Aims and Scope
Many methods have been suggested for the removal of heavy metals from water to protect human health and the environment. Methods like precipitation and adsorption were proposed for this purpose.
Electrocoagulation involves the generation of coagulant by the action of electricity on two metal electrodes (iron or aluminium) to aid the process of water decontamination.
Electrodeposition cell was made with iron electrodes and application of voltage from the power supply (5-25 V) dipped in the working solution (Cu and Zn) at various concentrations (10-50 mg.mL-1) for 30-150 min. Samples were drawn and analysed by atomic absorption spectrophotometry.
The work indicated efficient removal of the metal ions. The dependence of removal efficiency on the three parameters was studied. The behaviour of the two metal ions was not identical. At low initial concentration, the electrolysis voltage was very important in the removal of Zn and Cu ions. Electrolysis time is essential in the removal process and shows a polynomial dependence of removal efficiency on time. Electrolysis time of 150 min resulted in almost complete removal (94-97%) regardless of the initial concentration. Both co-precipitation and adsorption mechanisms may be involved.
The removal efficiency was directly dependent on the initial metal ion concentration and electrolysis time. The process gave removal efficiency for copper that is higher than that of the zinc.
December 18, 2020
- July 03, 2020
- April 17, 2020
- November 20, 2020
Synthesis, Characterization of Mixed Cu(II) Pyridyl Tetrazoles and 1,10-Phenanthroline Complexes - DFT and Biological ActivityCh. Himasekar, Sheik Mustafa, Manabolu S. Babu
Mixed ligand copper complexes with 1,10-phenanthroline show good chemical nuclease activity and anticancer activity. Recently, tetrazole derivatives are also promising candidates for anticancer activity. Hence, it is significant to study the DNA binding and anticancer activity of two active N-donor ligands and their copper complexes.
The main objective of this study was to investigate the regioisomeric mixed ligand copper complexes response with calf thymus DNA binding and anti-toxic activity against MCF-7 cell line.
The DNA binding interactions of complexes 1-4 with calf thymus DNA (CT-DNA) were monitored by UV/VIS spectroscopy. The absorption spectra of the Cu complexes are compared with and without CT-DNA at 400-450 nm. The cell proliferation was measured by using the standard 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium- 5-carboxanilide (XTT) assay with four different concentrations of the compounds (5, 10, 50, and 100 mm) and cisplatin (as a positive control) was tested in triplicate for 48 h. The results obtained by the XTTassay are expressed as the average standard deviation of two experiments. The IC50 values of the complexes exhibited differential and dose-dependent inhibitory activities on the growth of MCF-7 cancer cells.
Based on the elemental analysis, molar conductance, magnetic moments, mass, electronic, ESR and IR spectral data, the copper is coordinated by N-atoms of 1,10- phenanthroline and pyridyl tetrazole with octahedral structure. DFT calculations of HOMO and LUMO studies showed that electron density is localized on pyridyl tetrazole ring and phenanthroline ring. The calculated DNA binding constant (Kb) values of 1-4 complexes are in the range 4.2 - 7.6 x104M-1 (Table 4) with similar binding affinity to reported copper tetrazole derivative complexes. The 1-4 complexes with CT DNA interaction are through planar phenanthroline and pyridyl tetrazole ring likely via π-stacking interactions. The IC50 values of complexes show excellent activity with 24(± 0.5); 18(± 0.5); 20(±0.5); (±0.5) and 38 (±0.8) for 1, 2, 3, 4 and cis platin complexes, respectively. After 72 h of the treatment of 1 on MCF-7 cell, IC50 values hinder the cell growth upto 24(± 0.5) µg/ml at 5 µM concentration range (Fig. 5). It is apparent from IC50 values that the order inhibition is 1 > 3 >2 > 4.
Experimental results are highly encouraging to explore the mixed ligand regio isomeric copper complexes which have shown the parallel result with Cisplatin. By proper structural modification of pyridyl tetrazole ligand, substituent better anticancer agents can be prepared.
January 28, 2019