Spectroscopic and voltammetric studies of copper(II) complexes of bis(pyrid-2-yl)-di/trithia ligands bound to calf thymus DNA

Mahadevan, Sethuraman; Palaniandavar, Mallayan

doi:10.1016/s0020-1693(96)05175-4

Cited by 146 publications

(94 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results reveal that the complexes 1 and 2 show relatively small changes in DNA viscosity, indicating that they bind weakly to DNA which is consistent with DNA groove binding suggested above. 38,39) The increased degree of viscosity, which may depend on its affinity to DNA follows the order of 2Ͼ1Ͼlig-and, which is consistent with our foregoing hypothesis.…”

Section: )supporting

confidence: 88%

Synthesis, Characterization, Antioxidant Activity, and DNA-Binding Studies of 1-Cyclohexyl-3-tosylurea and Its Nd(III), Eu(III) Complexes

Liu

et al. 2008

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

The sulfonylureas have a wide range use in biology, and many of their ramifications have been used as anti-diabetic medicine and herbicide.1,2) Sulfonylurea regulating biological functions of pancreatic islets, which has been used for the treatment of type 2 diabetes mellitus because of its insulin tropic activity on pancreatic islets.3) Subsequent interests were focused on the redox properties, structures and biological activity of their transition metal complexes.4) More recently, the lanthanide(III) complexes of sulfonylurea increasingly attracted attention, because of their certain anti-diabetic activities. Yet it is noticed that the DNA-binding investigation of such complexes have been done relatively few. Because the interaction between metal complexes and DNA is in close relationship with their potential biological and pharmaceutical activities, 5,6) studies on DNA-binding of metal complexes are very important in the development of new therapeutic reagents and DNA molecular probes. In order to find more effective and less toxic anti-diabetic drugs, thousands of analogues of sulfonlyureas were synthesized. 6,7)Here, we synthesized 1-cyclohexyl-3-tosylurea (H 2 L) and its two lanthanide(III) complexes. In addition DNA-binding property of two lanthanide(III) complexes with 1-cyclohexyl-3-tosylurea is reported in this paper. These lanthanide compounds possibly represent a new class of potential anti-diabetic agent. ExperimentalMaterials Nitroblue tetrazolium (NBT), methionine (MET), vitamin B 2 (VitB 2 ) were purchased from Sigma Chemical Co. Calf thymus DNA (CT-DNA) was purchased from Sigma without further purification. EDTA and Ln 2 O 3 (LnϭNd, Eu) were produced in China. All chemicals used were of analytical grade. The lanthanide(III) nitrates were prepared by dissolving Ln 2 O 3 in HNO 3 , and then crystallizing to get the products. All the experiments involving interaction of the ligand and the complexes with CT-DNA were carried out in doubly distilled water buffer containing 5 mM Tris[Tris(hydroxymethyl)-aminomethane] and 50 mM NaCl, and adjusted to pH 7.2 with hydrochloric acid. A solution of CT-DNA gave a ratio of UV absorbance at 260 and 280 nm of about 1.8-1.9, indicating that the CT-DNA was sufficiently free of protein.8) The CT-DNA concentration per nucleotide was determined spectrophotometrically by employing an extinction coefficient of 6600 M Ϫ1 cm Ϫ1 at 260 nm.9) The ligand and the complexes were dissolved in a solvent mixture of 1% CH 3 OH and 99% Tris-HCl buffer (5 mM Tris-HCl, 50 mM NaCl, pH 7.2) at concentration 1.0ϫ10 Ϫ5 M. An absorption titration experiment was performed by maintaining 10 mM compounds and varying the concentration of nucleic acid. While measuring the absorption spectra, an equal amount of CT-DNA was added to both the compound solution and the reference solution to eliminate the absorbance of CT-DNA itself. EDTA-Fe(II) and Na 2 HPO 4 -KH 2 PO 4 buffers were prepared with twice distilled water.Physical Measurements The melting points of the compounds were determined on a B...

show abstract

Section: )supporting

confidence: 88%

Synthesis, Characterization, Antioxidant Activity, and DNA-Binding Studies of 1-Cyclohexyl-3-tosylurea and Its Nd(III), Eu(III) Complexes

Liu

et al. 2008

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

show abstract

“…Interestingly K ϩ (nϪ1) and K n ϩ values of complexes 1 and 2 are near unity, which suggest that they are involved in DNA interaction favoring both oxidation states equally. A similar observation has been made by Mahadaven et al [58][59][60] Furthermore, the significant shift in the electrode potentials and peak current ratios on addition of CT DNA can be explained in terms of the diffusion of an equilibrium mixture of free and DNA bound metal complexes to the electrode surface 61) thus implying a strong binding of 1 and 2 with CT DNA. A summary of the voltammetric results for the complexes 1 and 2 in the absence and the presence of CT DNA are given in Table 3.…”

supporting

confidence: 76%

Synthesis and Characterization of Glucose-Bis(pyrazole)-Cu(II)/Ni(II) Complexes and Their in Vitro DNA Binding Studies

Tabassum

Bhat

2010

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

In the forefront is the recent area of glycobiology a "sweet and safe" approach for the development of new drugs in medicinal inorganic chemistry.1) The use of glycosyl substituents for enhanced tissue target, improved solubility and reduced toxicity has attracted many researchers to explore the possibility of carbohydrate-based drug strategies. [2][3][4][5] Chen et al. have synthesized a novel carbohydrate linked to cisplatin analogue, cis-dichloro [(2-b-D-glucopyranosidyl)propane-1,3-diamine]platinum and examined selective cytotoxicity towards cancer cells.6) This complex exhibits specific in vitro antitumour activity against human ovarian cancer cell A2780S and human melanoma cancer cell MeWo. Some of the cancer cell antigens are carbohydrates and several trials are being carried out to develop carbohydrate derived cancer vaccines.7) Globo H is a prominent epitope on cancer cells; therefore a potential vaccine was prepared consisting of the synthetic hexasaccharide chain of Globo H linked to KLH. 8)Recently, Nakase et al. have demonstrated artemisinin tagged to transferrin via carbohydrate chain exhibits high potency and specificity against cancer cells. 9) Carbohydrate linked to biologically relevant molecules like pyrazole and imidazole act as an attractive scaffold for transition metal ions. [10][11][12] The interaction of transition metal-saccharide complexes with DNA is significantly important (DNA is one of the main molecular targets in the action of anticancer drugs), as many naturally occurring antitumour agents are capable of modifying nucleic acids only in presence of metal ions and oxygen. [13][14][15][16] Of these antitumour agents, a vast majority usually contains sugar derivatives as their back bone. Thus, there has been profound interest in the design, study of DNA binding and cleavage properties of glucose-derived transition metal complexes and development of these complexes as metallo-drugs. 17,18) Since there are many alterations in the genes that code for the protein in tumor, the focus of such studies is also on proteins which drive and control cell cycle progression. 19,20) Herein, we describe the synthesis, characterization of Dglucose-bis pyrazolyl metal complexes of Cu(II) 1 and Ni(II) 2 and their binding properties with CT DNA. Furthermore, DNA cleavage of pBR322 DNA by complex 1 was carried out by employing agarose gel electrophoresis. The "binding study" of complex 1 towards human serum albumin (HSA), L-tryptophan and their mixtures with DNA was studied to recognize the most favoured biomolecule, for which it shows highest binding affinity. ExperimentalMaterials and Methods D-Glucose, CuCl 2 · 2H 2 O, NiCl 2 · 6H 2 O (Qualigens), pyrazole (Fluka). Tris (TrisϭTris(hydroxymethyl)aminomethane) base (Merck), 6ϫ loading dye (Fermental Life Science) and super coiled plasmid DNA pBR322 (Genei) were utilized as received. Disodium salt of calf thymus DNA, human serum albumin and L-tryptophan were purchased from Sigma Chemical Company and stored at 4°C. All reagent grade compounds were used w...

show abstract

“…7, b) [49]. These results support that the Cu II complex 1a interacts with CT-DNA, and that the binding event induces certain conformational changes in DNA [50].…”

supporting

confidence: 66%

Synthesis and Characterization of a New Macrocyclic Copper(II) Complex with an N‐Glycosidic Pendant Arm: in vitro Cytotoxicity and Binding Studies with Calf‐Thymus DNA

Mathur

Tabassum

2006

Chemistry & Biodiversity

View full text Add to dashboard Cite

The new macrocyclic complex 2-amino-2-deoxy-N-[2-(1,3,5,8,11-pentaazacyclotridecan-3-yl)ethyl]-beta-D-glucopyranosylamine copper(II) dichloride (1a) was prepared and thoroughly characterized by various techniques. Molar-conductance measurements showed that 1a (and its Ni analogue 1b) are ionic in nature. On the basis of spectroscopic data, both complexes were assigned a square-planar geometry, and found to be highly stabile and hydrolytically robust in H2O over a wide range of pH, as confirmed by cyclic voltammetry (CV). The Cu(II) complex 1a was found to bind to CT-DNA, with a binding constant Kb of 2.4x10(3) M(-1), as derived by UV/VIS titration, and confirmed by CV, circular dichroism (CD), and viscosity measurements. DNA binding seems to occur mostly via H-bonding. In an in vitro antitumor MTT assay, 1a exhibited significant anticancer activity against the SY5Y and PC-12 cell lines, with an estimated IC50 value in the micromolar range for SYSY, similar to the standard drug 5-fluorouracil.

show abstract

Spectroscopic and voltammetric studies of copper(II) complexes of bis(pyrid-2-yl)-di/trithia ligands bound to calf thymus DNA

Cited by 146 publications

References 57 publications

Synthesis, Characterization, Antioxidant Activity, and DNA-Binding Studies of 1-Cyclohexyl-3-tosylurea and Its Nd(III), Eu(III) Complexes

Synthesis, Characterization, Antioxidant Activity, and DNA-Binding Studies of 1-Cyclohexyl-3-tosylurea and Its Nd(III), Eu(III) Complexes

Synthesis and Characterization of Glucose-Bis(pyrazole)-Cu(II)/Ni(II) Complexes and Their in Vitro DNA Binding Studies

Synthesis and Characterization of a New Macrocyclic Copper(II) Complex with an N‐Glycosidic Pendant Arm: in vitro Cytotoxicity and Binding Studies with Calf‐Thymus DNA

Contact Info

Product

Resources

About