Design, synthesis, and integrated in silico analysis of novel difluoroboron curcumin analogues as potent inhibitors of the K562 leukemia cell line.

Curcumin, a natural polyphenol, exhibits broad anticancer properties but is limited by poor stability and bioavailability. To overcome these flaws while enhancing potency, a series of five novel difluoroboron curcumin analogues (Cox1-Cox5) were synthesized and characterized. Their cytotoxic activity was evaluated against the K562 human leukemia cell line using the MTT assay, revealing IC₅₀ values ranging from a potent 27.1 µg/mL to 58.6 µg/mL. To elucidate the structural basis of this activity, a comprehensive computational investigation was performed. Molecular docking studies identified human thymidylate synthase (hTS) as a plausible molecular target, with predicted binding energies showing a strong linear correlation (R² = 0.88) with the experimental IC₅₀ values. Density Functional Theory (DFT) calculations revealed that high electrophilicity is the key determinant of potent binding, with the nitro-substituted emerging as the most active compound. Finally, a Molecular Dynamics (MD) simulation of the Cox5-hTS complex confirmed the dynamic stability of the docked pose and the persistence of key hydrogen-bonding interactions. This integrated study validates a rational design strategy where stabilizing the curcumin scaffold and introducing potent electron-withdrawing groups yields compounds with superior and mechanistically understandable anti-leukemic activity.