Synthesis, anticancer and antimalarial activities of organosulfur and organoselenium derivatives of cyclopentadienyliron dicarbonyl as photoCORMs

Abstract

The reactions of [CpFe(CO)2]2 with 2 mol equivalents of R2E2 (R = C6H11, C4H3S, CH2C6H5; E = S, Se) have yielded dinuclear products of [CpFe(CO)(μ-L)]2 (L = C6H11S (1), C4H3S2 (2) and CH2C6H5Se (3)), respectively. An additional trinuclear compound, C24H22O2Se2Fe3 (4) was isolated only from the reaction with dibenzyl diselenide. All the products have been fully characterized by FT-IR,1H and13C NMR, CHN elemental analysis, and structurally elucidated by single crystal X-ray diffraction. The stability of 1–3 both under dark and UV conditions were investigated by monitoring the changes in their respective UV–Vis spectra in phosphate buffered saline (PBS) solution. Their potential application as photoCORMs were also evaluated by standard myoglobin assay. 2 showed the shortest half-life and highest equivalent of CO-released. The anticancer studies of 1–3 were evaluated in-vitro on breast cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB-468) and the cytotoxicity of 2 had increased approximately 4 times against MDA-MB-468 cell line upon UV irradiation, which was 11.5 ± 2.7 μM. All complexes exhibited cytotoxic effect on specific sub-types of breast cancer cells. Antimalarial activities of 1–3 had also been studied and reported in this work. Unfortunately, these complexes did not display any significant effect on the Plasmodium falciparum 3D7 strains.