Mutagenesis, Vol. 16, No. 3, 271-275,
May 2001
© 2001 UK Environmental Mutagen Society/Oxford University Press
Fast repair of the radical cations of dCMP and poly C by quercetin and rutin
School of Life Science, Lanzhou University, Lanzhou, 730000, China, 1 Laboratory of Radiation Chemistry, Shanghai Institute of Nuclear Research, Chinese Academy of Sciences, Shanghai, 201800, China, 2 State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, 730000, China and 3 Institute de Topologie et de Dynamique des Systems, University Paris 7, Paris 75005, France
The effects of quercetin and rutin on the repair of the radical cations of dCMP and poly C were studied using the technique of pulse radiolysis. The radical cations of dCMP and poly C were formed by the reaction of dCMP and poly C with SO 4–. After pulse irradiation of nitrogen-saturated aqueous solutions containing dCMP, 20 mM K2S2O8, 200 mM t-BuOH and either rutin or quercetin, the initially formed radical cation of dCMP, detected spectrophotometrically, rapidly decayed with the concurrent formation of the phenoxyl radical of rutin or quercetin within 8–40 µs. The repair efficiencies of the tested compounds towards the poly C radical cation were also determined using the same procedure. The results indicate that dCMP and poly C radical cations can be rapidly repaired by quercetin and rutin. The rate constants of the repair reactions were determined to be 4.3–8.8x108 M/s and 1.5–3.6x108 M/s for dCMP and poly C radical cations, respectively. Together with findings from our previous studies, the present results demonstrate that non-enzymatic fast repair may be a universal form of repair involving phenolic antioxidants.
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