Discovery and rational design of 2-aminopyrimidine-based derivatives targeting Janus kinase 2 (JAK2) and FMS-like tyrosine kinase 3 (FLT3)

Herein, with the help of computer-aided drug design (CADD), we describe the structure-based rational drug design, structure-activity relationships, and synthesis of a series of 2-aminopyrimidine derivatives that inhibit both JAK2 and FLT3 kinases. These screening cascades revealed that compound 14l demonstrated the most inhibitory activity with IC50 values of 1.8 and 0.68 nM against JAK2 and FLT3 respectively. 14l also showed potent anti-proliferative activities against HEL (IC50 = 0.84 mu M) and Molm-13 (IC50 = 0.019 mu M) cell lines, but relatively weak cytotoxicity against K562 and PC-3 cell lines, which proved that it might have high target specificity. In vitro metabolism assay, 14l exhibited moderate stability in RLM (Rat Liver Microsomes) with a half-life time of 31 min. In the cellular context of Molm-13, 14l induced cell cycle arrest in G1/S phase and enhanced apoptosis in a dose-dependent manner. These results indicate that 14l is a promising dual JAK2/FLT3 inhibitor and worthy of further development.