scholarly journals Structure of the 4-O-[1-Carboxyethyl]-d-Mannose-Containing O-Specific Polysaccharide of a Halophilic Bacterium Salinivibrio sp. EG9S8QL

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 508
Author(s):  
Elena N. Sigida ◽  
Ibrahim M. Ibrahim ◽  
Maxim S. Kokoulin ◽  
Hussein H. Abulreesh ◽  
Khaled Elbanna ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr Spectroscopy ◽  
Halophilic Bacterium ◽  
Mild Acid Hydrolysis ◽  
1H And 13C Nmr ◽  
Specific Polysaccharide ◽  
Lake Qarun ◽  
Phenol Water ◽  
Hydrolysis Of ◽  
Mild Acid

The moderately halophilic strain Salinivibrio sp. EG9S8QL was isolated among 11 halophilic strains from saline mud (Emisal Salt Company, Lake Qarun, Fayoum, Egypt). The lipopolysaccharide was extracted from dried cells of Salinivibrio sp. EG9S8QL by the phenol–water procedure. The OPS was obtained by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with 1H and 13C NMR spectroscopy, including 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, and HMBC experiments. The OPS was found to be composed of linear tetrasaccharide repeating units of the following structure: →2)-β-Manp4Lac-(1→3)-α-ManpNAc-(1→3)-β-Rhap-(1→4)-α-GlcpNAc-(1→, where Manp4Lac is 4-O-[1-carboxyethyl]mannose.

scholarly journals Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

2016 ◽  
Vol 12 ◽  
pp. 636-642 ◽  
Author(s):  
Elena N Sigida ◽  
Yuliya P Fedonenko ◽  
Alexander S Shashkov ◽  
Nikolay P Arbatsky ◽  
Evelina L Zdorovenko ◽  
...  
Keyword(s):  
Soil Bacteria ◽  
Side Chain ◽  
Glucose Residue ◽  
Mild Acid Hydrolysis ◽  
Methyl Group ◽  
Specific Polysaccharide ◽  
Phenol Water ◽  
Hydrolysis Of ◽  
Mild Acid ◽  
C Nmr

An O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide isolated by the phenol–water extraction from the halotolerant soil bacteria Azospirillum halopraeferens type strain Au4. The polysaccharide was studied by sugar and methylation analyses, selective cleavages by Smith degradation and solvolysis with trifluoroacetic acid, one- and two-dimensional 1H and 13C NMR spectroscopy. The following masked repeating structure of the O-specific polysaccharide was established: →3)-α-L-Rhap2Me-(1→3)-[β-D-Glcp-(1→4)]-α-D-Fucp-(1→2)-β-D-Xylp-(1→, where non-stoichiometric substituents, an O-methyl group (~45%) and a side-chain glucose residue (~65%), are shown in italics.

scholarly journals Structural and Serological Studies of the O6-Related Antigen of Aeromonas veronii bv. sobria Strain K557 Isolated from Cyprinus carpio on a Polish Fish Farm, which Contains L-perosamine (4-amino-4,6-dideoxy-L-mannose), a Unique Sugar Characteristic for Aeromonas Serogroup O6

Marine Drugs ◽  
2019 ◽  
Vol 17 (7) ◽  
pp. 399 ◽  
Author(s):  
Dworaczek ◽  
Drzewiecka ◽  
Pękala-Safińska ◽  
Turska-Szewczuk
Keyword(s):  
Mass Spectrometry ◽  
13C Nmr Spectroscopy ◽  
Fish Farm ◽  
Chemical Analyses ◽  
1H And 13C Nmr ◽  
O Antigen ◽  
Aeromonas Veronii ◽  
Serological Studies ◽  
Specific Polysaccharide ◽  
Mild Acid

Amongst Aeromonas spp. strains that are pathogenic to fish in Polish aquacultures, serogroup O6 was one of the five most commonly identified immunotypes especially among carp isolates. Here, we report immunochemical studies of the lipopolysaccharide (LPS) including the O-specific polysaccharide (O-antigen) of A. veronii bv. sobria strain K557, serogroup O6, isolated from a common carp during an outbreak of motile aeromonad septicemia (MAS) on a Polish fish farm. The O-polysaccharide was obtained by mild acid degradation of the LPS and studied by chemical analyses, mass spectrometry, and 1H and 13C NMR spectroscopy. It was revealed that the O-antigen was composed of two O-polysaccharides, both containing a unique sugar 4-amino-4,6-dideoxy-L-mannose (N-acetyl-L-perosamine, L-Rhap4NAc). The following structures of the O-polysaccharides (O-PS 1 and O-PS 2) were established:

scholarly journals (2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Molbank ◽  
10.3390/m1140 ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. M1140
Author(s):  
Jack Bennett ◽  
Paul Murphy
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
13C Nmr ◽  
Conjugate Addition ◽  
13C Nmr Spectroscopy ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Esi Mass Spectrometry ◽  
The One

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.

scholarly journals Structural Studies of the Lipopolysaccharide of Aeromonas veronii bv. sobria Strain K133 which Represents New Provisional Serogroup PGO1 Prevailing among Mesophilic Aeromonads on Polish Fish Farms

2021 ◽  
Vol 22 (8) ◽  
pp. 4272
Author(s):  
Katarzyna Dworaczek ◽  
Maria Kurzylewska ◽  
Magdalena Laban ◽  
Dominika Drzewiecka ◽  
Agnieszka Pękala-Safińska ◽  
...  
Keyword(s):  
Epidemiological Data ◽  
13C Nmr Spectroscopy ◽  
Freshwater Species ◽  
Fish Farms ◽  
1H And 13C Nmr ◽  
Aeromonas Veronii ◽  
Specific Polysaccharide ◽  
O Antigens ◽  
Unique Composition

In the present work, we performed immunochemical studies of LPS, especially the O-specific polysaccharide (O-PS) of Aeromonas veronii bv. sobria strain K133, which was isolated from the kidney of carp (Cyprinus carpio L.) during an outbreak of motile aeromonad infection/motile aeromonad septicemia (MAI/MAS) on a Polish fish farm. The structural characterization of the O-PS, which was obtained by mild acid degradation of the LPS, was performed with chemical methods, MALDI-TOF mass spectrometry, and 1H and 13C NMR spectroscopy. It was revealed that the O-PS has a unique composition of a linear tetrasaccharide repeating unit and contains a rarely occurring sugar 2,4-diamino-2,4,6-trideoxy-D-glucose (bacillosamine), which may determine the specificity of the serogroup. Western blotting and ELISA confirmed that A. veronii bv. sobria strain K133 belongs to the new serogroup PGO1, which is one of the most commonly represented immunotypes among carp and trout isolates of Aeromonas sp. in Polish aquacultures. Considering the increase in the MAI/MAS incidences and their impact on freshwater species, also with economic importance, and in the absence of an effective immunoprophylaxis, studies of the Aeromonas O-antigens are relevant in the light of epidemiological data and monitoring emergent pathogens representing unknown antigenic variants and serotypes.

scholarly journals Experimental and Computational Studies on N-alkylation Reaction of N-Benzoyl 5-(Aminomethyl)Tetrazole

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 704-713
Author(s):  
Younas Aouine ◽  
Aaziz Jmiai ◽  
Anouar Alami ◽  
Abdallah El Asri ◽  
Souad El Issami ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Computational Study ◽  
Benzyl Bromide ◽  
13C Nmr Spectroscopy ◽  
Alkylation Reaction ◽  
Computational Studies ◽  
Functional Theory ◽  
1H And 13C Nmr

The N-alkylation reaction of N-benzoyl 5-(aminomethyl)tetrazole (5-AMT) with benzyl bromide was carried out in the presence of K2CO3 as a base. Two separable regioisomers were obtained, thus their purification led to determine the proportion of each of them, and their structures were attributed essentially based on 1H and 13C NMR spectroscopy in addition to the elemental analysis and MS data. In order to confirm the results obtained at the synthesis level, a computational study was carried out by application of density functional theory (DFT) using the Becke three-parameter hybrid exchange functional and the Lee-Yang-Parr correlation functional (B3LYP).

scholarly journals NEW PHARMACOLOGICALLY ACTIVE COMPOUNDS BASED ON 5-HYDROXY-7-METHOXY-2-PHENYLCHROMAN-4-ONE

2021 ◽  
Vol 3 ◽  
pp. 119-127
Author(s):  
G.M. Baisarov ◽  
◽  
S.M. Adekenov ◽  
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Potassium Carbonate ◽  
13C Nmr Spectroscopy ◽  
1H And 13C Nmr ◽  
Pharmacologically Active ◽  
Pharmacologically Active Compounds ◽  
First Time

The reaction of 5-hydroxy-7-methoxy-2-phenylchroman-4-one with dibromoalkanes in acetone in the presence of potassium carbonate proceeds according to the Michael’s retro-reaction O-alkylation and leads to the formation of the corresponding 2-(bromo-alkoxy) chalcones. The structure of the synthesized compounds was confirmed by IR-, 1H- and 13C-NMR spectroscopy. The cytotoxic, hepatoprotective and anti-inflammatory effects of chalcone derivatives (2-3) were studied for the first time in vitro and in vivo.

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