Identification of novel <i>N</i>-benzyloxy-amino acid hydroxamates as inhibitors of the virulence factor LasB from <i>Pseudomonas aeruginosa</i>

The emergence of multidrug-resistant pathogens, particularly <i>Pseudomonas aeruginosa</i>, represents a global health concern. Among its major virulence factors, elastase B (LasB), a zinc-dependent metalloprotease, plays a pivotal role in host tissue degradation, immune evasion, and biofilm formation. Targeting LasB with selective inhibitors offers a promising therapeutic strategy to mitigate bacterial virulence while minimizing selective pressure for resistance development. In this study, a series of <i>N</i>-benzyloxy amino acid derivatives were designed, synthesized, and evaluated for their inhibitory activity against LasB. Structure-based optimization led to the identification of compound 12 as the most potent inhibitor (<i>K</i> _i = 0.92 μM), exhibiting high selectivity for LasB over human matrix metalloproteinases. Cell-based assays demonstrated its ability to inhibit LasB proteolytic activity and reduce biofilm formation without affecting bacterial viability. These findings highlight the potential of LasB inhibitors as pathoblockers, providing a targeted approach to disarm bacterial virulence rather than exerting bactericidal pressure.