Synthesis and Structure–Activity Relationships of DCLK1 Kinase Inhibitors Based on a 5,11-Dihydro-6<i>H</i>-benzo[<i>e</i>]pyrimido[5,4-<i>b</i>][1,4]diazepin-6-one Scaffold
Fleur M. Ferguson, Yan Liu, Wayne Harshbarger, Ling Huang, Jinhua Wang, Xianming Deng, Stephen J. Capuzzi, Eugene Muratov, Alexander Tropsha, Senthil K. Muthuswamy, Kenneth D. Westover, Nathanael S. Gray
Abstract
Doublecortin-like kinase 1 (DCLK1) is a serine/threonine kinase that is overexpressed in gastrointestinal cancers, including esophageal, gastric, colorectal, and pancreatic cancers. DCLK1 is also used as a marker of tuft cells, which regulate type II immunity in the gut. However, the substrates and functions of DCLK1 are understudied. We recently described the first selective DCLK1/2 inhibitor, DCLK1-IN-1, developed to aid the functional characterization of this important kinase. Here we describe the synthesis and structure–activity relationships of 5,11-dihydro-6H-benzo[e]pyrimido[5,4-b][1,4]diazepin-6-one DCLK1 inhibitors, resulting in the identification of DCLK1-IN-1.