Figure 5. Compound B binds selectively to class I PI3K.

Compound B specificity was tested in a kinase-selectivity profiling assay on a panel of 456 kinases. Compound B (10 μM) was tested in an ATP site competition assay. Compound B was considered active for a kinase when the kinase fraction that remained bound to ATP was less than 30%. Red circles indicate the kinases for which Compound B shows binding activity. Compound B showed no significant binding activity outside the PI3K family.