Abstract
Full text: Cancer 'chemoprevention' is now an important area of research providing a practical approach to identifying potentially useful inhibitors of cancer development. One such class of compounds, which have emerged from epidemiological studies are constituents of tea, commonly referred to as catechins or flavonols. These compounds have been shown to be highly active antioxidants and anticarcinogens. The flavonols are efficient scavengers of free radicals per se but their measured low concentrations in human serum after ingestion of foods rich in flavanols, even after supplementation, means that it is very unlikely that direct free radical scavenging plays a part in their beneficial effects. We are investigating other free radical mechanisms of the flavanols which may give rise to their beneficial effects. By irradiating dilute aqueous solutions of plasmid DNA under 'constant radical scavenging conditions' with and without added flavonols, we have found that the flavanols afford some protection against strand breaks and base damage induced by OH radical attack. Complementary pulse radiolysis studies indicate that the flavonols can undergo electron transfer or H-atom transfer to oxidative damage sites on the DNA. A trend has emerged in that flavonols which act as good protectors of strand breaks and base damage undergo
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Anderson, R F
[1]
- The University of Auckland, Auckland, (New Zealand). Department of Chemistry
Citation Formats
Anderson, R F.
Fast chemical repair of oxidative damage of DNA by flavonoid antioxidants.
Australia: N. p.,
2000.
Web.
Anderson, R F.
Fast chemical repair of oxidative damage of DNA by flavonoid antioxidants.
Australia.
Anderson, R F.
2000.
"Fast chemical repair of oxidative damage of DNA by flavonoid antioxidants."
Australia.
@misc{etde_20157690,
title = {Fast chemical repair of oxidative damage of DNA by flavonoid antioxidants}
author = {Anderson, R F}
abstractNote = {Full text: Cancer 'chemoprevention' is now an important area of research providing a practical approach to identifying potentially useful inhibitors of cancer development. One such class of compounds, which have emerged from epidemiological studies are constituents of tea, commonly referred to as catechins or flavonols. These compounds have been shown to be highly active antioxidants and anticarcinogens. The flavonols are efficient scavengers of free radicals per se but their measured low concentrations in human serum after ingestion of foods rich in flavanols, even after supplementation, means that it is very unlikely that direct free radical scavenging plays a part in their beneficial effects. We are investigating other free radical mechanisms of the flavanols which may give rise to their beneficial effects. By irradiating dilute aqueous solutions of plasmid DNA under 'constant radical scavenging conditions' with and without added flavonols, we have found that the flavanols afford some protection against strand breaks and base damage induced by OH radical attack. Complementary pulse radiolysis studies indicate that the flavonols can undergo electron transfer or H-atom transfer to oxidative damage sites on the DNA. A trend has emerged in that flavonols which act as good protectors of strand breaks and base damage undergo a higher degree of electron transfer than other compounds. Pulse radiolysis has been used to determine the one electron reduction potentials of the radicals of DNA bases and peroxy-alkyl radicals, which are formed upon one-electron oxidation of DNA by radical anions and OH radicals. Similarly obtained data for the flavonols now allow for a rational approach to understanding the antioxidant reactions between the flavonols and DNA radicals. The relatively long life-times of the DNA radicals allow for the kinetics of electron transfer to be studied by pulse radiolysis and the long lifetimes we believe may partially account for the effectiveness of even low concentrations of the flavonols to act in an antioxidant manner. The reactivities of different classes of the flavanols is discussed in this framework.}
place = {Australia}
year = {2000}
month = {Jul}
}
title = {Fast chemical repair of oxidative damage of DNA by flavonoid antioxidants}
author = {Anderson, R F}
abstractNote = {Full text: Cancer 'chemoprevention' is now an important area of research providing a practical approach to identifying potentially useful inhibitors of cancer development. One such class of compounds, which have emerged from epidemiological studies are constituents of tea, commonly referred to as catechins or flavonols. These compounds have been shown to be highly active antioxidants and anticarcinogens. The flavonols are efficient scavengers of free radicals per se but their measured low concentrations in human serum after ingestion of foods rich in flavanols, even after supplementation, means that it is very unlikely that direct free radical scavenging plays a part in their beneficial effects. We are investigating other free radical mechanisms of the flavanols which may give rise to their beneficial effects. By irradiating dilute aqueous solutions of plasmid DNA under 'constant radical scavenging conditions' with and without added flavonols, we have found that the flavanols afford some protection against strand breaks and base damage induced by OH radical attack. Complementary pulse radiolysis studies indicate that the flavonols can undergo electron transfer or H-atom transfer to oxidative damage sites on the DNA. A trend has emerged in that flavonols which act as good protectors of strand breaks and base damage undergo a higher degree of electron transfer than other compounds. Pulse radiolysis has been used to determine the one electron reduction potentials of the radicals of DNA bases and peroxy-alkyl radicals, which are formed upon one-electron oxidation of DNA by radical anions and OH radicals. Similarly obtained data for the flavonols now allow for a rational approach to understanding the antioxidant reactions between the flavonols and DNA radicals. The relatively long life-times of the DNA radicals allow for the kinetics of electron transfer to be studied by pulse radiolysis and the long lifetimes we believe may partially account for the effectiveness of even low concentrations of the flavonols to act in an antioxidant manner. The reactivities of different classes of the flavanols is discussed in this framework.}
place = {Australia}
year = {2000}
month = {Jul}
}