Identification of Benzyloxy Carbonimidoyl Dicyanide Derivatives as Novel Type III Secretion System Inhibitors via High-Throughput Screening.

摘要: The type III secretion system (T3SS) in many Gram-negative bacterial pathogens is regarded as the most critical virulence determinant and an attractive target for novel anti-virulence drugs. In this study, we constructed a T3SS reporter containing β-lactamase gene fused with signal peptide sequence of effector gene, established high-throughput screening inhibitors plant pathogenic bacterium Acidovorax citrulli. From library 12,000 chemical compounds, identified series benzyloxy carbonimidoyl dicyanide (BCD) derivatives that effectively blocked T3SS-dependent secretion. Substitution halogens or nitro groups at para-position on benzene ring contributed to increased inhibitory activity. One representative compound, BCD03 (3,4-dichloro-benzyloxy dicyanide), dramatically reduced pathogenicity A. citrulli melon seedlings, attenuated hypersensitive responses non-host Nicotiana tabacum caused by bacteria citrulli, Xanthomonas oryzae pv. Pseudomonas syringae tomato sub-MIC concentrations. Western blotting assay further confirmed inhibited from above via liquid medium. Taken together, our data suggest BCD act multiple pathogens.