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Synergistic or antagonistic antioxidant combinations - a case study exploring flavonoid-nitroxide hybrids
Astrid C R Larin1,2, Michael C Pfrunder1,2, Kathleen M Mullen1,2
1School of Chemistry and Physics, Faculty of Science, Queensland University of Technology, Brisbane, Queensland, 4001, Australia.
Organic & Biomolecular Chemistry
|February 2, 2023
Summary
Hybrid antioxidants combining nitroxides and flavonoids show reduced activity against reactive oxygen species (ROS). This study highlights challenges in developing multitargeted antioxidants for neurodegenerative diseases.
Area of Science:
- Medicinal Chemistry
- Neuroscience
- Biochemistry
Background:
- Neurodegenerative diseases present a significant global health challenge.
- Oxidative stress, driven by reactive oxygen species (ROS), is implicated in disease progression.
- Current treatments for neurodegeneration lack sufficient potency.
Purpose of the Study:
- To develop novel multitargeted antioxidants by hybridizing nitroxides and flavonoids.
- To evaluate the antioxidant potential and mechanism of these novel hybrid compounds.
- To explore the intricacies of drug hybridization for therapeutic development.
Main Methods:
- Synthesis of flavonoid-nitroxide hybrids using a modified Baker-Venkataraman reaction.
- Antioxidant evaluation via cyclic voltammetry to assess redox activity.
- Peroxyl radical scavenging ability measured using the ORAC assay.
Main Results:
- Flavonoid-nitroxide hybrids were synthesized in modest yields.
- Cyclic voltammetry confirmed the activity of both redox functionalities.
- Hybrid compounds exhibited reduced antioxidant activity compared to individual components in the ORAC assay.
Conclusions:
- The hybridization strategy resulted in compounds with diminished antioxidant capacity.
- The phenolic component of flavonoids may interfere with the nitroxide catalytic cycle.
- Drug hybridization requires careful consideration of potential functional interferences for effective therapeutic design.
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