The inner core region of Yersinia enterocolitica Ye75R (0:3) lipopolysaccharide

摘要: The inner-core region of the lipopolysaccharide an UDPGalNAc-4-epimerase-deficient mutant Yersinia enterocolitica 0:3, designated as Ye75R, was investigated using methylation analysis, 1D-13C-NMR and 2D-13C-NMR 1H-NMR, well 31P-NMR, fast-atom-bombardment mass spectrometry (FAB MS) FAB MS/MS in positive negative modes. isolated core heptasaccharide (OS) composed 2 units d-glucose, 3 ld-heptose 1 unit each dd-heptose 3-deoxy-d-manno-octulosonic acid. Methylation analysis indicated that OS highly branched with terminal location two glucoses unit, which partially (to about 40%) phosphorylated at C7. These combined studies allowed us to formulate structure inner shown Scheme 1. The substitution 7-position terminally linked by phosphate could be recognized MS characterization permethylated dd-heptose-7-phosphate (alditol acetate) extent ratio separated 1H signals 500-MHz 1H-NMR. Negative also presence smaller amounts hexasaccharides, differing from lacking either one d-glucose or dd-heptose, additionally a pentasaccharide heptosyl units, namely subterminal ld-heptose. oligosaccharides fraction analysis.