title: The structures of the carbohydrate backbones of the lipopolysaccharides from Escherichia coli rough mutants F470 (R1 core type) and F576 (R2 core type).
abstract: The lipopolysaccharides (LPS) from Escherichia coli rough mutant strains F470 (R1 core type) and F576 (R2 core type) were deacylated yielding in each case a mixture of oligosaccharides with one predominant product which was isolated using high-performance anion-exchange chromatography. In addition, one oligosaccharide present in minor quantities was isolated from LPS of E. coli strain F576 (R2 core type). The structures of the oligosaccharides were determined by chemical analyses and NMR spectroscopic experiments. Furthermore, de-O-acylated and dephosphorylated LPS preparations were investigated by fast-atom bombardment and collision induced dissociation tandem mass spectrometry. The combined data allow us to deduce the following carbohydrate backbones of the E. coli R1 and R2 core types which share the following structure (Scheme 1): but differ in the substituents R1 and R2 which for the R1 core type are predominantly: and to a minor extent: and for the R2 core type predominantly: and to a minor extent: in which all sugars are d-pyranoses (l,d-Hep, lglycerodmanno-heptopyranose; P, phosphate).
authors.affiliation: Center for Medicine and Biosciences, Borstel Research Center, Germany.
authors.forename: E V
authors.initials: EV
authors.lastname: Vinogradov
authors.forename: K
authors.initials: K
authors.lastname: Van Der Drift
authors.forename: J E
authors.initials: JE
authors.lastname: Thomas-Oates
authors.forename: S
authors.initials: S
authors.lastname: Meshkov
authors.forename: H
authors.initials: H
authors.lastname: Brade
authors.forename: O
authors.initials: O
authors.lastname: Holst
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004926:Escherichia coli / Q000737:chemistry* / Q000235:genetics; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009154:Mutation; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D008070:Lipopolysaccharides