Abstract
Pulse radiolysis has been used to investigate the reaction of hydroxyl radical (·OH) and oxide radical anion (O·−) with 2-aminopurine (2AP), a fluorescent analogue of adenine, in aqueous medium. The second-order rate constant for the reaction of ·OH with 2AP was determined to be 3 × 109 dm3 mol−1s−1 and for the reaction of O·− it was 7.1 × 108 dm3 mol−1s−1. The transient absorption spectrum obtained in the reaction of ·OH at pH 7 has absorption maxima at 370 and 470 nm. The spectrum undergoes a time-dependent transformation at higher time-scale. The intermediate species was found to react with N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD). The yield of TMPD·+ was calculated in terms of G(TMPD·+) to be 3.3 × 10−7 mol J−1 at pH 7. The ·OH reactions were also carried out at pH 10 and the transient absorption spectra have λ max at 400 and 480 nm. The transient spectra obtained in the reaction of O·− at pH ≈14 have maxima at 400 and 480 nm. The transient intermediate species at pH 7 are assigned to the formation of 2AP-4-OH· (54%), 2AP-5-OH· (7%) and 2AP-8-OH· (39%) based on the spectral evidence and TMPD·+ build-up. Both 2AP-4-OH· and 2AP-5-OH· undergo OH− elimination to form a radical cation. At higher pH (pH 10), the dehydration reaction of these OH-adducts leads to a N-centered radical (2AP-N(9)·, 71%). Formation of 2AP-8-OH· (29%) is also proposed at this pH. In the reaction of O·− with 2AP, it is proposed that a similar nitrogen centered 2AP-N(9)· radical is formed by an electron-transfer reaction at N(9).
Similar content being viewed by others
References
A. J. Bertinchamps (Ed.), in: Effect of Ionising Radiation on DNA, p. 153. Springer, Berlin (1978).
C. von Sonntag, Radiat. Phys. Chem. 30, 313 (1987).
C. von Sonntag, Chemical Basis of Radiation Biology, Taylor and Francis, London (1987).
C. J. Burrows and J. G. Muller, Chem. Rev. 98, 1109 (1998).
S. Fujita and S. Steenken, J. Am. Chem. Soc. 103, 2540 (1981).
D. K. Hazra and S. Steenken, J. Am. Chem. Soc. 105, 4380 (1983).
S. Steenken, Chem. Rev. 89, 503 (1989).
A. J. S. C. Vieira and S. Steenken, J. Am. Chem. Soc. 112, 6986 (1990).
A. J. S. C. Vieira and S. Steenken, J. Am. Chem. Soc. 109, 7441 (1987).
A. J. S. C. Vieira and S. Steenken, J. Phys. Chem. 91, 4138 (1987).
G. Scholes, in: Radiation chemistry of Aqueous Systems, G. Stein (Ed.), p. 259. Interscience, New York, NY (1968).
G. Scholes, in: Photochemistry and Photobiology of Nucleic Acids, S. Y. Wang (Ed.), Vol. 1, p. 521. Academic Press, New York, NY (1976).
S. Steenken, Biol. Chem. 378, 1293 (1997).
C. Wan, T. Fiebig, O. Schiemann, J. K. Barton and A. H. Zewail, Proc. Natl. Acad. Sci. USA 97, 14052 (2000).
F. D. Lewis, T. Wu, Y. Whang, R. L. Letsinger, S. R. Greenfield and M. R. Wasielewski, Science 277, 673 (1997).
S. O. Kelley and J. K. Barton, Science 283, 375 (1999).
C. Wan, T. Fiebig, S. O. Kelley, C. R. Treadway, J. K. Barton and A. H. Zewail, Proc. Natl. Acad. Sci. USA 96, 6014 (1999).
V. Sharovich, A. Dourandin, W. Huang, N. P. Luneva and N. E. Geacintov, J. Phys. Chem. B. 103, 10924 (1999).
V. Sharovich, A. Dourandin, W. Huang, N. P. Luneva and N. E. Geacintov, Phys. Chem. Chem. Phys. 2, 4399 (2000).
O. F. A. Larsen, I. H. M. van Stokkum, F. L. de Weerd, M. Vengris, C. T. Aravindakumar, R. van Grondelle, N. E. Geacintov and H. van Amerongen, Phys. Chem. Chem. Phys. 6, 154 (2004).
S. N. Guha, P. N. Moorthy, K. Kishore, D. B. Naik and K. N. Rao, Proc. Indian Acad. Sci. (Chem. Sci.) 99, 261 (1987).
R. H. Schuler, A. L. Hartzell and B. Behar, J. Phys. Chem. 85, 192 (1981).
M. Ioele, C. Chatgilialoglu and Q. G. Mulazzani, J. Phys. Chem. 102, 6259 (1998).
T. L. Luke, H. Mohan, V. M. Manoj, P. Manoj, J. P. Mittal and C. T. Aravindakumar, Res. Chem. Intermed. 28, 303 (2002).
M. L. Scholes, M. N. Schuchmann and C. von Sonntag, Int. J. Radiat. Biol. 61, 443 (1992).
M. S. Vinchurkar, B. S. M. Rao, H. Mohan and J. P. Mittal, Res. Chem. Intermed. 25, 471 (1999).
E. Hayon and M. Simic, J. Am. Chem. Soc. 95, 1029 (1973).
A. Hissung and C. von Sonntag, Z. Naturforsch. 33b, 321 (1978).
P. Neta, Radiat. Res. 49, 1 (1972).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Manoj, P., Mohan, H., Manoj, V.M. et al. Reactions of hydroxyl radical (·OH) and oxide radical anion (O·−) with 2-aminopurine in aqueous medium. Res Chem Intermed 32, 817–826 (2006). https://doi.org/10.1163/156856706778938446
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1163/156856706778938446