STRUCTURAL STUDIES OF THE SACCHARIDE PART OF THE CELL-ENVELOPE LIPOOLIGOSACCHARIDE FROM HAEMOPHILUS-INFLUENZAE STRAIN GALEGALK

The structure of the saccharide part of the lipooligosaccharide from Haemophilus influenzae strain galEgalK has been investigated. On treatment of the lipooligosaccharide with acid under mild conditions, followed by reduction with sodium borohydride and gel permeation chromatography, a main fraction was obtained which was studied by methylation analysis, NMR spectroscopy, and FABMS. The material was heterogeneous and contained two major compounds, A and B, and one minor, C. GRAPHICS A R(1) = beta-D-Glcp-(1 --> 4); R(2) = beta-D-Glcp-(1 --> 4)-alpha-D-Glcp-(1 --> 3) B R(1) = H; R(2) = beta-D-Glcp-(1 --> 4)-alpha-D-Glcp-(1 --> 3) C R(1) = beta-D-Glcp-(1 --> 4); R(2) = H In the structure, PEA is phosphoethanolamine, and L-D-Hep is L-glycero-D-manno-heptose. Kdo exists in reduced anhydro forms. The carbohydrate backbone is the same as that proposed for the saccharide part of the major component from H. influenzae type b strain A2