Despite significant advances in targeted therapies and immunotherapies, non-small cell lung cancer (NSCLC) continues to present a global health challenge, with a modest five-year survival rate of 28 %, largely due to the emergence of treatment-resistant and metastatic tumors. In response, we synthesized a novel bioactive compound, ethyl 6-chlorocoumarin-3-carboxylyl L-theanine (TClC), which significantly inhibited NSCLC growth, epithelial mesenchymal transition (EMT), migration, and invasion