Structure determination of the exopolysaccharide produced by Lactobacillus rhamnosus strains RW-9595M and R

2002 ◽  
Vol 363 (1) ◽  
pp. 7-17 ◽  
Author(s):  
Marie-Rose van CALSTEREN ◽  
Corinne PAU-ROBLOT ◽  
André BÉGIN ◽  
Denis ROY
Keyword(s):  
Incubation Temperature ◽  
Periodate Oxidation ◽  
Lactobacillus Rhamnosus ◽  
Gel Permeation Chromatography ◽  
Spectroscopic Techniques ◽  
Methylation Analysis ◽  
1H And 13C Nmr ◽  
Nmr Data ◽  
Molecular Masses

Exopolysaccharides (EPSs) were isolated and purified from Lactobacillusrhamnosus strains RW-9595M, which has been shown to possess cytokine-stimulating activity, and R grown under various fermentation conditions (carbon source, incubation temperature and duration). Identical 1H NMR spectra were obtained in all cases. Molecular masses were determined by gel permeation chromatography. The primary structure was elucidated using chemical and spectroscopic techniques. Organic acid, monosaccharide and absolute configuration analyses gave the following composition: pyruvate, 1; d-glucose, 2; d-galactose, 1; and l-rhamnose, 4. Methylation analysis indicated the presence of three residues of 3-linked rhamnose, and one residue each of 2,3-linked rhamnose, 2-linked glucose, 3-linked glucose and 4,6-linked galactose. The EPS was submitted to periodate oxidation followed by borohydride reduction. Monosaccharide analysis of the resulting polysaccharide gave the new composition: rhamnose, 4; and glucose, 1. Methylation analysis confirmed the loss of the 2-linked glucose and 4,6-linked galactose residues. On the basis of one- and two-dimensional 1H and 13C NMR data, the structure of the native EPS was consistent with the following heptasaccharide repeating unit: {3Rhaα-3Glcβ-3[Gal4,6(R)Pyα-2]Rhaα-3Rhaα-3Rhaα-2Glcα-}n where Rha corresponds to rhamnose (6-deoxymannose) and Py corresponds to pyruvate acetal. Complete 1H and 13C assignments are reported for the native and the corresponding pyruvate-hydrolysed polysaccharide. Electrospray MS and MS/MS data are given for the oligosaccharide produced by Smith degradation.

Glucan isolated from leaves of Althaea officinalis L.

1983 ◽  
Vol 48 (7) ◽  
pp. 2082-2087 ◽  
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.

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

2003 ◽  
Vol 68 (11) ◽  
pp. 805-809 ◽  
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.

Determination of the molecular masses of tetrafluoroethylene telomers by gel-permeation chromatography

2009 ◽  
Vol 51 (7) ◽  
pp. 785-790 ◽  
Author(s):  
A. I. Kuzaev ◽  
I. P. Kim ◽  
D. P. Kiryukhin ◽  
V. M. Buznik
Keyword(s):  
Gel Permeation Chromatography ◽  
Gel Permeation ◽  
Molecular Masses

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

2010 ◽  
Vol 56 (5) ◽  
pp. 367-372 ◽  
Author(s):  
Evgeny Vinogradov ◽  
Leann L. MacLean ◽  
Malcolm B. Perry
Keyword(s):  
Periodate Oxidation ◽  
Enterohemorrhagic Escherichia Coli ◽  
Structural Determination ◽  
Two Dimensional ◽  
Methylation Analysis ◽  
Polysaccharide Antigen ◽  
Antigenic Polysaccharide ◽  
Oxidation Degradation ◽  
C Nmr

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.

scholarly journals Determination of the enol form of asymmetric 1,3-dicarbonyl compounds: 2D HMBC NMR data and DFT calculations

2018 ◽  
Vol 83 (9) ◽  
pp. 953-968
Author(s):  
Meltem Tan ◽  
İshak Bildirici ◽  
Nurettin Mengeş
Keyword(s):  
Experimental Data ◽  
Driving Force ◽  
Theoretical Calculations ◽  
Enol Form ◽  
Dihedral Angles ◽  
Dicarbonyl Compounds ◽  
1H And 13C Nmr ◽  
Nmr Data ◽  
Cdcl3 Solution

In this study, a series of asymmetric aryl 1,3-dicarbonyl compounds were synthesized and their enol forms were observed via experimental data and theoretical calculations. According to the 1H- and 13C-NMR results, all the investigated compounds were found as a single enol form in CDCl3 solution. Moreover, their HMBC spectra were applied to identify the observed enol forms and correlations between certain protons and carbon atoms were considered. The dihedral angles of the asymmetric compounds that have aryl units on both sides were calculated by DFT to understand the reason for the observed enol forms. Small dihedral angles caused longer conjugation, resulting in more stable compounds and it was found that the observed enol forms were based on small dihedral angles, namely, resonance is the driving force. Furthermore, the compounds possessing both aryl and alkyl moieties prefer the enol form towards the aromatic ring side due to longer conjugation.

scholarly journals Characterisation of Lactobacillus rhamnosus VT1 and its effect on the growth of Candida maltosa YP1

2008 ◽  
Vol 25 (No. 5) ◽  
pp. 272-282 ◽  
Author(s):  
D. Liptáková ◽  
Ľ. Valík ◽  
A. Lauková ◽  
V. Strompfová
Keyword(s):  
Growth Rate ◽  
Incubation Temperature ◽  
Lactobacillus Rhamnosus ◽  
Microbial Interactions ◽  
Lag Phase ◽  
Regression Equations ◽  
Candida Maltosa ◽  
Food Protection ◽  
Spoilage Yeast ◽  
Standard Response

The combined effect of initial amount of 18 h <i>L. rhamnosus</i> VT1 inoculum and incubation temperature on the growth of <i>Candida maltosa</i> YP1, an oxidative food spoilage yeast strain, was primarily modelled and studied by standard response surface methodology. This study resulted in the following linear regression equations characterising lag time and growth rate of <i>C. maltosa</i> YP1 in milk in competition with the potentially protective lactobacillus strain. Lag-phase of <i>C. maltosa</i> was strongly influenced by the amount of lactobacillus inoculum (<i>V</i><sub>0</sub>) and incubation temperature (1/<i>T</i>). The synergic effect of both these factors was also evident as results from the equation lag = –33.50 + 186.38 × <i>V</i><sub>0</sub> × 1/<i>T</i> + 512.27 × 1/<i>T</i> – 5.511 × <i>V</i><sub>0</sub> (<i>R</i><sup>2</sup><sub>(λ)</sub> = 0.849). The growth rate was sufficiently described by the linear relation: <i>Gr</i><sub>Cm</sub> = –0.00046 + 0.0033 × <i>T</i> – 0.0016 × <i>V</i><sub>0 (<i>R</i><sup>2</sup><sub>(Gr)</sub> = 0.847). On the basis of these equations, the mutual microbial interactions and the potential application of the lactobacillus strains to food protection are discussed.

Sign in / Sign up

Export Citation Format

Share Document