Characterization of an aromatic trifluoromethyl ketone as a new warhead for covalently reversible kinase inhibitor design.

An aromatic trifluoromethyl ketone moiety was characterized as a new warhead for covalently reversible kinase inhibitor design to target the non-catalytic cysteine residue. Potent and selective covalently reversible inhibitors of FGFR4 kinase were successfully designed and synthesized by utilizing this new warhead. The binding mode of a representative inhibitor was fully characterized by using multiple technologies including MALDI-TOF mass spectrometry, dialysis assay and X-ray crystallographic studies etc. This functional group was also successfully applied to discovery of a new JAK3 inhibitor, suggesting its potential application in designing other kinase inhibitors.