scholarly journals Extraction of the same novel homoglycan mixture from two different strains of Bifidobacterium animalis and three strains of Bifidobacterium breve

2018 ◽  
Vol 9 (4) ◽  
pp. 663-674 ◽  
Author(s):  
M. Alhudhud ◽  
S. Sadiq ◽  
H.N. Ngo ◽  
C. Hidalgo-Cantabrana ◽  
P. Ruas-Madiedo ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Aqueous Sodium Hydroxide ◽  
2D Nmr ◽  
Low Molecular Weight ◽  
Cell Wall Polysaccharides ◽  
2D Nmr Spectroscopy ◽  
Selective Precipitation ◽  
Bifidobacterium Breve ◽  
Bifidobacterium Animalis ◽  
Cell Biomass

Three strains of Bifidobacterium breve (JCM 7017, JCM 7019 and JCM 2258) and two strains of Bifidobacterium animalis subsp. lactis (AD011 and A1dOxR) were grown in broth cultures or on plates, and a standard exopolysaccharide extraction method was used in an attempt to recover exocellular polysaccharides. When the extracted materials were analysed by NMR it was clear that mixtures of polysaccharides were being isolated including exopolysaccharides (EPS) cell wall polysaccharides and intracellular polysaccharides. Treatment of the cell biomass from the B. breve strains, or the B. animalis subsp. lactis AD011 strain, with aqueous sodium hydroxide provided a very similar mixture of polysaccharides but without the EPS. The different polysaccharides were partially fractionated by selective precipitation from an aqueous solution upon the addition of increasing percentages of ethanol. The polysaccharides extracted from B. breve JCM 7017 grown in HBM media supplemented with glucose (or isotopically labelled D-glucose-1-13C) were characterised using 1D and 2D-NMR spectroscopy. Addition of one volume of ethanol generated a medium molecular weight glycogen (Mw=1×105 Da, yield 200 mg/l). The addition of two volumes of ethanol precipitated an intimate mixture of a low molecular weight β-(1→6)-glucan and a low molecular weight β-(1→6)-galactofuranan which could not be separated (combined yield 46 mg/l). When labelled D-glucose-1-13C was used as a carbon supplement, the label was incorporated into >95% of the anomeric carbons of each polysaccharide confirming they were being synthesised in situ. Similar 1H NMR profiles were obtained for polysaccharides recovered from the cells of B. animalis subsp. lactis AD011and A1dOxR (in combination with an EPS), B. breve JCM 7017, B. breve JCM 7019, B. breve JCM 2258 and from an EPS (-ve) mutant of B. breve 7017 (a non-EPS producer).

scholarly journals Neuroprotective Metabolites from Vietnamese Marine Derived Fungi of Aspergillus and Penicillium Genera

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 608
Author(s):  
Elena V. Girich ◽  
Anton N. Yurchenko ◽  
Olga F. Smetanina ◽  
Phan Thi Hoai Trinh ◽  
Ngo Thi Duy Ngoc ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Secondary Metabolites ◽  
Cell Viability ◽  
Chemical Structure ◽  
Aspergillus Terreus ◽  
Marine Fungi ◽  
2D Nmr ◽  
Natural Source ◽  
Low Molecular Weight ◽  
First Time

Low molecular weight secondary metabolites of marine fungi Aspergillus flocculosus, Aspergillus terreus and Penicillium sp. from Van Phong and Nha Trang Bays (Vietnam) were studied and a number of polyketides, bis-indole quinones and terpenoids were isolated. The structures of the isolated compounds were determined by 1D and 2D NMR and HR-ESI-MS techniques. Stereochemistry of some compounds was established based on ECD data. A chemical structure of asterriquinone F (6) was thoroughly described for the first time. Anthraquinone (13) was firstly obtained from a natural source. Neuroprotective influences of the isolated compounds against 6-OHDA, paraquat and rotenone toxicity were investigated. 4-Hydroxyscytalone (1), 4-hydroxy-6-dehydroxyscytalone (2) and demethylcitreoviranol (3) have shown significant increasing of paraquat- and rotenone-treated Neuro-2a cell viability and anti-ROS activity.

Structural features of low-molecular-weight heparins affecting their affinity to antithrombin

2009 ◽  
Vol 102 (11) ◽  
pp. 865-873 ◽  
Author(s):  
Antonella Bisio ◽  
Davide Vecchietti ◽  
Laura Citterio ◽  
Marco Guerrini ◽  
Rahul Raman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nmr Spectra ◽  
Biological Activities ◽  
Anticoagulant Activity ◽  
2D Nmr ◽  
Structural Features ◽  
Size Exclusion ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
2D Nmr Spectra

SummaryAs part of a more extensive investigation on structural features of different low-molecular-weight heparins (LMWHs) that can affect their biological activities, Enoxaparin,Tinzaparin and Dalteparin were characterised with regards to the distribution of different chain length oligosaccharides as determined by size-exclusion (SE) chromatography, as well as their structure as defined by 2D-NMR spectra (HSQC). The three LMWHs were also fractionated into high affinity (HA) and no affinity (NA) pools with regards to their ability to bind antithrombin (AT).The HA fractions were further subfractionated and characterised. For the parent LMWHs and selected fractions,molecular weight parameters were measured using a SE chromatographic system with a triple detector (TDA) to obtain absolute molecular weights. The SE chromatograms clearly indicate that Enoxaparin is consistently richer in shorter oligosaccharides than Tinzaparin and Dalteparin. Besides providing the content of terminal groups and individual glucosamine and uronic acid residues with different sulfate substituents, the HSQC-NMR spectra permitted us to evaluate and correlate the content of the pentasaccharide, AT-binding sequence A-G-A*-I-A (AT-bs) through quantification of signals of the disaccharide sequence G-A*.Whereas the percent content of HA species is approximately the same for the three LMWHs, substantial differences were observed for the chain distribution of AT-bs as a function of length, with the AT-bs being preferentially contained in the longest chains of each LMWH. The above information will be useful in establishing structure-activity relationships currently under way. This study is therefore critical for establishing correlations between structural features of LMWHs and their AT-mediated anticoagulant activity.

scholarly journals Bioluminescence chemistry of fireworm Odontosyllis

2019 ◽  
Vol 116 (38) ◽  
pp. 18911-18916 ◽  
Author(s):  
Alexey A. Kotlobay ◽  
Maxim A. Dubinnyi ◽  
Konstantin V. Purtov ◽  
Elena B. Guglya ◽  
Natalja S. Rodionova ◽  
...  
Keyword(s):  
Light Emission ◽  
Structural Similarity ◽  
2D Nmr ◽  
Spectral Studies ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
2D Nmr Spectroscopy ◽  
Luciferase Enzyme ◽  
Sulfur Containing ◽  
Bright Blue

Marine polychaetes Odontosyllis undecimdonta, commonly known as fireworms, emit bright blue-green bioluminescence. Until the recent identification of the Odontosyllis luciferase enzyme, little progress had been made toward characterizing the key components of this bioluminescence system. Here we present the biomolecular mechanisms of enzymatic (leading to light emission) and nonenzymatic (dark) oxidation pathways of newly described O. undecimdonta luciferin. Spectral studies, including 1D and 2D NMR spectroscopy, mass spectrometry, and X-ray diffraction, of isolated substances allowed us to characterize the luciferin as an unusual tricyclic sulfur-containing heterocycle. Odontosyllis luciferin does not share structural similarity with any other known luciferins. The structures of the Odontosyllis bioluminescent system’s low molecular weight components have enabled us to propose chemical transformation pathways for the enzymatic and nonspecific oxidation of luciferin.

scholarly journals Structural Characterization and Heparanase Inhibitory Activity of Fucosylated Glycosaminoglycan from Holothuria floridana

Marine Drugs ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 162
Author(s):  
Xiang Shi ◽  
Ruowei Guan ◽  
Lutan Zhou ◽  
Zhichuang Zuo ◽  
Xuelin Tao ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Structural Characteristics ◽  
2D Nmr ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Molar Ratio ◽  
2D Nmr Spectroscopy ◽  
Inhibitory Activities ◽  
Terminal Structure ◽  
Holothuria Floridana

Unique fucosylated glycosaminoglycans (FG) have attracted increasing attention for various bioactivities. However, the precise structures of FGs usually vary in a species-specific manner. In this study, HfFG was isolated from Holothuria floridana and purified by anion exchange chromatography with the yield of ~0.9%. HfFG was composed of GlcA, GalNAc and Fuc, its molecular weight was 47.3 kDa, and the -OSO3−/-COO− molar ratio was 3.756. HfFG was depolymerized by a partial deacetylation–deaminative cleavage method to obtain the low-molecular-weight HfFG (dHfFG). Three oligosaccharide fragments (Fr-1, Fr-2, Fr-3) with different molecular weights were isolated from the dHfFG, and their structures were revealed by 1D and 2D NMR spectroscopy. HfFG should be composed of repeating trisaccharide units -{(L-FucS-α1,3-)d-GlcA-β1,3-d-GalNAc4S6S-β1,4-}-, in which sulfated fucose (FucS) includes Fuc2S4S, Fuc3S4S and Fuc4S residues linked to O-3 of GlcA in a ratio of 45:35:20. Furthermore, the heparanase inhibitory activities of native HfFG and oligosaccharide fragments (Fr-1, Fr-2, Fr-3) were evaluated. The native HfFG and its oligosaccharides exhibited heparanase inhibitory activities, and the activities increased with the increase of molecular weight. Additionally, structural characteristics such as sulfation patterns, the terminal structure of oligosaccharides and the presence of fucosyl branches may be important factors affecting heparanase inhibiting activity.

Structural characterization of the O-chain polysaccharide from Proteusmirabilis strain 7570

1995 ◽  
Vol 73 (10) ◽  
pp. 1600-1604 ◽  
Author(s):  
Dušan Uhrín ◽  
Vandana Chandan ◽  
Eleonora Altman
Keyword(s):  
Molecular Weight ◽  
Nmr Spectroscopy ◽  
Chemical Analysis ◽  
High Molecular Weight ◽  
Structural Characterization ◽  
Galacturonic Acid ◽  
2D Nmr ◽  
Chain Structure ◽  
2D Nmr Spectroscopy

The O-chain polysaccharide produced by Proteusmirabilis strain 7570 was shown by chemical analysis and 1D and 2D NMR spectroscopy to be a high molecular weight acidic linear polymer of tetrasaccharide repeating units, composed of D-galacturonic acid, 2-acetamido-2-deoxy-D-galactose, and 2-acetamido-2-deoxy-D-glucose (2:1:1). In addition, native O-chain was randomly substituted by O-acetyl groups. Keywords: Proteus, lipopolysaccharide, O-chain, structure, NMR.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
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