DNA-binding and Kinetics AChE Inhibition studies of Cobalt(II) and Copper(II) Complexes Derived from 5-[4-(dimethylamino) phenyl]-3-(2-oxo-2H-chromen-3-yl)-1H-pyrazole-1-carbothioamide

Document Type : Original Article


Mustansiriyah University,College of Science, Department of Chemistry


A series of transition metal complexes of the general formula [MLCl(H2O)2] ,M=Co(II) and Cu(II) and L=3-(pyridine-2-yl)-4,5-dihydro-1H-pyrazole-1-thiocarboxamides (L) have been synthesized by a two steps reaction sequence starting from substituted Benz aldehydes and 2-acetyl pyridine. The cobalt(II) and copper(II) complexes were isolated in their solid state by the direct reactions of ligand ,L with CoCl2.6H2O and CuCl2•2H2O solutions. The structure and geometry of the metal complexes were determined their chemical structures on the basis of (CHNS) elemental analyses, FT-IR,LC-MS and UV-Visible spectra beside the measurements of magnetic susceptibility at room temperature and molar conductance in DMSO solvent. The application part of the recent paper was the screening of the new poly dentate-based pyrazoline ligand and its CoL and CuL complexes with thymus DNA act as powerful sequence-specific gene modulators, by exerting their effect from transcription regulation to gene modification. The DNA binding abilities of the 5-[4-(dimethylamino)phenyl]-3-(2-oxo-2H-chromen-3-yl)-1H-pyrazole-1-carbithioamide and it Cu , Co complexes was evaluated by UV–Vis titration experiments, which was a useful method to calculate the DNA binding constants in vitro. After Calf Thymus DNA (CT DNA) was added to the phosphate buffer solution containing constant ligand and complexes concentrations, all of the solutions exhibited a slight hypochromic without any significant spectral shift. The binding constants of the compounds were calculated by using a plot of D/∆Ɛapp versus D. Close ,Cu and Co showed the largest binding constant (7.8 * 104 , 8 * 108 , 6.1* 103 ) M for binding with DNA respectively . Specifically, both compounds showed hypochromicity upon increasing DNA concentration, indicating that both compounds interacted with the DNA helix. However, a weak hypochromic effect is indeed observed, and no red shift is apparent. In a third part of study ,a series of chromene and its complexes with Co and Cu were synthesized and their acetyl cholinesterase enzyme (AChE) inhibitory effects were investigated. All carben were synthesized from the corresponding carboxylic acids via of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The chromene and its complexes with Co and Cu were determined to be very good inhibitors against for AChE with different type of inhibition (mix and non-competitive) inhibition.


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