Design, synthesis and biological evaluation of novel benzimidazole-2-substituted phenyl or pyridine propyl ketene derivatives as antitumour agents.

A series of novel benzimidazole-2-subsituted phenyl or pyridine propyl ketene derivatives were designed and synthesized. The biological activities of these derivatives were then evaluated as potential antitumour agents. These compounds were assayed for growth-inhibitory activity against HCT116, MCF-7 and HepG2 cell lines in vitro. The IC 50 values of compounds A 1 and A 7 against the cancer cells were 0.06–3.64 μM and 0.04–9.80 μM, respectively. Their antiproliferative activities were significantly better than that of 5-Fluorouracil (IC 50 : 56.96–174.50 μM) and were close to that of Paclitaxel (IC 50 : 0.026–1.53 μM). The activity of these derivatives was over 100 times more effective than other reported structures of chalcone analogues (licochalcone A). A preliminary mechanistic study suggested that these compounds inhibit p53-MDM2 binding. Compounds A 1 , A 7 and A 9 effectively inhibited tumour growth in BALB/c mice with colon carcinoma HCT116 cells. The group administered 200 mg/kg of compound A 7 showed a 74.6% tumour growth inhibition with no signs of toxicity at high doses that was similar to the inhibition achieved with the 12.5 mg/kg irinotecan positive control (70.2%). Therefore, this class of benzimidazole-2-subsituted phenyl or pyridine propyl ketene derivatives represents a promising lead structure for the development of possible p53-MDM2 inhibitors as new antitumour agents. [ABSTRACT FROM AUTHOR]