No abstract

Novel palladium(II) complexes (7a–7e) of substituted quinoline derivatives were synthesized. The complexes were characterized using various techniques such as thermogravimetric analysis (TGA), elemental analysis, conductance measurement, mass, absorption, infra‐red (IR), 1H NMR, 13C NMR and energy‐dispersive X‐ray spectroscopy (EDX). Complexes for herring sperm DNA (HS DNA) binding were explored and absorption titration and the binding constant (Kb) as well as Gibb's free energy were evaluated. Complex 7d exhibited the highest binding constant, therefore the thermodynamic parameters of 7d at different temperatures were evaluated. To support the results of the absorption titration, fluorescence titration, viscosity measurement and molecular docking studies were performed. The fluorescence quenching data as evaluated from Stern–Volmer equation were used to calculate KSV, Kf and the number of binding sites. The results of all these studies were in good agreement with the absorption study. DNA electrophoretic mobility was performed to explore the possible application of metal complexes as artificial metallonucleases. The antibacterial activity of the complexes was accessed against different pathogenic bacteria and cytotoxicity was measured using brine shrimp and S. pombe.

No abstract

No abstract

No abstract

No abstract

Five imidazo [1,2- a ]pyridine derivatives and their Au(III) complexes were synthesized. The compounds were characterized by 1 H-NMR, 13 C-NMR, IR, mass, UV-visible, elemental analysis, conductivity and magnetic measurement studies. All the compounds were screened for diverse biological activities to check the effect of coordination of Au(III) with imidazo [1,2- a ]pyridine heterocycles. The DNA interaction ability of compounds were studied as the change in absorption maxima and position of HS-DNA in presence of compounds and viscosity measurement due to change in DNA length under the influence of compounds. The computational insight of compound-DNA interaction was taken in docking study. All the results suggest intercalation mode of binding. The cellular level cytotoxic nature of compounds was evaluated using trypan blue dye staining of dead cell in cell viability assay. The smearing of DNA was observed, while DNA extracted from S. pombe cells in presence of complexes was subjected to gel electrophoresis, which shows their toxic effect on DNA. The complexes were evaluated for cytotoxicity on human A549 (Lung adenocarcinoma) cell line by MTT assay (IC 50 values). The in vitro cytotoxicity in terms of LC 50 value was checked on a simple zoological organism, brine shrimp.

Our work emphasized on synthesizing and characterizing neutral mononuclear copper(II) complexes with second generation fluoroquinolone drug ciprofloxacin (CFL) and some bipyridine derivatives (A n ) of type [Cu(CFL)(A n )Cl]·2H 2 O. The DNA binding free energies were evaluated by studying the effect of salt concentrations on DNA binding. DNA interactions were investigated by using DNA melting temperature studies, viscosity measurements, absorption ti-The elemental analysis is in good concurrence with the proposed 1:1:1, metal:CFL:A n formulation. IR SpectroscopyRing mode vibrations of the ligands are affected by coordination to Cu II , corresponding to shift in energy for bands in the 1700-500 cm -1 region of IR spectra. In the IR spectra of complexes, these bands are also slightly sensitive to the substituent of ligands. The prominent IR spectroscopic data of the complexes are shown in Table 1. The broad band in quinolone at approx. 3010 cm -1 is due to hydrogen bonding, which contributes to ionic resonance structure and the observed peak was of free hydroxyl stretching vibration. The complete elimination of this broad band can be ascribed to presence of covalent bond between copper and -COOof ciprofloxacin. The ν(C=O) stretching vibration band appears at 1708 cm -1 for ciprofloxacin, whereas for the complexes it appears at 1619-1627 cm -1 . This shift towards lower energy suggests that coordination occurs through the carbonyl oxygen of pyridine ring. [25] The strong absorption bands at 1624 cm -1 and 1340 cm -1 in ciprofloxacin could be assigned for ν(COO) asymmetric and symmetric vibrations respectively, whereas in the metal complexes, these bands are observed at 1561-1581 and 1355-1378 cm -1 . The difference Δ = ν asym (CO 2 )ν sym (CO 2 ) is very much informative in determining the coordination mode of the ligands. If the difference is greater than 200 cm -1 , it would point towards monodentate coordination