![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
The classical Fenton system composed of Fe(II) and H2O2 uses harsh oxidative conditions and cannot realistically simulate physiological oxidations which are less severe. Here, reactive oxygen species (ROS) were generated with a combination of CoSO4 and H2O2 to provide milder conditions. DNA was used as a biologically meaningful probe for monitoring the oxidative conversion. Oxidative hazard on DNA was accomplished in ammonia/ammonium chloride buffer at 37 °C, and the Fenton reaction was stopped with trichloroacetic acid (TCA). A suitable aliquot of this solution was added to cupric ion reducing antioxidant capacity (CUPRAC) reaction mixture, and the absorbance at 450 nm was recorded. The oxidized species derived from DNA were CUPRAC-reactive while intact DNA was not. The protective effects of antioxidants (AOxs), known to have radical scavenging effects, were tested; green tea and a synthetic fetal bovine serum (FBS) were also successfully used as real ROS scavengers. Although the classical iron-based Fenton procedure applied in ethanol medium generated CUPRAC-responsive products, the proposed system was perfectly ethanol-tolerant, enabling the CUPRAC measurement of DNA oxidation products against an unaffected reagent blank. The protective effects of phenolic antioxidants, perfectly solubilized in ethanol, could also be measured.
Acknowledgments
The authors would like to express their gratitude to Istanbul University – Cerrahpasa Scientific Research Projects for the HIZAP project 27799 and to Istanbul University – Cerrahpasa - Application and Research Center for the Measurement of Food Antioxidants (IU-GAAM) for using certain facilities.
Disclosure statement
No potential conflict of interests was reported by the authors.