title: Synthesis of mononuclear copper(II) complexes of acyclic Schiff's base ligands: spectral, structural, electrochemical, antibacterial, DNA binding and cleavage activity.
abstract: The mononuclear copper(II) complexes (1&2) of ligands L(1) [N,N'-bis(2-hydroxy-5-methylbenzyl)-1,4-bis(3-iminopropyl)piperazine] or L(2) [N,N'-bis(2-hydroxy-5-bromobenzyl)-1,4-bis(3-iminopropyl) piperazine] have been synthesized and characterised. The single crystal X-ray study had shown that ligands L(1) and L(2) crystallize in a monoclinic crystal system with P21/c space group. The mononuclear copper(II) complexes show one quasireversible cyclic voltammetric response near cathodic region (-0.77 to -0.85 V) in DMF assignable to the Cu(II)/Cu(I) couple. Binding interaction of the complexes with calf thymus DNA (CT DNA) investigated by absorption studies and fluorescence spectral studies show good binding affinity to CT DNA, which imply both the copper(II) complexes can strongly interact with DNA efficiently. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid as reducing agent through a mechanistic pathway involving formation of singlet oxygen as the reactive species. The Schiff bases and their Cu(II) complexes have been screened for antibacterial activities which indicates that the complexes exhibited higher antimicrobial activity than the free ligands.
authors: DDE, Alagappa University, Karaikudi 630 003, India.
authors: Arumugam
authors: A
authors: Jayamani
authors: DDE, Alagappa University, Karaikudi 630 003, India.
authors: Vijayan
authors: V
authors: Thamilarasan
authors: DDE, Alagappa University, Karaikudi 630 003, India. Electronic address: nsvelan1975@yahoo.com.
authors: Nallathambi
authors: N
authors: Sengottuvelan
authors: Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003, India.
authors: Paramasivam
authors: P
authors: Manisankar
authors: Department of Chemistry, Chungnam National University, Daejeon 305-764, Republic of Korea.
authors: Sung Kwon
authors: SK
authors: Kang
authors: Department of Chemistry Education and Interdisciplinary Program of Advanced Information and Display Materials, Pusan National University, Pusan 609-735, Republic of Korea.
authors: Young-Inn
authors: YI
authors: Kim
authors: AcmeProGen Biotech (India) Pvt. Ltd., Salem 636 004, India.
authors: Vengatesan
authors: V
authors: Ganesan
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism*; D053837:DNA Cleavage / Q000187:drug effects*; D055664:Electrochemical Techniques; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008024:Ligands; D008968:Molecular Conformation; D010957:Plasmids / Q000378:metabolism; D012545:Schiff Bases / Q000138:chemical synthesis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D000900:Anti-Bacterial Agents; D056831:Coordination Complexes; D008024:Ligands; D012545:Schiff Bases; D003300:Copper; D004247:DNA
keywords: Acyclic Schiff’s base; Anti bacterial activity; Copper(II) complexes; DNA binding and cleavage studies; Electrochemical studies