κ-Carrageenan Interaction with Bovine and Caprine Caseins As Shown by Sedimentation and Nuclear Magnetic Resonance Spectroscopic Techniques

1998 ◽  
Vol 46 (12) ◽  
pp. 4987-4996 ◽  
Author(s):  
Adela Mora-Gutierrez ◽  
Thomas F. Kumosinski ◽  
Harold M. Farrell
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Techniques ◽  
Nuclear Magnetic

Uses of Nuclear Magnetic Resonance Spectroscopy Technique in Pharmaceutical Analysis: A Review

2017 ◽  
Vol 8 (02) ◽  
Author(s):  
Imad Hadi Zohra ◽  
Abeer Fauzi Al-Rubaye ◽  
Mohanad Jawad Kadhim
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Ratio Method ◽  
Resonance Spectroscopy ◽  
Spectroscopic Techniques ◽  
Nuclear Magnetic

Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a magnetic field absorb and re-emit electromagnetic radiation. Many scientific techniques exploit NMR phenomena to study molecular physics, crystals, and non-crystalline materials through nuclear magnetic resonance spectroscopy. NMR phenomena are also utilized in low-field NMR, NMR spectroscopy and MRI in the Earth's magnetic field (referred to as Earth's field NMR), and in several types of magnetometers. Modern NMR spectroscopy has been emphasizing the application in biomolecular systems and plays an important role in structural biology. NMR spectroscopy is very important to identify a drug or an excipient, evaluate the level of impurities (and to elucidate the structure), observe the course of a decomposition, to evaluate residual solvents, determine the isomeric composition, i.e. the ratio of diastereomers and the enantiomeric excess by means of chiral additive, assess a single drug or drug composition, characterize a polymer mostly being a mixture and used as excipients, identify counter ions (if of organic origin and having protons), characterize an entire formulation, e.g. a tablet. Fundamentals of quantitative NMR spectroscopy NMR spectroscopy can be considered as a primary ratio method of measurement being characterized by the fact that the ratio of substances can be determined directly from the physical context of the measurement without referencing to another substance. NMR has become one of the most powerful and versatile spectroscopic techniques for the analysis of biomacromolecules, allowing characterization of biomacromolecules and their complexes up to 100 kDa. Together with X-ray crystallography.

Nuclear Magnetic Resonance Detection of the Consequences of Transgene Expression

Physiology ◽  
1994 ◽  
Vol 9 (5) ◽  
pp. 197-202 ◽  
Author(s):  
AP Koretsky
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Transgene Expression ◽  
Spectroscopic Techniques ◽  
Resonance Imaging ◽  
Neuronal Function ◽  
Physiological Processes ◽  
Specific Manner ◽  
Resonance Detection ◽  
Nuclear Magnetic

Physiological processes can be altered in a very specific manner using transgenic mouse techniques. Physiological processes can be noninvasively monitored using nuclear magnetic resonance imaging and spectroscopic techniques. Three illustrations of the combination of these two rapidly developing techniques to study neuronal function, energy metabolism, and sickle cell anemia are discussed.

An Application of the Polarizable Continnum Model for Obtaining Chalcones Magnetic Properties

2020 ◽  
Vol 12 (7) ◽  
pp. 939-950
Author(s):  
Agnes Jalowitzki Silva ◽  
Thaís F. Giacomello ◽  
Gunar V. da S. Mota ◽  
Antônio M. de J. Chaves ◽  
Fabio L. P. Costa
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Population Distribution ◽  
Chemical Shifts ◽  
Biological Activities ◽  
Geometry Optimization ◽  
Analytical Techniques ◽  
Spectroscopic Techniques ◽  
Nuclear Magnetic

Chalcones exhibit a wide variety of beneficial biological activities. In addition, these compounds include the prevention of diseases related to oxidative stress. The structural characterization of these molecules by means of analytical techniques can become a difficult task due to the complexity of some structures. However, cases of erroneously established natural product structure review are still found in the literature despite recent advances in spectroscopic techniques. Therefore, it is necessary to develop quantum calculation protocols that can aid in the correct structural ascertainment of these compounds. Thus, in this work, we tried to develop a parameterized protocol for calculations of chemical shift of carbon-13 nuclear magnetic resonance, in order to ensure a correct structural determination of polyphenols, with a focus on chalcones. For this, a series of molecules belonging to this class, with complex and varied structural skeletons, reliably elucidated in the literature, was selected and subjected to stochastic conformational searches using the Monte Carlo method and the Merk molecular force filed. The lower energy conformations of each molecule were selected for the geometry optimization step, performed at the mPW1PW91/6-31G(d) level. The chemical shifts of carbon-13 were calculated at the same level of theory, taking into account the population distribution of Boltzmann. The calculations were affected in both liquid phases, using the Polarizable Continuous Model as an implicit solvation model. The results show that the level of theory applied in the liquid phase allows a good reproduction of the experimental data. The application of the scaling factor allows the cancellation of systematic errors, which means that the values of scaled chemical shift are closer to the experimental ones. Thus, the parameterized protocol proved to be an important tool for the structural elucidation of polyphenols by calculations of carbon-13 nuclear magnetic resonance chemical shifts.

Aqueous Phase Behavior of Tetraethylene Glycol Decanoyl Ester (C9COE4) and Ether (C10E4) Investigated by Nuclear Magnetic Resonance Spectroscopic Techniques

Langmuir ◽  
2007 ◽  
Vol 23 (23) ◽  
pp. 11443-11450 ◽  
Author(s):  
Anne-Gaëlle Fournial ◽  
Ying Zhu ◽  
Valérie Molinier ◽  
Gaston Vermeersch ◽  
Jean-Marie Aubry ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Phase Behavior ◽  
Aqueous Phase ◽  
Tetraethylene Glycol ◽  
Spectroscopic Techniques ◽  
Nuclear Magnetic

Simultaneous In Situ Monitoring of Trimethoxysilane Hydrolysis Reactions Using Raman, Infrared, and Nuclear Magnetic Resonance (NMR) Spectroscopy Aided by Chemometrics and Ab Initio Calculations

2018 ◽  
Vol 72 (9) ◽  
pp. 1404-1415
Author(s):  
Xiaoyun Chen ◽  
Donald Eldred ◽  
Jing Liu ◽  
Hsu Chiang ◽  
Xianghuai Wang ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Reaction Rates ◽  
In Situ Monitoring ◽  
Spectroscopic Techniques ◽  
Wide Range ◽  
Nuclear Magnetic ◽  
Hydrolysis Reactions

Sol-gels are found in many different scientific fields and have very broad applications. They are often prepared by the hydrolysis and condensation of alkoxysilanes such as trimethoxysilanes, which are commonly used as precursors in the preparation of silsequioxanes via the sol-gel process. The reaction rates of such reactions are influenced by a wide range of experimental factors such as temperature, pH, catalyst, etc. In this study, we combined multiple in situ spectroscopic techniques to monitor the hydrolysis and partial condensation reactions of methyltrimethoxysilane and phenyltrimethoxysilane. A rich set of kinetics information on intermediate species of the hydrolysis reactions were obtained and used for kinetics modeling. Raman and nuclear magnetic resonance (NMR) spectroscopy provided the most information about hydrolysis and NMR provided the most information about condensation. A quantitative method based on Raman spectra to quantify the various transient intermediate hydrolysis products was developed using NMR as the primary method, which can be deployed in the field where it is impractical to carry out NMR measurements.

scholarly journals Spectroelectrochemistry, the future of visualizing electrode processes by hyphenating electrochemistry with spectroscopic techniques

The Analyst ◽  
2020 ◽  
Vol 145 (7) ◽  
pp. 2482-2509 ◽  
Author(s):  
Jasper J. A. Lozeman ◽  
Pascal Führer ◽  
Wouter Olthuis ◽  
Mathieu Odijk
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Spectroscopic Techniques ◽  
Electrode Processes ◽  
The Future ◽  
Nuclear Magnetic

Reviewing the future of electrochemistry combined with infrared, Raman, and nuclear magnetic resonance spectroscopy as well as mass spectrometry.

Magnetic resonance studies of enzymesubstrate complexes with paramagnetic probes as illustrated by creatine kinase

1970 ◽  
Vol 3 (1) ◽  
pp. 61-89 ◽  
Author(s):  
Mildred Cohn
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Active Site ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Enzyme Substrate ◽  
Yield Information ◽  
Nuclear Magnetic

Only two spectroscopic methods are capable of detecting individual atoms in macromolecular systems, X-ray diffraction in the crystalline state and nuclear magnetic resonance (NMR) in the liquid state. For an enzyme-substrate complex, X-ray diffraction can yield information on the geometric structure at the active site and nuclear magnetic resonance absorption can, in principle, yield information on the electronic structure at the active site and on the conformation of enzyme-substrate complexes. Both types of information are needed for unraveling the mechanism of enzyme catalysis on the molecular level. The exciting successes of X-ray diffraction in delineating active sites are already established; NMR, a comparative latecomer among spectroscopic techniques is just beginning to demonstrate its potentialities. McDonald & Phillips have summarized in their excellent review (1969) the work on direct observation of hydrogen atoms (protons) by NMR spectroscopy which has advanced our knowledge of protein structure. The extensive studies of Jardetzky and his co-workers on the NMR of ribonuclease and its inhibitor complexes has culminated in a suggested mechanism of catalytic action (Roberts et al. 1969).

Applications of Computerized Nuclear Magnetic Resonance and Infrared Spectroscopic Techniques to Rubber Analyses

1982 ◽  
Vol 55 (3) ◽  
pp. 913-930 ◽  
Author(s):  
Robert C. Hirst
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Small Computer ◽  
Spectroscopic Techniques ◽  
Special Effect ◽  
Ir Instrumentation ◽  
Nuclear Magnetic

Abstract Fourier transform spectroscopy is without doubt one of the most important developments in spectroscopy in the last few years. Although the basic principle had been known for many years, its applications in spectroscopy became practical only because of advances in small computer technology. In the case of nuclear magnetic resonance and infrared spectroscopy, the digital computer has had a special effect, in that it has caused, or at least made possible, the total redesign of NMR and IR instrumentation based on the Fourier transform (FT) concept. Because of its advantages over conventional methods, the FT method has caused great changes in NMR and IR spectroscopy, and FT instruments have made possible the solutions to many problems which previously were technically too difficult. NMR spectroscopy was reviewed in this Journal in 1976 and infrared spectroscopy was reviewed in 1972. Developments since those reviews will be emphasized here. In a short, selective review of this type, it is necessary to omit references to many excellent contributions in the literature. For very comprehensive listings of literature references, the reader may wish to consult the biennial reviews in “Analytical Chemistry” on NMR spectroscopy, infrared spectroscopy, rubber, analysis of high polymers, and coatings.

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