Eleutherin and Isoeleutherin Activity against Staphylococcus aureus and Escherichia coli Strain’s: Molecular Docking and Antibacterial Evaluation

Abstract

Naphthoquinones eleutherin and isoeleutherin have demonstrated promising antibacterial activity, probably due to their quinone structure, which can generate reactive oxygen species. The study examines the activities of pathogens, such as Staphylococcus aureus and Escherichia coli, associated with antimicrobial resistance and explores their potential mechanisms of action. The MIC, IC50, and MBC were determined. PharmMapper 2017 server and GOLD 2020.1 software were utilized for molecular docking to identify protein targets and interaction mechanisms. The docking predictions were verified by redocking, focusing on structures with RMSD below 2 Å. The molecular docking revealed a significant affinity of eleutherin for the peptide, transcriptional regulator QacR, and regulatory protein BlaR1 with better interactions with BlaR1 than the crystallographic ligand (benzylpenicillin). Isoeleutherin demonstrated specific interactions with methionine aminopeptidase, indicating specificity and affinity. In summary, the difference in naphthoquinones activities may be related to structural differences. Eleutherin exhibits potential as a therapeutic adjuvant to reverse bacterial resistance in S. aureus, suggesting this molecule interferes with the antibiotic resistance mechanism. The absence of homologous proteins or variations in the structure of the target proteins could be the cause of the inactivity against E. coli.