Structural determination of the O-antigenic polysaccharide of enteropathogenicEscherichia coliO103:H2

The structure of the antigenic O-polysaccharide isolated from the lipopolysaccharide produced by enterohemorrhagic Escherichia coli O103:H2 was determined and shown to be composed of d-glucose (1 part), 2-acetamido-2-deoxy-d-glucose (2 parts), 2-acetamido-2-deoxy-d-galactose (1 part), and 3-deoxy-3-(R)-3-hydroxybutyramido-d-fucose (1 part). From the results of methylation analysis, Smith-type periodate oxidation degradation studies, and the use of one- and two-dimensional1H and13C NMR spectroscopy, the O-polysaccharide antigen was found to be an unbranched polymer of a repeating pentasaccharide unit having the following structure: →2)-β-d-Glcp-(1→2)-β-d-Fucp3NBu-(1→6)-α-d-GlcpNAc-(1→4)-α-d-GalpNAc-(1→3)-β-d-GlcpNAc-(1→, where Bu is (R)-3-hydroxybutyramido.

Download Full-text

Glucan isolated from leaves of Althaea officinalis L.

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19832082 ◽

1983 ◽

Vol 48 (7) ◽

pp. 2082-2087 ◽

Cited By ~ 6

Author(s):

Alžbeta Kardošová ◽

Jozef Rosík ◽

Rudolf Toman ◽

Peter Capek

Keyword(s):

Medicinal Plant ◽

Periodate Oxidation ◽

Linear Structure ◽

Water Soluble ◽

Partial Hydrolysis ◽

Methylation Analysis ◽

Glycosidic Bonds ◽

Nmr Data ◽

Althaea Officinalis ◽

C Nmr

A water-soluble low-molecular D-glucan was isolated from leaves of the medicinal plant marsh-mallow (Althaea officinalis L.). The results of methylation analysis, partial hydrolysis, periodate oxidation, and 13C NMR data indicated a virtually linear structure with α-(1→6) glycosidic bonds.

Download Full-text

Structural Determination of the Hydrofullerene C60D36 by Neutron Diffraction

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768198000093 ◽

1998 ◽

Vol 54 (3) ◽

pp. 345-350 ◽

Cited By ~ 8

Author(s):

L. E. Hall ◽

D. R. McKenzie ◽

R. L. Davis ◽

M. I. Attalla ◽

A. M. Vassallo

Keyword(s):

Neutron Diffraction ◽

Density Function ◽

Diffraction Data ◽

Fourier Transformation ◽

Structural Determination ◽

Molecular Models ◽

Reduced Density ◽

C Nmr

A mixture of C60D36 with 24.5 \pm 4.5% C60 by weight has been analysed by neutron diffraction techniques. The diffraction data was converted to a reduced density function G(r) by Fourier transformation. The C60 component of the G(r) was subtracted out. This enabled a comparison for five molecular models of C60D36, with symmetries T, Th , S 6 and two D 3 d isomers, with the experimental G(r). This specimen of C60D36 was found to be best described by a T symmetry isomer, in agreement with 13C NMR and IR data for C60H36 [Attalla et al. (1993). J. Phys. Chem. pp. 6329–6331].

Download Full-text

ChemInform Abstract: Methylation of 2,4-Dihydro-3H-1,2,4-triazol-3-ones. A Structural Determination of Anhydro-5-aryl-1,4-dimethyl-3-hydroxy-1,2,4- triazolium Hydroxides by Two-Dimensional NMR.

ChemInform ◽

10.1002/chin.199120169 ◽

2010 ◽

Vol 22 (20) ◽

pp. no-no

Author(s):

E. W. HUBER ◽

J. M. KANE

Keyword(s):

Structural Determination ◽

Two Dimensional

Download Full-text

A glucan from active dry baker’s yeast (Saccharomyces cerevisiae): A chemical and enzymatic investigation of the structure

Journal of the Serbian Chemical Society ◽

10.2298/jsc0311805z ◽

2003 ◽

Vol 68 (11) ◽

pp. 805-809 ◽

Cited By ~ 10

Author(s):

Dragan Zlatkovic ◽

Dragica Jakovljevic ◽

Djordje Zekovic ◽

Miroslav Vrvic

Keyword(s):

Saccharomyces Cerevisiae ◽

Optical Rotation ◽

Linear Chain ◽

Periodate Oxidation ◽

Methylation Analysis ◽

Yeast Saccharomyces Cerevisiae ◽

New Approach ◽

Main Structural Feature ◽

Or Groups

The structure of a polysaccharide consisting of D-glucose isolated from the cell-wall of active dry baker?s yeast (Saccharomyces cerevisiae) was investigated by using methylation analysis, periodate oxidation, mass spectrometry, NMR spectroscopy, and enzymic hydrolysis, as a new approach in determination of structures. The main structural feature of the polysaccharide deduced on the basis of the obtained results is a linear chain of (1?3)-linked ?-D-glucopyranoses, a part of which is substituted through the positions O-6. The side units or groups are either a single D-glucopyranose or (1?3)-?-oligoglucosides, linked to the main chaing through (1?6)-glucosidic linkages. The low optical rotation as well as the 13C-NMR and FTIR spectra suggest that the glycosidic linkages are in the ?-D-configuration.

Download Full-text

Structural analysis of the specific capsular polysaccharide of Streptococcuspneumoniae type 22F

Canadian Journal of Chemistry ◽

10.1139/v89-158 ◽

1989 ◽

Vol 67 (6) ◽

pp. 1038-1050 ◽

Cited By ~ 20

Author(s):

James C. Richards ◽

Malcolm B. Perry ◽

Peter J. Kniskern

Keyword(s):

Capsular Polysaccharide ◽

Glucuronic Acid ◽

Periodate Oxidation ◽

Resonance Spectroscopy ◽

Methylation Analysis ◽

Chemical Shift Correlation ◽

Structure Formula ◽

Correlation Techniques ◽

Heteronuclear Chemical Shift ◽

C Nmr

The structure of the specific capsular polysaccharide produced by Streptococcuspneumoniae type 22F (American type 22) was investigated by high-field 1H and 13C nuclear magnetic resonance spectroscopy, composition, methylation analysis, and periodate oxidation studies. The polysaccharide was found to be a high molecular weight acidic polymer composed of D-glucose, D-galactose, D-glucuronic acid, and L-rhamnose residues to form a regular repeating hexasaccharide unit having the structure[Formula: see text]in which the β-L-rhamnopyranosyl residues were substituted by O-acetyl groups in 80% of the repeating units. The 1H and 13C nmr resonances of the O-deacetylated type 22F polysaccharide were completely assigned by application of two-dimensional homo- and heteronuclear chemical shift correlation techniques. Keywords: Streptococcuspneumoniae polysaccharide, NMR analysis.

Download Full-text