A new triazine bearing a pyrazolone group capable of copper, nickel, and zinc chelation

Abstract

Interests in inorganic applications of triazines is growing. In this report, metal complexes of copper(II), nickel(II), and zinc(II) and a novel class of chelates comprising a triazine ring substituted with a hydrazine group and pyralozone are evaluated using spectrophotometric methods, single crystal X-ray diffractometry, and electrochemistry. Complexes with copper(II) include a single chelate and two chloride atoms to satisfy a trigonal bipryamidal coordination sphere. The nickel(II) and zinc(II) complexes are comprised of two chelating groups that adopt an octahedral geometry around the metal ion. Irreversible redox activity was observed with the copper(II) complex but no redox activity was observed with the ligand alone or zinc(II) and nickel(II) complexes. Use of the coumarin carboxylic acid assay shows that the ligand motif is capable of preventing redox cycling of copper in biological conditions and could thus serve as an antioxidant preventative agent. Cellular toxicity studies show that the new triazine molecule could have therapeutic applications in the µM concentration range based on the measured EC=1.183±2 mM. Altogether this work shows that by merging triazine chemistry into inorganic compounds, there is potential to explore a range applications thanks to the new architecture.

Enhancement of the Antioxidant Activity and Neurotherapeutic Features through Pyridol Addition to Tetraazamacrocyclic Molecules

“…The overproduction of ROS is hypothesized to lead to the development of neurodegenerative diseases. − A good model for such redox cycling in the brain is the copper/ascorbate redox system (Scheme ). ,, The hydroxyl radicals generated by copper­(II) in the presence of ascorbate and oxygen stoichiometrically convert CCA to the fluorescent hydroxy-CCA species (Figure , inset). , Metal-ion redox chemistry is known to be modulated by coordination to strongly donating small molecules. , Therefore, this model system was used to evaluate the capacity of L4 to halt metal-ion redox cycling under these conditions. The results are compared to L2 to determine if the number of pyridol moieties may play a role in this reactivity as well.…”

“…91−94 A good model for such redox cycling in the brain is the copper/ascorbate redox system (Scheme 2). 50,95,96 The hydroxyl radicals generated by copper(II) in the presence of ascorbate and oxygen stoichiometrically convert CCA to the fluorescent hydroxy-CCA species (Figure 5, inset). 95,96 Metalion redox chemistry is known to be modulated by coordination to strongly donating small molecules.…”

Tautomerism and antioxidant activity of some 4-acylpyrazolone-based Schiff bases: a theoretical study

“… 2 Other derivatives that possess analgesic, 3 antimicrobial, 4 anti-inflammatory, 5 antioxidant, 6 and antiprion 7 activities have also been reported. Some pyrazolones have been used as fungicides and herbicides for crop protection, as dyes for cotton, wool, and silk, 3 as ligands for synthesis of metal complexes, 8 and as corrosion inhibitors. 9 …”

Synthesis of Macrocycles Derived from Substituted Triazines

“…Morpholine is then added at room temperature to yield 6 or 7 . Microwave irradiation is employed to facilitate substitution with ethyl glycinate to yield intermediate 8 or 9 . Following saponification of each to 10 or 11 , EDC‐mediated couplings with 1‐amino‐3,3‐diethyoxypropane completes the syntheses.…”