The dissociation of iodine by singlet molecular oxygen; role of the vibrational reservoir state A’(2u)

1989 ◽  
Vol 91 (3) ◽  
pp. 1938-1940 ◽  
Author(s):  
M. Nota ◽  
A. J. Bouvier ◽  
R. Bacis ◽  
A. Bouvier ◽  
P. Crozet ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Singlet Molecular Oxygen ◽  
Reservoir State

Role of Singlet Molecular Oxygen in the Oxidative Damage to Biomolecules

2011 ◽  
pp. 344-358
Author(s):  
Graziella Eliza Ronsein ◽  
Glaucia Regina Martinez ◽  
Eduardo Alves de Almeida ◽  
Sayuri Miyamoto ◽  
Marisa Helena Gennari de Medeiros ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Molecular Oxygen ◽  
Singlet Molecular Oxygen

Oxidation of 1-N2-etheno-2′-deoxyguanosine by singlet molecular oxygen results in 2′-deoxyguanosine: a pathway to remove exocyclic DNA damage?

2018 ◽  
Vol 399 (8) ◽  
pp. 859-867
Author(s):  
Glaucia Regina Martinez ◽  
Hulyana Brum ◽  
Guilherme Lanzi Sassaki ◽  
Lauro Mera de Souza ◽  
Ana Paula de Melo Loureiro ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Dna Adducts ◽  
High Performance ◽  
Chemical Reactivity ◽  
Water Soluble ◽  
Modified Nucleosides ◽  
Quenching Rate ◽  
Singlet Molecular Oxygen ◽  
Aldehyde Groups

Abstract Exocyclic DNA adducts are considered as potential tools for the study of oxidative stress-related diseases, but an important aspect is their chemical reactivity towards oxidant species. We report here the oxidation of 1-N2-etheno-2′-deoxyguanosine (1,N2-εdGuo) by singlet molecular oxygen (1O2) generated by a non-ionic water-soluble endoperoxide [N,N′-di(2,3-dihydroxypropyl)-1,4-naphthalenedipropanamide endoperoxide (DHPNO2)] and its corresponding oxygen isotopically labeled [18O]-[N,N′-di(2,3-dihydroxypropyl)-1,4- naphthalenedipropanamide endoperoxide (DHPN18O2)], and by photosensitization with two different photosensitizers [methylene blue (MB) and Rose Bengal (RB)]. Products detection and characterization were achieved using high performance liquid chromatography (HPLC) coupled to ultraviolet and electrospray ionization (ESI) tandem mass spectrometry, and nuclear magnetic resonance (NMR) analyses. We found that dGuo is regenerated via reaction of 1O2 with the ε-linkage, and we propose a dioxetane as an intermediate, which cleaves and loses the aldehyde groups as formate residues, or alternatively, it generates a 1,2-ethanediol adduct. We also report herein the quenching rate constants of 1O2 by 1,N2-εdGuo and other etheno modified nucleosides. The rate constant (kt) values obtained for etheno nucleosides are comparable to the kt of dGuo. From these results, we suggest a possible role of 1O2 in the cleanup of etheno adducts by regenerating the normal base.

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