Spectroscopic Study of DNA Hydrolysis, DNA Intercalative, and Electrostatic Interaction Activity Exerted by Drug Based Coordination Compounds

Abstract

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

Fluorescence and absorption studies of DNA–Pd(II) complex interaction: Synthesis, spectroanalytical investigations and biological activities

“…Gel electrophoresis was performed to monitor cleavage of pUC19 DNA by synthesized complexes. The experiment procedure was performed as previously published …”

Spectroscopic and electrochemical study for evaluating DNA interaction activity of 4‐(3‐halophenyl)‐6‐(pyridin‐2‐yl)pyrimidin‐2‐amine based piano stool Cp* Rh (III) and Ir (III) complexes

“…Data are presented as ( η / η 0 ) 1/3 versus [complex]/[DNA], where η is the viscosity of DNA in the presence of complex and η 0 is the viscosity of DNA alone. Viscosity values were calculated from the observed flow time of DNA–containing solutions (t) corrected for that of the buffer alone (t 0 ), η = (t‐t 0 ) …”

DNA as a target for antimicrobials

“…7) [30] or ciprofloxacin (complexes 17 and 18, Fig. 7) [31][32][33]. These antibiotics, which function by inhibition of one step in DNA gyrase activity, were coordinated to copper complexes with the general structure [Cu(B-SA)(I L )(NO 3 (20).…”