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Antioxidant activity assay based on laccase-generated radicals
Endry Nugroho Prasetyo1, Tukayi Kudanga, Walter Steiner
1Department of Environmental Biotechnology, Graz University of Technology, Petersgasse 12/1, 8010, Graz, Austria.
Analytical and Bioanalytical Chemistry
|October 30, 2008
Summary
A new antioxidant assay uses laccase-oxidized syringaldazine for measuring antioxidant activity. This method provides results comparable to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay.
Area of Science:
- Biochemistry
- Analytical Chemistry
Background:
- Conventional antioxidant activity assays often rely on stable radicals like DPPH.
- Developing novel, reliable, and efficient antioxidant assays is crucial for various scientific fields.
Purpose of the Study:
- To develop a novel antioxidant activity assay using laccase-oxidized phenolics.
- To evaluate syringaldazine as a substrate for this new assay.
Main Methods:
- Phenolic compounds were oxidized by laccase and stabilized with methanol.
- Antioxidant activities of ascorbic acid and Trolox were measured using oxidized phenolics.
- Syringaldazine was identified as the optimal phenolic substrate.
Main Results:
- The laccase-syringaldazine assay demonstrated stoichiometric reduction similar to the DPPH assay.
- A direct correlation between oxygen consumption by laccase and antioxidant activity was established.
- One oxygen molecule reduction corresponded to four syringaldazine oxidations, reduced by two antioxidant molecules.
Conclusions:
- Laccase-oxidized syringaldazine offers a promising alternative for antioxidant activity measurement.
- The assay correlates antioxidant capacity with oxygen consumption, providing a novel mechanistic insight.
- This method shows potential for broad application in evaluating antioxidant compounds.
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