To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

7-Nitro-4-(phenylthio)ben… - University of Gothenburg, Sweden Till startsida
Sitemap
To content Read more about how we use cookies on gu.se

7-Nitro-4-(phenylthio)benzofurazan is a potent generator of superoxide and hydrogen peroxide

Journal article
Authors Erik V. Patridge
Emma S. E. Eriksson
Philip G. Penketh
Raymond P. Baumann
Rui Zhu
Krishnamurthy Shyam
Leif A Eriksson
A. C. Sartorelli
Published in Archives of Toxicology
Volume 86
Issue 10
Pages 1613-1625
ISSN 0340-5761
Publication year 2012
Published at Department of Chemistry and Molecular Biology
Pages 1613-1625
Language en
Links dx.doi.org/10.1007/s00204-012-0872-...
Keywords Benzofurazan, Reactive oxygen species, Oxidative stress, Electrochemistry, Electrophilic stress, performance liquid-chromatography, immunosuppressive drugs, fluorogenic, reagent, escherichia-coli, carboxylic-acids, reduction, oxygen, mechanism, benzofurazans, inhibitors, kabatake t, 1990, chemical & pharmaceutical bulletin, v38, p128, kabatake t, 1991, chemical & pharmaceutical bulletin, v39, p1352, kabatake t, 1992, chemical & pharmaceutical bulletin, v40, p1644, kabatake t, 1992, journal of biological chemistry, v267, p4613
Subject categories Toxicology, Chemical Sciences, Physical Chemistry, Theoretical Chemistry, Biophysical chemistry

Abstract

Here, we report on 7-nitro-4-(phenylthio)benzofurazan (NBF-SPh), the most potent derivative among a set of patented anticancer 7-nitrobenzofurazans (NBFs), which have been suggested to function by perturbing protein-protein interactions. We demonstrate that NBF-SPh participates in toxic redox-cycling, rapidly generating reactive oxygen species (ROS) in the presence of molecular oxygen, and this is the first report to detail ROS production for any of the anticancer NBFs. Oxygraph studies showed that NBF-SPh consumes molecular oxygen at a substantial rate, rivaling even plumbagin, menadione, and juglone. Biochemical and enzymatic assays identified superoxide and hydrogen peroxide as products of its redox-cycling activity, and the rapid rate of ROS production appears to be sufficient to account for some of the toxicity of NBF-SPh (LC50 = 12.1 mu M), possibly explaining why tumor cells exhibit a sharp threshold for tolerating the compound. In cell cultures, lipid peroxidation was enhanced after treatment with NBF-SPh, as measured by 2-thiobarbituric acid-reactive substances, indicating a significant accumulation of ROS. Thioglycerol rescued cell death and increased survival by 15-fold to 20-fold, but pyruvate and uric acid were ineffective protectants. We also observed that the redox-cycling activity of NBF-SPh became exhausted after an average of approximately 19 cycles per NBF-SPh molecule. Electrochemical and computational analyses suggest that partial reduction of NBF-SPh enhances electrophilicity, which appears to encourage scavenging activity and contribute to electrophilic toxicity.

Page Manager: Webmaster|Last update: 9/11/2012
Share:

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?