Structural elucidation of the core-lipid A backbone from the lipopolysaccharide of Acinetobacter radioresistens S13,an organic solvent tolerant Gram-negative bacterium

摘要

The structure of the core oligosaccharide of the lipopolysaccharide from an organic solvent tolerant Gram-negative bacterium,Acinetobacter radioresistens S13,was investigated by chemical analysis,NMR spectroscopy and MALDI-TOF mass spec-trometry.All the experiments were performed on the oligosaccharides obtained either by alkaline degradation or mild acid hydrolysis.The data showed the presence of two novel oligosaccharide molecules containing a trisaccharide of 3-deoxy-D-manno-octulopyranosonic acid in the inner core region and a glucose rich outer core whose structure is the following:R=H in the main oligosaccharide and beta-Glc in the minor product.The bacterium was grown on aromatic (phenol and benzoic acid) and nonaromatic carbon sources and the core oligosaccharide resulted to occur always with this novel structure.