Fast repair of the radical cations of dCMP and poly C by quercetin and rutin

Abstract

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 SO4-. 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 4.3-8.8 × 108 M/s and 1.5-3.6 × 108 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.