Structure of the O-polysaccharide from the lipopolysaccharide of Providencia stuartii O43 containing an amide of D-galacturonic acid with L-serine

摘要

The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia stuartii 043:H28 and studied by sugar and methylation analyses, Smith degradation and H-1 and C-13 NMR spectroscopy, including 2D ROESY, and H-detected H-1, C-13 HSQC and HMBC experiments, as well as a NOESY experiment in a 9:1 H2O/D2O mixture to reveal correlations for NH protons. It was found that the polysaccharide is built up of linear tetrasaccharide repeating units containing an amide of D-galacturonic acid with L-serine [D-GalA6(L-Ser)] and has the following structure:[3)-beta-D-GalpA6(L-Ser)-(1 -> 3)-beta-D-GlcpNAc-(1 -> 2)-alpha-D-Rhap4NAc-(1 -> 4)-beta-D-GlcpA-(1 ->](n) (c) 2005 Elsevier Ltd. All rights reserved.