Guanine oxidation product

The guanine radical cation is a weak acid = 3.9) [22]. Therefore deprotonation will depend on the environment. Bachler and Hildenbrand [38] have studied the guanine oxidation product in aqueous solution of 5 -dGMP. The best fit to their EPR spectra seems to be from the radical cation (Gua " ). 

W.L. Neeley et al., Mechanisms of formation, genotoxicity, and mutation of guanine oxidation products. Chem. Res. Toxicol. 19, 491-505 (2006)... 

The surface coverage (T) and heterogeneous electron transfer rate constant (ks) of adsorbed redox couple were about 9.5 10 9 mol cm 2 and 3.18 ( 0.20) s 1, respectively, indicating the high loading ability of ZnOx nanoparticles toward guanine oxidation product and great facilitation of the electron transfer between redox couple and ZnOx nanoparticles. The modified electrode exhibited excellent electrocatalytic activity toward L-cysteine oxidation. The kcat for L-cysteine oxidation was found to be 4.20( 0.20)x 103 M V1. The catalytic oxidation current allows the amperometric detection of L-cysteine at potential of 0.5 V with detection limit of 50 nM, linear response up to 20 p, M and sensitivity of 215.4 nA.p A" em"2 This results indicate ZnO nanoparticles modified electrodes are suitable microenvironment for observation and stabilization of unusual and unstable redox couples. 

Spectrum of Guanine Oxidation Products Caused by ONOO", ONOOCO), and NO)... 

Yu, H., Venkatarangan, L., Wishnok, J.S., and Tannenbaum, S.R. (2005) Quantitation of four guanine oxidation products from reaction of DNA with varying doses of peroxynitrite. Chem. 

Gimisis, T. and Cismas, C. (2006) Isolation, characterization, and independent synthesis of guanine oxidation products. Eur. J. Org. Chem., 1351-1378. 

Table VII Hyperfine Coupling Parameters for Guanine Oxidation Products ...

Isolation, characterization, and independent synthesis of guanine oxidation products 06EJO1351. 

V. Verdolino, R. Cammi, B.H. Munk, and H.B. Schlegel, Calculation ofpK values ofnucleobases and the guanine oxidation products guanidinohydan-toin and spiroiminodihydantoin using density functional theory and a polarizable continuum model, J. Phys. Chem. B 112 (2008), pp. 16860-16873. 

Neeley WL, Henderson PT, Delaney JC, Essigmann JM (2004) In vivo bypass elEcien-cies and mutational signatures of the guanine oxidation products 2-aminoimidazolone and 5-guanidino-4-nitroimidazole. J Biol Chem 279 43568-43573... 

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