Sialic acids nature

Blix FG, Gottschalk A, Klenk E. Proposed nomenclature in the field of neuraminic and sialic acids. Nature 1957 179 1088. 

Paulson, J.C., Skehel, J.J., and Wiley, D.C. (1988) Structure of the influenza virus haemagglutinin complexed with its receptor, sialic acid. Nature, 333,... 

Barry GT, Goebel WF (1957) Colominic acid, a substance of bacterial origin related to sialic acid. Nature 179 206... 

Barry, G. T., Tsai, T., and Chen, F. P., 1960, Chemical and serological relationships of certain bacterial polysaccharides containing sialic acid, Nature 185 597. 

Figure S.21 The hemaggiutinin moiecuie is formed from three subunits. Each of these subunits Is anchored In the membrane of the influenza vims. The globular heads contain the receptor sites that bind to sialic acid residues on the surface of eukaryotic cells. A major part of the subunit interface is formed by the three long intertwining helices, one from each subunit. (Adapted from I. Wilson et al.. Nature 289 366-373, 1981.)...

Commercial A -acetylneuraminic acid aldolase from Clostridium perfringens (NeuAcA EC 4.1.3.3) catalyzes the addition of pyruvate to A-acetyl-D-mannosamine. A number of sialic acid related carbohydrates are obtained with the natural substrate22"24 or via replacement by aldose derivatives containing modifications at positions C-2, -4, or -6 (Table 4)22,23,25 26. Generally, a high level of asymmetric induction is retained, with the exception of D-arabinose (epimeric at C-3) where stereorandom product formation occurs 25 2t The unfavorable equilibrium constant requires that the reaction must be driven forward by using an excess of one of the components in order to achieve satisfactory conversion (preferably 7-10 equivalents of pyruvate, for economic reasons). 

Figure 10.10 Natural substrates of the 2-keto-3-deoxy-monno-octosonic acid aldolase, and nonnatural sialic acids obtained by KdoA catalysis.

Matrosovich M, Klenk H-D (2003) Natural and synthetic sialic acid-containing inhibitors of influenza virus receptor binding. Rev Med Virol 13 85-97 Matrosovich MN, Matrosovich TY, Gray T, Roberts NA, Klenk H-D (2004) Neuraminidase is important for the initiation of influenza virus infection in human airway epithelium. J Virol 78 12665-12667... 

Varghese IN, Colman PM (1991) Three-dimensional structure of the neuraminidase of influenza virus A/Tokyo/3/67 at 2.2 A resolution. 1 Mol Biol 221 473 86 Varghese IN, Laver WG, Colman PM (1983) Structure of the influenza virus glycoprotein antigen neuraminidase at 2.9 A resolution. Nature 303 35 0 Varghese IN, McKimm-Breschkin IL, Caldwell IB, Kortt AA, Colman PM (1992) The structure of the complex between influenza virus neuraminidase and sialic acid, the viral receptor. Proteins 14 327-332... 

Figure 1.35 The complex structure of an asparagine-linked polysaccharide. Note the branched nature of polymer with terminal sialic acid residues on each chain. 

Host cell mimicry Sialic acid is part of the glycocalyx of many host cells. The coat of some bacteria contain sialic acid which may reduce the effectiveness of the response of the immune system to the foreign nature of the coat. 

The use of S-2-phenylselenopropanal in the synthesis of the naturally occurring (8R) antipode of the title compound is described. This chemistry was adapted to achieve a total synthesis of a sialic acid glycoside in a stereospecific fashion. 

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