Synthesis and In Vitro Biological Evaluation of New Pyrido[2,3‐b]pyrazinone‐Based Cytotoxic Agents and Molecular Docking as BRAF Inhibitors

In this study, synthesis of new pyrido[2,3‐ b ]pyrazinone derivatives were identified. The in vitro cytotoxic activity of synthesized compounds against human colon cancer cell line (HCT 116) and kinase assay ( V600E BRAF) were investigated. The results revealed that compounds 4 b and 4 c (4‐nitro and 4‐methoxy benzylidene acid hydrazide substitution, respectively) were the most active compounds among the synthesized derivatives (IC 50 12.120 and 13.103 μM, respectively). Moreover, they exhibited inhibitory activity against V600E BRAF (Inh % 79.23 and 81.33, respectively). In addition, the designed derivatives were subjected to be simulated with the active site of mutated BRAF kinase domain using a suitable molecular docking protocol. Docking results coincided with good activity of compound 4 c and showed high docking score with BRAF protein kinase domain −21.85171 kcal/mol better than native ligand. The results of this study consider pyridopyrazinone scaffold (with substituted phenyl ring through a spacer) a key nucleus for further molecular and structural optimization.