Fast repair of deoxythymidine radical anions by two polyphenols: rutin and quercetin.
The effects of rutin and quercetin on the repair of the deoxythemindine radical anion (dT*) were studied using the technique of pulse radiolysis. The radical anion of dT was formed by the reaction of hydrated electron with dT. After pulse irradiation of nitrogen-saturated aqueous solutions containing dT, 0.2M t-BuOH and either rutin or quercetin, the initially formed dT*(-), detected spectrophotometrically, rapidly decayed with the concurrent formation of the radical anion of rutin or quercetin. The results indicated that dT*(-) can be rapidly repaired by rutin or quercetin. The rate constants of the repair reactions were determined to be 3.1 and 4.1 x 10(9)M(-1)s(-1) for rutin and quercetin, respectively. With substitution by glycosyl groups at C(3)-OH bond being neighbor to C(4) keto group, which is the active site for electron transfer, rutin has a lower repair reaction rate constant toward dT*(-) than quercetin. Together with findings from our previous studies, the present results demonstrated that nonenzymatic fast repair may be a universal form of repair involving phenolic antioxidants.
Zhao
Chenyang
C
School of life Sciences, Lanzhou University, China.
Shi
Yimin
Y
Wang
Wenfeng
W
Jia
Zhongjian
Z
Yao
Side
S
Fan
Botao
B
Zheng
Rongliang
R
D000838:Anions / Q000737:chemistry*; D004579:Electron Transport; D005419:Flavonoids; D005609:Free Radicals / Q000737:chemistry; D010636:Phenols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011675:Pulse Radiolysis; D011794:Quercetin / Q000737:chemistry*; D012431:Rutin / Q000737:chemistry*; D013936:Thymidine / Q000737:chemistry*
D000838:Anions; D005419:Flavonoids; D005609:Free Radicals; D010636:Phenols; D011108:Polymers; D012431:Rutin; D011794:Quercetin; D013936:Thymidine