Design, synthesis, radiolabeling, and mechanistic insights of hydrazinyl imidazolones as broad spectrum antitumor agents with potential carbonic anhydrase inhibition: In vitro, in vivo, and in silico studies.

Applying molecular hybridization and ring variation as drug design approaches, a set of 2-hydrazinyl-5-(3-phenylallylidene)imidazole-4-ones 5 and 6a-k was designed and synthesized as multi-carbonic anhydrases inhibitors. The stereochemistry of the imine double bond in the newly synthesized compounds was evidenced by NOESY and ROESY analyses of a representative example. National Cancer Institute (NCl) evaluated all these synthesized compounds against 60 cancer cells, one dose preliminary antitumor estimation, where five compounds 6c, 6d, 6h, 6i, and 6k were the most active. It is noticeable that the presence of electron releasing groups with +M effect at the phenyl ring of arylidene hydrazinyl moiety significantly elevated the antitumor effect. The superior anticancer analogs 6h and 6i were chosen by the NCI for five-dose assessment. The mechanistic analysis of the most potent anticancer compounds was accomplished by assessing the inhibitory activity of these analogs toward hCAs I, II, IX, and XII. The outcomes displayed that compound 6i was the most promising CA inhibitor showing IC50 range of 0.04-0.16 μM. Additionally, compound 6i stimulated its antitumor and hCA inhibition effects by arresting the SK-MEL-5 cell cycle at G2/M phase as well as promoting the apoptotic cascade. Furthermore, in vivo bio-distribution of 131I-6i in tumor induced mice indicated a high level of localization in the tumor site without any significant accumulation in other body organs. The molecular docking study have been performed to assess their potentiality as considerable anticancer candidates.