Structures of two O-polysaccharides of the lipopolysaccharide of Citrobacter youngae PCM 1538 (serogroup O9)

摘要

Mild acid degradation of the lipopolysaccharide of Citrobacter youngae O9,strain PCM 1538 released a homopolysaccharide of 4-acetamido-4,6-dideoxy-D-mannose (D-Rha4NAc,N-acetyl-D-perosamine).Studies by methylation analysis and ~1H and ~(13)C NMR spectroscopy,using two-dimensional ~1H,~1H COSY,TOCSY,NOESY and H-detected ~1H,~(13)C HSQC experiments showed the presence of two structurally different polysaccharides consisting of the following units:->2)-alpha-D-Rhap4NAc-(1->and ->3)-alpha-D-Rhap4NAc-(l->3)-beta-D-Rhap4NAc-(l->.