Structure-Activity Relationship of Flavonoids as Antibacterial Agents: Insights from in vitro and in silico Evaluation

Background

Flavonoids, a large class of polyphenols, have wide structural diversity which can be exploited to design potential leads for treating bacterial infections. However, the effect of the functional groups present in these flavonoids on their antibacterial actions remains largely unexplored.

Objectives

To evaluate the antibacterial activity of various flavonoid classes against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria, as well as to validate the results using in silico molecular docking studies.

Materials and Methods

The Minimum Inhibitory Concentration (MIC) of 21 flavonoids was determined by the microbroth dilution method. Their structures were docked against proteins of both bacterial strains using Python Prescription (PyRx) software and visualized via Biovia Discovery Studio.

Results

Different flavonoids exhibited stark differences in MIC values across both strains. Molecular docking suggested binding preferences based on the type, number, and positions of functional groups.

Conclusion

The study established the Structure-Activity Relationship (SAR) of these natural compounds, providing insights into structural modifications like glycosylation and hydroxylation, alongside physicochemical properties like lipophilicity.