Synthesis and reactivity of the monosaccharide esters of amino acids as models of teichoic acid fragment

The increasing prevalence of sepsis from Gram-positive bacterial pathogens necessitates further evaluation of the basic assumptions about the molecula r pathogenesis of septic shock. Since diverse physiological functions of Gr am-positive bacteria are controlled by the degree of esterification of teic hoic acids with D-alanine, we examined the reactivity of monosaccharide est ers in which anomerically free or protected D-glucose is linked through its C-6 hydroxy group to either phenylalanyl or tyrosyl residues as models for teichoic acid fragment. We show that the attached sugar moiety induces act ivation of the amino acid residue. Due to the enhanced reactivity of the NH 2 group in the monosaccharide esters studied, the formation of products gen erated by intramolecular and intermolecular glycation reactions is accelera ted resulting in heterogeneous mixture of compounds. These findings suggest that, if similar adducts are formed by glycation of D-alanine in teichoic acid of Gram-positive bacteria, they should be examined as potential bioact ive ligands or chemical message for infection.