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Spin trapping study of antioxidant properties of neopterin and 7,8-dihydroneopterin.
- Source :
-
Biochemical and biophysical research communications [Biochem Biophys Res Commun] 1997 May 29; Vol. 234 (3), pp. 774-8. - Publication Year :
- 1997
-
Abstract
- Previously, it has been shown that pteridine derivatives are capable of modulating the action of free radicals and both prooxidant and antioxidant properties have been described. However, the mechanism of manifestation of these properties is still unclear. We studied the radical scavenging properties of 7,8-dihydroneopterin and neopterin using the spin trap 5,5-dimethyl-1-pyrroline-1-oxide (DMPO). It was found that dihydroneopterin acts generally as a radical scavenger. In the presence of dihydroneopterin the ESR signal was reduced by 30 to 90% compared to the control signal. The rate constants for the reactions of 7,8-dihydroneopterin with superoxide (10(3) M(-1) s(-1)) and peroxyl radicals (10(7) M(-1) s(-1)) were determined. Neopterin in contrast showed no reduction of the ESR signal except with superoxide radicals produced by xanthine oxidase. However, this effect was shown to be due to an inhibition of enzyme rather than to radical scavenging. Our results provide a basis for understanding previous observations of radical scavenger activity of 7,8-dihydroneopterin.
- Subjects :
- Antioxidants chemistry
Biopterins chemistry
Biopterins pharmacology
Electron Spin Resonance Spectroscopy
Kinetics
Neopterin
Oxidation-Reduction
Peroxides chemistry
Pteridines chemistry
Spin Labels
Superoxides chemistry
Antioxidants pharmacology
Biopterins analogs & derivatives
Pteridines pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-291X
- Volume :
- 234
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Biochemical and biophysical research communications
- Publication Type :
- Academic Journal
- Accession number :
- 9175792
- Full Text :
- https://doi.org/10.1006/bbrc.1997.6712