Synthesis, characterization of new copper (ii) Schiff base and 1,10 phenanthroline complexes and study of their bioproperties.

Three mononuclear Cu(II) complexes [Cu(naph-phe)phen] (1), [Cu(naph-tyr)(phen)] (2) and [Cu(naph-trp)(phen)] (3) were synthesized, characterized and their biological properties were studied. Complexes 1, 2, 3 exhibit square pyramidal geometry where Schiff base acts as a binegative tridentate ONO donor ligand and phen acts as NN donor ligand. CT-DNA binding studies revealed that the complexes bind through intercalative mode and show good binding propensity.

New Bio-Based Cu(II) Complexes and Study of their Anti-Cancer Activities.

Two new Cu(II) complexes with Picolinic acid and Tryptophan [Cu(II)(DPTR)(H2O)2](1:1) (1) and [Cu(II)(DPTR)(Phen)] (1:1:1) (2) were synthesized, characterized and studied their DNA binding, cleavage, docking and anti-cancer properties. The molecular modeling studies were carried out with energy minimized structures of metal complexes. CT-DNA binding studies revealed that the complexes bind through an intercalative mode and show good binding propensity.

Picolinic acid based Cu(II) complexes with heterocyclic bases--crystal structure, DNA binding and cleavage studies.

In view of the importance of picolinic acid (PA) in preventing cell growth and arresting cell cycle, new PA based metallonucleases were designed with a view to study their DNA binding and cleavage abilities. Three new Cu(II) complexes [Cu(II)(DPPA)].4H2O (1),[Cu(II)(DPPA)(bpy)].

2-Hydroxynaphthalene-1-carbaldehyde- and 2-(aminomethyl)pyridine-based Schiff base Cu(II) complexes for DNA binding and cleavage.

Three mononuclear Cu(II) complexes, [CuCl(naph-pa)] (1), [Cu(bipy)(naph-pa)]Cl (2), and [Cu(naph-pa)(phen)]Cl (3) ((naph-pa)=Schiff base derived from the condensation of 2-hydroxynaphthalene-1-carbaldehyde and 2-picolylamine (=2-(aminomethyl)pyridine), bipy=2,2'-bypiridine, and phen=1,10-phenanthroline) were synthesized and characterized. Complex 1 exhibits square-planar geometry, and 2 and 3 exhibit square pyramidal geometry, where Schiff base and bipy/phen act as NNO and as NN donor ligands, respectively. CT (Calf thymus)-DNA-binding studies revealed that the complexes bind through intercalative mode and show good binding propensity (intrinsic binding constant K(b): 0.

Synthesis, structure, DNA binding and cleavage properties of ternary amino acid Schiff base-phen/bipy Cu(II) complexes.

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.

Synthesis, characterization, and DNA binding and cleavage properties of copper(II)-tryptophanphenyl-alanine-1,10-phenanthroline/2,2'-bipyridine complexes.

The mononuclear dipeptide-based Cu(II) complexes [Cu(II) (trp-phe)(phen)(H₂O)] ⋅ ClO₄ (1) and [Cu(II) (trp-phe)(bpy)(H₂O)] ⋅ ClO₄ (2) (trp-phe=tryptophanphenylalanine, phen=1,10-phenanthroline, bpy=2,2'-bipyridine) were isolated, and their interaction with DNA was studied. They exhibit intercalative mode of interaction with DNA. The intercalative interaction was quantified by Stern-Volmer quenching constant (K(sq) =0.

A 1 : 2 copper(II)-tripeptide complex for DNA binding and cleavage agent under physiological conditions.

A 1 : 2 copper-tripeptide complex, [Cu(II)(Boc-His-Gly-His-OMe)(2)](2+), was synthesized and structurally characterized. The absorption band at 577 nm suggests a square-planar geometry around Cu(II). The DNA-binding and DNA-cleavage properties of the Cu(II) complex were investigated.

Synthesis, characterization, and DNA-binding studies of mononuclear copper(II)-phenanthroline-tyrosine complex.

The mononuclear complex [Cu(II)(phen)(L-Tyr)(H(2)O)] was synthesized and structurally characterized by elemental analysis, magnetic susceptibility, UV/VIS, IR, and EPR spectroscopy, and ESI mass spectrometry. The electronic and EPR spectral data suggest a square-pyramidal geometry around Cu(II). Absorption spectra, thermal denaturation, and fluorescence-spectroscopic studies were conducted to assess the interaction of the Cu(II) complex with calf thymus DNA (CT DNA).

Synthesis and DNA binding/cleavage of mononuclear copper(II) phenanthroline/bipyridine proline complexes.

The complexes [Cu(II)(phen)(L-Pro)(H2O)]+ ClO4(-) (1; phen = 1,10-phenanthroline) and [Cu(II)(bipy)(L-Pro)(H2O)]+ ClO4(-) (2; bipy = 2,2'-bipyridine) were synthesized and characterized by IR, magnetic susceptibility, UV/VIS, EPR, ESI-MS, elemental analysis, and theoretical calculations. The metal center was found in a square-pyramidal geometry. UV/VIS, thermal-denaturation, and fluorescence-spectroscopic studies were conducted to assess the interaction of the complexes with CT-DNA.

Mixed-ligand copper(II)-phenanthroline-dipeptide complexes: synthesis, characterization, and DNA-cleavage properties.

The mixed-ligand complexes [Cu(II)(HisLeu)(phen)](+) (1) and [Cu(II)(HisSer)(phen)](+) (2; phen=1,10-phenanthroline) were synthesized and characterized. The intercalative interaction of the Cu(II) complexes with calf-thymus DNA (CT-DNA) was probed by UV/VIS and fluorescence titration, as well as by thermal-denaturation experiments, and the intrinsic binding constants (K(b)) for the complexes with 1 and 2 were 4.2x10(3) and 4.

A new S4-ligated zinc-peptide 1:2 complex for the hydrolytic cleavage of DNA.

A new sulfur-ligated Zn-peptide 1:2 complex, [Zn(II)(Boc-NH-Cys-Gly-Cys-OMe)2]2- (2), was prepared, characterized, and tested for its DNA-binding and -cleavage properties. Complex 2 was found to cleave DNA hydrolytically. The negative charge in 2 reduces the affinity of the complex for DNA, and enhances its binding specificity.

Ternary nickel(II) complexes as hydrolytic DNA-cleavage agents.

A series of small model complexes made from Ni(II) and the ligands ethylenediamine (en), histamine (hist), and histidylleucine (HisLeu) were prepared and studied as potential hydrolytic DNA-cleavage agents. The stability constants and species-distribution curves for these complexes were determined as a function of pH. The 1 : 1 : 1 ternary complexes [Ni(II)(en)(HisLeu)] (1) and [Ni(II)(hist)(HisLeu)] (2) were the only major species present at the physiologically relevant pH of 6-7, as further corroborated by ESI-MS analysis.

Ternary zinc(II)-dipeptide complexes for the hydrolytic cleavage of DNA at physiological pH.

A series of Zn(II) complexes with cysteinylglycine (CysGly) and histidylserine (HisSer), and of CysGly and histidylphenylalanine (HisPhe) were investigated. Complex stabilities were determined potentiometrically, and binding geometries were probed by means of 1H-NMR spectroscopy, using Co(II) instead of Zn(II) as a spectroscopic marker. The ternary 1:1:1 complexes [Zn(II)(CysGly)(HisSer)] and [Zn(II)(CysGly)(HisPhe)] were shown by UV experiments, fluorescence titration, and gel electrophoresis to intercalate with DNA, and to hydrolytically cleave supercoiled DNA (form-I), partly also circular (form-II) DNA, under physiological conditions (37 degrees, H2O, pH 7.

Novel peptide-based copper(II) complexes for total hydrolytic cleavage of DNA.

Stable Cu(II) complexes with histamine- and histidine-containing dipeptides histidylserine and histidylphenylalanine have been developed. Their interaction in solution has been investigated, and the stability of their complexes was determined. The nature of binding in these complexes has been explained with the help of potentiometric pH titrations and 1H-NMR spectroscopy.

Copper(II) complexes containing N,N-donor ligands and dipeptides act as hydrolytic DNA-cleavage agents.

Copper(II) complexes are known to play a significant role in both naturally occurring biological systems and pharmaceutical agents. Recently, Cu(II) complexes have gained importance in DNA cleavage essential for the development of anticancer drugs and chemotherapeutic agents. Therefore, we have designed small molecules, consisting of a metal ion, N,N-donor ligands, and dipeptides, to probe their DNA-cleaving potential.