Search results for "complexes"

The Important Role of the Nuclearity, Rigidity, and Solubility of Phosphane Ligands in the Biological Activity of Gold(I) Complexes

2018

A series of 4-ethynylaniline gold(I) complexes containing monophosphane (1,3,5-triaza-7-phosphaadamantane (pta; 2), 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane (3), and PR3 , with R=naphthyl (4), phenyl (5), and ethyl (6)) and diphosphane (bis(diphenylphosphino)acetylene (dppa; 7), trans-1,2-bis(diphenylphosphino)ethene (dppet; 8), 1,2-bis(diphenylphosphino)ethane (dppe; 9), and 1,3-bis(diphenylphosphino)propane (dppp; 10)) ligands have been synthesized and their efficiency against tumor cells evaluated. The cytotoxicity of complexes 2-10 was evaluated in human colorectal (HCT116) and ovarian (A2780) carcinoma as well as in normal human fibroblasts. All the complexes showed a hi…

SELECTIVE G-QUADRUPLEX STABILIZERS: SALPHEN-LIKE COMPLEXES WITH ANTIPROLIFERATIVE ACTIVITY

2013

Schiff base complexes derived from N,N!-bridged tetradentate ligands involving N2O2 donor atoms present very favourable features to act as G4 binders. Thus, a series of square-planar and square pyramidal metal complexes, ML2+ (M = Ni, Cu, and Zn), have been synthesized and characterized.

Targeting G-quadruplex DNA as Potential Anti-cancer Therapy

2017

This chapter provides an introduction and also a review on non-canonical DNA structures such as guanine-quadruplexes (G-quadruplexes) and their targeting by small molecules for applications in Pharmacology. The articles considered in this chapter are mainly from 2016.

The Interaction of Metal Complexes with G-quadruplex DNA

Un approccio computazionale è stato proposto per lo studio dell’interazione di complessi metallici di basi di Schiff con DNA. Nel capitolo 2, è stato investigato il meccanismo di azione di complessi di Nichel(II), Rame(II) e Zinco(II) con B e G-quadruplex DNA. Il G-quadruplex è una conformazione non canonica adottata da particolari sequenze ricche in guanina. Recentemente, è stata dimostrata la sua esistenza in cellule umane, in regioni telomeriche e non telomeriche, ed è stato proposto come un possibile target per una nuova categoria di agenti antineoplastici. I capitoli successivi sono basati su dati raccolti durante due periodi di ricerca all’estero. Nel capitolo 3, basato sugli studi es…

Apoptosis induced in hepatoblastoma HepG2 cells by the proteasome inhibitor MG132 is associated with hydrogen peroxide production, expression of Bcl-…

2002

This report is focused on the apoptotic effect induced by MG132, an inhibitor of 26S proteasome, in human hepatoma HepG2 cells. The results were compared with those obtained with non-transformed human Chang liver cells. MG132 reduced the viability of HepG2 cells in a time- and dose-dependent manner. The effect was in tight connection with the induction of apoptosis, as indicated by fluorescence microscopy and cytometric analysis, and was accompanied by a remarkable increase in the production of H2O2 and a reduction in mitochondrial transmembrane potential (Deltapsim). In addition cell death was prevented by antioxidants such as GSH, N-acetylcysteine or catalase. Western blot analysis showed…

Proteomic analysis of the photosystem I light-harvesting antenna in tomato (Lycopersicon esculentum).

2004

Until now, more genes of the light-harvesting antenna of higher-plant photosystem I (PSI) than proteins have been described. To improve our understanding of the composition of light-harvesting complex I (LHCI) of tomato (Lycopersicon esculentum), we combined one- and two-dimensional (1-D and 2-D, respectively) gel electrophoresis with immunoblotting and tandem mass spectrometry (MS/ MS). Separation of PSI with high-resolution 1-D gels allowed separation of five bands attributed to proteins of LHCI. Immunoblotting with monospecific antibodies and MS/MS analysis enabled the correct assignment of the four prominent bands to light-harvesting proteins Lhcal -4. The fifth band was recognized by o…

Water and temperature contribution to the structuration of starch matrices in the presence of flavour.

2016

The effect of hydrothermal treatments and flavours addition on starch structure and its physical properties were studied. Native wheat starch was treated at 2 different hydrations (water-starch ratios: 50/50 and 80/20 g w/w) and temperatures (65 and 85 °C) in the presence of flavours (ethyl hexanoate and 2-hexanone). The freshly prepared samples were subjected to DSC and flavour analysis. Flavour inclusion complex could not be detected by DSC, however the result of flavour analysis proved that there were flavours interactions with starch. Both ethyl hexanoate and 2-hexanone interacted with starch at similar rates. The highest flavour loss was found in the samples at high hydration and heate…

Structural stability and properties of three isoforms of the major light-harvesting chlorophyll a/b complexes of photosystem II.

2008

AbstractThree isoforms of the major light-harvesting chlorophyll (Chl) a/b complexs of photosystem II (LHCIIb) in the pea, namely, Lhcb1, Lhcb2, and Lhcb3, were obtained by overexpression of apoprotein in Escherichia coli and by successfully refolding these isoforms with thylakoid pigments in vitro. The sequences of the protein, pigment stoichiometries, spectroscopic characteristics, thermo- and photostabilities of different isoforms were analysed. Comparison of their spectroscopic properties and structural stabilities revealed that Lhcb3 differed strongly from Lhcb1 and Lhcb2 in both respects. It showed the lowest Qy transition energy, with its reddest absorption about 2 nm red-shifted, an…

Cobalt complex based on cyclam for reversible binding of nitric oxide

2008

We report the synthesis and theoretical calculations of nitrosyl cobalt complexes based on saturated tetraazamacrocycle for the reversible binding of nitric oxide (NO). Density-functional theory provides a rigorous theoretical framework for analysing, interpreting and investigating important parameters in order to further tune the properties of these complexes to the target application. We focus on understanding the stability of complexes in methanol solution as well as their reactivity and stability evolution in the presence of NO, O2 and higher nitrogen oxides intermediates. Calculations have been used to explore appropriate combinations of different macrocycles, metal centres and ligands…

UV laser induced photolysis of glycolic acid isolated in argon matrices

2021

The photochemistry of matrix-isolated glycolic acid, induced by UV light, was studied by FTIR spectroscopy and B3LYPD3/6-311++G(3df,3pd) calculations. Several decomposition pathways were found to take place upon 212 nm and 226 nm wavelengths irradiation. A number of complexes formed between photoproducts were identified, among them those of formaldehyde with water, carbon monoxide and carbon dioxide as well as the H2O-CO complexes. The structure and spectroscopic assignment of the photoproducts were made comparing the experimental results with the theoretical predictions and available literature data. The observed formation of different complexes indicates various pathways for their formati…