Binding of an Acetic Acid Ligand to Adenosine:  A Low-Temperature NMR Study

2004 ◽  
Vol 126 (7) ◽  
pp. 2135-2141 ◽  
Author(s):  
Eline M. Basílio Janke ◽  
Hans-Heinrich Limbach ◽  
Klaus Weisz
Keyword(s):  
Acetic Acid ◽  
Low Temperature ◽  
Acid Ligand ◽  
Nmr Study

scholarly journals FODMAP Fingerprinting of Bakery Products and Sourdoughs: Quantitative Assessment and Content Reduction through Fermentation

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 894
Author(s):  
Johannes Pitsch ◽  
Georg Sandner ◽  
Jakob Huemer ◽  
Maximilian Huemer ◽  
Stefan Huemer ◽  
...  
Keyword(s):  
Irritable Bowel Syndrome ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Low Temperature ◽  
Quantitative Assessment ◽  
Bakery Products ◽  
Fermentation Products ◽  
Fermentation Temperature ◽  
Digestive Disorders ◽  
Irritable Bowel

Fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) are associated with digestive disorders and with diseases such as irritable bowel syndrome. In this study, we determined the FODMAP contents of bread, bakery products, and flour and assessed the effectiveness of sourdough fermentation for FODMAP reduction. The fermentation products were analyzed to determine the DP 2–7 and DP >7 fructooligosaccharide (FOS) content of rye and wheat sourdoughs. FOSs were reduced by Acetobacter cerevisiae, Acetobacter okinawensis, Fructilactobacillus sanfranciscensis, and Leuconostoc citreum to levels below those in rye (−81%; −97%) and wheat (−90%; −76%) flours. The fermentation temperature influenced the sourdough acetic acid to lactic acid ratios (4:1 at 4 °C; 1:1 at 10 °C). The rye sourdough contained high levels of beneficial arabinose (28.92 g/kg) and mannitol (20.82 g/kg). Our study contributes in-depth knowledge of low-temperature sourdough fermentation in terms of effective FODMAP reduction and concurrent production of desirable fermentation byproducts.

scholarly journals Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Resonant Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Acetic Acid Esters ◽  
Acid Esters ◽  
Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

scholarly journals 51V-NMR study of low-temperature phase in δ-Ag2/3V2O5

2015 ◽  
Vol 592 ◽  
pp. 012042 ◽  
Author(s):  
Y Kawasaki ◽  
R Morioka ◽  
Y Kishimoto ◽  
K Nakamura ◽  
K Nishiyama ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Phase ◽  
51V Nmr ◽  
Nmr Study ◽  
Low Temperature Phase

Conformational sampling of bioactive conformers: a low-temperature NMR study of15N-Leu–enkephalin

1998 ◽  
Vol 4 (4) ◽  
pp. 253-265 ◽  
Author(s):  
Pietro Amodeo ◽  
Fred Naider ◽  
Delia Picone ◽  
Teodorico Tancredi ◽  
Piero A. Temussi
Keyword(s):  
Low Temperature ◽  
Conformational Sampling ◽  
Nmr Study

Low‐Temperature Fast Production of Carbon and Acetic Acid Dual‐Promoted Pd/C Catalysts

2019 ◽  
Vol 25 (60) ◽  
pp. 13683-13687
Author(s):  
Xiuchao Yao ◽  
Lin Ni ◽  
Chang Yu ◽  
Mengdi Zhang ◽  
Qianbing Wei ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Low Temperature

Dynamisches Verhalten dimerer 1,3,2,4λ2-Diazasilastannetidine und -plumbetidine in Lösung — eine Multikern-NMR-Studie/Dynamic Behaviour of Dimeric 1,2,3,4λ2-Diazasilastannetidines and -plumbetidines in Solution — a Multinuclear NMR Study

1989 ◽  
Vol 44 (3) ◽  
pp. 288-292 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Klaus Horchler ◽  
Hong Zhou ◽  
Michael Veith
Keyword(s):  
Low Temperature ◽  
Dynamic Process ◽  
Room Temperature ◽  
Dynamic Behaviour ◽  
The Other ◽  
Multinuclear Nmr ◽  
Nmr Data ◽  
Nmr Study ◽  
Intramolecular Process

1,3-Diisopropyl-2,2-dimethyl-1,3,2,4λ2-diazasilastannetidine (1b) and -plumbetidine (2b) are dimeric [(1b)2, (2b)2] in solution. At room temperature the structure of (1b)2 is fluxional. The dynamic behaviour is interpreted - on the basis of 1H. 13C, 29Si and 119Sn NMR data - as an intramolecular process in which the four-membered rings keep their identity. Such a process involves either concerted opening of the two coordinative Sn - N bonds and mutual slippage of the two rings, or consecutive cleavage of one of the coordinative Sn - N bonds and rotation about the other one. At room temperature the dimer (2b)2 is in equilibrium with its monomer 2b, whereas at low temperature the dynamic process corresponds to that established for (1b)2. In solutions which contain a mixture of the dimers (1b)2 and (2b)2, the presence of the mixed dimer 1b/2b can be proved unambiguously by consistent 29Si, 119Sn and 207Pb NMR data.

Mécanisme de la réaction de glycosylation par réversion acide en présence d'anhydride trifluorométhane sulfonique comme agent de condensation

1981 ◽  
Vol 59 (2) ◽  
pp. 482-489 ◽  
Author(s):  
André A. Pavia ◽  
Sak N. Ung-Chhun
Keyword(s):  
Low Temperature ◽  
Necessary Conditions ◽  
Free Acid ◽  
Trifluoromethanesulfonic Acid ◽  
Nmr Study ◽  
Trifluoromethanesulfonic Anhydride ◽  
Glycosylation Reaction ◽  
Comme Agent ◽  
Mechanism Of The Reaction

The acid-catalysed mechanism of the reaction using trifluoromethanesulfonic anhydride to synthesize symmetrical 1,1′-glycosyl-glycosides such as trehalose and galacto, manno, arabino, xylo etc. analogues has been elucidated. The authors were able to prove by 19F nmr study at low temperature that the efficiency of the system is due to the peculiar property of trifluoromethanesulfonic acid generated in situ to form a stable, insoluble hydroxonium trifluoromethanesulfonate CF3SO3− H3O+. The procedure satisfies the two necessary conditions for a glycosylation reaction being workable: (i) the presence in catalytic amounts of free acid which is regenerated during the condensation step; (ii) a very efficient trapping of the water liberated during the protonation step which displaces the equilibrium towards the formation of the glycoside. The α-stereoselectivity of the reaction is discussed in terms of anomerisation of the β-anomers on to the thermodynamically more stable α ones, through a cyclic oxonium intermediate.

NMR study of the synthesis of17O-enriched acetic acid by hydrolysis of acetic anhydride with17O-enriched water

2003 ◽  
Vol 41 (11) ◽  
pp. 959-961 ◽  
Author(s):  
Heidi M. Hultman ◽  
Kristina Djanashvili ◽  
Joop A. Peters
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Nmr Study ◽  
Hydrolysis Of
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