Structure of the O-specific polysaccharide of Proteus vulgaris O4 containing a new component of bacterial polysaccharides,4,6-dideoxy-4-{N-[(R)-3-hydroxybutyryl]-L-alanyl} amino-D-glucose

摘要

A high-molecular-mass O-specific polysaccharide was obtained by mild acid degradation of Proteus vulgaris 04 lipopolysaccharide followed by GPC. The polysaccharide was studied by chemical methods along with lH and ~(l3)C NMR spectroscopy, including two-dimensional COSY, TOCSY, NOESY, H-detected lH,~(l3)C HMQC, and lH,~(l3)C HMBC experiments. Solvolysis of the polysaccharide with trifluoromethanesulfonic (triflic) acid resulted in a GlcpA-(l -+ 3)-GlcNAc disaccharide and a novel amino sugar derivative, 4,6-dideoxy-4-{N -[(R)-3-hydroxybutyryl)-L- alanyl}amino-D-glucose [Qui4N(HbAla?). On the basis of the data obtained, the following structure of the tetrasaccharide repeating unit of the O-specific polysaccharide was established: —>4_#beta#-D-Glcp A-(1—>3)-#beta#-DGlcp NAc-(1—>2)-#beta#-D-Quip4N(HbAla)-(1—>3)-#alpha#-D-Galp-(1—>This structure is unique among the O-specific polysaccharides, which is in accordance with classification of the strain studied in a separate Proteus serogroup.