Figure 3.

Structures of Fsr quorum-sensing system inhibitors: Siamycin I (IC₅₀ approximately 100 nM) extracted from soil Streptomyces sp [109]; Sviceucin obtained from Streptomyces sviceus, (1 and 10 µM concentrations inhibited 50–70% and >90% of gelatinase production, respectively) [111]; ZBzl-YAA5911 is a synthetic inhibitor with an IC₅₀ of 26.2 nM [113]; Ambuic acid (IC₅₀ approximately 10 µM), extracted from fungal secondary metabolites [112]; and WS9326A (IC₅₀ approximately 19 µM), extracted from a culture of actinomycetes [114].