Optimization and SAR investigation of novel 2,3-dihydropyrazino[1,2-a]indole-1,4-dione derivatives as EGFR and BRAFV600E dual inhibitors with potent antiproliferative and antioxidant activities.

Using a single drug to treat cancer with dual-targeting is an unusual approach when compared to other drug combinations. Dual-targeting agents were developed as a result of insufficient efficacy and drug resistance when single-targeting agents were used. As a result, the 2,3-dihydropyrazino[1,2-a]indole-1,4-dione derivatives 13-22 have been developed as dual EGFR and BRAFV600E inhibitors. The target compounds were synthesized and tested in vitro against four cancer cell lines, with compounds 15, and 19-22 demonstrating potent antiproliferative activity. In vitro studies revealed that these compounds have dual inhibitory effect on EGFR and BRAFV600E. Compounds 15, and 19-22 exhibited inhibitions of EGFR with IC50 ranging from 32 nM to 63 nM which were superior to erlotinib (IC50 = 80 ± 10 nM). Compounds 20, 21 and 22 showed promising inhibitory activity of BRAFV600E (IC50 = 55, 45 and 51 nM, respectively) and were found to be potent inhibitors of cancer cell proliferation (GI50 = 51, 35 and 44 nM, respectively). Compounds 20, 21 and 22 showed good antioxidant activity comparable to the reference Trolox. Lastly, the best active dual inhibitors were docked inside EGFR and BRAFV600E active sites to clarify their binding modes.

Design, synthesis, and biological evaluation of novel EGFR inhibitors containing 5-chloro-3-hydroxymethyl-indole-2-carboxamide scaffold with apoptotic antiproliferative activity.

New EGFR inhibitor series of fifteen 5-chloro-3-hydroxymethyl-indole-2-carboxamide derivatives has been designed, synthesized, and tested for antiproliferative activity against a panel of cancer cell lines. The results showed that p-substituted phenethyl derivatives 10, 11, 13, 15 and 17-19 showed superior antiproliferative activity compared to their m-substituted counterparts 12, 14, 16 and 20. Compounds 15, 16, 19 and 20 displayed promising EGFR inhibitory activity as well as an increase in caspase 3 levels. Compounds 15 and 19 increased caspase-8 and 9 levels, as well as inducing Bax and decreasing Bcl-2 protein levels. Compound 19 demonstrated cell cycle arrest at pre-G1 and G2/M phases. The results of the docking study into the active site of EGFR revealed strong fitting of the new compounds with higher binding affinities compared to erlotinib.