Bioevaluation of (Z)-2-methyl-5-(1-methyl-1H-indol-3-yl)-1,1-bis(methylthio)penta-1,4-dien-3-one (ZMPD) against multidrug resistant pathogen Enterococcus faecium

Indole-derived compounds have garnered significant attention due to their potent bactericidal properties. In light of the growing issue of antibiotic resistance among bacterial strains, the development of novel antibacterial agents with enhanced efficacy remains a critical priority., The antibacterial activity of ZMPD, an indole derived heterocyclic compound was evaluated against Enterococcus faecium , a clinically relevant multidrug-resistant pathogen. The minimum inhibitory concentration (MIC) of ZMPD was determined to be 25 mg/mL. Additionally, cytotoxicity assessment via the MTT assay revealed an IC₅₀ value of 30 mg/mL. Time-kill kinetics indicated a lethal time 50 (LT₅₀) of approximately 7.5 h, suggesting a time-dependent bactericidal effect. In-silico molecular docking studies demonstrated strong binding interactions between ZMPD and specific protein targets of E. faecium . Notably, the predicted binding sites of ZMPD were distinct from those targeted by ampicillin, indicating a potentially novel mechanism of action. These findings position ZMPD as a promising candidate for the treatment of infections caused by multidrug-resistant Enterococcus faecium .