Synthesis, Biological Evaluation, and Molecular Modeling Studies of 1-Aryl-1-pyrazole-Fused Curcumin Analogues as Anticancer Agents.

Addressing the growing burden of cancer and the shortcomings of chemotherapy in cancer treatment are the current research goals. Research to overcome the limitations of curcumin and to improve its anticancer activity via its heterocycle-fused monocarbonyl analogues (MACs) has immense potential. In this study, 32 asymmetric MACs fused with 1-aryl-1-pyrazole () were synthesized and characterized to develop new curcumin analogues. Subsequently, via initial screening for cytotoxic activity, nine compounds exhibited potential growth inhibition against MDA-MB-231 (IC 2.43-7.84 μM) and HepG2 (IC 4.98-14.65 μM), in which seven compounds showing higher selectivities on two cancer cell lines than the noncancerous LLC-PK1 were selected for cell-free screening for effects on microtubule assembly activity. Among those, compounds , , and showed effective inhibitions of microtubule assembly at 20.0 μM (40.76-52.03%), indicating that they could act as microtubule-destabilizing agents. From the screening results, three most potential compounds, , , and , were selected for further evaluation of cellular effects on breast cancer MDA-MB-231 cells. The apoptosis-inducing study indicated that these three compounds could cause morphological changes at 1.0 μM and could enhance caspase-3 activity (1.33-1.57 times) at 10.0 μM in MDA-MB-231 cells, confirming their apoptosis-inducing activities. Additionally, in cell cycle analysis, compounds and at 2.5 μM and at 5.0 μM also arrested MDA-MB-231 cells in the G/M phase. Finally, the results from studies revealed that the predicted absorption, distribution, metabolism, excretion, and the toxicity (ADMET) profile of the most potent MACs might have several advantages in addition to potential disadvantages, and compound could bind into (Δ -10.08 kcal·mol) and access wider space at the colchicine-binding site (CBS) than that of colchicine or nocodazole via molecular docking studies. In conclusion, our study serves as a basis for the design of promising synthetic compounds as anticancer agents in the future.