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001-es BibID:BIBFORM081486
Első szerző:Baranyai Zsolt (vegyész)
Cím:The Role of Equilibrium and Kinetic Properties in the Dissociation of Gd[DTPA-bis(methylamide)] (Omniscan) at near to Physiological Conditions / Zsolt Baranyai, Ernő Brücher, Fulvio Uggeri, Alessandro Maiocchi, Imre Tóth, Melinda Andrási, Attila Gáspár, László Zékány, Silvio Aime
Dátum:2015
ISSN:0947-6539 1521-3765
Megjegyzések:[Gd(DTPA?BMA)] is the principal constituent of Omniscan, a magnetic resonance imaging (MRI) contrast agent. In body fluids, endogenous ions (Zn2+, Cu2+, and Ca2+) may displace the Gd3+. To assess the extent of displacement at equilibrium, the stability constants of DTPA?BMA3? complexes of Gd3+, Ca2+, Zn2+, and Cu2+ have been determined at 37?°C in 0.15?M NaCl. The order of these stability constants is as follows: GdL?CuL>ZnL?CaL. Applying a simplified blood plasma model, the extent of dissociation of Omniscan (0.35?mM [Gd(DTPA?BMA)]) was found to be 17?% by the formation of Gd(PO4), [Zn(DTPA?BMA)]? (2.4?%), [Cu(DTPA?BMA)]? (0.2?%), and [Ca(DTPA?BMA)]? (17.7?%). By capillary electrophoresis, the formation of [Ca(DTPA?BMA)]? has been detected in human serum spiked with [Gd(DTPA?BMA)] (2.0?mM) at pH?7.4. Transmetallation reactions between [Gd(DTPA?BMA)] and Cu2+ at 37?°C in the presence of citrate, phosphate, and bicarbonate ions occur by dissociation of the complex assisted by the endogenous ligands. At physiological concentrations of citrate, phosphate, and bicarbonate ions, the half?life of dissociation of [Gd(DTPA?BMA)] was calculated to be 9.3?h at pH?7.4. Considering the rates of distribution and dissociation of [Gd(DTPA?BMA)] in the extracellular space of the body, an open two?compartment model has been developed, which allows prediction of the extent of dissociation of the GdIII complex in body fluids depending on the rate of elimination of the contrast agent.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
complex stability
gadolinium
kinetics
magnetic
resonance imaging
reaction mechanisms
Megjelenés:Chemistry-A European Journal. - 21 : 12 (2015), p. 4789-4799. -
További szerzők:Brücher Ernő (1935-) (vegyész) Uggeri, Fulvio Maiocchi, Alessandro (vegyész) Tóth Imre (1950-) (vegyész) Andrási Melinda (1979-) (gyógyszerész) Gáspár Attila (1970-) (vegyész, kémikus) Zékány László (1948-) (vegyész) Aime, Silvio
Pályázati támogatás:TÁMOP 4.2.4. A/2-11-1-2012-0001
TÁMOP
A2-MZPD-12-0038
Egyéb
OTKA K109029
OTKA
OTKA K111932
OTKA
OTKA PD83071
OTKA
TÁMOP-4.2.2 A-11/1/KONV-2012-0043
TÁMOP
Internet cím:Szerző által megadott URL
DOI
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2.

001-es BibID:BIBFORM047932
Első szerző:Baranyai Zsolt (vegyész)
Cím:Equilibrium, Kinetic and Structural Studies of AAZTA Complexes with Ga3+, In3+ and Cu2+ / Zsolt Baranyai, Fulvio Uggeri, Alessandro Maiocchi, Giovanni B. Giovenzana, Camilla Cavallotti, Anett Takács, Imre Tóth, István Bányai, Attila Bényei, Ernő Brücher, Silvio Aime
Dátum:2013
Megjegyzések:A detailed study of the structures, thermodynamic stabilities and kinetics of the dissociation of Ga3+, In3+ and Cu2+ complexes formed with the heptadentate ligand AAZTA is reported. The stability constants (logKML) of the AAZTA complexes of Ga3+, In3+ and Cu2+ are 22.18, 29.58 and 22.27, respectively, which suggests that the seven-membered-ring skeleton is suited to the accommodation of these metal ions. The solid-state structure of Cu(H2AAZTA)]?H2O shows a distorted octahedral coordination. The equatorial coordination sites of Cu2+ are occupied by one of the ring N atoms, a water O atom, one of the carboxylate O atoms and the N atom of the iminodiacetate moiety. The other ring N atom and thecarboxylate O atom of the iminodiacetate moiety coordinate to the Cu2+ in the axial positions. In the pH range 4.5?8.5, Ga3+ is present in the form of the highly stable [Ga(AAZTA)OH]2? (log ?GaLH?1 = 17.69) The exchange reactions of [Ga(AAZTA)OH]2? with Cu2+ and transferrin are very slow and mainly occur through the spontaneous dissociation of the complex close to physiological conditions. The half-life for the dissociation of [Ga(AAZTA)OH]2? is t1/2 = 23 h at pH = 7.5 and 25 ?C in 0.025 M NaHCO3 and 0.15 M NaCl. The high conditional stability, fast formation and sufficiently slow dissociation of [Ga(AAZTA)OH]2? represent promising properties for the complexation and diagnostic applications of radioactive Ga isotopes.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Gallium
Indium
Copper
Complexation
Thermodynamics
Kinetics
Radiopharmaceuticals
Imaging agents
Molekulatudomány
Doktori iskola
Megjelenés:European Journal Of Inorganic Chemistry. - 2013 : 1 (2013), p. 147-162. -
További szerzők:Uggeri, Fulvio Maiocchi, Alessandro (vegyész) Giovenzana, Giovanni Battista Cavallotti, Camilla Takács Anett Tóth Imre (1950-) (vegyész) Bányai István (1953-) (vegyész) Bényei Attila (1962-) (vegyész) Brücher Ernő (1935-) (vegyész) Aime, Silvio
Pályázati támogatás:K-84291
OTKA
TÁMOP-4.2.1/B-09/1/KONV-2010-0007
TÁMOP
Bimodális kontrasztanyagok tervezése, előállítása és komplexeik fizikai-kémiai tulajdonságaik jellemzése
TÁMOP-4.2.2/B-10/1-2010-0024
TÁMOP
Kémiai Tudományok Doktori Iskola
EU COST (TD1004) "Theragnostics Imaging and Therapy" Action Program.
Egyéb
HU11MO2-TET_10-1-2011-0202
Egyéb
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DOI
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3.

001-es BibID:BIBFORM016454
Első szerző:Baranyai Zsolt (vegyész)
Cím:Equilibrium Studies on the Gd3+, Cu2+ and Zn2+ Complexes of BOPTA, DTPA and DTPA-BMA Ligands: Kinetics of Metal-Exchange Reactions of Gd(BOPTA) (2-) / Zsolt Baranyai, Zoltán Pálinkás, Fulvio Uggeri, Ernő Brücher
Dátum:2010
ISSN:1434-1948
Megjegyzések:The stability and protonation constants of the complexes formed between the ligand BOPTA [H(5)BOPTA: 4-carboxy-5,8,11-tris(carboxymethyl)-1-phenyl-2-oxa-5,8,11-triazatrideca n-13-oic acid] and Gd3+, Cu2+, and Zn2+ have been determined by pH potentiometry (Gd3+, Zn2+) and spectrophotometry (Cu2+) at 25 degrees C and at constant ionic strength maintained by 0.15 M NaCl. For comparison, the stability and protonation constants of the complexes of Gd3+, Cu2+, and Zn2+ formed with DTPA and DTPA-BMA {H(5)DTPA: diethylenetriamine-N,N,N',N '',N ''-pentaacetic acid, H(3)DTPA-BMA: 2,2'-[(carboxymethyl)imino]bis[ethylenebis(methylcarbamoyl-methyl)imino] diacetic acid} have also been determined under similar conditions. The stability constants (log K-ML) of the complexes of BOPTA and DTPA are very similar, but in 0.15 m NaCl the protonation constants of the ligands (log K-j(H)) and the log K-ML values are lower than those obtained in 0.1 M KCl or Me4NCl by 0.3-0.9 log K units. The order of selectivity of the ligands for Gd3+ over Zn2+ is BOPTA > DTPA > DTPA-BMA. The complex [Cu(DTPA-BMA)](-) deprotonates in the pH range 7-10 with the dissociation of an amide NH group and the coordination of the amide N atom. The kinetics of the exchange/transmetallation reactions between the complex [Gd(BOPTA)](2-) and the metal ions Cu2+, Zn2+, and Eu3+ have been studied by spectrophotometry (Cu2+, Eu3+) and relaxometry (Zn2+) in the pH range 3.3-6 at 25 degrees C in 0.15 m NaCl. The reactions with Cu2+ and Zn2+ occur predominantly with direct attack of the metal ions on the [Gd(BOPTA)](2-) complex. The kinetic activity of Eu3+ is lower, and in the exchange reactions with Eu3+ the proton-assisted dissociation of [Gd(BOPTA)](2-) (which is followed by fast reaction between the free ligand and Eu3+) could be also investigated. The rate constants, characterizing the proton-assisted dissociation of [Gd(BOPTA)](2-) and the exchange reactions occurring with the direct attack of Cu2+, Zn2+, and Eu3+ on the complex, are lower by about 30-90% than the rate constants obtained earlier for similar transmetallation reactions of [Gd(DTPA)](2-). The half-time for the dissociation of [Gd(BOPTA)](2-) at pH 7.4 and at 25 degrees C in the presence of 1 x 10(-5) m Zn2+ and 1 x 10(-5) M Cu2+ is 169 h.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Lanthanides
Thermodynamics
Kinetics
Reaction mechanisms
mri contrast agents
diethylenetriaminepentaacetic acid
stability
ions
dissociation
dimeglumine
constants
biodistribution
thermodynamics
gadopentetate
Megjelenés:European Journal of Inorganic Chemistry. - 13 (2010), p. 1948-1956. -
További szerzők:Pálinkás Zoltán (1984-) (vegyész) Uggeri, Fulvio Brücher Ernő (1935-) (vegyész)
Internet cím:DOI
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4.

001-es BibID:BIBFORM008188
Első szerző:Baranyai Zsolt (vegyész)
Cím:Equilibrium and kinetic properties of the lanthanoids(III) and varioous divalent metal complexes of the heptadentate ligand AAZTA / Zsolt Baranyai, Fulvio Uggeri, Giovanni B. Giovenzana, Attila Bényei, Ernő Brücher, Silvio Aime
Dátum:2009
Megjegyzések:The heptadentate ligand 1,4-bis(hydroxycarbonylmethyl)-6-[bis(hy-droxycarbonylmethyl)]amino-6-methyl-perhydro-1,4-diazepine (AAZTA) and its derivatives were recently reported to give stable complexes with Gd3+ with superior efficiency as MRI contrast agents. Nevertheless, only preliminary data are available on the coordination behavior of this interesting ligand. In this work, thermodynamic and kinetic stability data are determined for the formation of complexes with AAZTA and the lanthanoid metal ions, and other divalent metal ions of interest for this application. The AAZTA ligand binds the lanthanoid ions with logKML values of 17.53-21.85 with its affinity steadily increasing from La3+ to Lu3+, suggesting that the seven-membered skeleton is better suited to accommodate smaller metal ions. Even though the denticity is lower, the stability of the heavier lanthanoid complexes is comparable to those of the classical ligand diethylene-triaminepentaacetic acid (DTPA). The transmetalation reactions of [Gd-(AAZTA)] with Cu2+ and Eu3+ predominantly occur through proton-assisted dissociation of the complex. The role of the direct attack of Cu2+ or Eu3+ in the exchange reactions is limited, although the formation of dinuclear complexes decreases the proton-assisted dissociation. Near physiological conditions, [Gd(AAZTA)] is significantly more inert than [Gd(DTPA)]2-, allowing its potentially safe use as contrast agent in magnetic resonance imaging.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
kinetics
lanthanides
Megjelenés:Chemistry-A European Journal. - 15 : 7 (2009), p. 1691-1705. -
További szerzők:Uggeri, Fulvio Giovenzana, Giovanni Battista Bényei Attila (1962-) (vegyész) Brücher Ernő (1935-) (vegyész) Aime, Silvio
Internet cím:DOI
elektronikus változat
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5.

001-es BibID:BIBFORM068358
Első szerző:Nagy Gábor (radiokémikus, vegyész)
Cím:AAZTA : an Ideal Chelating Agent for the Development of 44Sc PET Imaging Agents / Nagy Gábor, Szikra Dezső, Trencsényi György, Fekete Anikó, Garai Ildikó, Giani Arianna M., Negri Roberto, Masciocchi Norberto, Maiocchi Alessandro, Uggeri Fulvio, Tóth Imre, Aime Silvio, Giovenzana Giovanni B., Baranyai Zsolt
Dátum:2017
ISSN:1433-7851
Megjegyzések:Unprecedented fast and efficient complexation of ScIII was demonstrated with the chelating agent AAZTA (AAZTA=1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)]amino-6-methylperhydro-1,4-diazepine) under mild experimental conditions. The robustness of the 44Sc(AAZTA)? chelate and conjugated biomolecules thereof is further shown by in?vivo PET imaging in healthy and tumor mice models. The new results pave the way towards development of efficient Sc-based radiopharmaceuticals using the AAZTA chelator.
Tárgyszavak:Orvostudományok Klinikai orvostudományok kutatási jelentés
AAZTA
labeling
44Sc
Sc-44
scandium
Megjelenés:Angewandte Chemie-International Edition. - 56 : 8 (2017), p. 2118-2122. -
További szerzők:Szikra Dezső Péter (1983-) (vegyész) Trencsényi György (1978-) (biológus, biokémikus, molekuláris biológus) Fekete Anikó (1973-) (vegyész) Garai Ildikó (1966-) (radiológus) Giani, Arianna Maria Negri, Roberto Masciocchi, Norberto Maiocchi, Alessandro (vegyész) Uggeri, Fulvio Tóth Imre (1950-) (vegyész) Aime, Silvio Giovenzana, Giovanni Battista Baranyai Zsolt (1977-) (vegyész)
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DOI
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