Design, Synthesis, Crystal Structure, Biological Activity and Molecular Modeling of Novel Schiff Bases Derived from Chalcones and 5-Hydrazino-1,3-Dimethyl-4-Nitropyrazole as Anticancer Agents

The synthesis of novel 5-(2-((1(E/Z),2E)-1,3-disubstitutedallylidene)hydrazinyl)-1,3-dimethyl-4-nitro-1H-pyrazole (4a-k) was attempted via reaction involves a nucleophilic attack which takes place at the carbonyl group of the alpha,beta-unsaturated carbonyls. The transformation proceeds via an effective addition-elimination reaction in the presence of catalytic amount of concentrated H2SO4. The cytotoxicity of synthesized compounds was evaluated against two tumor cell lines, MCF-7 and MDA-MB-231, via MTT assay. The compounds 4a-d showed better toxicity than tamoxifen on MCF-7 cells, ranging from 26.28 to 12.96 mu M with 4b having the lowest IC50 among the compounds tested. On the other hand, the compounds have moderate toxicity on MDA-MB-231 with 4c showing the lowest IC50. The docking study suggests that these Schiff bases chalcone scaffolds might facilitate the further development of investigated compounds as anticancer agents.