Unveiling Antibacterial and Antibiofilm Mechanisms of Methyleugenol: Implications for Ecomaterial Functionalization

Bacterial resistance evolution necessitates the continuous adaptation of antimicrobial agents. In this study, we systematically investigated the antibacterial and biofilm-inhibition mechanisms of plant extracts, including methyleugenol and eugenol, and further explored their potential for immobilization in practical applications. Our findings revealed that eugenol exhibited robust antibacterial activity by disrupting bacterial redox balance and membrane permeability. Methyleugenol, on the other hand, efficiently mitigated biofilm formation by inhibiting the quorum sensing (QS) system and depolarizing the cell membrane. Through gene expression analysis and molecular docking studies, we confirmed that methyleugenol suppressed the transcriptional expression of QS regulatory genes by competitively binding to the RhlR receptor protein, thereby reducing the secretion of extracellular polymeric substances and inhibiting the biofilm formation. Furthermore, we observed an upregulation of multiple efflux pump MexAB-OprM as a response to bacterial reductive stress during compound exposure. To expand the practical utility of these findings, we successfully grafted methyleugenol onto glass surfaces using the atom transfer radical polymerization method, demonstrating enduring antibacterial and antibiofilm properties. Overall, our study offers a comprehensive understanding of the antibacterial and antibiofilm mechanisms of methyleugenol and eugenol, with promising applications for enhancing ecomaterial functionalization.