A novel ferrocenyl-bearing monocarbonyl curcumin derivative as highly potent photosensitizer for anticancer photodynamic therapy

The first unsymmetricalferrocenyl/2-methoxyphenyl monocarbonyl curcumin derivative, compound 1 , has been synthesized aiming to investigate its photophysical properties and photodynamic activity against A431 Cutaneous squamous cell carcinoma. Compound 1 exhibits a metal-to-ligand charge transfer as witnessed by the UV–Vis absorption band at ca. 540 nm. The ferrocene/ferrocenium photooxidation was readily apparent after one-minute irradiation time which consequently caused the production of a considerable amount of reactive oxygen species (ROS). The potential photosensitizer was not cytotoxic in the dark up to the concentration of 10 μΜ, whereas at this concentration efficient PDT activity against A431 cancer cells was observed since upon irradiation at 430 nm for 2 min 50 % of the cell population was killed (1.6 J/cm 2 ). These results demonstrate that ferrocene-bearing monocarbonyl curcumin derivatives, which are easily and economically prepared in high-yield and purity, merit further study for developing efficient anticancer PDT agents. • A ferrocenyl-bearing monocarbonyl curcumin derivative has shown λ max at 540 nm. • The ferrocene/ferrocenium photooxidation occurred rapidly after 1-min irradiation. • A considerable amount of reactive oxygen species was produced after irradiation. • The photosensitizer was not cytotoxic in A431 cancer cells, in the dark, up to 10 μΜ. • Upon irradiation at 430 nm for 2 min (1.6 J/cm 2 ), 50 % of A431 cells were killed.