Design, Synthesis, biological Evaluation, and molecular docking studies of novel Pyrazolo[3,4-d]Pyrimidine derivative scaffolds as potent EGFR inhibitors and cell apoptosis inducers

A series of novel hybrid pyrazolo[3,4-d]pyramidine derivatives was designed and chemically synthesized in useful yields. The synthesized compounds were structurally characterized by the usual techniques. All the new synthesized compounds were biologically screened in vitro for their antiproliferative activities against a panel of four cancer cell lines, namely HepG-2, MCF-7, HCT-116, and Hela. The results of cytotoxic evaluation indicated that compound 14d was appeared to be the most prominent broad-spectrum cytotoxic activity and significantly more potent than sorafenib with IC50 values of 4.28, 5.18, 3.97, and 9.85 µM against four cell lines (HePG2, Hela, HCT-116 and MCF-7). In addition, compound 15 was displayed promising antiproliferative effect against all tested cell lines with IC50 value less than 11 µM compared with sorafenib as a control drug. Besides, structurally pharmacophoric features indicated that pyrazolo[3,4-d]pyrimidine scaffold having an amide linker and substituted with phenyl moiety at the 5-position was more potent than those possessing azomethine methyl, azomethine proton and carbomethene linkers, which lead to significant decrease in antiproliferative activity. The most potent compounds were further selected and evaluated for their activities against epidermal growth factor receptor (EGFR) kinase inhibitors according to homogenous time resolved fluorescence (HTRF) assay. The most potent compound 14d exhibited the most promising inhibitory activity against EGFRWT with IC50 value of 56.02 ± 1.38 µM compared with gefitinib as control drug with IC50 value of 41.79 ± 1.07 µM. Moreover, the inhibition of cell cycle progression and induction of apoptosis in the A549 cell line at G2/M and pre-G1 phases of cell cycle might contribute to cancer treatment that evaluated by Annexin V-FITC/PI double staining detection method. Finally, molecular docking studies were conducted to investigate that probable binding conformations of these anticancer agents and ADME properties were calculated to predict pharmacokinetics and toxic properties of the target compounds.