One of the first discovered in the screening of inhibitors of FGFR1 classes are flavones. These compounds belong to a class of chromones which are widely represented in nature. They and their derivatives have long been known as inhibitors of protein kinases, including CDK. After primary search inhibitors of this class we find several compounds that inhibit FGFR1 with IC50 in the range 3-5 µM. Molecular modeling confirmed their position in the binding site, similar to those obtained for structurally analogous inhibitors of CDK.
Flavone inhibitors FGFR1 with IC50 less than 100 nM were found in further, but they had low selectivity of action. Non-specific inhibition is a known flavones problem, so optimization of this class as inhibitors of FGFR1 is not performed.