Synthesis, spectroscopic studies of new water-soluble Co(II) and Cu(II) macrocyclic complexes of 4,15-bis(2-hydroxyethyl)-2,4,6,13,15,17-hexaazatricyclodocosane: their interaction studies with calf thymus DNA and guanosine 5′ monophosphate

Copper(ii) complexes of 2-methyl-8-hydroxyquinoline and tri/diimine co-ligand: DFT calculations, DNA and BSA binding, DNA cleavage, cytotoxicity and induction of apoptosis

Four-coordinate copper(ii) complex cleaves supercoiled ϕX174 RF DNA without reductant while five-coordinate complex cleaves with reductant. The cytotoxicity against cancer cells are higher than cisplatin, less-toxic to normal cells and induce apoptosis.

Synthesis, Characterization, DNA Binding, Anticancer, and Molecular Docking Studies of Novel Imidazolium-Based Ionic Liquids with Fluorinated Phenylacetamide Tethers

Newer imidazolium ionic liquid (IL) halides 4a-f appending variety of fluorinated phenylacetamide side chains were designed and synthesized through quaternization of 1-methyl and/or 1,2-dimethylimidazole with appropriate 2-chloro-N-(fluorinatedphenyl)acetamides. The resulting ILs were converted to their respective ionic liquid analogues carrying fluorinated counteranions (PF₆ ^-, BF₄ ^-, and/or CF₃COO^-) 5a-r. All newly synthesized ILs were fully characterized using several spectroscopic experiments such as ¹H, ¹³C, ¹¹B, ¹⁹F, ³¹P NMR, and mass analysis. The synthesized ionic liquids were investigated for their DNA binding and anticancer activities. The obtained DNA binding constants ranged from 1.444 × 10⁵ to 3.518 × 10⁵, indicating a reasonably good binding affinity. The percentage of anticancer activities ranged from 48 to 59 with H-1229 cell line, showing quite good anticancer potential. The modeling studies indicated the interactions of the reported molecules with DNA via hydrogen bonds. These were in agreement with those of DNA binding and anticancer results. Briefly, the designed ionic liquids may be used as good anticancer candidates for treating human cancer.

Macrocyclic complexes: synthesis, characterization, antitumor and DNA binding studies

The present paper deals with the synthesis of novel macrocyclic complexes of the type [MLX]X, where [(M = Co(II) (1), and Ni(II) (2) X = (Cl₂)]. The complexes are synthesized by the reaction of ligand(L)diquinolineno[1,3,7,9]tetraazacyclododecine-7,15-ethane(14H,16H)-benzene with the corresponding metal salts. The synthesized complexes are thoroughly characterized by elemental analysis, FT-IR, ¹H-NMR, Mass and electronic spectra. The complexes (1) and (2) were evaluated for in vitro cytotoxicity against human breast adenocarcinoma cell (MCF-7). MTT cytotoxicity studies shows both the complexes are most effective. The binding properties of these complexes with calf thymus-DNA were studied by absorption, emission spectra, viscosity measurements, and thermal denaturation studies. On binding to CT-DNA, the absorption spectrum undergoes bathochromic and hypochromic shifts. The absorption spectral results indicate that the intrinsic binding constant (K_b) are 4.8 × 10⁵ M^-1 for (1) and 3.9 × 10⁵ M^-1 for (2) respectively, suggesting that complex (1) binds more strongly to CT-DNA than complex (2). The viscosity measurement results revealed the viscosity of sonicated rod like DNA fragments increased when the complex was added to the solution of CT-DNA. The synthesized ligand and its metal complexes are screened for antibacterial and antifungal activities.

Synthesis, crystal structures, molecular docking and in vitro cytotoxicity studies of two new copper(ii) complexes: special emphasis on their binding to HSA

Two new copper(ii) complexes bound efficiently to Sudlow's site I of HSA, and exhibited prominent cytotoxicity against Eca-109 through the apoptosis pathway.

In vitro antitumor activity of free and nano-encapsulated Na5[PMo10V2O40]·nH2O and its binding properties with ctDNA by using combined spectroscopic methods

Free and nanosized starch and lipid encapsulated Na5[PMo10V2O40]·nH2O complexes (abbreviated as PMoV, SEP and LEP, respectively) have been prepared and structurally characterized by Fourier transform infrared (FT-IR) spectroscopy, inductively coupled plasma (ICP) analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. The results show that the PMoV retains its parent structure after encapsulation by starch and lipid nanoparticles. The in vitro antitumor activity of PMoV in its free and nano-encapsulated forms was investigated using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay that was carried out on two types of human cancer cells, MCF-7 (breast cancer cells) and HEK-293 (Human Embryonic Kidney). The results represent the enhancement of cell penetration and antitumor activity of PMoV due to its encapsulation in starch or lipid nanoparticles. However, this observed enhancement for the lipid relative to the starch nanocapsule can be attributed to its smaller size. In order to investigate the molecular nature of antitumor activity, the binding properties of PMoV with calf thymus DNA (ctDNA) were also comprehensively evaluated using UV-vis absorption spectroscopy, fluorescence quenching and fluorescence Scatchard plots. The results rule out the intercalating binding mode and propose the groove or outside stacking binding for PMoV. However, a biphasic binding behavior that is due to the change in the binding mode was observed by varying of [PMoV]/[ctDNA] mole ratio. The results of cell culture assay and DNA binding experiments represent that the rate of cell penetration is more important than DNA binding affinity in the antitumor activity for POM.

Multispectral studies of DNA binding, antioxidant and cytotoxic activities of a new pyranochromene derivative

The binding properties of a new pyranochromene derivative, 2-amino-4-(3-hydroxyphenyl)-5-oxo-4H, 5H-pyrano-[3, 2-c] chromene-3-carbonitrile (3-HC) with calf thymus DNA (ctDNA) have been investigated by UV-vis absorption, circular dichroism, fluorescence spectroscopy and viscosity measurement. These results indicated that 3-HC can interact with DNA through non-intercalative mode and the intrinsic binding constant (Kb) for 3-HC with DNA was estimated to be 3.6 × 10(3)M(-1). The antioxidant activity experiments show that 3-HC also exhibit good antioxidant activity in DPPH free radical scavenging and ferric reducing ability methods. Moreover, 3-HC exhibited cytotoxic activity against K562, human chronic myelogenous leukemia cells, with IC50 value of 146 μM and the cells responded to the treatment with mostly through apoptosis.

Anticancer metallodrugs of glutamic acid sulphonamides: in silico, DNA binding, hemolysis and anticancer studies

In response to an increased demand for effective anticancer drugs, a series of disodium sulphonamides ofl-glutamic acid (L1–L3) was synthesized. Sulphonamides were complexed with copper(ii), nickel(ii) and ruthenium(iii) ions, separately and respectively.

Studies of interaction between terbium(III)-deferasirox and double helix DNA by spectral and electrochemical methods

DNA binding studies of terbium(III)-deferasirox (Tb3+-DFX) complex were monitored to understand the reaction mechanism and introduce a new probe for the assay of DNA. In the present work, UV absorption spectrophotometry, fluorescence spectroscopy, circular dichroism (CD), cyclic voltammetry (CV) and viscosity measurement were employed to study the interactions of Tb3+-DFX with calf thymus DNA (ctDNA). The binding of Tb3+-DFX complex to ctDNA showed a hyperchromic effect in the absorption spectra and the increase in fluorescence quenching effect (amount) of Tb3+-DFX complex in the presence of ctDNA. The binding constants (Kb) for the complex with ctDNA were estimated to be 1.8×10(4) M(-1) through UV absorption spectrophotometry and fluorescence spectroscopy. Upon addition of the complex, clear decreases were observed in the viscosity of ctDNA. The CD spectra indicated that there are certain detectable conformational changes in the DNA double helix when the complex was added. The CV method showed that both anodic and cathodic peak potentials of Tb3+-DFX complex showed negative shifts on the addition of the ctDNA. Further, competitive methylene blue binding studies with fluorescence spectroscopy have shown that the complex can bind to ctDNA through nonintercalative mode. The experimental results suggest that Tb3+-DFX complex binds to DNA via groove binding and/or electrostatic binding mode.

New heterobimetallic Cu(II)-Sn2(IV) complex as potential topoisomerase I inhibitor: in vitro DNA binding, cleavage and cytotoxicity against human cancer cell lines

The new heterobimetallic Cu(II)-Sn(2)(IV)/Ni(II)-Sn(2)(IV) complexes 1 and 2 bearing bioactive pharmacophore ligand scaffold; 1,10-phenanthroline and ethylenediamine were synthesized and characterized by spectroscopic (IR, UV-vis, NMR, ESI-MS) and analytical methods. The in vitro DNA binding studies of 1 and 2 with CT-DNA were carried out by employing various biophysical methods which reveal strong electrostatic binding via phosphate backbone of DNA helix, in addition to partial intercalation in the minor groove and stabilized by intramolecular hydrogen bonding. To gain further insight into the molecular recognition at the target site, UV-vis titrations of 1 with 5'-GMP was carried out and validated by (1)H and (31)P NMR. Complex 1 cleaved pBR322 DNA via oxidative pathway and exhibited high inhibition activity against Topo-I at 20 μM. Furthermore, the cytotoxicity of 1 was examined on a panel of human tumor cell lines of different histological origins showing promising antitumor activity.

DNA-binding studies of fluoxetine antidepressant

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) antidepressant that is widely prescribed. The DNA-binding behavior of fluoxetine antidepressant and calf thymus DNA was investigated in Tris-HCl buffer at physiological pH 7.4 with a series of techniques, including UV-Vis and circular dichroism spectroscopies, competitive study with Hoechst 33258, viscometry, and cyclic voltammetry. Fluoxetine molecules bind to DNA via groove mode as illustrated by hypochromism with no red shift in the UV absorption band of fluoxetine, decrease in Hoechst-DNA solution fluorescence, and no significant changes in viscosity of DNA. The CD spectra of DNA molecules show a little change in stacking mode of base pair but no modification changes in DNA conformation, for example, from B-DNA to A or C-DNA. The binding constant (K(b)) of DNA with fluoxetine was calculated to be 6.7 × 10(4) M(-1), which is in the range of reported and known groove binders, such as distamycin. All results showed the groove-binding mode of interaction of fluoxetine with DNA.

Copper, gold and silver compounds as potential new anti-tumor metallodrugs

Although platinum-based drugs such as cisplatin are powerful anticancer agents, they have undesirable side effects and are effective against only a few kinds of cancers. There is, therefore, a need for new drugs with an improved spectrum of efficacy and lower toxicity. Complexes of copper, gold and silver (coinage metals) are potential candidates to fullfill this need. The development of anticancer drugs based on these metals is currently a very active field. Considerable effort has also been put into elucidating the mechanisms of action of these complexes and optimizing their bioactivity through structural modification. In this review, we highlight recent developments in the design of coinage metal complexes with anti-tumor activity and discuss the emerging importance of quantitative structure–activity relationship methods in the study of anticancer metal complexes. Future work in this field, including likely coinage metal complexes that will attract attention, are proposed.

Synthesis of carbohydrate-conjugate heterobimetallic Cu(II)-Sn(2)(IV) and Zn(II)-Sn(2)(IV) complexes; their interactions with CT DNA and nucleotides; DNA cleavage, in-vitro cytotoxicity

The new heterobimetallic Ni(II)-Sn(2)(IV) (1), Cu(II)-Sn(2)(IV) (2) and Zn(II)-Sn(2)(IV) (3) complexes, containing D-glucosamine, 1,8-diamino-3,6-diazaoctane and imidazole were isolated and characterized by spectral and analytical methods. The proposed geometry of Ni(II) and Cu(II) in 1 and 2 was square pyramidal, Zn(II) in 3 exhibited tetrahedral while Sn(IV) exhibits hexacoordinate environment, respectively. The X-ray powder diffraction (XRPD) confirmed the amorphous nature of all the complexes. The interaction studies of 2 and 3 with CT DNA were carried out by various biophysical techniques to show the mode of binding. The interaction of 2 and 3 with nucleotides viz 5'-GMP and 5'-TMP, respectively were further confirmed by (1)H, (31)P and (119)Sn NMR spectroscopy. The complex 2 exhibited effective cleavage activity with pBR322 DNA. Furthermore, the cytotoxicity of 2 was examined on a panel of human tumor cell lines of different histological origins and showed good activity against Colo205 and A2780 (GI50 < 10 μg/ml).