Synthesis and evaluation of novel isoxazolyl chalcones as potential anticancer agents

A series of novel isoxazolyl chalcones were synthesized and evaluated for their activities in vitro against four types of human non-small cell lung cancer cells, including H1792, H157, A549 and Calu-1 cells. The preliminary biological screening showed that compounds 5d and 5f – i exhibited significant cytotoxicity, particularly, compounds 5f and 5h were identified as the most potent anticancer agents with IC 50 values 1.35–2.07 μM and 7.27–11.07 μM against H175, A549 and Calu-1 cell lines, respectively. Compounds 5f–i could induce apoptosis in A549 cells by death receptor 5 (DR5) mediated extrinsic pathways. The preliminary structure–activity relationship study showed that compounds bearing electron withdrawing groups (EWG) at the 2-position of the phenyl ring in Ar group were more effective than those with EWG at 4-position. These results further demonstrated that the scaffolds designed in this work might lead to the discovery of novel anti-lung cancer agents.