A method of inhibiting a microbial infection can include: providing a compound of the invention or prodrugs or pharmaceutically acceptable salts thereof； and administering the compound to a subject in a therapeutically effective amount to inhibit the microbial infection. The therapeutically effective amount can be sufficient to inhibit a biological activity of a transcriptional activator of the microbe. The inhibited transcriptional activator is an AraC bacterial transcriptional activator. The AraC bacterial transcriptional activator can be RhaS, RhaR, Rns, or VirF. The microbe can be selected from Vibrio, Pseudomonas, Enterotoxigenic E. coli, and Shigella.
