Design, synthesis and mechanistic studies of novel imidazo[1,2-a]pyridines as anticancer agents.

Herein, the design, synthesis and mechanistic study of five series of imidazo[1,2-a]pyridines 8a-d, 9a-f, 11a-c, 12a-d and 14a-d as anticancer agents were discussed. The cytotoxicity of imidazo[1,2-a]pyridine derivatives was screened against NCI 60 cancer cell lines. The cytotoxicity of compounds 8b, 8c, 9e and 9f was then evaluated against leukemia K-562 cancer cell line and normal lung fibroblasts (WI38). The hydrazone derivatives 8b and 8c exhibited significant cytotoxic activities against the leukemia K-562 cancer cell line with good safety margins (IC50 = 2.91 µM, SI = 8.32 and IC50 = 1.09 µM, SI = 10.54, respectively). In addition, compounds 8b, 8c, 9e and 9f were tested for their EGFR and COX-2 inhibitory activities. The hydrazone derivatives 8b and 8c were the most active EGFR inhibitors with IC50 values of 0.123 and 0.072 µM, respectively. Compound 8c selectively inhibited COX-2 (IC50 = 1.09 µM, SI = 13.78). Moreover, the potential of compound 8c to induce apoptosis in leukemia K-562 cell line was determined. Compound 8c showed a pre-G1 apoptosis and a growth arrest of leukemia K-562 cell line at G1 phase of cell cycle. Also, compound 8c was able to induce caspase-3 overexpression (6.98 folds), if compared to control. Finally, molecular docking studies and physicochemical properties calculation of compounds 8b, 8c, 9e and 9f were carried out to explain the biological data and to predict bioavailability of the most active compounds.

Design, synthesis and molecular docking of new fused 1H-pyrroles, pyrrolo[3,2-d]pyrimidines and pyrrolo[3,2-e][1, 4]diazepine derivatives as potent EGFR/CDK2 inhibitors.

A new series of 1H-pyrrole (6a-c, 8a-c), pyrrolo[3,2-d]pyrimidines (9a-c) and pyrrolo[3,2-e][1, 4]diazepines (11a-c) were designed and synthesised. These compounds were designed to have the essential pharmacophoric features of EGFR Inhibitors, they have shown anticancer activities against HCT116, MCF-7 and Hep3B cancer cells with IC50 values ranging from 0.009 to 2.195 µM. IC50 value of doxorubicin is 0.008 µM, compounds 9a and 9c showed IC50 values of 0.011 and 0.009 µM respectively against HCT-116 cells. Compound 8b exerted broad-spectrum activity against all tested cell lines with an IC50 value less than 0.05 µM. Compound 8b was evaluated against a panel of kinases. This compound potently inhibited CDK2/Cyclin A1, DYRK3 and GSK3 alpha kinases with 10-23% compared to imatinib (1-10%). It has also arrested the cell cycle of MCF-7 cells at the S phase. Its antiproliferative activity was further augmented by molecular docking into the active sites of EGFR and CDK2 cyclin A1.