Targeting breast cancer with 1,2,4-trioxanes: synthesis, cytotoxicity, and molecular docking insights

Abstract

Breast cancer remains the most common malignancy among women to date, with increasing incidence and resistance to conventional therapies driving the search for novel treatments. 1,2,4-Trioxanes, known for their antimalarial activity, have emerged as promising anticancer agents due to their ability to generate reactive oxygen species (ROS) through iron-mediated activation, selectively inducing apoptosis in cancer cells. In this study, a series of hydroxy-functionalized and hemi-succinate trioxane derivatives were synthesized and evaluated against the MCF-7 breast cancer cell line. Among them, compound 10b3 showed the highest potency with an IC50 of 0.642 µM, outperforming the reference drug doxorubicin (IC50 = 0.857 µM). To complement the experimental findings, Boltz-2–guided binding affinity prediction was employed to estimate protein–ligand interaction free energies, enabling rapid and accurate assessment of binding strength beyond conventional scoring approaches. To explore the probable iron-mediated activation mechanism molecular docking experiments were further conducted to investigate binding orientation, active-site interactions, and the spatial proximity of the endoperoxide bridge to the catalytic iron atom. The compounds preferentially occupied hydrophobic pockets within the active site, stabilized mainly by hydrophobic contacts along with occasional hydrogen-bonding interactions. Notably, compound 10b3 exhibited a favourable binding orientation and interaction profile consistent with its superior in vitro activity. Density functional theory (DFT) analysis indicated that electrophilicity and electronic softness correlate with cytotoxic potency. These findings highlight the mechanistic relevance and therapeutic potential of 1,2,4-trioxanes as promising leads for further development as breast cancer therapeutics.