Discovery of potent and highly selective covalent inhibitors of Bruton's tyrosine kinase bearing triazine scaffold.

Bruton's tyrosine kinase (BTK), as a key regulator of the B cell receptor (BCR) signaling pathway, is an attractive therapeutic target for the treatment of various diseases such as leukemia and B-cell malignancies. Herein, a series of compounds bearing 1, 3, 5-triazine core were prepared, and their biological activities on BTK were determined. Then the molecular docking study and ADME property prediction were made and a highly potent selective BTK inhibitor B8 (IC50 = 21.0 nM) was discovered. Compound B8 exhibited excellent activity with 5.14 nM inhibition of Raji cells and 6.14 nM inhibition of Ramos cells respectively. Additionally, B8 potently inhibited BTK kinase Y223 auto-phosphorylation, arrested cell cycle in G2/M phase and induced apoptosis in Ramos cells. The high selectivity for BTK and high potency in TMD8 cells of B8 suggested a low risk of off-target related adverse effects. Further molecular docking and dynamic simulation on B8 furnished insights into its binding profile within BTK. With significant efficacy in cellular assays and good ADME and safety profiles, B8 can be identified as a promising BTK inhibitor worthy of further profiling.