Kevin W. Williams

Synthesis of potential inhibitors of hemagglutination by influenza virus: chemoenzymic preparation of N-5 analogs of N-acetylneuraminic acid.☆

Abstract A chemoenzymic route to neuraminic acid 2 is described. This method is based on conversion of N-carbobenzoxymannosamine (ManCBz) 3 to N-carbobenzoxyneuraminic acid (Neu5CBz) 4, catalyzed by Neu5Ac aldolase. The Neu5CBz 4 was converted to the α-methyl glycoside 8 and deprotected to afford the free amine 2. This procedure has been scaled up to generate 10-gram quantities of 2. N-Acylation of 2 produced several new N-acyl neuraminic acid analogs; these have been evaluated as inhibitors of adhesion of influenza virus to chicken erythrocytes in a hemagglutination inhibition assay (HAI). This preparation of neuraminic acid 2 is compared with other literature procedures.

Synthesis of methyl α-sialosides N-substituted with large alkanoyl groups, and investigation of their inhibition of agglutination of erythrocytes by influenza A virus☆

The synthesis of a series of new inhibitors of the binding of influenza virus to erythrocytes is described. The inhibitors are derivatives of sialic acid with C4 – C14 alkanoic acids groups attached at the N5 position as acyl groups. These molecules were evaluated for their ability to prevent virus-induced agglutination of erythrocytes. There appears to be a correlation between increased chain length and increased inhibition of virus-induced agglutination of erythrocytes These derivatives did not, however, show increased binding to BHA, a soluble form of the lectin hemagglutinin that is responsible for the attachment of virus to cell.

Inorganic environment derived from the sol-gel route does not improve the thermal or oxidative stability of 2,4-dinitroaniline in coatings

Abstract The relative thermal and oxidative stabilities of N -[3-(triethoxysilyl)propyl]2,4-dinitroaniline (1), incorporated covalently into sol-gel coatings and of 2,4-dinitroaniline, incorporated non-covalently into similar coatings, showed no significant difference in relative thermal stability in sol-gel derived films under a variety of conditions: with no overcoat of SiO 2 ; with a dense sol-gel-derived overcoat of SiO 2 ; with a porous overcoat of SiO 2 ; over a porous, high surface area coating of SiO 2 ; and copolymerized with or physically incorporated into dense and porous SiO 2 films derived from tetraethylorthosilicate.