Catalytic oxidation of organic sulfides by new iron-chloro Schiff base complexes: The effect of methoxy substitution and ligand isomerism on the electronic, electrochemical and catalytic performance of the complexes

Design, Synthesis, Electrochemical, and Biological Evaluation of Fluorescent Chlorido[N,N'-bis(methoxy/hydroxy)salicylidene-1,2-bis(4-methoxyphenyl)ethylenediamine]iron(III) Complexes as Anticancer Agents

The impact of methoxy and hydroxyl groups at the salicylidene moiety of chlorido[N,N'-bis(methoxy/hydroxy)salicylidene-1,2-bis(4-methoxyphenyl)ethylenediamine]iron(III) complexes was evaluated on human MDA-MB 231 breast cancer and HL-60 leukemia cells. Methoxylated complexes (C1-C3) inhibited proliferation, migration, and metabolic activity in a concentration-dependent manner following the rank order: C2 > C3 > C1. In particular, C2 was highly cytotoxic with an IC50 of 4.2 μM which was 6.6-fold lower than that of cisplatin (IC50 of 27.9 μM). In contrast, hydroxylated complexes C4-C6 were almost inactive up to the highest concentration tested due to lack of cellular uptake. C2 caused a dual mode of cell death, ferroptosis, and necroptosis, whereby at higher concentrations, ferroptosis was the preferred form. Ferroptotic morphology and the presence of ferrous iron and lipid reactive oxygen species proved the involvement of ferroptosis. C2 was identified as a promising lead compound for the design of drug candidates inducing ferroptosis.

Electroporation Enhances the Anticancer Effects of Novel Cu(II) and Fe(II) Complexes in Chemotherapy-Resistant Glioblastoma Cancer Cells

Schiff base ligand (L) was obtained by condensation reaction between 4-aminopyrimidin-2(1H)-one (cytosine) with 2-hydroxybenzaldehyde. The synthesized Schiff base was used for complexation with Cu(II) and Fe(II) ions used by a molar (2 : 1 mmol ration) in methanol solvent. The structural features of ligand, Cu(II), and Fe(II) metal complexes were determined by standard spectroscopic methods (FT-IR, elemental analysis, proton and carbon NMR spectra, UV/VIS, and mass spectroscopy, magnetic susceptibility, thermal analysis, and powder X-ray diffraction). The synthesized compounds (Schiff base and its metal complexes) were screened in terms of their anti-proliferative activities in U118 and T98G human glioblastoma cell lines alone or in combination with electroporation (EP). Moreover, the human HDF (human dermal fibroblast) cell lines was used to check the bio-compatibility of the compounds. Anti-proliferative activities of all compounds were ascertained using an MTT assay. The complexes exhibited a good anti-proliferative effect on U118 and T98G glioblastoma cell lines. In addition, these compounds had a negligible cytotoxic effect on the fibroblast HDF cell lines. The use of compounds in combination with EP significantly decreased the IC₅₀ values compared to the use of compounds alone (p<0.05). These results show that newly synthesized Cu(II) and Fe(II) complexes can be developed for use in the treatment of chemotherapy-resistant U118 and T98G glioblastoma cells and that treatment with lower doses can be provided when used in combination with EP.