Synthesis and CDK2 kinase inhibitory activity of 7/7′-azaindirubin derivatives

Abstract A series of novel 7′-azaindirubin ( 1a – g ) and 7-azaindirubin ( 2a , 2c , 2e and 2f ) derivatives were designed and synthesized. Their structures were characterized by 1 H NMR and MS spectroscopy as well as by elemental analysis. Their inhibitory properties against CDK2/cylinA were evaluated in vitro . In contrast to indirubin, some of the described azaindirubins emerged as potent inhibitors of CDK2/cylinA and compound 2b had more potent activity. Biological tests also showed that nitrogen atom at 7-position of azaindirubin was more beneficial to enhance the kinase inhibitory activity.