Journal article
Catalytic Metals, Ascorbate and Free Radicals: Combinations to Avoid
Radiation research, Vol.145(5), pp.532-541
05/1996
DOI: 10.2307/3579271
PMID: 8619018
Abstract
Trace levels of transition metals can participate in the metal-catalyzed Haber-Weiss reaction (superoxide-driven Fenton reaction) as well as catalyze the oxidation of ascorbate. Generally ascorbate is thought of as an excellent reducing agent; it is able to serve as a donor antioxidant in free radical-mediated oxidation processes. However, as a reducing agent it is also able to reduce redox-active metals such as copper and iron, thereby increasing the pro-oxidant chemistry of these metals. Thus ascorbate can serve as both a pro-oxidant and an antioxidant. In general, at low ascorbate concentrations, ascorbate is prone to be a pro-oxidant, and at high concentrations, it will tend to be an antioxidant. Hence there is a crossover effect. We propose that the "position" of this crossover effect is a function of the catalytic metal concentration. In this presentation, we discuss: (1) the role of catalytic metals in free radical-mediated oxidations; (2) ascorbate as both a pro-oxidant and an antioxidant; (3) catalytic metal catalysis of ascorbate oxidation; (4) use of ascorbate to determine adventitious catalytic metal concentrations; (5) use of ascorbate radical as a marker of oxidative stress; and (6) use of ascorbate and iron as free radical pro-oxidants in photodynamic therapy of cancer.
Details
- Title: Subtitle
- Catalytic Metals, Ascorbate and Free Radicals: Combinations to Avoid
- Creators
- Garry R BuettnerBeth Anne Jurkiewicz
- Resource Type
- Journal article
- Publication Details
- Radiation research, Vol.145(5), pp.532-541
- DOI
- 10.2307/3579271
- PMID
- 8619018
- ISSN
- 0033-7587
- eISSN
- 1938-5404
- Language
- English
- Date published
- 05/1996
- Academic Unit
- Radiation Oncology
- Record Identifier
- 9984047601202771
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