scholarly journals Morpholine Degradation Pathway of Mycobacterium aurumMO1: Direct Evidence of Intermediates by In Situ 1H Nuclear Magnetic Resonance

1998 ◽  
Vol 64 (1) ◽  
pp. 153-158 ◽  
Author(s):  
B. Combourieu ◽  
P. Besse ◽  
M. Sancelme ◽  
H. Veschambre ◽  
A. M. Delort ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Direct Detection ◽  
Quantitative Information ◽  
Degradation Pathway ◽  
H Nmr ◽  
Mycobacterium Aurum ◽  
Kinetics Of ◽  
Nuclear Magnetic

ABSTRACT Resting Mycobacterium aurum MO1 cells were incubated with morpholine, a waste from the chemical industry. The kinetics of biodegradation was monitored by using in situ nuclear magnetic resonance (NMR). The incubation medium was directly analyzed by1H NMR. This technique allowed the unambiguous identification of two intermediates of the metabolic pathway involved in the biodegradation process, glycolate and 2-(2-aminoethoxy)acetate. The latter compound, which was not commercially available, was synthesized, in three steps, from 2-(2-aminoethoxy)ethanol. Quantitative analysis of the kinetics of degradation of morpholine was performed by integrating the signals of the different metabolites in1H-NMR spectra. Morpholine was degraded within 10 h. The intermediates increased during the first 10 h and finally disappeared after 20 h incubation. Assays of degradation were also carried out with glycolate and ethanolamine, hypothetical intermediates of the morpholine degradation pathway. They were degraded within 4 and 8 h, respectively. Until now, no tool for direct detection of intermediates or even morpholine has been available, consequently, only hypothetical pathways have been proposed. The approach described here gives both qualitative and quantitative information about the metabolic routes used in morpholine degradation by M. aurum MO1. It could be used to investigate many biodegradative processes.

In situ enzymatic removal of orthophosphate by the nucleoside phosphorylase catalyzed phosphorolysis of nicotinamide riboside

1982 ◽  
Vol 60 (9) ◽  
pp. 917-921 ◽  
Author(s):  
John W. Shriver ◽  
Brian D. Sykes
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nucleoside Phosphorylase ◽  
Nicotinamide Riboside ◽  
Time Required ◽  
Removal System ◽  
Nuclear Magnetic

An enzymatic orthophosphate removal system is described which can be effectively used to continuously remove orthophosphate from biochemical samples. The phosphorolysis of nicotinamide riboside is catalyzed by calf spleen nucleoside phosphorylase to give ribose-1-PO4 and nicotinamide along with a proton. At pH 8 the production of ribose-1-PO4 from orthophosphate is essentially quantitative. This reaction can be monitored optically or by 31P nuclear magnetic resonance (NMR). Equations are given for determining the time required to remove a given amount of phosphate from a typical NMR sample with a known amount of nucleoside phosphorylase. The effects of a competing orthophosphate-producing reaction are considered.

Anesthetic-membrane interaction: A 2H nuclear magnetic resonance study of the binding of specifically deuterated tetracaine and procaine to phosphatidylcholine

1984 ◽  
Vol 62 (2-3) ◽  
pp. 178-184 ◽  
Author(s):  
Eric C. Kelusky ◽  
Ian C. P. Smith
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Local Anesthetics ◽  
Nuclear Magnetic Resonance Study ◽  
Weakly Bound ◽  
Slow Exchange ◽  
H Nmr ◽  
Line Shapes ◽  
Acyl Chains ◽  
Nuclear Magnetic

The binding of the local anesthetics tetracaine and procaine with multilamellar dispersions of egg phosphatidylcholine has been studied by 2H nuclear magnetic resonance (NMR). The 2H-NMR line shapes of specifically deuterated local anesthetics are found to be very dependent on the attainment of a true equilibrium. The equilibrium could be most properly reached by the use of repeated freeze–thaw–vortex cycles. The data for tetracaine are consistent with the three-site exchange model proposed earlier. Tetracaine is in slow exchange between a strongly bound site and a weakly bound site and in fast exchange between the weakly bound site and free in solution. The slow exchange rate is estimated, from temperature and dilution studies, to be approximately 1.5 × 103 s−1 at pH 5.5 and slightly faster at pH 9.5. Comparisons of the quadrupole splittings with those seen for our earlier work in egg phosphatidylethanolamine suggest that the location of the strongly bound site in phosphatidylcholine is dependent on the anesthetic charge. This is in contrast to egg phosphatidylethanolamine, where molecular shapes appear to be the determining factor for the location of the anesthetic. Procaine bound very weakly to the model membranes, to yield only a broad resonance and no quadrupole splitting. It appears that procaine, unlike tetracaine, is not bound by the ordered acyl chains.

scholarly journals Nuclear Magnetic Resonance Spectroscopy for In Situ Monitoring of Porous Materials Formation under Hydrothermal Conditions

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1416 ◽  
Author(s):  
Mohamed Haouas
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Porous Materials ◽  
Local Environment ◽  
In Situ Monitoring ◽  
Resonance Spectroscopy ◽  
Hydrothermal Conditions ◽  
Technological Advances ◽  
Nuclear Magnetic

The employment of nuclear magnetic resonance (NMR) spectroscopy for studying crystalline porous materials formation is reviewed in the context of the development of in situ methodologies for the observation of the real synthesis medium, with the aim of unraveling the nucleation and growth processes mechanism. Both liquid and solid state NMR techniques are considered to probe the local environment at molecular level of the precursor species either soluble in the liquid phase or present in the reactive gel. Because the mass transport between the liquid and solid components of the heterogeneous system plays a key role in the synthesis course, the two methods provide unique insights and are complementary. Recent technological advances for hydrothermal conditions NMR are detailed and their applications to zeolite and related materials crystallization are illustrated. Achievements in the field are exemplified with some representative studies of relevance to zeolites, aluminophosphate zeotypes, and metal-organic frameworks.

scholarly journals Structural Characterization of Amadori Rearrangement Product of Glucosylated Nα-Acetyl-Lysine by Nuclear Magnetic Resonance Spectroscopy

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Chuanjiang Li ◽  
Hui Wang ◽  
Manuel Juárez ◽  
Eric Dongliang Ruan
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Maillard Reaction ◽  
Structural Characterization ◽  
Resonance Spectroscopy ◽  
H Nmr ◽  
Amadori Rearrangement ◽  
C Nmr ◽  
Nuclear Magnetic

Maillard reaction is a nonenzymatic reaction between reducing sugars and free amino acid moieties, which is known as one of the most important modifications in food science. It is essential to characterize the structure of Amadori rearrangement products (ARPs) formed in the early stage of Maillard reaction. In the present study, the Nα-acetyl-lysine-glucose model had been successfully set up to produce ARP, Nα-acetyl-lysine-glucose. After HPLC purification, ARP had been identified by ESI-MS with intense [M+H]+ ion at 351 m/z and the purity of ARP was confirmed to be over 90% by the relative intensity of [M+H]+ ion. Further structural characterization of the ARP was accomplished by using nuclear magnetic resonance (NMR) spectroscopy, including 1D 1H NMR and 13C NMR, the distortionless enhancement by polarization transfer (DEPT-135) and 2D 1H-1H and 13C-1H correlation spectroscopy (COSY) and 2D nuclear overhauser enhancement spectroscopy (NOESY). The complexity of 1D 1H NMR and 13C NMR was observed due to the presence of isomers in glucose moiety of ARP. However, DEPT-135 and 2D NMR techniques provided more structural information to assign the 1H and 13C resonances of ARP. 2D NOESY had successfully confirmed the glycosylated site between 10-N in Nα-acetyl-lysine and 7′-C in glucose.

Sign in / Sign up

Export Citation Format

Share Document