Modified Flavonoids with Diamines and Polyamines Provide Enhanced Fluorescence and Antimicrobial Activity

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Materials Science

Background:

• Flavonoids, a class of polyphenolic compounds, possess diverse health benefits including antioxidant, anti-inflammatory, anticancer, and antibacterial properties.
• Natural products serve as a basis for developing biologically active materials for human health and disease management.
• Chemical modification of natural products can enhance their properties and expand their applications.

Purpose of the Study:

• To design and synthesize novel Schiff base derivatives of flavonoids.
• To investigate the photoluminescence properties of these new derivatives.
• To evaluate the antimicrobial efficacy of the synthesized flavonoid derivatives.

Main Methods:

• Synthesis of flavonoid derivatives using condensation reactions with various diamines and polyamines (e.g., ethylenediamine, spermidine).
• Characterization of synthesized compounds using spectroscopic techniques (FT-IR, UV-Visible, ESI-MS, NMR) and elemental analysis.
• Photoluminescence studies and antimicrobial screening against Gram-positive and Gram-negative bacterial strains.

Main Results:

• Successful synthesis and characterization of novel naringin and naringenin-based Schiff base derivatives.
• Photoluminescence studies revealed enhanced activity in naringin derivatives and quenching in others, indicating modification of conjugated systems.
• Antibacterial screening demonstrated selective efficacy against *Escherichia coli*.

Conclusions:

• Chemically modified flavonoids, specifically the synthesized Schiff base derivatives, exhibit promising photoluminescent properties.
• These novel flavonoid-(poly)amine materials show potential as selective antimicrobial agents, particularly against *E. coli*.
• The findings suggest these compounds can serve as multifunctional agents, acting as both antimicrobial agents and fluorescent probes.