Search results for "Chelation"
showing 10 items of 286 documents
Preferential patterns of myocardial iron overload by multislice multiecho T2* CMR in thalassemia major patients.
2010
T*(2) multislice multiecho cardiac MR allows quantification of the segmental distribution of myocardial iron overload. This study aimed to determine if there were preferential patterns of myocardial iron overload in thalassemia major. Five hundred twenty-three thalassemia major patients underwent cardiac MR. Three short-axis views of the left ventricle were acquired and analyzed using a 16-segment standardized model. The T*(2) value on each segment was calculated, as well as the global value. Four main circumferential regions (anterior, septal, inferior, and lateral) were defined. Significant segmental variability was found in the 229 patients with significant myocardial iron overload (glob…
Selective recovery of phosphorus as AlPO4 from silicon-free CFB-derived fly ash leachate
2018
The prospect of phosphorus (P) recovery from siliceous fly ash was investigated. The phosphorus content in the pristine fly ash was 1.21%. Obtaining pure phosphorus products from fly ash is very challenging because of high concentration of other elements, silicon (Si) at 17.3% being the major contaminant. The fly ash was fractionated with sieve size of 125 μm to concentrate the phosphorus in the small-size fraction, which also facilitated the removal of 78% of silica (Si) in the solid phase. The fractionated fly ash was treated with 8 M HCl in order to remove 98% of Si by aging (5 h) of leachate until precipitation of Si-gel, and a phosphorus-rich solution is obtained. Iron (Fe) is also con…
Synthesis, antimony-121 mössbauer and infrared spectral characterization of antimony trifluoride and catecholatoantimony(III) fluoride adducts with t…
1988
Abstract The synthesis of the adducts SbF 3 (L) and (C 6 H 4 O 2 )SbF(L) [L = pyridine-2-carboxaldehyde- 2-pyridylhydrazone (paphyH); 2,2′:6′,2″-terpyridine (terpy) and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tpta)] is reported. Infrared data are consistent with the occurred chelation from the terdentate ligand providing an overall pseudo-seven coordination at Sb. The stereoactivity of the antimony lone pair is inferred from the large value of the Mossbauer quadrupole coupling constant observed for all the compounds.
Preparation of C-23 esterified silybin derivatives and evaluation of their lipid peroxidation inhibitory and DNA protective properties.
2009
A diverse series of C-23 esterified silybin derivatives (1a-n) were designed and synthesized. The antioxidative properties of these compounds were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radical scavenging, ferrous ion chelation, and inhibition of rat liver homogenate lipid peroxidation. Their protective effects on the prevention of hydrogen peroxide induced DNA damage were also investigated. Most of the synthesized compounds exhibited more effective antioxidant activities than silybin. The esterified silybin analogues displayed satisfactory performance especially on iron chelation and antiperoxidative activity. Compound 1n in particular exhibited remarkable a…
Antioxidant and neuroprotective effects of synthesized sintenin derivatives
2009
Three series of sintenin derivatives (compounds 1-14) were designed and prepared and their antioxidative and neuroprotective effects were evaluated. The in vitro models of scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, chelating ferrous ions, inhibiting the rat brain homogenates lipid peroxidation, and protecting neurons damaged by hydrogen peroxide were employed for bioassays. It was found that sintenin derivatives 4 and 13 showed remarkable antioxidative and neuroprotective activities.
Improved Efficacy of Synthesizing *MIII-Labeled DOTA Complexes in Binary Mixtures of Water and Organic Solvents. A Combined Radio- and Physicochemica…
2018
Typically, the synthesis of radiometal-based radiopharmaceuticals is performed in buffered aqueous solutions. We found that the presence of organic solvents like ethanol increased the radiolabeling yields of [68Ga]Ga-DOTA (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacatic acid). In the present study, the effect of organic cosolvents [ethanol (EtOH), isopropyl alcohol, and acetonitrile] on the radiolabeling yields of the macrocyclic chelator DOTA with several trivalent radiometals (gallium-68, scandium-44, and lutetium-177) was systematically investigated. Various binary water (H2O)/organic solvent mixtures allowed the radiolabeling of DOTA at a significantly lower temperature than …
Complex formation of copper( ), nickel( ) and zinc( ) with ethylophosphonoacetohydroxamic acid: solution speciation, synthesis and structural charac…
2019
We present herein the thermodynamic and X-ray characterisation of a novel ethyl phosphonohydroxamic acid-based Cu( ) metallacrown, predominating in solution in a broad pH range.
Sequestration of alkyltin(IV) cations by complexation with amino-polycarboxylic chelating agents
2013
Abstract The binding capacity of four amino-polycarboxylic ligands (APCs) [nitrilotriacetate (NTA), ethylenediamine- N , N , N′ , N′ -tetraacetate (EDTA), (S,S)-ethylenediamine- N , N ′-disuccinic acid (S,S-EDDS) and diethylenetriamine- N , N , N′ , N″ , N″ -pentaacetate (DTPA)] towards mono-, di- and tri-alkyltin(IV) cations [(CH 3 )Sn 3 + , (CH 3 ) 2 Sn 2 + , (C 2 H 5 ) 2 Sn 2 + , (CH 3 ) 3 Sn + or (C 2 H 5 ) 3 Sn + ] was studied, in aqueous solutions, by ISE-H + potentiometry, at I = 0.1 mol L − 1 (NaCl) and at T = 298.15 K. In all the systems R x Sn (4 − x)+ − APC (R = CH 3 or C 2 H 5 ) a strong 1:1 species is formed together with protonated, hydroxo and dinuclear complexes. The valu…
New cyclic tetranuclear copper(II) complexes containing quadrilateral cores: Synthesis, structure, spectroscopy and their interactions with DNA in aq…
2017
Abstract Three new cyclic tetranuclear copper(II) complexes, Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrachloro)tetracopper(II)methanolhydrate (1·CH3OH·H2O), Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrathiocyanato)tetracopper(II) (2) and Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetraazido)tetracopper(II) (3) have been synthesized by exploiting the chelating ability and bridging potential of a carboxyamine functionalized tridentate ligand, HL (HL = 3-[(2-Pyridylmethyl)-amino]-propionic acid). Complexes 1, 2 and 3 have been synthesized by carrying out reaction of the ligand HL with stoichiometric amounts of CuCl2·2H2O, CuCl2·2H2O/NH4SCN, and CuCl2·2H2O/NaN3, respec…
Attenuated total reflectance infrared determination of sodium nitrilotriacetate in alkaline liquid detergents
2005
Abstract An attenuated total reflectance infrared (ATR–FTIR) method has been developed for the direct determination of the chelating agent sodium nitrilotriacetate (NTA) in high pH cleaning formulations. Aqueous samples and standards were placed directly on the diamond ATR cell without any pre-treatment and FTIR spectra were recorded between 4000 and 600 cm−1. Measurement conditions were evaluated. Results obtained for five different commercial formulations containing from 6.22 to 9.25% (w/w) of NTA were in good agreement with the manufacturer's declared content (differences between 3.2 and −3.7%). Recovery studies evidenced the accuracy of the developed method, having found values between …