Formation of 8-Hydroxydeoxyguanosine from Deoxyguanosine by Fe2+/Ascorbic Acid/EDTA/H2O2 System.

Abstract

8-Hydroxydeoxyguanosine (8-OH-dG) was formed in deoxyguanosine (dG) solution by the addition of Fe²⁺, ascorbic acid (AscA), EDTA, and H₂O₂, and was then detected by ECD after separation by HPLC. 8-OH-dG was not formed in significant amounts when either Fe²⁺, AscA, or H₂O₂ was added separately, or when two of these were added in combination. When Fe²⁺, AscA, and H₂O₂ were added simultaneously, however, 0.87nmol of 8-OH-dG was formed from 2.5μmol of dG. And the addition of EDTA (in the same concentration as Fe²⁺) to the Fe²⁺/AscA/H₂O₂ system caused a remarkable increase in the amount of 8-OH-dG formed (up to 2.89nmol from 2.5μmol of dG). The amount of 8-OH-dG formed increased as the concentration of AscA increased up to 1mM (the same concentration as Fe²⁺). However, higher concentrations of AscA inhibited the formation of 8-OH-dG.