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Reaction between ortho-semiquinones and oxygen: pulse radiolysis, electron spin resonance, and oxygen uptake studies. Arch Biochem Biophys 1988 Oct;266(1):277-84

Date

10/01/1988

Pubmed ID

2845864

DOI

10.1016/0003-9861(88)90259-7

Scopus ID

2-s2.0-0023720112 (requires institutional sign-in at Scopus site)   35 Citations

Abstract

The cytotoxicity to tumor cells or cardiotoxic side effects of certain para-quinone antitumor drugs have been attributed to the corresponding semiquinones and derived superoxide and hydroxyl radicals. It has also been suggested that ortho-semiquinones, including those that arise during melanogenesis, produced via either the one-electron oxidation of catechol(amine)s or the one-electron reduction of the corresponding quinones, react with molecular oxygen to give superoxide and hydrogen peroxide. Furthermore it has been shown that catechol(amine)s which form noncyclizable quinones are more cytotoxic toward melanogenic cells than those forming cyclizable quinones. In order to provide further kinetic information on the interaction of oxygen with ortho-semiquinones, using pulse radiolysis we directly measured the rates of reaction of various ortho-semiquinones with molecular oxygen. The semiquinones of the corresponding catechol(amine)s were also produced by the horseradish peroxidase/hydrogen peroxide system, and detected by electron spin resonance spectroscopy using the spin stabilization method. Oxygen consumption was monitored using a standard Clark oxygen electrode. Our data indicate that while ortho-semiquinones from catechol(amine)s and catechol estrogens do not react with molecular oxygen at a rate equal to or greater than k less than or equal to 10(5) M-1 s-1, semiquinones from hydroxy-substituted catechol(amine)s react with dioxygen with rates in the range k = 10(6)-10(7) M-1 s-1.

Author List

Kalyanaraman B, Korytowski W, Pilas B, Sarna T, Land EJ, Truscott TG

Author

Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Antineoplastic Agents
Catecholamines
Catechols
Chemical Phenomena
Chemistry
Electron Spin Resonance Spectroscopy
Estrogens, Catechol
Free Radicals
Oxidation-Reduction
Oxygen
Oxygen Consumption
Quinones