The effect of anthracene-based chalcone derivatives in the resazurin dye reduction assay mechanisms for the investigation of Gram-positive and Gram-negative bacterial and fungal infection

A novel series of anthracene-based chalcone derivatives (ANNP, ANMNP, ANFL, ANAT, ANID, ANPT and ANTP) containing naphthalene, 6-methoxy naphthalene, fluorene, anthracene, indole, phenothiazine and thiophene were synthesized and evaluated in terms of their antibacterial and antifungal activities. Most of the synthesized compounds showed potent inhibitory activity towards various bacteria and fungi with minimum inhibitory concentrations (MICs) ranging from 0.39 to 100 μg mL−1. Their antibacterial and antifungal activities have been evaluated using a resazurin dye reduction assay method. These compounds showed moderate to good antibacterial and antifungal activities. Compounds ANNP, ANFL, ANID and ANPT were found to be the most potent with an MIC value of 3.12 (μg mL−1) against bacterial strains Bacillus cereus and Staphylococcus aureus. Compounds ANFL and ANAT also exhibited the same inhibitory activity with a MIC value of 3.12 (μg mL−1) against the fungal strains Candida albicans and Candida cruzi while the remaining compounds showed moderate to weak activities as compared to the corresponding standard drugs.