Synthesis, Characterization and Interaction of Drug Based Cobalt (II) Complex with Herring Sperm DNA and Biological Activity

Abstract

Novel complexes of copper (II), cobalt (II) and nickel (II) with sulphapyridine and aminothiazole were synthesized and characterized using spectral and analytical techniques. The interaction of cobalt (II) complexes with herring sperm DNA has been performed using absorption titration, viscometric measurements and cyclic voltammetry. The protective activity of metal complexes has been carried out using arose gel electrophoresis. The results indicate that cobalt (II) complex bind to DNA via electrostatic or groove binding with binding constant K b = 4.5 x 10 4 M -1. The antioxidant activity for cobalt (II) complex was also checked. Keywords: hypochromism, peak potential and binding constant. I. INTRODUCTIONThe binding of metal complexes to DNA has been extensively studied over the past decade. Many coordination compounds are able to bind DNA as structural probes[1], DNA foot printing [2], DNA cleaving agents [3][4] and as potential anticancer drugs [5][6]. It is generally believed that many anticancer, antiviral, and antiseptic agents take action through binding DNA [4,[7][8], since the interaction between small molecules and DNA can often cause DNA damage in cancer cells, blocking the division of cancer cells and resulting in cell death [9][10][11]. Many studies indicate that transition metal complexes can bind to DNA via both covalent (replacement of labile coordinating ligand by nitrogen base of DNA (i.e. adenine, Cytosine, guanine, thymine) and or non covalent interaction (intercalation, electrostatic or groove binding) [12]. Many important applications of these complexes require that they can bind via intercalative mode or groove binding [13]. Therefore interaction of complexes especially with planar aromatic heterocyclic ligands, which can insert into the base pairs of DNA duplex has attracted considerable attention [14][15][16]. is an essential element widely distributed in biological system [6,[17][18]. Numerous cobalt complexes has been studied as hydrolytic agent for DNA cleavage [19-20], antitumor, antproli-ferative[21-23], antimicrobial[24-26] and antifungal [21,27], antiviral [28,29], antioxidant [12 ,30] and ant inflammatory activity [30]. They have exhibited antitumorogenic activity by reducing the number and size of carcinogen induced colon tumors and play synergistic role on the activity of certain antitumor drugs, although the mechanism has not been completely clarified [31][32][33]. Ligands having nitrogen donors received considerable attention because of their mixed hard-soft donor character, versatile coordination behavior [34][35] and for their biological activity (i.e., toxicity against bacterial growth [36], anticancer [37] and other biochemical properties [38]). The coordination geometry and nature of donor atoms play key roles in determining the binding extent of complexes to DNA. The importance of central metal ion at the core of the structure is noteworthy [39,40]. Many DNA heterocyclic compounds such as benzothiazole and benzopyra zine derivatives have been evaluated and f...