6-Substituted imidazo[1,2-a]pyridines: synthesis and biological activity against colon cancer cell lines HT-29 and Caco-2

A range of 6-substituted imidazo1,2-a]pyridines were synthesized using a multicomponent coupling reaction. Most of these compounds were found to exhibit excellent activity against the colon cancer cell lines HT-29 and Caco-2, whilst not showing significant toxicity against white blood cells. Our studies have shown that the proteolytic phase of apoptosis was initiated 2 h after treatment with these imidazo-1,2-a]pyridines. The data suggests that the imidazo1,2-a]pyridine-induced cell death in HT-29 and Caco-2 cells is mediated via pathway(s) that include the release of cytochrome c from the mitochondria to the cytosol and the activation of caspase 3 and caspase 8.