Search results for "Intercalation"
showing 10 items of 126 documents
Toward the development of metal-based synthetic nucleases: DNA binding and oxidative DNA cleavage of a mixed copper(II) complex with N-(9H-purin-6-yl…
2009
Abstract The complex [Cu(N9-ABS)(phen) 2 ]·3.6H 2 O, H 2 N9-ABS = N -(9 H -purin-6-yl)benzenesulfonamide and phen = 1,10-phenanthroline, has been synthesized and then characterized with the aid of X-ray diffraction, analytical, and spectroscopic techniques. The geometry of Cu(II) is distorted square pyramidal with the equatorial positions occupied by three N atoms from two phenantroline molecules and one N atom from the adenine ring of the sulfonamide ligand. The interaction of the complex with DNA was studied by means of viscosity measurements and fluorescence spectroscopy. The results pointed to a classic intercalation of the complex between the DNA base pairs. The complex was found to b…
Hybrid Materials Based on Magnetic Layered Double Hydroxides: A Molecular Perspective
2015
Design of functional hybrids lies at the very core of synthetic chemistry as it has enabled the development of an unlimited number of solids displaying unprecedented or even improved properties built upon the association at the molecular level of quite disparate components by chemical design. Multifunctional hybrids are a particularly appealing case among hybrid organic/inorganic materials. Here, chemical knowledge is used to deploy molecular components bearing different functionalities within a single solid so that these properties can coexist or event interact leading to unprecedented phenomena. From a molecular perspective, this can be done either by controlled assembly of organic/inorga…
On the synthesis and characterization of layered antimony(III) phosphate and its interaction with moist ammonia and amines
1998
Samples of antimony(III) phosphate, a layered material, were prepared at room temperature, using the two allotropic forms of Sb2O3, layered valentinite and cubic senarmontite. The compounds were characterized by infrared spectroscopy, X-ray diffraction, and thermogravimetric–differential thermal analysis. Solids exposed to ammonia, ethylenediamine, or hydrazine vapors also were studied. The interaction between SbPO4 and the bases always led to the formation of stoichiometric amounts of Sb2O3 and hydrogen phosphate(–2) salts of the bases. With ammonia, the SbPO4 raw materials gave rise to valentinite or senarmontite, depending on which Sb2O3 allotropic form was used to prepare antimony phosp…
Vanadyl phosphate dihydrate, a solid acid: the role of water in VOPO4�2H2O and its sodium derivatives Na x (VIV x VV 1?x O)PO4�(2?x)H2O
1988
Sodium-containing intercalates having as general formula Na x VOPOP4·(2−x)H2O (0.25≤x<0.50) have been obtained and characterized. Orthorhombic phases, which essentially maintain the structure of the layered oxide hydrate VOPO4·2H2O result. Intercalated sodium ions act as ‘pillars’. The presence of H3O+ ions in the parent VOPO4·2H2O and also in some reduced phases, is detected. The understanding of the structural role of the water molecules is advanced and the topotactic dehydration/rehydration processes are studied. The formation of a new metastable VOPO4·H2O phase is established.
Docking and synthesis of pyrrolopyrimidodiazepinone derivatives (PPDs) and their precursors: New scaffolds for DNA-interacting agents
2007
New classes of pyrrolopyrimidodiazepinone derivatives (PPDs) and their precursors were studied in silico for their ability to form stable complex with DNA fragment. In the docking studies two binding modes can be envisaged: groove mode and intercalating mode. In the case of the best ligands the docking studies revealed a common binding mode with the chromophore intercalated between GC base pairs whereas the side chain lies close to the minor groove. Synthetic approach to the PPD ring systems is discussed.
Clay-biosurfactant materials as functional drug delivery systems: Slowing down effect in the in vitro release of cinnamic acid
2017
Abstract The main objectives of the present paper were the preparation and characterization of new surfactant-modified clays and the evaluation of their potential applicability as drug delivery systems for the oral administration of the cinnamic acid (CA) drug. The organoclays (OC) were prepared by loading different amounts of the biocompatible nonionic polyoxyethylene sorbitan monolaurate surfactant (Tween20) onto K10 montmorillonite (Mt) clay and characterized through the construction of the adsorption isotherms by means of the spectrophotometric method. The performance of the prepared material was verified by gathering the adsorption isotherms of the cinnamic acid onto the Mt/Tween20 org…
Spectroscopic study of the interaction of Ni(II)-5-triethyl ammonium methyl salicylidene ortho-phenylendiiminate with native DNA.
2009
The interaction of native calf thymus DNA with the cationic Ni(II) complex of 5-triethyl ammonium methyl salicylidene ortho-phenylendiimine (NiL(2+)), in 1mM Tris-HCl aqueous solutions at neutral pH, has been monitored as a function of the metal complex-DNA molar ratio by UV absorption spectrophotometry, circular dichroism (CD) and fluorescence spectroscopy. The dramatic modification of the DNA CD spectrum, the appearance of a broad induced CD band in the range 350-400nm, the strong increase of the DNA melting temperature (T(m)) and the fluorescence quenching of ethidium bromide-DNA solutions, in the presence of increasing amounts of the NiL(2+) metal complex, support the existence of a tig…
Acid–base behaviour and binding to double stranded DNA/RNA of benzo[g]phthalazine-based ligands
2019
The affinity and the binding mode of two benzo[g]phthalazine compounds, functionalized with one or two 2-(imidazole-4-yl)-ethylamine groups, to DNA and RNA models have been evaluated by means of UV-Vis, fluorescence and circular dichroism (CD) spectroscopies in combination with viscometry and molecular dynamics. Both organic molecules bind strongly to all nucleic acid models via the intercalation mode in the duplex structure, especially compound 1. Intriguingly, 1 exhibits different emission responses depending on the base composition of duplex DNA/RNAs, which points out the possibility of using it as a base selective nucleic acid probe. Moreover, the acid-base behaviour of both compounds h…
(Dipyrido[3,2-a:2',3'-c]phenazine)(glycinato)copper(II) perchlorate: a novel DNA-intercalator with anti-proliferative activity against thyroid cancer…
2012
Abstract A novel copper(II) heteroleptic complex of dipyrido[3,2-a:2′,3′-c]phenazine (dppz) and glycinato (gly) as chelating ancillary ligand, [Cu(dppz)(gly)]ClO 4 ( 1 ), was synthesized and characterized. X-ray crystallography revealed that the coordination geometry of the cationic [Cu(dppz)(gly)] + unit is hexacoordinated and shows a distorted octahedral coordination geometry in the solid state, with the N,N and N,O chelating atoms of dppz and glycinato, respectively, in the square plane and in which the planar units are connected in a monodimensional polymeric array by the apical copper coordination of the second carboxylic oxygen atom. Biological assays showed that 1 exhibits a remarkab…
The interaction of native calf thymus DNA with FeIII-dipyrido[3,2-a:2’,3’-c]phenazine
2008
The mono and bis dipyrido[3,2-a:2',3'-c]phenazine (dppz) adducts of iron(III) chloride, i.e. [Fe(dppz)]Cl(3) and [Fe(dppz)(2)]Cl(3), have been synthesized and characterized. The interaction of the Fe(III)dppz hydrolyzed aquo complex with native calf thymus DNA has been monitored as a function of the metal complex-DNA molar ratio, by variable temperature UV absorption spectrophotometry, circular dichroism (CD) and fluorescence spectroscopy. The results obtained in solution at various ionic strength values give support for a tight intercalative binding of the Fe(III)dppz cation with DNA. In particular, the appearance of induced CD bands, caused by the addition of Fe(III)dppz, indicate the exi…