In vivo nuclear overhauser effect in31P- {1H} double-resonance experiments in a 1.5-T whole-body MR system

1990 ◽  
Vol 15 (1) ◽  
pp. 165-172 ◽  
Author(s):  
P. Bachert-Baumann ◽  
F. Ermark ◽  
H.-J. Zabel ◽  
R. Sauter ◽  
W. Semmler ◽  
...  
Keyword(s):  
Nuclear Overhauser Effect ◽  
Double Resonance ◽  
Whole Body ◽  
Overhauser Effect ◽  
Nuclear Overhauser

Nuclear electron double resonance and scalar interactions in solutions

1966 ◽  
Vol 291 (1427) ◽  
pp. 487-499 ◽  
Keyword(s):  
Magnetic Fields ◽  
Diffusion Coefficients ◽  
Nuclear Overhauser Effect ◽  
Double Resonance ◽  
Nuclear Resonance ◽  
Phenoxy Radical ◽  
Scalar Interaction ◽  
Overhauser Effect ◽  
Nuclear Overhauser ◽  
And Diffusion

The electron-nuclear Overhauser effect at two magnetic fields has been investigated for solutions of 2, 4, 6-tri- tert . -butyl phenoxy radical in several protonated and fluorinated organic solvents. In some cases the enhancement of the nuclear resonance is positive in sign, and the results have been interpreted in terms of the theory of Hubbard (1966) in which both dipolar and scalar interactions between the electrons and nuclei are considered. Hubbard assumes two models for the scalar interaction which he calls the sticking and diffusion models. The experimental results may be best explained in terms of the diffusion model. The theory permits calculation of the diffusional correlation times, distances of closest approach of the nuclei to the electrons, and relative diffusion coefficients of the solvent and radical molecules. Reasonable values are obtained for the systems investigated.

1H NMR studies of [N-MeAib1, Tyr(Me)4]ANGII and [N-MeAib1, Tyr(Me)4, Ile8]ANGII in dimethylsulfoxide by nuclear Overhauser effect (NOE) enhancement spectroscopy: cis-trans Isomerism of the His-Pro bond

1990 ◽  
Vol 55 (4) ◽  
pp. 1106-1111 ◽  
Author(s):  
John Matsoukas ◽  
Paul Cordopatis ◽  
Raghav Yamdagni ◽  
Graham J. Moore
Keyword(s):  
1H Nmr ◽  
Nuclear Overhauser Effect ◽  
Nmr Studies ◽  
Restricted Rotation ◽  
Overhauser Effect ◽  
Major Isomer ◽  
Conformational Properties ◽  
Nuclear Overhauser

The conformational properties of the Sarmesin analogues [N-MeAib1, Tyr(Me)4]ANGII and [N-MeAib1, Tyr(Me)4, Ile8]ANGII in hexadeutero-dimethysulfoxide were investigated by Nuclear Overhauser Effect (NOE) Enhancement Studies. Cis-trans isomers (ratio 1 : 6) due to restricted rotation of the His-Pro bond were observed. Interresidue interactions between the His Cα proton and the two Pro Cδ protons revealed that the major isomer was the trans.

scholarly journals Cylindromicin from Arctic-Derived Fungus Tolypocladium sp. SCSIO 40433

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1080
Author(s):  
Imran Khan ◽  
Jing Peng ◽  
Zhuangjie Fang ◽  
Wei Liu ◽  
Wenjun Zhang ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Nuclear Overhauser Effect ◽  
Inhibition Activity ◽  
Tyrosinase Inhibition ◽  
Bioactive Natural Products ◽  
Chemical Structures ◽  
Overhauser Effect ◽  
Spectroscopic Analyses ◽  
Potential Resource ◽  
Nuclear Overhauser

The fungus strain SCSIO 40433 was isolated from an Arctic-derived glacier sediment sample and characterized as Tolypocladium cylindrosporum. A new compound, cylindromicin (1), and seven known secondary metabolites (2–8) were isolated from this strain. The chemical structures of these compounds were elucidated by comprehensive spectroscopic analyses. Cylindromicin (1) featured a 3,4-dihydro-2H-pyran skeleton. The absolute configuration of compound 1 was assigned via interpretation of key Nuclear Overhauser Effect Spectroscopy (NOESY) correlations and Electronic Circular Dichroism (ECD) calculation. Cylindromicin (1) exhibited significant tyrosinase inhibition activity. This study highlights Polar fungi as a potential resource for new bioactive natural products.

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