BT2 is a BCKDC kinase (BDK) inhibitor with an IC50 of 3.19 μM. BT2 binding to BDK triggers helix movements in the N-terminal domain, resulting in the dissociation of BDK from the branched-chain α-ketoacid dehydrogenase complex (BCKDC). BT2 (compound 4) is also a potent and selective Mcl-1 inhibitor with a Ki value of 59 μM.