Novel 5-Oxopyrrolidine-3-carbohydrazides as Potent Protein Kinase Inhibitors: Synthesis, Anticancer Evaluation, and Molecular Modeling

A series of novel hydrazones bearing diphenylamine and 5-oxopyrrolidine moieties, along with benzene and naphthalene rings substituted with hydroxy, alkoxy, or carboxylic groups, were synthesized. Their anticancer activity was evaluated in vitro using both 2D (MTT and 'wound healing' assays) and 3D (cell spheroid) models against human melanoma IGR39 cells, the triple-negative breast cancer cell line MDA-MB-231, and pancreatic carcinoma Panc-1 cell line. Compounds <b>8</b> (2-hydroxybenzylidene derivative) and <b>12</b> (2-hydroxynaphthalenylmethylene derivative) demonstrated the highest cytotoxicity in both 2D and 3D assays, while compounds <b>4</b> (2,5-dimethoxybenzylidene derivative) and <b>6</b> (2,4,6-trimethoxybenzylidene derivative) were most effective at inhibiting cell migration. Notably, all compounds exhibited lower activity against the Panc-1 cancer cell line in a cell monolayer, but the effects on spheroid cell viability in 3D models were comparable across all tested cancer cell lines. Molecular docking studies of the most active hydrazones suggested that these compounds may act as multikinase inhibitors. In particular, 2-hydroxynaphthalenylmethylene derivative <b>12</b> showed high binding affinity values (-11.174 and -11.471 kcal/mol) to the active sites of two key protein kinases-a non-receptor TK (SCR) and STPK (BRAF)-simultaneously.