62697-16-9Relevant articles and documents
Highly diastereoselective synthesis of nucleoside adducts from the carcinogenic benzo[a]pyrene diol epoxide and a computational analysis
Lakshman, Mahesh K.,Keeler, John C.,Ngassa, Felix N.,Hilmer, John H.,Pradhan, Padmanava,Zajc, Barbara,Thomasson, Kathryn A.
, p. 68 - 76 (2008/04/18)
A diastereoselective synthesis of the nucleoside adducts corresponding to a cis ring-opening of the carcinogen (±)-7β,8α-dihydroxy- 9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BaP DE-2) by 2′-deoxyadenosine and 2′-deoxyguanosine is described. The key
Chloride ion catalyzed conformational inversion of carbocation intermediates in the hydrolysis of a benzo[a]pyrene 7,8-diol 9,10-epoxide
Doan, Lanxuan,Yagi, Haruhiko,Jerina, Donald M.,Whalen, Dale L.
, p. 14382 - 14387 (2007/10/03)
A highly efficient procedure for converting 7β,8α-dihydroxy-9α,10α-epoxy-7,8,9, 10-tetrahydrobenzo[a]pyrene (1) to its trans-9,10-chlorohydrin (5) with excellent yield and purity by the reaction of anhydrous HCI in THF has been developed. The rate of reac
Nitrogen dioxide as an oxidizing agent of 8-oxo-7,8-dihydro-2′-deoxyguanosine but not of 2′-deoxyguanosine
Shafirovich,Cadet,Gasparutto,Dourandin,Geacintov
, p. 233 - 241 (2007/10/03)
The redox reactions of guanine and its widely studied oxidation product, the 8-oxo-7,8-dihydro derivative, are of significant importance for understanding the mechanisms of oxidative damage in DNA. Employing 2′-deoxyguanosine 5′-monophosphate (dGMP) and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxo-dG) in neutral aqueous solutions as model systems, we have used nanosecond laser flash photolysis to demonstrate that neutral radicals, dGMP(-H)?, derived by the one-electron oxidation and deprotonation of dGMP, can oxidize nitrite anions (NO2-) to the nitrogen dioxide radical ?NO2. In turn, we show that ?NO2 can give rise to a one-electron oxidation of 8-oxo-G, but not of dGMP. The one-electron oxidation of dGMP was initiated by a radical cation generated by the laser pulse-induced photoionization of a pyrene derivative with enhanced water solubility, 7,8,9,10-tetrahydroxytetrahydrobenzo[α]pyrene (BPT). The dGMP(-H)? neutral radicals formed via deprotonation of the dGMP?+ radical cations and identified by their characteristic transient absorption spectrum (λmax ～ 310 nm) oxidize nitrite anions with a rate constant of(2.6 ± 0.3) × 106 M-1 s-1. The 8-oxo-dG is oxidized by ?NO2 with a rate constant of (5.3 ± 0.5) × 106 M-1 s-1. The 8-oxo-dG(-H)? neutral radicals thus generated are clearly identified by their characteristic transient absorption spectra (λmax ～ 320 nm). The rate constant of 8-oxo-dG oxidation (k12) by the ?NO2 one-electron oxidant (the ?NO2/NO2- redox potential, E° ≈ 1.04 V vs NHE) is lower than k12 for a series of oxidizing aromatic radical cations with known redox potentials. The k12 values for 8-oxo-dG oxidation by different aromatic radical cations derived from the photoionization of their parent compounds depend on the redox potentials of the latter, which were in the range of 0.8-1.6 V versus NHE. The magnitude of k12 gradually decreases from a value of 2.2 × 109 M-1 s-1 (E° = 1.62 V) to 5.8 × 108 M-1 s-1 (E° = 1.13 V) and eventually to 5 × 107 M-1 s-1 (E° = 0.91 V). The implications of these results, including the possibility that the redox cycling of the ?NO2/NO2- species can be involved in the further oxidative damage of 8-oxo-dG in DNA in cellular environments, are discussed.
