Synthesis and Antimicrobial Evaluation of 1,4‐Naphthoquinone Derivatives as Potential Antibacterial Agents

Abstract

1,4-Naphthoquinones are an important class of compounds present in a number of natural products. In this study, a new series of 1,4-naphthoquinone derivatives were synthesized. All the synthesized compounds were tested for <i>in vitro</i> antimicrobial activity. In this present investigation, two Gram-positive and five Gram-negative bacterial strains and one pathogenic yeast strain were used to determine the antibacterial activity. Naphthoquinones tested for its antibacterial potencies, among seven of them displayed better antimicrobial activity against <i>Staphylococcus aureus</i> (<i>S. aureus</i>; 30-70 μg/mL). Some of the tested compounds showed moderate to low antimicrobial activity against <i>Pseudomonas aeruginosa</i> (<i>P. aeruginosa</i>) and <i>Salmonella bongori</i> (<i>S. bongori</i>; 70-150 μg/mL). In addition, most active compounds against <i>S. aureus</i> were evaluated for toxicity to human blood cells using a hemolysis assay. For better understanding, reactive oxygen species (ROS) generation, time-kill kinetic study, and apoptosis, necrosis responses were investigated for three representative compounds.