Dimerization of
proteins/receptors plays a critical role in various cellular processes, including cell proliferation and differentiation. Therefore, targeting such dimeric
proteins/receptors by dimeric small molecules could be a potential therapeutic approach to treating various diseases, including
inflammation-associated diseases like
cancer. A novel series of bis-
imidazoles (13-18) and bis-imidazo[1,2-a]
pyridines (19-28) were designed and synthesized from
Schiff base dimers (1-12) for their anticancer activities. All the synthesized compounds were screened for anticancer activities against three
cancer cell lines, including cervical (HeLa), breast (MDA-MB-231), and
renal cancer (ACHN). From structure-activity relationship studies, imidazo[1,2-a]
pyridines (19-28) showed remarkable cytotoxic activities, with compounds 19 and 24 showing the best inhibitory activities against all three cell lines. Especially, both 19 and 24 were very effective against the
breast cancer cell line (19, GI50 = 0.43 µM; 24, GI50 = 0.3 µM), exceeding the activity of the control
adriamycin (GI50 = 0.51 µM). The in vivo anticancer activity results of compounds 19 and 24 were comparable with those of the animals treated with the standard
drug tamoxifen. Therefore, the dimeric imidazo[1,2-a]
pyridine scaffold could serve as a potential lead for the development of novel
anticancer agents.