scholarly journals Morphological and Metabolic Changes in the Cortex of Mice Lacking the Functional Presynaptic Active Zone Protein Bassoon: A Combined 1H-NMR Spectroscopy and Histochemical Study

2007 ◽  
Vol 18 (4) ◽  
pp. 890-897 ◽  
Author(s):  
F. Angenstein ◽  
L. Hilfert ◽  
W. Zuschratter ◽  
W. D. Altrock ◽  
H. G. Niessen ◽  
...  
2018 ◽  
Vol 22 (2) ◽  
pp. 235-239
Author(s):  
O. B. Shevelev ◽  
M. P. Moshkin

Deviations in brain metabolism are the result of longterm pathological processes, which finally are manifested as symptoms of Parkinson’s or Alzheimer’s diseases or multiple sclerosis and other neuropathologies, as for example diabetic neuropathy. A deficiency of available energy for brain cells under neurodegenerative diseases is either developed due to age-dependent underexpression of genes that encode glycolytic enzymes or induced due to the uncoupling of oxidation and phosphorylation that could be mediated by inflammatory cytokines. Since the activity of many enzymes is under the control of adenosine triphosphate (ATP) or cofactors, such as nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH), energy deficiency can cause metabolic changes in brain tissue. Some clinical studies using proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy) revealed metabolic changes in brain tissue in patients with neurodegenerative diseases. However, data from different authors are quite contradictory, probably because of the complex genesis of metabolic disorders. In the present study, we tested the hypothesis of multidirectional changes in metabolism under the impact of the oxidation and phosphorylation uncoupler 2,4-dinitrophenol (2,4-DNP) and under the impact of 2-deoxy-Dglucose (2-DG), blocking the access of glucose to the brain cells. 1H NMR spectroscopy showed that 2-DG leads to the predominance of excitatory (glutamine + glutamate) neurotransmitters over inhibitory ones (gamma-aminobutyric acid), and 2,4 DNP causes opposite effects. The biochemical mechanisms of the observed changes require a special study, but it can be noted that the ATP deficiency caused by inhibition of glycolysis and the ATP deficiency caused by the uncouplers are accompanied by differently directed changes in the intensity of the tricarboxylic acid cycle. These changes in the intensity of the Krebs cycle are correlated with differently directed changes in the balance of the exciting and inhibitory neurotransmitters. The obtained results show that 1H NMR spectroscopy can be an effective method of differentiated lifetime assessment of the available energy deficit caused by a general suppression of energy exchange in nerve cells or oxidation and phosphorylation uncoupling.


2012 ◽  
Vol 47 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Hong-Chang Gao ◽  
Huan Zhu ◽  
Cai-Yong Song ◽  
Li Lin ◽  
Yun Xiang ◽  
...  

2005 ◽  
Vol 81 (4) ◽  
pp. 407-414 ◽  
Author(s):  
Øystein Risa ◽  
Oddbjørn Sæther ◽  
Manoj Kakar ◽  
Vino Mody ◽  
Stefan Löfgren ◽  
...  

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Maria Maganu ◽  
Filip Chiraleu ◽  
Constantin Draghici ◽  
Gheorghe Mihai

The previous data obtained by 1H-NMR spectroscopy established the existence of an asymmetry of the bond between Pd and p-allylic groups, even in the p-allyl-Pd complexes dimers which are considered usually symmetric dimers. The asymmetry of the bond depends by the substitutes of the allylic group. Other analytical methods were investigated for additional proof of the obtained results. Thus, this paper discusses how this asymmetry would be reflected in the infrared spectra and in the reaction of the complexes with carbon monoxide.


2020 ◽  
Vol 07 ◽  
Author(s):  
Christian Trapp ◽  
Corinna Schuster ◽  
Chris Drewniok ◽  
Dieter Greif ◽  
Martin Hofrichter

Background:: Chiral β-hydroxy esters and α-substituted β-hydroxy esters represent versatile building blocks for pheromones, β-lactam antibiotics and 1,2- or 1,3-aminoalcohols. Objective:: Synthesis of versatile α-substituted β-keto esters and their diastereoselective reduction to the corresponding syn- or anti-α-substituted β-hydroxy esters. Assignment of the relative configuration by NMR-spectroscopy after a CURTIUS rearrangement of α-substituted β-keto esters to 4-substituted 5-methyloxazolidin-2-ones. Method:: Diastereoselective reduction was achieved by using different LEWIS acids (zinc, titanium and cerium) in combination with complex borohydrides as reducing agents. Assignment of the relative configuration was verified by 1H-NMR spectroscopy after CURTIUS-rearrangement of α-substituted β-hydroxy esters to 4-substituted 5-methyloxazolidin-2-ones. Results:: For the syn-selective reduction, titanium tetrachloride (TiCl4) in combination with a pyridine-borane complex (py BH3) led to diastereoselectivities up to 99% dr. High anti-selective reduction was achieved by using cerium trichloride (CeCl3) and steric hindered reducing agents such as lithium triethylborohydride (LiEt3BH). After CURTIUS-rearrangement of each α-substituted β-hydroxy ester to the corresponding 4-substituted 5-methyloxazolidin-2-one, the relative configuration was confirmed by 1H NMR-spectroscopy. Conclusion:: We have expanded the procedure of LEWIS acid-mediated diastereoselective reduction to bulky α-substituents such as the isopropyl group and the electron withdrawing phenyl ring.


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