Identification and characterization of potent, selective and metabolically stable IKKβ inhibitor.

We have previously reported the identification of a rhodanine compound (1) with well-balanced inhibitory activity against IKKβ and collagen-induced TNFα activated cells. However, we need more optimized compounds because of its instability over plasma and microsome. As part of a program directed toward the optimization of IKKβ inhibitor, we modified a substituent of parent compound to a series of functional groups. Among substituted compounds, fluorine substituent (12) on the para position of phenyl ring restored the stability toward plasma and microsome while retaining inhibitory potency and selectivity against IKKβ over other kinases. Also, we have demonstrated that compound 12 is an ATP non-competitive inhibitor and safe enough to apply to animal experiment from an acute toxicity test.