Glycoside cluster

A. Dondoni, A. Marra, and M. G. Zampolli, Synthesis of all carbon linked glycoside clusters round benzene scaffold via Sonogashira-Heck-Cassar cross coupling of iodobenzenes with ethynyl C-glycosides, Synlett, 11 (2002) 1850-1854. 

A. Dondoni, M. Kleban, X. Hu, A. Marra, and H. D. Banks, Glycoside-clustering round calixarenes toward the development of multivalent carbohydrate ligands. Synthesis and conformational analysis of calix[4]arene O- and C-glycoconjugates, J. Org. Chem., 67 (2002) 4722 -733. 

A. Dondoni and A. Marra, C-glycoside clustering on calix[4]arene, adamantane, and benzene scaffolds through 1, 2, 3-triazole linkers, J. Org. Chem., 71 (2006) 7546-7557. 

FIGURE 16.5 A schematic representation of (a) SPR competitive and (b) direct binding assays of Con A-Man recognition, (c) The structure of clicked [G3]-Man glycodendrimer used for studying the glycoside cluster effect. 

Glycoside cluster effect A mnltivalency effect, based on the interaction a particle exposing saccharide ligands and a mnltimeric protein. 

Carbohydrates, similarly to peptides, are natural sources of chirality and also offer a wide range of ncm-covalent interactions. Molecular recognition of carbohydrates by biological receptors mediates a variety of physiologically relevant processes, including recruitment of leucocytes to inflammatory sites, clearance of glycoproteins from the circulatory system, cell interactions in the immune system, as well as adhesion of bacteria or viruses to host cells. It has been shown that multivalency is especially important for carbohydrate-receptor interactions. The glycoside cluster... 

Triton-solubilized, affintiy-purified HL still expresses glycoside cluster effect, albeit to a much lesser extent than the HL on the hepatocyte surface. The best di-valent oligosaccharide, PENTA-2,4, had 20-fold higher affinity than the mono-antennary structure, as compared to 1000-fold for the hepatocyte surface receptors, while the best triantennary oligosaccharide, NONA I, had 700-fold higher affinity over the monovalent structure, as compared to 100,000-fold enhacement for the hepatocyte system. Presumably organization of subunits in the soluble form is somewhat relaxed compared to the cell surface HLs. 

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