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Australian Journal of Chemistry Australian Journal of Chemistry Society
An international journal for chemical science
RESEARCH ARTICLE

Oxidative Damage of Pyrimidine Nucleosides by the Environmental Free Radical Oxidant NO3 in the Absence and Presence of NO2 and Other Radical and Non-Radical Oxidants

Catrin Goeschen A , Jonathan M. White B , Robert W. Gable C and Uta Wille A D
+ Author Affiliations
- Author Affiliations

A ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Chemistry and BIO21 Molecular Science and Biotechnology Institute, The Universityof Melbourne, 30 Flemington Road, Parkville, Vic. 3010, Australia.

B School of Chemistry and BIO21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Vic. 3010, Australia.

C School of Chemistry, The University of Melbourne, Grattan Street, Parkville, Vic. 3010, Australia.

D Corresponding author. Email: uwille@unimelb.edu.au

Australian Journal of Chemistry 65(4) 427-437 https://doi.org/10.1071/CH11446
Submitted: 23 November 2011  Accepted: 24 February 2012   Published: 26 April 2012

Abstract

Analysis of the products formed in the reaction of the environmental free radical oxidant NO3 with permethylated uridine 1 and thymidine 2 in solution revealed highly complex reaction pathways following initial NO3 induced oxidative electron transfer at the pyrimidine ring. Product formation was found to depend not only on the nature of the nucleobase, but also on the presence of other free radical oxidants, namely NO2. In the reaction of 1 with NO3, which was generated through CAN photolysis, apart from formation of the highly oxidized nucleoside derivative 4 as the major product, cleavage of the C–N glycosidic bond did also occur, resulting in formation of ribolactone 5 and the free nucleobase 6. The suggested mechanism involves in situ generation of NO2 during the course of the reaction, which promotes conversion of the initially formed radical cation 7 to 4 in an autocatalytic fashion.

When the reaction of NO2 with O3 was used to generate NO3, the initially formed radical cation 7 in the reaction with permethylated uridine 1 is rapidly trapped by NO2 to give 5-nitrouridine 18 in a radical mediated vinylic substitution reaction. In contrast to this, under similar conditions in the reaction involving thymidine 2 the highly oxidized products 20 and 21 are obtained as major compounds, which result from addition to the C5–C6 double bond. No direct reaction between NO3 and the carbohydrate moiety in 1 and 2 was found. Also, no reaction occurred between the nucleosides and mixtures of NO2/N2O4 and O3/O2, respectively.


References

[1]  C. J. Burrows, J. G. Muller, Chem. Rev. 1998, 98, 1109.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXis12htrY%3D&md5=01f34f42ff862d2eb253fa752fc39411CAS |

[2]  W. K. Pogozelski, T. D. Tullius, Chem. Rev. 1998, 98, 1089.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXis12gtL8%3D&md5=f6dc4aac5f40b47032b273c17d01a734CAS |

[3]  S. Steenken, Chem. Rev. 1989, 89, 503.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXitVyms7w%3D&md5=8fbef0534cc4d53ea4cbde3be7de3237CAS |

[4]  D. Schulte-Frohlinde, K. Hildenbrandt, in Free Radicals in Synthesis and Biology (Ed. F. Minisci) 1989, pp. 335–359. (Kluwer Academic Press: Dordrecht).

[5]  R. Lomoth, S. Naumov, O. Brede, J. Phys. Chem. A 1999, 103, 6571.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXlt1Wjsr8%3D&md5=7543a046c84ddac6339fd6408a1f3329CAS |

[6]  D. K. Hazra, S. Steenken, J. Am. Chem. Soc. 1983, 105, 4380.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXkt1arsbs%3D&md5=01a1a4535e9afe795a34a94f6415f21bCAS |

[7]  W. F. Ho, B. C. Gilbert, M. J. Davies, J. Chem. Soc., Perkin Trans. 2 1997, 2525.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXhvVGgtQ%3D%3D&md5=5f60dbf700163dadd83444d79d009b83CAS |

[8]  W. F. Ho, B. C. Gilbert, M. J. Davies, J. Chem. Soc., Perkin Trans. 2 1997, 2533.
         | Crossref | GoogleScholarGoogle Scholar |

[9]  D. J. Deeble, M. N. Schuchmann, S. Steenken, C. von Sonntag, J. Phys. Chem. 1990, 94, 8186.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXlvFWjtrs%3D&md5=bf1d2ad60d16a2e4c120217fbbc92e04CAS |

[10]  K. Chabita, P. C. Mandal, S. N. Bhattacharyya, Bull. Chem. Soc. Jpn. 1994, 67, 2751.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXmslGgsbc%3D&md5=07a29fce5742fd3e523fd568cebc5478CAS |

[11]  M. Faraggi, F. Broitman, J. B. Trent, M. H. Klapper, J. Phys. Chem. 1996, 100, 14751.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28Xksl2gtr0%3D&md5=9754f0d021a9822dbaab97b297584383CAS |

[12]  M. Martini, J. Termini, Chem. Res. Toxicol. 1997, 10, 234.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXhsVSktro%3D&md5=b25a58948800deedb2963d5c1657da68CAS |

[13]  T. Itahara, Y. Fujii, M. Tada, J. Org. Chem. 1988, 53, 3421.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXhsFCjsrY%3D&md5=347d682b457bec5ab9ce0a3482594d06CAS |

[14]  J. R. Wagner, J. Cadet, G. J. Fisher, Photochem. Photobiol. 1984, 40, 589.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2MXnsVyjtA%3D%3D&md5=7e7e3b442bd54c0643c733c878904c49CAS |

[15]  C. Lagercrantz, J. Am. Chem. Soc. 1973, 95, 220.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3sXmvVeguw%3D%3D&md5=4a20e44031f9f9082a9e69d901376102CAS |

[16]  P. Neta, Radiat. Res. 1972, 49, 1.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE38XlvFGmtw%3D%3D&md5=0a6286e652a5d0298963a941c44de714CAS |

[17]  S. Fujita, S. Steenken, J. Am. Chem. Soc. 1981, 103, 2540.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3MXktVKisrw%3D&md5=4b9b45be57b02d4616832381cb4cc04aCAS |

[18]  J. Cadet, R. Téoule, Bull. Soc. Chim. Fr. 1975, 891.
         | 1:CAS:528:DyaE28XisVegtQ%3D%3D&md5=e7a45ede617cf6d1f38e0dfa216b1073CAS |

[19]  H. Catterall, M. J. Davies, B. C. Gilbert, J. Chem. Soc., Perkin Trans. 2 1992, 1379.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXit1Giuw%3D%3D&md5=4054f098b63b9dceee3c67a1ec2e4c88CAS |

[20]  H. Catterall, M. J. Davies, B. C. Gilbert, N. P. Polack, J. Chem. Soc., Perkin Trans. 2 1993, 2039.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXpvFSmsw%3D%3D&md5=f70a6b2ed0cc788a494f621d754b88efCAS |

[21]  K. Hildenbrand, G. Behrens, D. Schulte-Frohlinde, J. Chem. Soc., Perkin Trans. 2 1989, 283.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXktVOksbg%3D&md5=6141b24aa6a2e46e59a5611549390430CAS |

[22]  R. P. Wayne, I. Barnes, P. Biggs, J. P. Burrows, C. E. Canosa-Mas, J. Hjorth, G. Le Bras, G. K. Moortgat, D. Perner, G. Restelli, H. Sidebottom, Atmos. Environ., A 1991, 25, 1.

[23]  R. Atkinson, J. Phys. Chem. Ref. Data 1991, 20, 459.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3MXltlGitLo%3D&md5=c12706c6292a0fc505589e46abeb0a39CAS |

[24]  R. P. Wayne, in N-Centered Radicals, (Ed. Z. B. Alfassi) 1998, pp. 207–258 (John Wiley & Sons: Chichester).

[25]  O. Ito, in N-Centered Radicals, (Ed. Z. B. Alfassi) 1998, pp. 345–370 (John Wiley & Sons: Chichester).

[26]  U. Wille, C. Goeschen, Aust. J. Chem. 2011, 64, 833.
         | 1:CAS:528:DC%2BC3MXotFOqurk%3D&md5=89e94c980f94cccebf0eb3b04c83ee59CAS |

[27]  D. C. E. Sigmund, U. Wille, Chem. Commun. (Camb.) 2008, 2121.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXltFyntb8%3D&md5=59f7bb9ce13e5fa3c9660908250be3aeCAS |

[28]  L. Dogliotti, E. Hayon, J. Phys. Chem. 1967, 71, 3802.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF1cXisFequg%3D%3D&md5=731180e1273909b194e2ea3559adfe5aCAS |

[29]  E. Baciocchi, T. Del Giacco, S. M. Murgia, G. V. Sebastiani, J. Chem. Soc. Chem. Commun. 1987, 1246.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1cXhsV2rtrY%3D&md5=99671fbb16ff430f55b4689f6d83ab40CAS |

[30]  It should be noted that, in principle, residual water could influence the reaction outcome in two ways through (i) direct reaction with NO3, and (ii) through trapping of intermediates produced in the reaction of NO3 with nucleosides. The reaction of NO3 with water is not very fast (k = 3 × 102 M–1 s–1; see: G. A. Poskrebyshev, P. Neta, R. E. Huie, J. Geophys. Res. 2001, 106, 4995), but leads to highly reactive HO, which reacts rapidly with pyrimidines and can induce strand cleavage in DNA.[14,7,8] On the other hand, it has been shown that the mechanism of NO3 reactions with organic compounds in water is similar to that in organic solvents (see ref. above).

[31]  P. Neta, R. E. Huie, J. Phys. Chem. 1986, 90, 4644.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL28Xlt1WlsrY%3D&md5=7c060b19d3a99b126ff3f154b9d02100CAS |

[32]  L. Eberson, Adv. Phys. Org. Chem. 1982, 18, 79.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL38XkvFWhsLk%3D&md5=8988f297c6186a4551119dd1a9d84ab8CAS |

[33]  C. Goeschen, N. Wibowo, J. M. White, U. Wille, Org. Biomol. Chem. 2011, 9, 3380.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXks12is70%3D&md5=90c59cbff50418f52219de7692b273f3CAS |

[34]  O. Krüger, U. Wille, Org. Lett. 2001, 3, 1455.
         | Crossref | GoogleScholarGoogle Scholar |

[35]  U. Wille, in Highlights in Bioorganic Chemistry: Methods and Applications (Eds C. Schmuck, H. Wennemers) 2003 pp. 352–368 (Wiley-VCH: Weinheim).

[36]  J. J. Ritter, P. P. Minieri, J. Am. Chem. Soc. 1948, 70, 4045.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaH1MXhtVyjsw%3D%3D&md5=a16d99931270e166f9513289d55d3d34CAS |

[37]  There is some controversy in literature about the role of the N(3) proton. In aqueous systems reversible deprotonation at N(3) in pyrimidine radical cations obtained after oxidation of the pyrimdines by SO4•– has been proposed to occur with water acting as the base (ref. [9]), whereas other experimental and computational studies suggest that N(3) deprotonation is an unlikely process (ref. [5], and cited literature).

[38]  It was not possible to determine relative product ratios from the HPLC data, since the UV spectra of the products were different.

[39]  V. Nair, A. Deepthi, Chem. Rev. 2007, 107, 1862.[E0 (Ce4+/Ce3+) = 1.61 V vs NHE].
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXktFCqsr8%3D&md5=f5c9d83ca7e9e38b5c04028684c2f725CAS |

[40]  Because of the low solubility of CAN in many organic solvents the photochemical reactions could not be performed in dichloromethane.

[41]  It has been shown that CAN can be used as nitrating agent for electron-rich aromatic systems and malonates; see for example ref. [39] and
      (b) J. R. Peterson, H. D. Do, A. J. Dunham, Can. J. Chem. 1988, 66, 1670.
      (c) H. M. Chawla, R. S. Mittal, Synthesis 1984, 70.
      (d) U. Holzgrabe, J. Reinhardt, E. Stoll, Arch. Pharm. 1993, 326, 985.
      (e) J. M. Mellor, S. Mittoo, R. Parkes, R. W. Millar, Tetrahedron 2000, 56, 8019.
      (f) N. Ganguly, A. K. Sukai, S. De, Synth. Commun. 2001, 31, 301.
      (g) J. L. Grenier, J. P. Catteau, P. Cotelle, Synth. Commun. 1999, 29, 1201.
      In these reactions the nitrosyl cation NO2+ is formally considered as the nitrating agent. Since the aromatic ring in uridine 1 is electron-deficient, such a CAN mediated nitration is not likely to occur. This conclusion is also supported by our finding that no reaction occurred between CAN and 1 in the absence of light (see text).

[42]  T. Del Giacco, E. Baciocchi, S. Steenken, J. Phys. Chem. 1993, 97, 5451.The oxidation could principally occur through an outer-sphere or inner-sphere electron transfer. In the case of the latter, initial addition of the electrophilic NO3 at the more electron-rich C5 of the double bond may be suggested; see also:
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXltFKlsLg%3D&md5=41ccc0a98281f61571d4858a30a10acbCAS |

[43]  M. Faraggi, F. Broitman, J. B. Trent, M. H. Klapper, J. Phys. Chem. 1996, 100, 14751.A related cleavage of the C–N glycosidic bond has been proposed to occur in the course of the azidyl radical mediated oxidation of guanosine; see
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28Xksl2gtr0%3D&md5=9754f0d021a9822dbaab97b297584383CAS |

[44]  It has been suggested from EPR data that the uridine radical cation could transfer the spin from the nucleobase to C2′ of the ribose moiety (see ref. [4]). At pH < 2, the resulting radical can undergo acid-catalyzed cleavage of the C1′–O bond of the ribose (see ref. [8]). We have no indication for a similar opening of the ribose ring in the reaction of the permethylated uridine 1 with NO3.

[45]  P. S. Gradeff, K. Yunlu, T. J. Deming, J. M. Olofson, J. W. Ziller, W. J. Evans, Inorg. Chem. 1989, 28, 2600.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXkt1elsbY%3D&md5=65faaeec96b01bb7d395178f8bba97f9CAS |

[46]  T. Shono, Y. Yoshinari, K. Takigawa, H. Maekawa, M. Ishifune, S. Kashimura, Chem. Lett. 1994, 23, 1045.
         | Crossref | GoogleScholarGoogle Scholar |

[47]  U. Wille, J. Phys. Org. Chem. 2011, 24, 672. and literature cited.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXovVCktr0%3D&md5=584f431cdae548a4902eb2bc6300eef2CAS |

[48]  Kinetic studies in the gas-phase revealed that the latter reacts with unsaturated compounds by several orders of magnitude slower than NO3 (see: C. Pfrang, R. S. Martin, C. E. Canosa-Mas, R. P. Wayne, Phys. Chem. Chem. Phys. 2006, 8, 354), and N2O5 does not nitrate deactivated aromatic compounds in solution (see: R. R. Bak, A. J. Smallridge, Tetrahedron Lett. 2001, 42, 6767 and cited literature). By using inert and anhydrous solvents in our experiments, ionic dissociation of any N2O5 present in the system should be suppressed.

[49]  It is not possible to probe for formation of NO2 and its trapping by pyrimidine radical cations through addition of NO2 to the reaction system, since CAN oxidizes NO2 to NO2; see ref. [39] and cited literature.

[50]  O. Ito, S. Akiho, M. Iino, J. Org. Chem. 1989, 54, 2436.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXitFajtr0%3D&md5=afb1aa3182c0e99812497c6245b64a06CAS |

[51]  It has been shown that intramolecular HAT by a C6 peroxyl radical, which could lead to a C1′ radical that subsequently undergoes cleavage of the glycosidic bond to give a ribolactone of type 5, does occur but is a very slow process; see: C. A. Newman, M. J. E. Resendiz, J. T. Sczepanski, M. M. Greenberg, J. Org. Chem. 2009, 74, 7007. Since O2 was excluded in the experiments where CAN photolysis was used to generate NO3, peroxyl radicals should not be formed.

[52]  N2O4 can be oxidized with O3 to give N2O5; see also ref. [48].

[53]  E. Egert, H.-J. Lindner, W. Hillen, H. G. Gassen, Nucleic Acids Res. 1977, 4, 929.For a crystal structure of 5-nitrouridine see:
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2sXhvFygsLw%3D&md5=d2c7c6ff91ddb30fb5d766817dd2693dCAS |

[54]  W. Zhou, P. W. Doetsch, Proc. Natl Acad. Sci. USA 1993, 90, 6601.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXlvFygs7s%3D&md5=a153bf187f45c5bff73ee18cc3a9ba59CAS |

[55]  The finding that even seemingly small structural differences in pyrimidines, such as the presence or absence of the methyl group at C5, greatly influence the reaction pathway following initial oxidative electron transfer, is in accordance with literature, see for example refs. [4, 5].

[56]  C. Adriaanse, M. Sulpizi, J. Van de Vondele, M. Sprik, J. Am. Chem. Soc. 2009, 131, 6046.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXktF2nsr4%3D&md5=6654214a58acdf23921fe6ea3e4cdfe7CAS |

[57]  X.-B. Wang, J. B. Nicholas, L.-S. Wang, J. Phys. Chem. A 2000, 104, 504.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXotFKgtbs%3D&md5=53257bb70dd8724ab3e8ff52047607e3CAS |

[58]  J. E. Bloor, R. E. Sherrod, R. A. Paysen, Chem. Phys. Lett. 1978, 54, 309.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1cXksV2hsbw%3D&md5=42a742cf3616a500b041c1b22f27915cCAS |

[59]  W. H. Koppenol, J. F. Liebman, J. Phys. Chem. 1984, 88, 99.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXktFGlsw%3D%3D&md5=bbcdf2c29211ee92673090e0ec682dd2CAS |

[60]  C. E. Crespo-Hernández, D. M. Close, L. Corb, J. Leszczynsky, J. Phys. Chem. B 2007, 111, 5386.
         | Crossref | GoogleScholarGoogle Scholar |

[61]  R. E. Huie, C. L. Clifton, P. Neta, Int. J. Radiat. Appl. Instr. 1991, 38, 477.
         | 1:CAS:528:DyaK3MXmvVyhsbY%3D&md5=bf632d5608323eab22a3270f04cc6fe8CAS |

[62]  G. N. R. Tripathi, J. Am. Chem. Soc. 1998, 120, 4161.Electron transfer in HO reactions with electron rich aromatic compounds has been observed by time-resolved resonance Raman spectroscopy; see:
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXis12msbk%3D&md5=7261fb2ba6084f77ad83990c1d1517caCAS |

[63]  W. F. Bryant, P. D. Klein, Anal. Biochem. 1975, 65, 73.
         | Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2MXksFykt7s%3D&md5=8993c8f3ecf48e9004b8085ef14fb946CAS |