Synthesis, characterization, electrochemistry and kinetics of CTDNA binding of a bis ciprofloxacin borate copper(II) complex

A new boroderivative of ciprofloxacin and its Cu-II complex has been synthesized and characterized by elemental analysis, i.r., e.p.r., u.v. vis., n.m.r. spectroscopy. Molar conductance measurements show that the complex is ionic. E.p.r. values and electronic spectral data suggest that it possesses square planar geometry. The reaction kinetics of the ligand K[C34H36N6O6F2B] and its Cu-II complex with calf thymus DNA (CTDNA) has been monitored spectrophotometrically in aqueous media. The K-obs value has been calculated under pseudo-first order conditions and it has been observed that the Cu-II complex is a more efficient DNA inhibitor than the free borate of ciprofloxacin. The redox behavior of the Cu-II complex in the presence and in the absence of CTDNA in aqueous solution has been investigated by cyclic voltammetry. The cyclic voltammogram of the Cu-II complex exhibits one quasireversible redox wave for a one-electron transfer corresponding to Cu-II/Cu-I redox couple with E-1/2 values -0.613 and -0.649 V respectively. On interaction with CTDNA, the Cu-II complex exhibits a shift in E-1/2 values corresponding to 0.013 and 0.035 V respectively.