Synthesis and biological evaluation of 1,3,4-oxadiazole-linked bisindole derivatives as anticancer agents

A series of ten 1,3,4-oxadiazole-linked bisindole derivatives have been synthesized. All compounds were evaluated for anticancer activity against four human cancer cell lines (MCF-7, KB, Colo-205, and A-549). Most of these new compounds exhibited significant anticancer activity as compared to etoposide. Compounds' GI(50) values range from < 0.1 to 3.9 mu M, while the positive control etoposide has a GI(50) in the range of 0.13-3.08 mu M in the cell lines employed. Among them, four compounds showed a higher activity than etoposide.