Isolation and structural characterization of an R-form lipopolysaccharide from Yersinia enterocolitica serotype O:8

Abstract

The lipopolysaccharide (LPS) of strain 8081-c-R2, a spontaneous R-mutant of Yersinia enterocolitica serotype O:8, was isolated using extraction with phenol/chloroform/light petroleum. Its compositional analysis indicated the presence of D-GlcN, D-Glc, L-glycero-D-manno- and D-glycero-D-manno-heptose, 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) and phosphate. From deacylated LPS obtained after successive treatment with hydrazine and potassium hydroxide, three oligosaccharides (1-3) were isolated using high-performance anion-exchange chromatography, the structures of which were determined by compositional analysis and one- and two-dimensional NMR spectroscopy as in which all sugars are pyranoses, and R and R′ represent β-D-Glc (in 1 and 2) and β-D-GlcN (in 1 only), respectively. D-α-D-Hep is D-glycero-α-D-manno-heptose, L-α-D-Hep is L-glycero-α-D-manno-heptose, Kdo is 3-deoxy-D-manno oct-2-ulosonic acid, and P is phosphate. The liberated lipid A was analyzed by compositional analyses and MALDI TOF MS. Its β-D-GlcN4P-(1→6)-α-D-GlcN-1→P back bone is mainly tetra-acylated with two amide- and one ester-linked (at O3 of the reducing GlcN) (R)-3-hydroxy tetradecanoic acid residues, and one tetradecanoic acid that is attached to the 3-OH group of the amide-linked (R)-3-hydroxytetradecanoic acid of the nonreducing GlcN. Additionally, small amounts of tri- and hexa-acylated lipid A species occur.