Identification of novel N-benzyloxy-amino acid hydroxamates as inhibitors of the virulence factor LasB from Pseudomonas aeruginosa†

The emergence of multidrug-resistant pathogens, particularly Pseudomonas aeruginosa, 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 N-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 (K_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.