Scavenging effects of natural phenols on oxidizing intermediates of peroxynitrite.
Most of peroxynitrite (ONOO-/ONOOH) is formed via the diffusion-limited reaction between nitric oxide and superoxide. In biological systems, the decomposition of ONOO- yields 30-35% of carbonate radical (CO3*-) and nitrogen dioxide (NO2*), which are strongly oxidizing intermediates and are suggested to take a part of the responsibility for the toxicity of nitric oxide (NO*) or ONOO-. Therefore, the current study focuses on the scavenging activities of phenols toward CO3*- and NO2* to protect biomolecules from damage caused by NO* or ONOO- using the technique of pulse radiolysis. From the build-up kinetic of the phenoxyl radicals and the decay kinetic of CO3*- radical, the rate constants of scavenging reactions were determined to be 1.9-3.4 x 10(8) M(-1) x s(-1) and 0.11-1.9 x 10(8) M(-1) x s(-1) for CO3*- and NO2* respectively. The results indicated that the tested phenols are the efficient scavengers of CO3*- and NO2*.
Zhao
C Y
CY
School of life Sciences, Lanzhou University, Lanzhou, P.R. China.
Shi
Y M
YM
Yao
S D
SD
Jia
Z J
ZJ
Fan
B T
BT
Wang
W F
WF
Lin
W Z
WZ
Lin
N Y
NY
Zheng
R L
RL
D002254:Carbonates / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry*; D007700:Kinetics; D009573:Nitrites / Q000737:chemistry; D010084:Oxidation-Reduction; D030421:Peroxynitrous Acid / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D011675:Pulse Radiolysis; D011794:Quercetin / Q000737:chemistry; D012431:Rutin / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
D002254:Carbonates; D016166:Free Radical Scavengers; D009573:Nitrites; D010636:Phenols; D030421:Peroxynitrous Acid; D012431:Rutin; D011794:Quercetin