Details

Autor(en) / Beteiligte

• Kudo, Wataru
• Yamato, Mayumi
• Yamada, Ken-Ichi
• Kinoshita, Yuichi
• Shiba, Takeshi
• Watanabe, Toshiaki
• Utsumi, Hideo

Titel

Formation of TEMPOL-hydroxylamine during reaction between TEMPOL and hydroxyl radical: HPLC/ECD study

Ist Teil von

• Free radical research, 2008-05, Vol.42 (5), p.505-512

Ort / Verlag

England: Informa UK Ltd

Erscheinungsjahr

2008

Quelle

MEDLINE

Beschreibungen/Notizen

• Nitroxyl radicals are important antioxidants that have been used to protect animal tissues from oxidative damage. Their reaction with hydroxyl radical (*OH) is generally accepted to be the mechanism of antioxidant function. However, the direct interaction of nitroxyl radicals with *OH does not always provide a satisfactory explanation in various pH, because the concentration of hydrogen ion may affect the generation of secondary *OH-derived radicals. In the present study, it was confirmed that the reaction between 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL) and *OH generated TEMPOL-hydroxylamine, 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPON) and TEMPON-hydroxylamine using HPLC coupled with electrochemical detection. In the absence of NADH, TEMPOL-H may be generated by the reaction with secondary *OH-derived radicals in acidic condition. In the presence of NADH, a large proportion of the non-paramagnetic products was TEMPOL-H. Finally, it was clarified that TEMPOL-H was generated during dopamine metabolism, which is believed to be one of the *OH sources in pathological processes such as Parkinson's disease.