%0 Journal Article
%T Adenine oxidation by pyrite-generated hydroxyl radicals
%A Corey A Cohn
%A Shawn C Fisher
%A Bruce J Brownawell
%A Martin AA Schoonen
%J Geochemical Transactions
%D 2010
%I BioMed Central
%R 10.1186/1467-4866-11-2
%X Pyrite (FeS2), the most common metal sulfide mineral associated with coal and metal mine waste, has been shown to generate hydrogen peroxide (H2O2) [1,2] and hydroxyl radicals (£żOH) [3,4] when placed in water. In the presence of dissolved molecular oxygen, ferrous iron associated with pyrite can form superoxide anion (O2£ż)- (eq. 1), which reacts with ferrous iron to form H2O2 (eq. 2) and eventually £żOH (Fenton reaction, eq. 3).The formation of reactive oxygen species (ROS) such as H2O2 and £żOH is significant because of their reactivity; £żOH will typically react with nearly all molecules in aqueous solution at diffusion-limited rates [5]. Their extreme reactivity has been implicated in causing or contributing to disease and aging in humans [6-10]. Particles other than pyrite such as asbestos [11] and quartz [10] have also been shown to induce the formation of £żOH in lung cells that have been exposed to the particles. The particulate-induced formation of £żOH has been linked with oxidative stress [12,13] and genotoxicity [14,13]. Hence, £żOH formation in vitro and in vivo has been used as an indicator for mineral-induced toxicity potential [14,13,12,16,6].The extremely short half-life of £żOH hinders detection and quantification of £żOH concentrations directly [5]. Instead, detection requires the reaction of £żOH with a target molecule. Upon reaction, characteristics of the target molecule such as light absorption [2], fluorescence [17-19], or electron spin resonance [20-23] may change. The detection of these changes is then used to determine the presence and concentration of £żOH and other ROS. In the presence of cells or in tissue, the products of particle-induced radical oxidation include DNA strand-breaks [24,14], RNA degradation [4], and nucleobase oxidation [25-27]. Nucleic acids react with £żOH by hydrogen abstraction at the sugar or addition to the bases, both resulting in radical moieties and de-polymerization [28,29,24]. Oxidized base reaction products are typicall
%U http://www.geochemicaltransactions.com/content/11/1/2