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1.

001-es BibID:BIBFORM106980
035-os BibID:(WoS)000643574200067 (Scopus)85100045839
Első szerző:Garda Zoltán (vegyész)
Cím:Complexation of Mn(II) by Rigid Pyclen Diacetates: Equilibrium, Kinetic, Relaxometric, Density Functional Theory, and Superoxide Dismutase Activity Studies / Zoltán Garda, Enikő Molnár, Nadège Hamon, José Luis Barriada, David Esteban-Gómez, Balázs Váradi, Viktória Nagy, Kristof Pota, Ferenc Krisztián Kálmán, Imre Tóth, Norbert Lihi, Carlos Platas-Iglesias, Éva Tóth, Raphaël Tripier, Gyula Tircsó
Dátum:2021
ISSN:0020-1669 1520-510X
Megjegyzések:We report the Mn(II) complexes with two pyclen-based ligands (pyclen = 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene) functionalized with acetate pendant arms at either positions 3,6 (3,6-PC2A) or 3,9 (3,9-PC2A) of the macrocyclic fragment. The 3,6-PC2A ligand was synthesized in five steps from pyclen oxalate by protecting one of the secondary amine groups of pyclen using Alloc protecting chemistry. The complex with 3,9-PC2A is characterized by a higher thermodynamic stability [log K-MnL = 17.09(2)] than the 3,6-PC2A analogue [log K-MnL = 15.53(1); 0.15 M NaCl]. Both complexes contain a water molecule coordinated to the metal ion, which results in relatively high H-1 relaxivities (r(1p) = 2.72 and 2.91 mM(-1) s(-1) for the complexes with 3,6-PC2A and 3,9-PC2A, respectively, at 25 degrees C and 0.49 T). The coordinated water molecule displays fast exchange kinetics with the bulk in both cases; the rates (k(ex)(298)) are 140 x 10(6) and 126 x 10(6) s(-1) for [Mn(3,6-PC2A)(H2O)] and [Mn(3,9-PC2A)(H2O)], respectively. The two complexes were found to be remarkably inert with respect to their dissociation, with half-lives of 63 and 21 h, respectively, at pH = 7.4 in the presence of excess Cu(II). The r(1p) values recorded in blood serum remain constant at least over a period of 120 h. Cyclic voltammetry experiments show irreversible oxidation features shifted to higher potentials with respect to [Mn(EDTA)(H2O)](2-) (H(4)EDTA = ethylenediaminetetraacetic acid) and [Mn(PhDTA)(H2O)](2-) (H(4)PhDTA = phenylenediamine-N,N,N',N'-tetraacetic acid), indicating that the PC2A complexes reported here have a lower tendency to stabilize Mn(III). The superoxide dismutase activity of the Mn(II) complexes was tested using the xanthine/xanthine oxidase/p-nitro blue tetrazolium chloride assay at pH = 7.8. The Mn(II) complexes of 3,6-PC2A and 3,9-PC2A are capable of assisting decomposition of the superoxide anion radical. The kinetic rate constant of the complex of 3,9-PC2A is smaller by 1 order of magnitude than that of 3,6-PC2A.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Inorganic Chemistry. - 60 : 2 (2021), p. 1133-1148. -
További szerzők:Molnár Enikő (1991-) (vegyész) Hamon, Nadège Barriada, José Luis Esteban-Gómez, David Váradi Balázs (1990-) (vegyész) Nagy Viktória Póta Kristóf Kálmán Ferenc K. (1978-) (vegyész) Tóth Imre (1950-) (vegyész) Lihi Norbert (1990-) (vegyész) Platas-Iglesias, Carlos Tóth Éva (1967-) (koordinációs kémia) Tripier, Raphaël Tircsó Gyula (1977-) (vegyész, kémia tanár)
Pályázati támogatás:K-120224
OTKA
128201
OTKA
134694
OTKA
PD-128326
OTKA
2019-2.1.11- 1179 TET-2019-00084
Egyéb
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2.

001-es BibID:BIBFORM103530
035-os BibID:(WOS)000541873600033 (Scopus)85084399701
Első szerző:Garda Zoltán (vegyész)
Cím:Unexpected Trends in the Stability and Dissociation Kinetics of Lanthanide(III) Complexes with Cyclen-Based Ligands across the Lanthanide Series / Zoltán Garda, Viktoria Nagy, Aurora Rodríguez-Rodríguez, Rosa Pujales-Paradela, Véronique Patinec, Goran Angelovski, Éva Tóth, Ferenc K. Kálmán, David Esteban-Gómez, Raphaël Tripier, Carlos Platas-Iglesias, Gyula Tircsó
Dátum:2020
ISSN:0020-1669 1520-510X
Megjegyzések:We report a detailed study of the thermodynamic stability and dissociation kinetics of lanthanide complexes with two ligands containing a cyclen unit, a methyl group, a picolinate arm, and two acetate pendant arms linked to two nitrogen atoms of the macrocycle in either cis (1,4-H(3)DO2APA) or trans (1,7-H(3)DO2APA) positions. The stability constants of the Gd3+ complexes with these two ligands are very similar, with log K-GdL values of 16.98 and 16.33 for the complexes of 1,4-H(3)DO2APA and 1,7-H(3)DO2APA, respectively. The stability constants of complexes with 1,4-H(3)DO2APA follow the usual trend, increasing from log K-LaL = 15.96 to log K-LuL = 19.21. However, the stability of [Ln(1,7-DO2APA)] complexes decreases from log K = 16.33 for Gd3+ to 14.24 for Lu3+. The acid-catalyzed dissociation rates of the Gd3+ complexes differ by a factor of similar to 15, with rate constants (k(1)) of 1.42 and 23.5 M(-1)s(-1) for [Gd(1,4-DO2APA)] and [Gd(1,7DO2APA)], respectively. This difference is magnified across the lanthanide series to reach a 5 orders of magnitude higher k(1) for [Yb(1,7-DO2APA)] (1475 M(-1)s(-1)) than for [Yb(1,4-DO2APA)] (5.79 x 10(-3)M(-1)s(-1)).The acid catalyzed mechanism involves the protonation of a carboxylate group, followed by a cascade of proton-transfer events that result in the protonation of a nitrogen atom of the cyclen unit. Density functional theory calculations suggest a correlation between the strength of the Ln-O-carboxylate bonds and the kinetic inertness of the complex, with stronger bonds providing more inert complexes. The H-1 NMR resonance of the coordinated water molecule in the [Yb(1,7-DO2APA)] complex at 176 ppm provides a sizable chemical exchange saturation transfer effect thanks to a slow water exchange rate of (15.9 +/- 1.6) x 10(3) s(-1).
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Inorganic Chemistry. - 59 : 12 (2020), p. 8184-8195. -
További szerzők:Nagy Viktória Rodríguez-Rodríguez, Aurora Pujales-Paradela, Rosa Patinec, Véronique Angelovski, Goran Tóth Éva Kálmán Ferenc K. (1978-) (vegyész) Esteban-Gómez, David Tripier, Raphaël Platas-Iglesias, Carlos Tircsó Gyula (1977-) (vegyész, kémia tanár)
Pályázati támogatás:GINOP-2.3.2-15-2016-00008
GINOP
NKFIH-K-120224
Egyéb
NKFIH-K-128201
Egyéb
2019-2.1.11-TÉT-2019-00084
Egyéb
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3.

001-es BibID:BIBFORM106987
035-os BibID:(Wos)000645403400001 (Scopus)85103919865 (cikkazonosító)1524
Első szerző:Kálmán Ferenc K. (vegyész)
Cím:Expanding the Ligand Classes Used for Mn(II) Complexation: Oxa-aza Macrocycles Make the Difference / Ferenc K. Kálmán, Viktória Nagy, Rocío Uzal-Varela, Paulo Pérez-Lourido, David Esteban-Gómez,Zoltán Garda, Kristof Pota, Roland Mezei, Agnès Pallier, Éva Tóth, Carlos Platas-Iglesias, Gyula Tircsó
Dátum:2021
ISSN:1420-3049
Megjegyzések:We report two macrocyclic ligands based on a 1,7-diaza-12-crown-4 platform functionalizedwith acetate (tO2DO2A2?) or piperidineacetamide (tO2DO2AMPip) pendant arms and a detailed char-acterization of the corresponding Mn(II) complexes. The X?ray structure of [Mn(tO2DO2A)(H2O)]·2H2Oshows that the metal ion is coordinated by six donor atoms of the macrocyclic ligand and one watermolecule, to result in seven-coordination. The Cu(II) analogue presents a distorted octahedral coor-dination environment. The protonation constants of the ligands and the stability constants of thecomplexes formed with Mn(II) and other biologically relevant metal ions (Mg(II), Ca(II), Cu(II) andZn(II)) were determined using potentiometric titrations (I= 0.15 M NaCl, T = 25?C). The conditionalstabilities of Mn(II) complexes at pH 7.4 are comparable to those reported for the cyclen-basedtDO2A2?ligand. The dissociation of the Mn(II) chelates were investigated by evaluating the rateconstants of metal exchange reactions with Cu(II) under acidic conditions (I= 0.15 M NaCl, T = 25?C).Dissociation of the [Mn(tO2DO2A)(H2O)] complex occurs through both proton?and metal?assistedpathways, while the [Mn(tO2DO2AMPip)(H2O)] analogue dissociates through spontaneous andproton-assisted mechanisms. The Mn(II) complex oftO2DO2A2 is remarkably inert with respectto its dissociation, while the amide analogue is significantly more labile. The presence of a watermolecule coordinated to Mn(II) imparts relatively high relaxivities to the complexes. The parametersdetermining this key property were investigated using17O NMR (Nuclear Magnetic Resonance)transverse relaxation rates and1H nuclear magnetic relaxation dispersion (NMRD) profiles.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
manganese
magnetic resonance imaging
stability
dissociation kinetics
water exchange
contrast agents
macrocycles
Megjelenés:Molecules. - 26 : 6 (2021), p. 1-20. -
További szerzők:Nagy Viktória Uzal-Varela, Rocío Pérez-Lourido, Paulo Esteban-Gómez, David Garda Zoltán (1989-) (vegyész) Póta Kristóf Mezei Roland Pallier, Agnès Tóth Éva Platas-Iglesias, Carlos Tircsó Gyula (1977-) (vegyész, kémia tanár)
Pályázati támogatás:K-120224
OTKA
K-134694
OTKA
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4.

001-es BibID:BIBFORM106968
035-os BibID:(Wos)000779822100036 (Scopus)85126557192
Első szerző:Lucio-Martínez, Fátima
Cím:Rigidified Derivative of the Non-macrocyclic Ligand H4OCTAPA for Stable Lanthanide(III) Complexation / RFátima Lucio-Martínez, Zoltán Garda, Balázs Váradi, Ferenc Krisztián Kálmán, David Esteban-Gómez, Éva Tóth, Gyula Tircsó, Carlos Platas-Iglesias
Dátum:2022
ISSN:0020-1669 1520-510X
Megjegyzések:he stability constants of lanthanide complexes with the potentially octadentate ligand CHXOCTAPA4?, which contains a rigid 1,2-diaminocyclohexane scaffold functionalized with two acetate and two picolinate pendant arms, reveal the formation of stable complexes [log KLaL = 17.82(1) and log KYbL = 19.65(1)]. Luminescence studies on the Eu3+ and Tb3+ analogues evidenced rather high emission quantum yields of 3.4 and 11%, respectively. The emission lifetimes recorded in H2O and D2O solutions indicate the presence of a water molecule coordinated to the metal ion. 1H nuclear magnetic relaxation dispersion profiles and 17O NMR chemical shift and relaxation measurements point to a rather low water exchange rate of the coordinated water molecule (kex298 = 1.58 ? 106 s?1) and relatively high relaxivities of 5.6 and 4.5 mM?1 s?1 at 20 MHz and 25 and 37 ?C, respectively. Density functional theory calculations and analysis of the paramagnetic shifts induced by Yb3+ indicate that the complexes adopt an unprecedented cis geometry with the two picolinate groups situated on the same side of the coordination sphere. Dissociation kinetics experiments were conducted by investigating the exchange reactions of LuL occurring with Cu2+. The results confirmed the beneficial effect of the rigid cyclohexyl group on the inertness of the Lu3+ complex. Complex dissociation occurs following proton- and metal-assisted pathways. The latter is relatively efficient at neutral pH, thanks to the formation of a heterodinuclear hydroxo complex.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Inorganic Chemistry. - 61 : 12 (2022), p. 5157-5171. -
További szerzők:Garda Zoltán (1989-) (vegyész) Váradi Balázs (1990-) (vegyész) Kálmán Ferenc K. (1978-) (vegyész) Esteban-Gómez, David Tóth Éva Tircsó Gyula (1977-) (vegyész, kémia tanár) Platas-Iglesias, Carlos
Pályázati támogatás:K-134694
OTKA
K-128201
OTKA
FK-134551
OTKA
Bilateral Hungarian-Spanish Science and Technology Cooperation Program (2019-2.1.11-TET-2019-00084 supported by NKFIH).
Egyéb
Gedeon Richter's Talentum Foundation
Egyéb
Cooperative Doctoral Program of the Ministry of Innovation and Technology financed from the National Research, Development and Innovation Fund (NKFIH)
Egyéb
ÚNKP-21-4 new national excellence program of the Ministry of Human Capacities
Egyéb
János Bolyai Research Scholarship of the Hungarian Academy of Sciences
MTA
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5.

001-es BibID:BIBFORM118635
Első szerző:Nizou, Gwladys
Cím:Exploring the Limits of Ligand Rigidification in Transition Metal Complexes with Mono-Functionalized Pyclen Derivatives / Gwladys Nizou, Zoltán Garda, Enikő Molnár, David Esteban-Gómez, Mariane Le Fur, Olivier Fougere, Olivier Rousseaux, Carlos Platas-Iglesias, Raphaël Tripier, Gyula Tircsó, Maryline Beyler
Dátum:2024
ISSN:0020-1669 1520-510X
Megjegyzések:We report the synthesis of the new family of side-bridged pyclen ligands. The incorporation of an ethylene bridge between two adjacent nitrogen atoms was reached from the pyclen-oxalate described previously in the scientific literature. Three new side-bridged pyclen macrocycles were obtained: Hsb-3-pc1a, sb-3-pc1py and Hsb-3-pc1pa, with the aim to assess their coordination properties toward Cu2+ and Zn2+ ions. We also prepared their non-reinforced analogues H3-pc1a, 3-pc1py and H3-pc1pa as comparative benchmarks. The two series of ligands were characterized and their coordination properties were investigated in detail. The Zn2+ and Cu2+ complexes with the non-side-bridge series H3-pc1a, 3-pc1py and H3-pc1pa were successfully isolated and their structures were assessed by X-ray diffraction studies. In the case of the side-bridged family, the synthesis of the com-plexes was far more difficult and, in some cases, unsuccessful. The results of our studies demonstrate that this difficulty is related to the extreme stiffening and basicity of such side-bridged pyclens.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Macrocyclic ligands
rigidification
transition metal complexes
N-functionalized pyclen derivatives
syntheis
stability
Megjelenés:Inorganic Chemistry. - 63 : 8 (2024), p. 3931-3947. -
További szerzők:Garda Zoltán (1989-) (vegyész) Molnár Enikő (1991-) (vegyész) Esteban-Gómez, David Le Fur, Mariane Fougère, Olivier Rousseaux, Olivier Platas-Iglesias, Carlos Tripier, Raphaël Tircsó Gyula (1977-) (vegyész, kémia tanár) Beyler, Maryline
Pályázati támogatás:PD-138064
NKFIH
K-128201
NKFIH
134694
NKFIH
2019-2.1.11-TET-2019-00084
Egyéb
Internet cím:Szerző által megadott URL
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Intézményi repozitóriumban (DEA) tárolt változat
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6.

001-es BibID:BIBFORM076232
035-os BibID:(WoS)000434245500054 (Scopus)85047071870
Első szerző:Póta Kristóf
Cím:Taking the next step toward inert Mn2+ complexes of open-chain ligands: the case of the rigid PhDTA ligand / Kristof Pota, Zoltán Garda, Ferenc Krisztián Kálmán, José Luis Barriada, David Esteban-Gómez, Carlos Platas-Iglesias, Imre Tóth, Ernő Brücher, Gyula Tircsó
Dátum:2018
ISSN:1144-0546 1369-9261
Megjegyzések:In line with our research to find inert Mn(II) complexes as contrast agents for Magnetic Resonance Imaging, we have studied the aromatic?ring rigidified EDTA-analogue o-phenylenediamine-N,N,N',N'-tetraacetic acid (PhDTA). The protonation constants (Ki H) of PhDTA and stability constants of complexes formed between this open-chain ligand and several different biogenic metal ions (Ca2+, Mg2+, Zn2+, Cu2+, Mn2+) have been determined in 0.15 M NaCl at 25 ?C and compared with the values reported in the literature previously. Protonation constants are lower than those of the corresponding cis- and trans-CDTA complexes, which might be attributed to the electron withdrawing effect of the phenylene group. The lower total basicity of the ligand leads to lower stability constants for all the examined metal complexes. On the contrary, we have found that the conditional stability constants of [Mn(PhDTA)]2- and [Mn(trans- CDTA)]2- are approximately the same, as both complexes are 100% formed by pH 5 and their pM values are also comparable. The relaxivity of [Mn(PhDTA)]2- is nearly identical (r1 = 3.72 mM-1s-1) to that determined previously for the [Mn(trans-CDTA)]2- complex (r1 = 3.62 mM-1s-1), and its pH-dependence confirms the equilibrium model used for the fitting of the titration data. The results of kinetic studies of the metal exchange reactions reveal that the [Mn(PhDTA)]2- complex possesses a slightly better dissociation kinetics profile than [Mn(trans-CDTA)]2-, which has been tested in vivo recently (including human injections). The half-life of the dissociation of the complex near to physiological pH at 25 ?C is 19 hours. By using the rate constant calculated for the dissociation (pH=7.4, cCu2+=10 ?M) and the half-life of excretion (1.6 hour), the ratio of the dissociated complex is estimated to represent 8% of the injected dose. DFT studies reveal that the metal coordination environment of [Mn(PhDTA)]2- is very similar to that of [Mn(EDTA)]2-, both containing an inner-sphere water molecule. Cyclic voltammetry studies indicate that [Mn(PhDTA)]2- is slightly more resistant towards oxidation to the Mn3+ complex than the EDTA analogue.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:New Journal Of Chemistry. - 42 : 10 (2018), p. 8001-8011. -
További szerzők:Garda Zoltán (1989-) (vegyész) Kálmán Ferenc K. (1978-) (vegyész) Barriada, José Luis Esteban-Gómez, David Platas-Iglesias, Carlos Tóth Imre (1950-) (vegyész) Brücher Ernő (1935-) (vegyész) Tircsó Gyula (1977-) (vegyész, kémia tanár)
Pályázati támogatás:OTKA K-120224
OTKA
GINOP-2.3.2-15-2016-00008
GINOP
GINOP-2.3.3-15-2016-00004
GINOP
Bolyai János Kutatási Ösztöndíj
Egyéb
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7.

001-es BibID:BIBFORM067433
Első szerző:Rodríguez-Rodríguez, Aurora
Cím:Stable Mn2+, Cu2+ and Ln3+ complexes with cyclen-based ligands functionalized with picolinate pendant arms / Aurora Rodríguez-Rodríguez, Zoltán Garda, Erika Ruscsák, David Esteban-Gómez, Andrés de Blas, Teresa Rodríguez-Blas, Luís M. P. Lima, Maryline Beyler, Raphaël Tripier, Gyula Tircsó, Carlos Platas-Iglesias
Dátum:2015
ISSN:1477-9226
Megjegyzések:In this study we present the results of the equilibrium, dissociation kinetics, DFT and X-ray crystallographic studies performed on the complexes of metal ions of biomedical importance (Mn2+, Cu2+ and Gd3+) formed with octadentate ligands based on a cyclen platform incorporating two picolinate pendant arms (dodpa2? and Medodpa2?). The stability constants of the complexes were accessed by multiple methods (pH-potentiometry, direct and competition UV-vis spectrophotometry and 1H-relaxometry). The stability constants of the complexes formed with dodpa2? and Medodpa2? do not differ significantly (e.g. log K[Mn(dodpa)] = 17.40 vs. log K[Mn(Medodpa)] = 17.46, log K[Cu(dodpa)] = 24.34?25.17 vs. log K[Cu(Medodpa)] = 24.74 and log K[Gd(dodpa)]+ = 17.27 vs. log K[Gd(Medodpa)]+ = 17.59), which indicates that the steric hindrance brought by the methyl groups has no significant effect on the stability of the complexes. The stability constants of the Mn2+ complexes formed with the cyclen dipicolinates were found to be ca. 3 log K units higher than those determined for the complex of the cyclen monopicolinate (dompa?), which indicates that the second picolinate moiety attached to the backbone of the macrocycle is very likely coordinated to the Mn2+ ion. However, the stability of the [Cu(dodpa)] and [Cu(Medodpa)] complexes agrees well with the stability constant of [Cu(dompa)]+, in line with the hexadentate coordination around the metal ion observed in the X-ray structure of [Cu(Medodpa)]. The [Gd(dodpa)]+ and [Gd(Medodpa)]+ complexes display a fairly high kinetic inertness, as the rate constants of acid catalysed dissociation (k1 = 2.5(4) ? 10?3 and 8.3(4) ? 10?4 M?1 s?1 for [Gd(dodpa)]+ and [Gd(Medodpa)]+, respectively) are smaller than the value reported for [Gd(do3a)] (k1 = 2.5 ? 10?2 M?1 s?1). The [Mn(dodpa)] complex was found to be more inert than [Mn(Medodpa)]. The results of the diffusion-ordered NMR spectroscopy (DOSY) and DFT calculations of diamagnetic [La(dodpa)]+ and [Lu(dodpa)]+ complexes indicate the formation of a trinuclear entity of the La complex in aqueous solution.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
cyclen-based ligand
transition metal
lanthanide
picolinate pendant
thermodynamic stability
kinetic inertness
Megjelenés:Dalton Transactions 44 (2015), p. 5017-5031. -
További szerzők:Garda Zoltán (1989-) (vegyész) Ruscsák Erika (1989-) (vegyész) Esteban-Gómez, David Blas, Andrès de Rodríguez-Blas, Teresa Lima, Luís M. P. Beyler, Maryline Tripier, Raphaël Tircsó Gyula (1977-) (vegyész, kémia tanár) Platas-Iglesias, Carlos
Pályázati támogatás:OTKA-84291
OTKA
OTKA-109029
OTKA
TÁMOP 4.2.2.A-11/1/KONV-2012-0043
TÁMOP
János Bolyai Research Scholarship
MTA
COST TD1004 " Theragnostics Imaging and Therapy: An Action to Develop Novel Nano-sized Systems for Imaging-Guided Drug Delivery "
Egyéb
CM1006 European F-Element Network (EUFEN) Actions
Egyéb
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8.

001-es BibID:BIBFORM057620
Első szerző:Rodríguez-Rodríguez, Aurora
Cím:Lanthanide(III) Complexes with a Reinforced Cyclam Ligand Show Unprecedented Kinetic Inertness / Aurora Rodríguez-Rodríguez, David Esteban-Gómez, Raphaël Tripier, Gyula Tircsó, Zoltán Garda, Imre Tóth, Andrés de Blas, Teresa Rodríguez-Blas, Carlos Platas-Iglesias
Dátum:2014
ISSN:0002-7863
Megjegyzések:Lanthanide(III) complexes of a cross-bridged cyclam derivative containing two picolinate pendant arms are kinetically inert in very harsh conditions such as 2 M HCl, with no dissociation being observed for at least 5 months. Importantly, the [Ln(dota)] complexes, which are recognized to be extremely inert, dissociate under these conditions with lifetimes in the range ca. 1 minute to 12 hours depending upon the Ln3+ ion. X-ray diffraction studies reveal octadentate binding of the ligand to the metal ion in the [Eu(cb-tedpa)]+ complex, while 1H and 13C NMR experiments in D2O point to the presence of a single diastereoisomer in solution with a very rigid structure. The structure of the complexes in the solid state is retained in solution, as demonstrated by the analysis of the Yb3+-induced paramagnetic shifts.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Lanthanide(III) Complexes
Reinforced Cyclam Ligand
kinetics inertness
picolinates
Megjelenés:Journal Of The American Chemical Society. - 136 : 52 (2014), p. 17954-17957. -
További szerzők:Esteban-Gómez, David Tripier, Raphaël Tircsó Gyula (1977-) (vegyész, kémia tanár) Garda Zoltán (1989-) (vegyész) Tóth Imre (1950-) (vegyész) de Blas, Andrés Rodríguez-Blas, Teresa Platas-Iglesias, Carlos
Pályázati támogatás:Ministerio de Educación y Ciencia (MEC, CTQ2009-10721), Fondo Europeo de Desarrollo Regional (FEDER, CTQ2009-10721) and Xunta de Galicia (CN 2012/011) for generous financial support and Centro de Supercomputación de Galicia (CESGA)
Egyéb
COST CM1006 "European F-Element Network (EuFen)
Egyéb
COST TD1004 "Theragnostics Imaging and Therapy: An Action to Develop Novel Nanosized Systems for Imaging-Guided Drug Delivery"
Egyéb
János Bólyai Research Scholarship of the Hungarian Academy of Sciences
MTA
K-84291
OTKA
K-109029
OTKA
TÁMOP-4.2.2.A-11/1/KONV-2012-0043
TÁMOP
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9.

001-es BibID:BIBFORM062881
035-os BibID:(WoS)000368906200009 (Scopus)84954489502
Első szerző:Tircsó Gyula (vegyész, kémia tanár)
Cím:Approaching the Kinetic Inertness of Macrocyclic Gadolinium(III)-Based MRI Contrast Agents with Highly Rigid Open-Chain Derivatives / Gyula Tircsó, Martín Regueiro-Figueroa, Viktória Nagy, Zoltán Garda, Tamás Garai, Ferenc Krisztián Kálmán, David Esteban-Gómez, Éva Tóth, Carlos Platas-Iglesias
Dátum:2016
ISSN:0947-6539
Megjegyzések:A highly rigid open-chain octadentate ligand (H4cddadpa), containing a diaminecyclohexane unit to replace the ethylenediamine bridge of 6,6'-((ethane-1,2 diylbis((carboxymethyl)azanediyl))bis(methylene))dipicolinic acid (H4octapa), was synthesized. This structural modification slightly improves the thermodynamic stability of the Gd3+ complex (logKGdL = 20.68 vs 20.23 for [Gd(octapa)]-), while other MRI-relevant parameters remain practically unaffected (number of coordinated water molecules, q=1; relaxivity, r1 =5.73 m?-1s-1 at 20 MHz and 295 K). Most remarkably, the kinetic inertness of the complex is improved to a great extent by the rigidifying effect of the diaminecyclohexane unit in the ligand skeleton: the half-live of dissociation calculated for physiological conditions is 6 orders of magnitude higher for [Gd(cddadpa)]- (t1/2=1.49x105 h) than for [Gd(octapa)]-. As compared to non-macrocyclic MRI contrast agents approved for clinical use ([Gd(dtpa-bma)], [Gd(dtpa-bmea)], [Gd(dtpa)]2- and [Gd(bopta)]2-), the kinetic inertness of this novel chelate is superior by 2-3 orders of magnitude, and it is the highest among all linear Gd3+ chelates known so far.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
gadolinium
NMR imaging
contrast agents
coordination compounds
lanthanides
Megjelenés:Chemistry-A European Journal. - 22 : 3 (2016), p. 896-901. -
További szerzők:Regueiro-Figueroa, Martín Nagy Viktória (1989-) (vegyész és kémia tanár) Garda Zoltán (1989-) (vegyész) Garai Tamás Kálmán Ferenc K. (1978-) (vegyész) Esteban-Gómez, David Tóth Éva (1967-) (koordinációs kémia) Platas-Iglesias, Carlos
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