DNA/BSA BINDING STUDY OF DINUCLEAR GOLD(III) COMPLEXES WITH AROMATIC NITROGEN-CONTAINING HETEROCYCLES AS BRIDGING LIGANDS

In recent decades, a special attention has been devoted to gold(III) complexes as potential antitumor agents due to their structural similarity to platinum(II) complexes. One of the possible mechanisms of the mode of antitumor activity of gold(III) complexes could include their interaction with DNA. However, the effectiveness of the therapeutic agents also depends on the degree of its binding to proteins present in the blood plasma, because, in this way, it is transported to the cell. Considering this, we investigated the interactions of three dinuclear gold(III) complexes of the general formula [{AuCl3}2(μ– L)], L = 4,4’-bipy (4,4’-bipyridine, Au1), bpe (1,2-bis(4-pyridyl)ethane, Au2) and dpe (1,2-bis(4- pyridyl)ethene, Au3) with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA). The main aim of the study was to evaluate the binding affinities of gold(III) complexes Au1–3 towards these biomolecules for possible insights on their mode of biological activity. The values of binding constants (KA) of Au1–3 to ct-DNA are higher than those for BSA, indicating greater affinity of the complexes towards this nucleic acid. The partition coefﬁcient (logP) value for Au1 is higher compared to the corresponding values for the other two complexes, what is in accordance with a higher cellular uptake efficiency of this complex.

Download Full-text

DNA AND BSA INTERACTIONS OF COPPER(II) AND ZINC(II) COMPLEXES WITH ANTIFUNGAL AGENT FLUCONAZOLE

10.46793/iccbi21.399s ◽

2021 ◽

Author(s):

Nevena Lj. Stevanović ◽

Mia Stanković ◽

Tina P. Andrejević ◽

Darko P. Ašanin ◽

Ivana M. Stanojević ◽

...

Keyword(s):

Cyclic Voltammetry ◽

Bovine Serum Albumin ◽

Emission Spectroscopy ◽

Antitumor Agents ◽

Fungal Infections ◽

Fluorescence Emission ◽

Binding Constants ◽

Special Importance ◽

Calf Thymus ◽

Ct Dna

Aromatic nitrogen-containing heterocycles (N-heterocycles) have attracted a considerable attention as scaffolds for compounds, which have an application in different pharmacological areas, ranging from vitamins to different antimicrobial and antitumor agents. In this respect, azoles are of special importance as potent and broad-spectrum agents used for the treatment of many invasive fungal infections. In the present study, the interaction of the clinically used antifungal drug fluconazole (fcz) and its copper(II) and zinc(II) complexes, {[CuCl2(fcz)2].5H2O}n (1) and {[ZnCl2(fcz)2]·2C2H5OH}n (2), with calf thymus DNA (ct- DNA) and bovine serum albumin (BSA) has been investigated. Fluorescence emission spectroscopy was applied for the binding study of complexes 1 and 2 and fcz with ct-DNA and BSA, while cyclic voltammetry was additionally used for investigation of their interactions with ct-DNA. The values of calculated binding constants (KA) of the investigated compounds towards ct-DNA and BSA follow the order fcz < 1 < 2 and 2 < fcz < 1, respectively.

Download Full-text

Synthesis of tetra(trimethylammonio)phthalocyanato zinc tetraiodide, [ZnPc(NMe3)4]I4, and a spectrometric investigation of its interaction with calf thymus DNA

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424609001625 ◽

2009 ◽

Vol 13 (12) ◽

pp. 1255-1261 ◽

Cited By ~ 23

Author(s):

Wubiao Duan ◽

Zhenxin Wang ◽

Michael J. Cook

Keyword(s):

Phosphate Buffer Solution ◽

Binding Constants ◽

Calf Thymus Dna ◽

Buffer Solution ◽

Solution Ph ◽

Step Procedure ◽

Calf Thymus ◽

Electrostatic Binding ◽

High Concentrations ◽

Ct Dna

The phthalocyanine salt [ ZnPc(NMe3)4]I4 was synthesized from 4-nitrophthalonitrile using a three-step procedure. The interaction of [ ZnPc(NMe3)4]4+ with calf thymus DNA (CT DNA) has been investigated by UV-vis and fluorescence spectrometric methods. [ ZnPc(NMe3)4]4+ exists in a non-monomeric form, proposed to be a dimer, in phosphate buffer solution (pH 6.82). Spectral changes show that in the presence of high concentrations of CT DNA added to the solution, [ ZnPc(NMe3)4]4+ is bound in a monomeric state with evidence suggesting it is located in a DNA groove. At lower concentrations of DNA there is evidence of stacking of non-monomeric [ ZnPc(NMe3)4]4+ onto the DNA. Two intrinsic binding constants for the interaction of [ ZnPc(NMe3)4]4+ with CT DNA, 1.33 × 105 and 2.56 × 104 M-1 have been obtained. Electrostatic binding is shown to play an important role in the interaction of [ ZnPc(NMe3)4]4+ with nucleic acids.

Download Full-text

Synthesis, Characterization, Cytotoxic Activity, and Interactions with CT-DNA and BSA of Cationic Ruthenium(II) Complexes Containing Dppm and Quinoline Carboxylates

Bioinorganic Chemistry and Applications ◽

10.1155/2017/2562780 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Edinaldo N. da Silva ◽

Paulo A. B. da Silva ◽

Angélica E. Graminha ◽

Pollyanna F. de Oliveira ◽

Jaqueline L. Damasceno ◽

...

Keyword(s):

Cell Lines ◽

Human Cancer ◽

Binding Constants ◽

Bidentate Coordination ◽

Human Cancer Cell Lines ◽

Cytotoxicity Assays ◽

Bsa Binding ◽

High Cytotoxicity ◽

Ct Dna ◽

Mcf 7

The complexes cis-[Ru(quin)(dppm)2]PF6 and cis-[Ru(kynu)(dppm)2]PF6 (quin = quinaldate; kynu = kynurenate; dppm = bis(diphenylphosphino)methane) were prepared and characterized by elemental analysis, electronic, FTIR, 1H, and 31P{H1} NMR spectroscopies. Characterization data were consistent with a cis arrangement for the dppm ligands and a bidentate coordination through carboxylate oxygens of the quin and kynu anions. These complexes were not able to intercalate CT-DNA as shown by circular dichroism spectroscopy. On the other hand, bovine serum albumin (BSA) binding constants and thermodynamic parameters suggest spontaneous interactions with this protein by hydrogen bonds and van der Waals forces. Cytotoxicity assays were carried out on a panel of human cancer cell lines including HepG2, MCF-7, and MO59J and one normal cell line GM07492A. In general, the new ruthenium(II) complexes displayed a moderate to high cytotoxicity in all the assayed cell lines with IC50 ranging from 10.1 to 36 µM and were more cytotoxic than the precursor cis-[RuCl2(dppm)2]. The cis-[Ru(quin)(dppm)2]PF6 were two to three times more active than the reference metallodrug cisplatin in the MCF-7 and MO59J cell lines.

Download Full-text

New barium, strontium and strontium-doped barium squarates: synthesis, crystal structures and DNA/BSA binding, antioxidant and in vitro cytotoxicity studies

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229619009082 ◽

2019 ◽

Vol 75 (8) ◽

pp. 1091-1101

Author(s):

K. T. Priya Vadhana ◽

S. Parveen ◽

B. Ushadevi ◽

R. Selvakumar ◽

S. Sangeetha ◽

...

Keyword(s):

Crystal Structures ◽

Binding Constants ◽

In Vitro Cytotoxicity ◽

Bsa Binding ◽

Barium Strontium ◽

Metal Atoms ◽

Cytotoxicity Studies ◽

Calf Thymus ◽

Coordinated Water

A new set of differently hydrated barium and strontium squarates, namely poly[[triaqua(μ-1,2-dioxocyclobut-3-ene-1,2-diolato)barium] monohydrate], {[Ba(C4O4)(H2O)3]·H2O} n (1), poly[[diaqua(μ-1,2-dioxocyclobut-3-ene-1,2-diolato)strontium] monohydrate], {[Sr(C4O4)(H2O)2]·H2O} n (2), and poly[[triaqua(μ-1,2-dioxocyclobut-3-ene-1,2-diolato)barium/strontium(0.85/0.15)] monohydrate], {[Ba0.85Sr0.15(C4O4)(H2O)3]·H2O} n (3), is reported. The study of their crystal structures indicates that all the complexes crystallize in the triclinic space group P\overline{1}. Complexes 1 and 3 have a rare combination of squarate units coordinated through monodentate O atoms to two different metal atoms and through two bidentate O atoms to three different metal atoms. Furthermore, they have three coordinated water molecules to give a coordination number of nine. The squarate ligands in complex 2 exhibit two different coordination modes: (i) monodentate O atoms coordinated to four different Sr atoms and (ii) two monodentate O atoms coordinated to two different metal atoms with the other two O atoms bidentate to four different Sr atoms. All the compounds decompose to give the respective carbonates when heated to 800 °C, as evidenced by thermogravimetry/differential thermal analysis (TG-DTA), which are clusters of nanoparticles. Complexes 1 and 3 show additional endothermic peaks at 811 and 820 °C, respectively, indicating the phase transition of BaCO3 from an orthorhombic (α-Pmcn) to a trigonal phase (β-R3m). All three complexes have significant DNA-binding constants, ranging from 2.45 × 104 to 9.41 × 104 M −1 against EB-CT (ethidium bromide–calf thymus) DNA and protein binding constants ranging from 1.1 × 105 to 8.6 × 105 with bovine serum albumin. The in vitro cytotoxicity of the complexes is indicated by the IC50 values, which range from 128.8 to 261.3 µg ml−1. Complex 3 shows better BSA binding, antioxidant activity against the DPPH radical and cytotoxicity than complexes 1 and 2.

Download Full-text

ComparativeIn VitroBinding Studies of TiCl2(dpme)2, Ti(ada)2(bzac)2, and TiCl2(bzac)(bpme) Titanium Complexes with Calf-Thymus DNA

Biochemistry Research International ◽

10.1155/2015/836928 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Pamita Awasthi ◽

Nitesh Kumar ◽

Raj Kaushal ◽

Mohan Kumar ◽

Shrikant Kukreti

Keyword(s):

Circular Dichroism ◽

Binding Constants ◽

Blue Shift ◽

Binding Mode ◽

Visible Absorption ◽

Calf Thymus ◽

Absorption Studies ◽

Uv Visible ◽

Ct Dna ◽

Circular Dichroïsm

The binding of TiCl2(dpme)2(1), (dpme = 6,6′-dimethyl-2,2′-bipyridine), Ti(ada)2(bzac)2(2), (ada = adamantylamine; bzac = benzoylacetone), and TiCl2(bzac)(bpme) (3), (bpme = 4,4′-dimethyl-2,2′-bipyrdine) with calf thymus (ct) DNA has been studied by UV-visible spectroscopy, thermal denaturation, and circular dichroism spectroscopy. In UV-visible study complexes1,2, and3showed red, blue, and red shifts, respectively, upon the addition of ct-DNA along with a significant hyperchromism. The intrinsic binding constants (Kb) calculated from UV-visible absorption studies were 2.3 × 103 M−1, 3.3 × 103 M−1and, 7.1 × 103 M−1for complexes1,2, and3, respectively. The change in melting temperature (ΔTm) was calculated to be 2-3°C for each complex. Circular dichroism (CD) study showed blue shift for complex2and red shift for complexes1and3along with rise in molecular ellipticity upon the addition of complexes. Results suggest a binding mode of complex2different than1and3.

Download Full-text