Biological and Catalytic Potential of Vanadium Complexes of -Methyl--phenylhydrazinecarbothioamide Based ONS Donor Ligands.

Designing vanadium complexes that can simultaneously address environmental and biomedical challenges is an emerging research direction. The ONS donor ligands derived from -methyl--phenylhydrazinecarbothioamide and salicylaldehyde (H) or 5-bromosalicylaldehyde (H) have been used to synthesize four different types of new vanadium complexes, [VO(/)(HO)] ( and ), [VO(OMe) (/)] ( and ), Cs/K(HO)[VO(/)] (-), and [(μ-O){VO(/)}] ( and ), to address these issues. Different instrumental methods have been used to characterize these complexes. The anticancer activities of - toward different cancer cell lines were evaluated through the MTT assay, and among these, exhibited pronounced cytotoxicity against A549 lung cancer cells (IC = 4.02 μM), nearly 4-fold more potent than cisplatin (IC = 17.07 μM), while remaining nontoxic to normal HEK293 cells. Its anticancer activity operates via chemodynamic therapy (CDT) through a Fenton-like reaction that generates intracellular hydroxyl radicals, as confirmed by EPR spectroscopy. Apoptosis induction was evidenced by DNA damage and chromatin condensation (DAPI assay), with live/dead staining that further validated its potential as an efficient CDT agent. Catalytically, they demonstrated excellent activity for the cycloaddition of CO with epoxide under mild conditions (45 °C, ∼1 atm (CO using a balloon)), affording cyclic carbonates with efficient conversion (99%) and selectivity (>99%).