Antimicrobial Activities and Mode of Flavonoid Actions
Amal Thebti,
Ahmed Meddeb,
Issam Ben Salem,
Coulibaly Bakary,
Sami Ayari,
Farhat Rezgui,
Khadija Essafi-Benkhadir,
Abdellatif Boudabous,
Hadda-Imene Ouzari
Affiliations
Amal Thebti
Laboratory of Microorganisms and Active Biomolecules, Department of Biology, LR03ES03, Faculty of Sciences of Tunis, University of Tunis-El Manar, El Manar I, Tunis 2092, Tunisia
Ahmed Meddeb
Laboratory of Structural Organic Chemistry and Macromolecular, LR99ES14, University of Tunis-El Manar, El-Manar I, Tunis 2092, Tunisia
Issam Ben Salem
Laboratory of Microbiology and LNR-Mycology, University Hospital of Abderahman Mami, Ariana 2038, Tunisia
Coulibaly Bakary
Environment and Agrifood Laboratory (ENVAL), Contaminant Group, Abidjan 21 BP 950, Côte d’Ivoire
Sami Ayari
Laboratory of Microorganisms and Active Biomolecules, Department of Biology, LR03ES03, Faculty of Sciences of Tunis, University of Tunis-El Manar, El Manar I, Tunis 2092, Tunisia
Farhat Rezgui
Laboratory of Structural Organic Chemistry and Macromolecular, LR99ES14, University of Tunis-El Manar, El-Manar I, Tunis 2092, Tunisia
Khadija Essafi-Benkhadir
Laboratory of Molecular Epidemiology and Experimental Pathology, LR16IPT04, Pasteur Institute of Tunis, University of Tunis El-Manar, Tunis 1002, Tunisia
Abdellatif Boudabous
Laboratory of Microorganisms and Active Biomolecules, Department of Biology, LR03ES03, Faculty of Sciences of Tunis, University of Tunis-El Manar, El Manar I, Tunis 2092, Tunisia
Hadda-Imene Ouzari
Laboratory of Microorganisms and Active Biomolecules, Department of Biology, LR03ES03, Faculty of Sciences of Tunis, University of Tunis-El Manar, El Manar I, Tunis 2092, Tunisia
The emergence of antibiotics-resistant bacteria has been a serious concern for medical professionals over the last decade. Therefore, developing new and effective antimicrobials with modified or different modes of action is a continuing imperative. In this context, our study focuses on evaluating the antimicrobial activity of different chemically synthesized flavonoids (FLAV) to guide the chemical synthesis of effective antimicrobial molecules. A set of 12 synthesized molecules (4 chalcones, 4 flavones and 4 flavanones), bearing substitutions with chlorine and bromine groups at the C6′ position and methoxy group at the C4′ position of the B-ring were evaluated for antimicrobial activity toward 9 strains of Gram-positive and Gram-negative bacteria and 3 fungal strains. Our findings showed that most tested FLAV exhibited moderate to high antibacterial activity, particularly against Staphylococcus aureus with minimum inhibitory concentrations (MIC) between the range of 31.25 and 125 μg/mL and that chalcones were more efficient than flavones and flavanones. The examined compounds were also active against the tested fungi with a strong structure-activity relationship (SAR). Interestingly, leakage measurements of the absorbent material at 260 nm and scanning electron microscopy (SEM) demonstrated that the brominated chalcone induced a significant membrane permeabilization of S. aureus.
