A Nuclear Magnetic Resonance Study
نویسنده
چکیده
Complexes of histidine with Co( 11) in aqueous solution have been examined by proton magnetic resonance spectroscopy. Coordinate interaction of histidine with paramagnetic Co( 11) produces large contact interaction shifts in the histidine proton resonance spectra. Four histidine-Co( 11) complexes have been distinguished : a weak 1: 1 histidine-Co(I1) complex a t low pH ( < 4 ) in which only the histidine carboxyl group is bonded to octahedral Co(I1); strong 1: 1 and 2: 1 histidine-Co( I1 j complexes a t intermediate pH values (4-10) in which histidine behaves as a tridentate ligand; and a tetrahedral 2 : 1 histidine-Co(I1) complex a t high pH (>11) in which histidine is bonded to cobalt via the NH? group and an imidazole nitrogen atom. I t was found that AF" for the 2: 1 octahedral histidine-Co(I1) complex composed of one D-histidine and one L-histidine is about 0.7 kcal./mole less than for the complex containing two histidine ligands of the same configuration ( D D or LL). Proton magnetic resonance spectra of complexes of several histidine derivatives with Co( 11) confirm the structures assigned to the various histidine-Co( 11) complexes.
منابع مشابه
NUCLEAR MAGNETIC RESONANCE STUDY OF THE STRUCTURE OF GLYOXALDIHYDRAZONE
Study of the nuclear magnetic resonance spectra of glyoxaldihydrazone in dimethylsulfoxide and deuterochlorofonn leads to the conclusion that this compound exists predominantly in non-chelate structure
متن کاملComputational study of energetic, stability, and nuclear magnetic resonance of BN nanotube as a nanosensor
Now a day study on boron nitrid nanotubes are in considerable attetion due to their unique properties in different field of science. In this letter, after final optimization, thermodynamic properties analysis, stabilities, electronic structure and nuclear magnetic resonance parameters including σ isotropic and σ anisotropic tensors and asymmetric parameters of 15N and 11B nuclei are calculated....
متن کاملDesigning and Fabrication of a New Radiofrequency Planar microcoil for mini-Nuclear Magnetic Resonance
Introduction Radiofrequency planar microcoils are used to increase the resolution of magnetic resonance images of small samples. In this study, we aimed to design and fabricate a spiral planar microcoil constructed on a double-sided printed circuit board (PCB). It has four rings with an internal diameter of 241 microns tuned and matched at 63.8 MHz. Materials and Methods To achieve the maximum ...
متن کاملComputational Investigation on Naphthoquinone Derivatives :Nuclear Magnetic Resonance (NMR) and Quantum mechanic
Naphthoquinones are natural aromatic compounds that can be discovered in various plant families. In recent times a diversity of biological activities of these compounds has been reported. In most cases, these pharmacological activities are related to redox and acid-base properties, which can be modulated synthetically by modifying the substituents attached to the 1, 4- naphthoquinone ring, in o...
متن کاملInvestigation of nuclear magnetic resonance (NMR) and Binding Energies Clonidine Drug-Carbon Nano Tube: A Theoretical Study
In this work, we have studied binding of Clonidine drug (C9H9Cl2N3) with zigzag single walled carbonnanotubes (SWCNT) (5, 0) by theoretical methods of theory using Gaussian 09 software package.Binding energies, NMR parameters and HOMO- LUMO Gap energy were calculated. Results frombinding energies indicate that it is possible thermodynamically to bind Clonidine drug to SWCNT.The calculated NMR p...
متن کاملAnalysis of Cerebrospinal Fluid in Diagnosis of Bacterial Meningitis; Using Nuclear Magnetic Resonance Spectroscopy: A Systematic Review
Background: Analysis of biofluids provides a unique window into the biochemical status of a living organism since the composition of a given biofluid will be modulated according to the level of function of the cells that are intimately concerned with its manufacture and secretion. One of the most successful approaches to biofluid analysis has been the application of NMR spectroscopy. Objective...
متن کامل