title: Synthesis, structure, DNA binding and cleavage properties of ternary amino acid Schiff base-phen/bipy Cu(II) complexes.
abstract: Ternary Cu(II) complexes [Cu(II)(saltrp)(B)] (1,2), (saltrp=salicylidene tryptophan, B=1,10 phenathroline (1) or 2,2' bipyridine (2)) were synthesized and characterized. Complex 2 was structurally characterized by single crystal X-ray crystallography. The molecular structure shows a distorted square pyramidal coordination geometry (CuN(3)O(2)) in which the ONO donor Schiff base is bonded to the Cu(II) in the basal plane. The N,N donor heterocyclic base displays an axial-equatorial binding mode. CT-DNA binding studies revealed that the complexes show good binding propensity (Intrinsic binding constant, K(b)=3.32×10(5) M(-1) for 1 and K(b)=3.10×10(5) M(-1) for 2). The catalytic role of these complexes in the oxidative and hydrolytic cleavage of DNA was studied in detail. Complex 1 binds and cleaves DNA more efficiently as compared to 2. From the kinetic experiments, rate constants for the hydrolysis of phosphodiester bond of DNA backbone were determined as 1.94 h(-1) and 1.05 h(-1) for 1 and 2 respectively. It amounts to (2.93-5.41)×10(7) fold rate enhancement compared to uncatalyzed double stranded DNA, which is impressive as compared to related Cu(II) Schiff base complexes.
authors: Department of Chemistry, Osmania University, Hyderabad, India. rabi_pr@rediffmail.com
authors: Pulimamidi Rabindra
authors: PR
authors: Reddy
authors: Addla
authors: A
authors: Shilpa
authors: Nomula
authors: N
authors: Raju
authors: Pallepogu
authors: P
authors: Raghavaiah
mesh_terms: D001667:Binding, Competitive; D003198:Computer Simulation; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D053837:DNA Cleavage; D003851:Deoxyribonucleases / Q000138:chemical synthesis / Q000737:chemistry; D004996:Ethidium / Q000737:chemistry; D007364:Intercalating Agents / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D044366:Transition Temperature; D014783:Viscosity
chemical_list: D056831:Coordination Complexes; D007364:Intercalating Agents; D004247:DNA; C427203:calf thymus DNA; D003851:Deoxyribonucleases; D004996:Ethidium