Synthesis, crystal structure, spectroscopic, thermal, catechol oxidase and catalase-like studies: New copper(II) complexes of 2-benzoylbenzoate and 2-pyridilpropanol ligands

A Dinuclear Copper(II) Complex Electrochemically Obtained via the Endogenous Hydroxylation of a Carbamate Schiff Base Ligand: Synthesis, Structure and Catalase Activity

In the present work, we report a neutral dinuclear copper(II) complex, [Cu2(L1)(OH)], derived from a new [N,O] donor Schiff base ligand L1 that was formed after the endogenous hydroxylation of an initial carbamate Schiff base H2L coordinated with copper ions in an electrochemical cell. The copper(II) complex has been fully characterized using different techniques, including X-ray diffraction. Direct current (DC) magnetic susceptibility measurements were also performed at variable temperatures, showing evidence of antiferromagnetic behavior. Its catalase-like activity was also tested, demonstrating that this activity is affected by temperature.

A di-Copper Peptidyl Complex Mimics the Activity of Catalase, a Key Antioxidant Metalloenzyme

Catalases (CAT) are antioxidant metalloenzymes necessary for life in oxygen-metabolizing cells to regulate H₂O₂ concentration by accelerating its dismutation. Many physiopathological situations are associated with oxidative stress resulting from H₂O₂ overproduction, during which antioxidant defenses are overwhelmed. We have used a combinatorial approach associated with an activity-based screening to discover a first peptidyl di-copper complex mimicking CAT. The complex was studied in detail and characterized for its CAT activity both in solutions and in cells using different analytical methods. The complex exhibited CAT activity in solutions and, more interestingly, on HyPer HeLa cells that possess a genetically encoded ratiometric fluorescent sensors of H₂O₂. These results highlight the efficiency of a combinatorial approach for the discovery of peptidyl complexes that exhibit catalytic activity.

Mixed azido/phenoxido bridged trinuclear Cu(ii) complexes of Mannich bases: Synthesis, structures, magnetic properties and catalytic oxidase activities

Three mixed azido/phenoxido bridged trinuclear Cu(ii) complexes of tetradentate Mannich base ligands, synthesised by a metalloligand approach show antiferromagnetic coupling and significant catecholase and phenoxazinone synthase like activities.