An approach to evaluate two-electron reduction of 9,10-phenanthraquinone and redox activity of the hydroquinone associated with oxidative stress.
Free Radic Biol Med
; 43(5): 789-99, 2007 Sep 01.
Article
en En
| MEDLINE
| ID: mdl-17664142
Quinones are widely used as medicines or redox agents. The chemical properties are based on the reactions against an electron donor. 9,10-Phenanthraquinone (PQ), which is a quinone contaminated in airborne particulate matters, forms redox cycling, not Michael addition, with electron donors. Redox cycling of PQ contributes to its toxicity, following generation of reactive oxygen species (ROS). Detoxification of quinones is generally thought to be two-electron reduction forming hydroquinones. However, a hydroquinone of PQ, 9,10-dihydroxyphenanthrene (PQH(2)), has been never detected itself, because it is quite unstable. In this paper, we succeeded in detecting PQH(2) as its stable derivative, 9,10-diacetoxyphenanthrene (DAP). However, higher concentrations of PQ (>4 microM) form disproportionately with PQH(2), producing the 9,10-phenanthraquinone radical (PQ(-)) which is a one-electron reducing product of PQ. In cellular experiments using DAP as a precursor of PQH(2), it was shown that PQH(2) plays a critical role in the oxidative protein damage and cellular toxicity of PQ, showing that two-electron reduction of PQ can also initiate redox cycling to cause oxidative stress-dependent cytotoxicity.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fenantrenos
/
Estrés Oxidativo
/
Electrones
/
Hidroquinonas
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
Free Radic Biol Med
Asunto de la revista:
BIOQUIMICA
/
MEDICINA
Año:
2007
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Estados Unidos