Novel nicotinoyl pyrazoline derivates bearing N-methyl indole moiety as antitumor agents: Design, synthesis and evaluation.

In the present work, twenty-five nicotinoyl pyrazoline derivates bearing N-methyl indole moiety have been designed and synthesized. The biological evaluation of these compounds as tubulin assembly inhibitors revealed that most of them were potential antitumor agents. Among them, compound 28 exhibited most potency against cancer cell line panels (GI50 = 29-90 nM for HeLa, HepG2 and MCF-7 cells) without toxicity to non-tumor cells (CC50 > 300 µM for 293 T cell), bound to the colchicine site of tubulin and displayed excellent inhibitory activity in tubulin assembly assay (IC50 = 1.6 µM, better than CA-4). Molecular dynamics simulation was carried out to validate the docking pose of compound 28 with tubulin crystalline. Further investigation on HepG2 and HeLa cells demonstrated that compound 28 could cause mitosis arrest to G2/M phase, and subsequently induced cell apoptosis. The efficiency in vivo of compound 28 was also evaluated on HeLa-Xenograft nude mice, and the relative tumor inhibition ration was up to 61.52% without noticeable weight loss and tissue damage (examined by H&E staining), which was comparable to CA-4 (inhibited 59.92%). In brief, compound 28 is a promising candidate for tumor therapy as tubulin assembly inhibitor.