Nuclear magnetic resonance spectroscopy. Spin-lattice relaxation of the acetic acid carboxyl carbon

1976 ◽  
Vol 98 (10) ◽  
pp. 2723-2726 ◽  
Author(s):  
Devens Gust ◽  
Harry Pearson ◽  
Ian M. Armitage ◽  
John D. Roberts
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Acetic Acid ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Resonance Spectroscopy ◽  
Spin Lattice ◽  
Carboxyl Carbon

Synthesis, reactions, and nuclear magnetic resonance spectroscopy of 4-methyl-6H-pyrazolo(3,4-b)azepin-7-ones

1979 ◽  
Vol 57 (23) ◽  
pp. 3034-3040 ◽  
Author(s):  
Suresh Chandra Sharma ◽  
Brian Maurice Lynch
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Acetic Acid ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Analgesic Effects ◽  
Ethyl Levulinate ◽  
Synthesis Reactions ◽  
Nuclear Magnetic

Reactions of various 5-aminopyrazoles with ethyl levulinate in acetic acid have been shown to furnish moderate to good yields of the correspondingly substituted 4-methyl-6H-pyrazolo-(3,4-b)azepin-7-ones, accompanied by the acetamidopyrazoles. The courses of methylation and of bromination reactions of some of the pyrazoloazepinones have been explored and defined, and conversion of one pyrazoloazepinone into 7-chloropyrazoloazepine and thence by nucleophilic displacements into 7-(substituted amino)pyrazoloazepines has been effected. Structural assignments, tautomeric preferences, and through-space interactions between substituents were established through nuclear magnetic resonance spectroscopy (1H and 13C). Some members of the pyrazoloazepinone series exhibit significant anti-inflammatory and analgesic effects in mice.

Na(+)-K(+)-ATPase in endothelial cell energetics: 23Na nuclear magnetic resonance and calorimetry study

1995 ◽  
Vol 268 (1) ◽  
pp. H351-H358 ◽  
Author(s):  
M. L. Gruwel ◽  
C. Alves ◽  
J. Schrader
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Vascular Endothelial Cells ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Shift Reagent ◽  
Spin Lattice Relaxation ◽  
Resonance Spectroscopy ◽  
Spin Lattice ◽  
Nuclear Magnetic

Sodium flux rate and energy consumption of the Na(+)-K+ pump in vascular endothelial cells of porcine aorta grown on micro-carrier beads were studied using a combination of nuclear magnetic resonance spectroscopy of intracellular 23Na and microcalorimetry. The Na+ flux into the cells was determined in the presence of the shift reagent Dy(P3O10)2(7-), while the Na(+)-K+ pump was inhibited with ouabain. Basal Na+ influx was 17 +/- 3 nmol.min-1.mg protein-1, and intracellular Na+ concentration was 23.5 +/- 3.8 mM, resulting in a complete exchange of intracellular Na+ within 5–6 min. Spin-lattice relaxation time (T1) measurements of intracellular Na+ showed a T1 of 19 +/- 1 ms under basal conditions and a T1 of 26.2 +/- 1.6 ms after pump inhibition with 50 microM ouabain. Such an increase is typical for a system in which the total amount of Na+ increases but where the amount of bound Na+ remains constant. The Na+ ionophore nystatin maximally increased the Na(+)-K+ pump rate about twofold, whereas the amount of intracellular Na+ only increased 14%. With microcalorimetry a cellular heat flux of 183 +/- 18 microW per mg endothelial protein was determined, which relates to 7.6 microW/mg endothelial protein generated by the Na(+)-K(+)-adenosinetriphosphatase. Our data demonstrate that small intracellular changes of Na+ can stimulate the endothelial Na(+)-K+ pump activity. The contribution of the Na(+)-K+ pump to total endothelial energy expenditure is approximately 4-5%.

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