base pairs (in this case a result of the E-1,6-and E-1,3-bonding pattern). 

Authors who provide 2-D maps of gangliosides typically use the nomenclature of Svennerholm (104). In this system, the subscript M, D, or T is used to indicate mono-, di-, or trisialogangliosides, respectively. Additionally, a numerical subscript is used to indicate the structure of the oligosaccharide backbone to which the sialic acid residues are attached. For further discussion of this topic, see Fishman, et al. (105). 

Fucosyl donor 77 was also used in the syntheses of octasaccharide tumor-related antigens N3 [57]. Bis-glycosylation of acceptors 79 and 80 at the last step of the assembly of the oligosaccharide backbone was highly effective and stereoselective and produced octasaccharides 81 and 82 in very good yields (Scheme 5.23). 

As shown Table 1, gangliosides are further classified into several subclasses depend on the structures of oligosaccharide backbone. 

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