COPPER CHELATION BY SYRINGIC HYDRAZONES: A PROMISING STRATEGY FOR COMBATING OXIDATIVE STRESS-RELATED DISEASES

Abstract

Oxidative stress is a critical factor in vascular damage and the development of diseases such as atherosclerosis. This study investigates the complexation properties of two syringic hydrazones, (E)-4-Hydroxy-3,5-dimethoxybenzaldehyde -1,3-benzothiazol-2-ylhydrazone 1 and (E)-4-Hydroxy-3,5-dimethoxybenzaldehyde phthalazin-1-ylhydrazone hydrochloride 2, with copper ions (CuSO₄·5H₂O and CuCl₂·2H₂O). Using UV spectrophotometry, we determined stability constants and stoichiometries of the complexes formed. Compound 1 forms three distinct types of complexes (ML, ML₂, and M₂L) with higher stability constants compared to those formed by compound 2, particularly when using CuCl₂·2H₂O. These findings extend our previous work, where syringic hydrazones demonstrated potent antioxidant properties through scavenging DPPH^● and ABTS^●+ radicals, inhibiting superoxide anion generation, and reducing TBARS formation in human cell-mediated LDL oxidation. These results highlight the dual potential of syringic hydrazones as radical scavengers and metal chelators.