An experimental NEXAFS and computational TDDFT and ΔDFT study of the gas-phase core excitation spectra of nitroxide free radical TEMPO and its analogues

2016 ◽  
Vol 18 (15) ◽  
pp. 10207-10217 ◽  
Author(s):  
Ivan Ljubić ◽  
Antti Kivimäki ◽  
Marcello Coreno
Keyword(s):  
Free Radical ◽  
Gas Phase ◽  
Excitation Spectra ◽  
Core Excitation ◽  
The Core ◽  
Nitroxide Free Radical ◽  
Phase Spectra ◽  
Stable Nitroxide

Core excitation (NEXAFS) C 1s, N 1s, and O 1s gas-phase spectra of stable nitroxide free radical TEMPO and two of its amide-substituted analogues are assigned from the onset of the absorptions to the vicinity of the core-ionization thresholds using the theoretical TDDFT and ΔDFT methods.

Photolytic studies on 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, a stable nitroxide free radical

1971 ◽  
Vol 36 (1) ◽  
pp. 209-211 ◽  
Author(s):  
John F. W. Keana ◽  
Robert J. Dinerstein ◽  
Friedhelm Baitis
Keyword(s):  
Free Radical ◽  
Nitroxide Free Radical ◽  
Stable Nitroxide

Spin-orbit relativistic calculations of the core excitation spectra of SO2

2007 ◽  
Vol 126 (13) ◽  
pp. 134308 ◽  
Author(s):  
G. Fronzoni ◽  
R. De Francesco ◽  
M. Stener ◽  
P. Decleva
Keyword(s):  
Spin Orbit ◽  
Excitation Spectra ◽  
Core Excitation ◽  
The Core

Nitroxides. IX. Synthesis of nitroxide free radical α-amino acids

1982 ◽  
Vol 60 (12) ◽  
pp. 1448-1451 ◽  
Author(s):  
László Lex ◽  
Kálmán Hideg ◽  
H. Olga Hankovszky
Keyword(s):  
Amino Acids ◽  
Free Radical ◽  
Amino Acid ◽  
Propionic Acid ◽  
Nitroxide Free Radical ◽  
Stable Nitroxide

Three methods are described for preparation of a new stable nitroxide free radical amino acid, 2-amino-3-(1-oxyl-2,2,5,5-tetramethyl-3-pyrrolin-3-yl) propionic acid and its derivates. This amino acid may be used as a paramagnetic amino acid synthon in studies of peptides.

scholarly journals Desferrioxamine (Desferal) and superoxide free radicals. Formation of an enzyme-damaging nitroxide

1987 ◽  
Vol 246 (3) ◽  
pp. 725-729 ◽  
Author(s):  
M J Davies ◽  
R Donkor ◽  
C A Dunster ◽  
C A Gee ◽  
S Jonas ◽  
...  
Keyword(s):  
Free Radical ◽  
Room Temperature ◽  
Chelation Therapy ◽  
Iron Chelation ◽  
Protonated Form ◽  
Water Soluble ◽  
Iron Chelation Therapy ◽  
Superoxide Free Radical ◽  
Nitroxide Free Radical ◽  
Stable Nitroxide

In neutral solutions, desferrioxamine (Desferal) can react with the superoxide free radical, O2.- (possibly through its protonated form HO2.), to form a relatively stable nitroxide free radical, which can have a half-life of approx. 10 min at room temperature. The formation of the radical can be largely prevented by the presence of superoxide dismutase. The radical reacts rapidly with cysteine, methionine, glutathione, vitamin C and a water-soluble derivative of vitamin E. It also reacts rapidly with alcohol dehydrogenase, causing a loss of enzyme activity. The implications of these findings for mechanistic free-radical biochemistry and iron-chelation therapy could be considerable.

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