Synthesis, cytotoxicities and DNA-binding affinities of benzofuran-3-ols and their fused analogs

A series of benzofuropyrazoles 2a-i were synthesized in 10-92% from the reaction of 2-aroylbenzofuran-3-ols 1a-i with hydrazine hydrate, and screened for their antitumor activities toward four human solid tumor cell lines, including gastric carcinoma cells MKN45, hepatocellular carcinoma cells HepG2, breast cancer cells MCF-7, and lung cancer cells A549. The results indicated that both compounds 1a-i and 2a-i displayed moderate antitumor activities. Among them, compound 2e exhibited potent inhibitory activity toward all the four tumor cell lines. In addition, compounds 1e and 2e showed strong DNA-binding affinities, and induced an increase in the viscosity of calf-thymus DNA, suggesting that they might act as an intercalator.