Tethered thiazolidinone dimers as inhibitors of the bacterial type III secretion system

Disruption of protein–protein interactions by small molecules is achievable but presents significant hurdles for effective compound design. In earlier work we identified a series of thiazolidinone inhibitors of the bacterial type III secretion system (T3SS) and demonstrated that this scaffold had the potential to be expanded into molecules with broad-spectrum anti-Gram negative activity. We now report on one series of thiazolidinone analogs in which the heterocycle is presented as a dimer at the termini of a series of linkers. Many of these dimers inhibited the T3SS-dependent secretion of a virulence protein at concentrations lower than that of the original monomeric compound identified in our screen.