%0 Journal Article %T Synthesis, Characterization, Antimicrobial, DNA Cleavage, and Antioxidant Studies of Some Metal Complexes Derived from Schiff Base Containing Indole and Quinoline Moieties %A Mahendra Raj Karekal %A Vivekanand Biradar %A Mruthyunjayaswamy Bennikallu Hire Mathada %J Bioinorganic Chemistry and Applications %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/315972 %X A new Schiff base of 5-chloro-3-phenyl-1H-indole-2-carboxyhydrazide and 3-formyl-2-hydroxy-1H-quinoline (HL), and its Cu(II), Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes have been synthesized and characterized in the light of microanalytical, IR, NMR, UV-Vis, FAB-mass, ESR, XRD, and TGA spectral studies. The magnetic susceptibility measurements and low conductivity data provide evidence for monomeric and neutral nature of the complexes. On the basis of spectral studies and analytical data, it is evident that the Schiff base acts as tridentate ligand. The Cu(II), Co(II), and Ni(II) complexes were octahedral, whereas Zn(II), Cd(II), and Hg(II) complexes were tetrahedral in nature. The redox behavior of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage experiment performed using agarose gel electrophoresis method showed the cleavage of DNA by all the metal complexes. The free radical scavenging activity of newly synthesized compounds has been determined at a different concentration range by means of their interaction with the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). 1. Introduction Numerous indole-containing natural and synthetic products such as reserpine, vincristine, indolemycin, mitomycin, pindolol, dolasetron mesylate, indomethacin, or sumatriptan are being used for the treatment of various illnesses. Therefore, indole structure represents a highly relevant heterocyclic system. Many pharmacodynamic compounds containing indole nucleus have been reported to possess a wide variety of biological properties, namely, anti-inflammatory [1, 2], anticonvulsant [3], cardiovascular [4], antibacterial [5], COX-2 inhibitor [6, 7], and antiviral activities [8]. More specifically, several reports describe that indole-2-carbohydrazides and related compounds are endowed with antihistaminic [9], antidepressant [10], and MAO inhibitory activities [11]. Particularly, the compounds having three substituted indole nucleus are being used as the starting materials for the synthesis of number of alkaloids, agrochemicals, pharmaceuticals, and perfumes [12]. Quinoline derivatives have also attracted the attention of the chemists because of their presence in many natural products possessing significant biological activities [13¨C17]. Small-molecule interactions with DNA continue to be %U http://www.hindawi.com/journals/bca/2013/315972/