DMPO-OH radical formation from 5,5-dimethyl-1-pyrroline N-oxide (DMPO) in hot water.
When an aqueous solution of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) was heated at 70 degrees C for 30 min, formation of DMPO-OH was observed by ESR. This DMPO-OH radical formation was suppressed under an argon atmosphere. When water was replaced with ultra-pure water for ICP-MS experiments, DMPO-OH radical formation was also diminished. Under an argon atmosphere in ultra-pure water, the intensity of the DMPO-OH signal decreased to about 1/20 of that observed under aerobic conditions with regular purified water. The addition of hydroxyl radical scavengers such as mannitol did not affect the formation of DMPO-OH, but the signal turned faint in the presence of EDTA. We suggest that DMPO reacted with dissolved oxygen to form DMPO-OH.
Shoji
Tomoko
T
Kyoritsu University of Pharmacy, Shibakoen, Minato, Tokyo, Japan.
Li
Linxiang
L
Abe
Yoshihiro
Y
Ogata
Masahiro
M
Ishimoto
Yoshihisa
Y
Gonda
Ryoko
R
Mashino
Tadahiko
T
Mochizuki
Masataka
M
Uemoto
Michihisa
M
Miyata
Naoki
N
D001128:Argon / Q000737:chemistry; D001272:Atmosphere / Q000737:chemistry; D003497:Cyclic N-Oxides / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry*; D008353:Mannitol / Q000737:chemistry; D013058:Mass Spectrometry; D010100:Oxygen / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D003497:Cyclic N-Oxides; D016166:Free Radical Scavengers; D014867:Water; D017665:Hydroxyl Radical; D008353:Mannitol; D001128:Argon; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D010100:Oxygen