Effect of electron donating groups on polyphenol-based antioxidant dendrimers

Area of Science:

• Medicinal Chemistry
• Polymer Science
• Nanotechnology

Background:

• Antioxidants combat diseases by reducing oxidative stress from reactive radicals.
• Antioxidant dendrimers represent a novel class of potent antioxidant compounds.
• The influence of electron-donating groups (EDGs) on antioxidant activity requires further elucidation.

Purpose of the Study:

• Synthesize novel polyphenol-based antioxidant dendrimers.
• Investigate the impact of electron-donating groups on dendrimer antioxidant activity.
• Evaluate the protective effects of dendrimers against free radical damage.

Main Methods:

• Synthesized six polyphenol-based dendrimers using syringaldehyde, vanillin, and 4-hydroxybenzaldehyde building blocks.
• Employed alkyne-azide 1,3-cycloaddition click chemistry with microwave energy for dendrimer synthesis.
• Assessed antioxidant activity using DPPH assay and evaluated protection of DNA and LDL against free radicals.

Main Results:

• Dendrimers with syringaldehyde and vanillin showed 70- and 170-fold higher antioxidant activity, respectively, compared to their parent molecules.
• Antioxidant activity increased with a higher number of electron-donating groups.
• Dendrimers effectively protected DNA and LDL from carbon and nitrogen-based radicals but not hydroxyl radicals.

Conclusions:

• Polyphenol-based antioxidant dendrimers with EDGs exhibit significantly enhanced antioxidant properties.
• These dendrimers offer protection against various free radicals without inducing pro-oxidant activity.
• Further research is needed to explore their therapeutic potential and limitations against specific radical species.