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

The lipopolysaccharide (LPS) of strain 8081-c-R2, a spontaneous R-mutant of Yersinia enterocolitica serotype O:8, was isolated using extraction with p henol/chloroform/ light petroleum. Its compositional analysis indicated the presence of D-GlcN, D-Glc, L-glycero-D-manno- and D-glycero-D-manno-heptos e, 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) and phosphate. From deacylated LE'S obtained after successive treatment with hydrazine and potassium hydr oxide, three oligosaccharides (1-3) were isolated using high-performance an ion-exchange chromatography, the structures of which were determined by com positional analysis and one- and two-dimensional NMR spectroscopy as [GRAPHICS] in which all sugars are pyranoses, and R and R' represent beta -D-Glc (in 1 and 2) and beta -D-GlcN (in 1 only), respectively. D-alpha -D-Hep is D-gly cero-alpha -D-manno-heptose, L-alpha -D-Hep is L-glycero-alpha -D-manno-hep tose, Kdo is 3-deoxy-D-manno-oct-2-ulosonic acid, and P is phosphate. The l iberated lipid A was analyzed by compositional analyses and MALDI-TOF MS. I ts beta -D-GlcN4P-(1-->6)-alpha -D-GlcN-1-->P backbone is mainly tetra-acyl ated with two amide- and one eater-linked (at O3 of the reducing GlcN) (R)- 3-hydroxytetradecanoic acid residues, and one tetradecanoic acid that is at tached to the 3-OH group of the amide-linked (R)-3-hydroxytetradecanoic aci d of the nonreducing GlcN. Additionally, small amounts of tri- and hexa-acy lated lipid A species occur.