A bacterial cyclic dipeptide; activates a LuxR-based AHL E. coli biosensor and blocks activation of the biosensor by the quorum sensing signal molecule 3-oxo-C6-HSL (IC50 = 0.8 mM); reduces S. liquefaciens colony expansion by 21% at 15 μM; inhibits interaction of kinases Ras and Raf-1 in a yeast two-hybrid assay in a concentration-dependent manner