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1.

001-es BibID:BIBFORM067302
035-os BibID:(WoS)000388546800022 (Scopus)84993990174
Első szerző:Garda Zoltán (vegyész)
Cím:Physico-chemical properties of MnII complexes formed with cis- and trans-DO2A : thermodynamic, electrochemical and kinetic studies / Zoltán Garda, Attila Forgács, Quyen N. Do, Ferenc K. Kálmán, Sarolta Timári, Zsolt Baranyai, Lorenzo Tei, Imre Tóth, Zoltán Kovács, Gyula Tircsó
Dátum:2016
ISSN:0162-0134 1873-3344
Megjegyzések:Manganese (MnII) is a promising alternative to gadolinium (GdIII) as a magnetic resonance imaging (MRI) agent. Unlike gadolinium, this biogenic metal might be better tolerated by the body, reducing the risk of toxicity associated with dissociation of the complex. Herein we report detailed equilibrium and kinetic studies performed with MnII complexes of 1,4,7,10-tetraazacyclododecane-1,4-diacetic acid (1,4-DO2A or cis-DO2A) and 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (1,7-DO2A or trans-DO2A). The protonation constants of the ligands as well as stability constants of their MnII complexes have been determined by pH-potentiometry. The stability constants of [Mn(cis-DO2A)] are slightly higher than those of [Mn(trans-DO2A)] (log KMnL = 15.68 and 15.22, respectively). Cyclic voltammetric (CV) experiments performed on [Mn(cis-DO2A)] and [Mn(trans-DO2A)] revealed quasireversible systems with a half-wave potential of + 636 and + 705 mV versus Ag/AgCl, respectively. These values indicate that the MnII ion in these complexes is more stabilized against the oxidation than in [Mn(EDTA)]2 ?. The kinetic inertness of the complexes has been studied in transmetallation reactions with CuII or ZnII ions. Kinetic measurements indicate that both MnII complexes primarily undergo acid catalyzed dissociation and positions of the acetate pendant arms do not influence kinetic inertness. The inertness of these complexes is comparable to that of [Mn(NOTA)]? (NOTA = 1,4,7-triazacyclononane-1,4,7-triacetic acid) and about twenty times lower than that of [Mn(DOTA)]2 ? (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). In conclusion, [Mn(cis-DO2A)] displays some very interesting features (thermodynamic and redox stability as well as kinetic inertness) which makes this complex a promising platform for the development of more efficient MnII complexes as alternatives to Gd-based MRI agents.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Magnetic resonance imaging
Contrast agents (CAs)
Manganese
Thermodynamic stability
Inertness
Electrochemistry
Megjelenés:Journal of Inorganic Biochemistry. - 163 (2016), p. 206-213. -
További szerzők:Forgács Attila (1988-) (vegyész) Do, Quyen N. (1975-) (vegyész) Kálmán Ferenc K. (1978-) (vegyész) Timári Sarolta (1984-) (vegyész, kémia tanár) Baranyai Zsolt (1977-) (vegyész) Tei, Lorenzo Tóth Imre (1950-) (vegyész) Kovács Zoltán (1963-) (vegyész, angol szakfordító) Tircsó Gyula (1977-) (vegyész, kémia tanár)
Pályázati támogatás:OTKA-84291
OTKA
OTKA-109029
OTKA
TÁMOP 4.2.4. A/2-11-1-2012-0001
TÁMOP
COST TD1004 Action "Theragnostics Imaging and Therapy: An Action to Develop Novel Nanosized Systems for Imaging-Guided Drug Delivery"
Egyéb
Bólyai János Kutatási Ösztöndíj
MTA
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2.

001-es BibID:BIBFORM103610
035-os BibID:(cikkazonosító)110978 (WOS)000522119300002 (Scopus)85077754827
Első szerző:Guillou, Amaury
Cím:Picolinate-appended tacn complexes for bimodal imaging: Radiolabeling, relaxivity, photophysical and electrochemical studies / Amaury Guillou, Margau Galland, Amandine Roux, Balázs Váradi, Réka Anna Gogolák, Patricia Le Saëc, Alain Faivre-Chauvet, Maryline Beyler, Christophe Bucher, Gyula Tircsó, Véronique Patinec, Olivier Maury, Raphaël Tripier
Dátum:2020
ISSN:0162-0134 1873-3344
Megjegyzések:Based on our previous works involving two 1,4,7-triazacyclononane (tacn)-based ligands Hno2py1pa (1-Picolinic acid-4,7-bis(pyridin-2-ylmethyl)-1,4,7-triazacyclononane) and Hno1pa (1-Picolinic acid-1,4,7-triazacyclononane), we report here the synthesis of analogues bearing picolinate-based rz-conjugated ILCT (IntraLigand Charge Transfer) transition antenna (HL1, HL2), using regiospecific N-functionalization of the tacn skeleton and their related transition metal complexes (e.g. Cu2+, Zn2+ and Mn2+). Coordination properties as well as their photophysical and electrochemical properties were investigated in order to quantify the impact of such antenna on the luminescent or relaxometric properties of the complexes. The spectroscopic properties of the targeted ligands and metal complexes have been studied using UV-Vis absorption and fluorescence spectrocopies. While the zinc complex formed with HL1 possesses a moderate quantum yield of 5%, complexation of Cu2+ led to an extinction of the luminescence putatively attributed to a photo-induced electron transfer, as supported by spectroscopic and electrochemical evidences. The [Mn(L2)](+) complex is characterized by a fluorescence quantum yield close to 8% in CH2Cl2. The potential interest of such systems as bimodal probes has been assessed from radiolabeling experiments conducted on HL1 and( 64)Cu(2+) as well as confocal microscopy analyses and from relaxometric studies carried out on the cationic [Mn(L2)](+) complex. These results showed that HL1 can be used for radiolabeling, with a radiochemical conversion of 40% in 15 min at 100 degrees C. Finally, the relaxivity values obtained for [Mn(L2)](+), r(1p) = 4.80 mM(-1).s(-1) and r(2p) = 8.72 mM(-1).s(-1), make the Mn(II) complex an ideal candidate as a probe for Magnetic Resonance Imaging.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Journal of Inorganic Biochemistry. - 205 (2020), p. 1-9. -
További szerzők:Galland, Margaux Roux, Amandine Váradi Balázs (1990-) (vegyész) Gogolák Réka Anna (kémia tanár) Le Saëc, Patricia Faivre-Chauvet, Alain Beyler, Maryline Bucher, Christophe Tircsó Gyula (1977-) (vegyész, kémia tanár) Patinec, Véronique Maury, Olivier Tripier, Raphaël
Pályázati támogatás:NKFIH-K-120224
Egyéb
GINOP-2.3.2-15-2016-00008
GINOP
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3.

001-es BibID:BIBFORM067445
Első szerző:Nagy Nóra Veronika
Cím:Copper(II) complexes of some N-substituted bis(aminomethyl)phosphinate ligands : An integrated EPR study of microspeciation and coordination modes by the two-dimensional simulation method / Nóra Veronika Nagy, Terézia Szabó-Plánka, Gyula Tircsó, Róbert Király, Zsuzsanna Árkosi, Antal Rockenbauer, Ernő Brücher
Dátum:2004
ISSN:0162-0134
Megjegyzések:Copper(II) complexes of bis(aminomethyl)phosphinic acid (L1), bis(N-glycino-N-methyl)phosphinic acid (L2), bis(N-benzylglycino-N-methyl)phosphinic acid (L3), bis(l-prolino-N-methyl)phosphinic acid (L4) and bis(iminodicarboxymethyl-N-methyl)phosphinic acid (L5) were studied in aqueous solution by pH-potentiometric and electron paramagnetic resonance (EPR) spectroscopic methods. The EPR spectrum packages recorded at various ligand-to-metal concentration ratios and pH's were analyzed (after matrix rank analysis by the method of residual intensities as a complementary method) by the two-dimensional computer simulation method, which simultaneously determines the formation constants and the EPR parameters of the various (micro)species. L1 forms mono and bis complexes in different protonation states; for the other ligands, the mono complexes are always prevalent. For steric reasons, the formation of CuL is shifted to increasingly higher pH regions in the sequence L2, L3 and L4. CuLH was identified for L3, L4 and L5, and also CuLH2 for L4 and L5. Cu2L2 was found in small amounts for L3 and L4, while it predominates at pH > 4 for L5. For L5, Cu2L2H2 was also detected. For the ligands that form dimeric metal complexes in equimolar solution or at a ligand excess, Cu2L is formed at a metal ion excess. Ligation of the phosphinate O was suggested by indirect proofs in the protonated complexes of L1. For the ligands L2, L3 and L4, the copper(II) coordination in various species in different protonation states is reminiscent of that in the mono and bis complexes of simple amino acids. For the bis(aminomethyl)phosphinates, however, the cis positions of the amino groups in CuL are ensured by the structure of the ligand, and the isomers differ from each other in the (equatorial or axial) position of the second carboxylate group.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Electron paramagnetic resonance
Copper(II) complexes
N-Substituted bis(aminomethyl)phosphinic acids
Microspeciation
Coordination modes
Megjelenés:Journal of Inorganic Biochemistry 98 : 11 (2004), p. 1655-1666. -
További szerzők:Szabó-Plánka Terézia Tircsó Gyula (1977-) (vegyész, kémia tanár) Király Róbert Árkosi Zsuzsanna Rockenbauer, Antal Brücher Ernő (1935-) (vegyész)
Pályázati támogatás:T-032929
OTKA
T-038364
OTKA
T-046953
OTKA
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4.

001-es BibID:BIBFORM106875
035-os BibID:(cikkazonosító)112124 (Scopus)85146456835
Első szerző:Póta Kristóf
Cím:Synthesis and characterization of two piperazine containing macrocycles and their transition metal complexes / Kristof Pota, Hannah M. Johnston, Enikő Madarasi, Gyula Tircsó, Kayla N. Green
Dátum:2023
ISSN:0162-0134 1873-3344
Megjegyzések:Rigidification of the ligand scaffolds has been a particular mechanism of interest employed to achieve properties suitable for MRI contrast, catalysis, or other applications of metal complexes. Towards the goal of targeting a 15-anePyN5Pip type ligand, a serendipitous isolation of a 30-anePy2N10Pip2 aza-macrocycle was achieved, instead. X-ray diffraction and determination of pKa events were carried out and compared to 17-anePyN5Pip. Furthermore, the X-ray diffraction of the Cu(II) and Zn(II) complexes of 17-anePyN5Pip was achieved and compared to previous reports of other first-row transition metal derivatives of this ligand. Determination of the log beta with both 30-anePy2N10Pip2 and 17-anePyN5Pip with the divalent Mnsingle bondZn metal-ion series was used to demonstrate the impact that the piperazine ring plays compared to other, less rigid macrocycles reported to date.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Piperazine
Macrocycle
Manganese
Log B
Pyridinophane
Megjelenés:Journal of Inorganic Biochemistry. - 241 (2023), p. 112124-. -
További szerzők:Johnston, Hannah M. Madarasi Enikő Tircsó Gyula (1977-) (vegyész, kémia tanár) Green, Kayla N.
Pályázati támogatás:K-134694
OTKA
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5.

001-es BibID:BIBFORM076234
035-os BibID:(WoS)000419812400002 (Scopus)85029510871
Első szerző:Prata, Maria I. M.
Cím:Gallium(III) chelates of mixed phosphonate-carboxylate triazamacrocyclic ligands relevant to nuclear medicine: Structural, stability and in vivo studies / Maria I. M. Prata, João P. André, Zoltán Kovács, Anett I. Takács, Gyula Tircsó, Imre Tóth, Carlos F. G. C. Geraldes
Dátum:2017
ISSN:0162-0134
Megjegyzések:Three triaza macrocyclic ligands, H6NOTP (1,4,7-triazacyclononane-N,N·,Nı-trimethylene phosphonic acid), H4NO2AP (1,4,7-triazacyclononane-N-methylenephosphonic acid-N·,Nı-dimethylenecarboxylic acid), and H5NOA2P (1,4,7-triazacyclononane-N,N·-bis(methylenephosphonic acid)-Nı-methylene carboxylic acid), and their gallium(III) chelates were studied in view of their potential interest as scintigraphic and PET (Positron Emission Tomography) imaging agents. A 1H, 31P and 71Ga multinuclear NMR study gave an insight on the structure, internal dynamics and stability of the chelates in aqueous solution. In particular, the analysis of 71Ga NMR spectra gave information on the symmetry of the Ga3+ coordination sphere and the stability of the chelates towards hydrolysis. The 31P NMR spectra afforded information on the protonation of the non-coordinated oxygen atoms from the pendant phosphonate groups and on the number of species in solution. The 1H NMR spectra allowed the analysis of the structure and the number of species in solution. 31P and 1H NMR titrations combined with potentiometry afforded the measurement of the protonation constants (log KHi) and the microscopic protonation scheme of the triaza macrocyclic ligands. The remarkably high thermodynamic stability constant (log KGaL =34.44 (0.04) and stepwise protonation constants of Ga (NOA2P)2? were determined by potentiometry and 69Ga and 31P NMR titrations. Biodistribution and gamma imaging studies have been performed on Wistar rats using the radiolabeled 67Ga(NO2AP)? and 67Ga (NOA2P)2?chelates, having both demonstrated to have renal excretion. The correlation of the molecular properties of the chelates with their pharmacokinetic properties has been analysed.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
NMR
Triaza Phosphinates
Gamma imaging
PET
Gallium
Megjelenés:Journal Of Inorganic Biochemistry. - 177 (2017), p. 8-16. -
További szerzők:André, João P. Kovács Zoltán Takács Anett Ildikó (1983-) (vegyész) Tircsó Gyula (1977-) (vegyész, kémia tanár) Tóth Imre (1950-) (vegyész) Geraldes, Carlos Frederico de Gusmão Campos
Pályázati támogatás:OTKA-109029
OTKA
OTKA K-120224
OTKA
Bolyai János Kutatási Ösztöndíj
Egyéb
GINOP-2.3.2-15-2016-00008
GINOP
COST Action TD1004
Egyéb
Internet cím:DOI
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6.

001-es BibID:BIBFORM103942
035-os BibID:(WOS)000528630900017 (Scopus)85080905990
Első szerző:Tircsó Gyula (vegyész, kémia tanár)
Cím:Comparison of the equilibrium, kinetic and water exchange properties of some metal ion-DOTA and DOTA-bis(amide) complexes / Gyula Tircsó, Enikő Tircsóné Benyó, Zoltán Garda, Jaspal Singh, Robert Trokowski, Ernő Brücher, A. Dean Sherry, Éva Tóth, Zoltán Kovács
Dátum:2020
ISSN:0162-0134 1873-3344
Megjegyzések:The 1,7-diacetate-4,10-diacetamide substituted 1,4,7,10-tetraazacyclododecane structural unit is common to several responsive Magnetic Resonance Imaging (MRI) contrast agents (CAs). While some of these complexes (agents capable of sensing fluctuations in Zn2+, Ca2+ etc. ions) have already been tested in vivo, the detailed physico-chemical characterization of such ligands have not been fully studied. To fill this gap, we synthesized a representative member of this ligand family possessing two acetate and two n-butylacetamide pendant side-arms (DO2A2M(nBu) = 1,4,7,10-tetraazacyclodoecane-1,7-di(acetic acid)-4,10-di(N-butylacetamide)), and studied its complexation properties with some essential metal and a few lanthanide(III) (Ln(III)) ions. Our studies revealed that the ligand basicity, the stability of metal ion complexes, the trend of stability constants along the Ln(III) series, the formation rates of the Ln(III) complexes and the exchange rate of the bound water molecule in the Gd (III) complex fell between those of Ln(DOTA) - and Ln(DOTA-tetra(amide))(3+) complexes (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, DOTAM = 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane). The only exception is the stability of Cu(DO2A2M(nBu)) which was found to be only slightly lower than that of Cu(DOTA)(2-) (log K-CuL = 19.85 vs. 21.98). This is likely reflects exclusive coordination of the negatively charged acetate donor atoms to the Cu2+ ion forming an octahedral complex with the amides remaining uncoordinated. The only anomaly observed during the study was the rates of acid assisted dissociation of the Ln(III) complexes, which occur at a rate similar to those observed for the Ln(DOTA)(-) complexes. These data indicate that even though the Ln(DO2A2M(nBu))(+) complexes have lower thermodynamic stabilities, their kinetic inertness should be sufficient for in vivo use.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény hazai lapban
folyóiratcikk
Coordination chemistry
Complexes
Physico-chemical parameters
Synthesis
Stability
Inertness
Water exchange rate
Megjelenés:Journal of Inorganic Biochemistry. - 206 (2020), p. 1-12. -
További szerzők:Tircsóné Benyó Enikő (1977-) (vegyész, kémia tanár) Garda Zoltán (1989-) (vegyész) Singh, Jaspal Trokowski, Robert Brücher Ernő (1935-) (vegyész) Sherry, A. Dean Tóth Éva Kovács Zoltán
Pályázati támogatás:NKFIH-K-120224
Egyéb
NKFIH-128201
Egyéb
GINOP-2.3.2-15-2016-00008
GINOP
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7.

001-es BibID:BIBFORM047601
035-os BibID:PMID:23850669
Első szerző:Tircsó Gyula (vegyész, kémia tanár)
Cím:Lanthanide(III) complexes of some natural siderophores : a thermodynamic, kinetic and relaxometric study / Gyula Tircsó, Zoltán Garda, Ferenc K. Kálmán, Zsolt Baranyai, István Pócsi, György Balla, Imre Tóth
Dátum:2013
ISSN:0162-0134
Megjegyzések:Stability constants of the complexes formed between the natural trihydroxamic acids desferrioxamine B (DFB) and desferricoprogen (DFC) with NdIII, GdIII and YbIII ions were determined using pH-potentiometry. The equilibrium in these systems can be described by models containing mononuclear protonated (Ln(HL), Ln(H2L) and Ln(H3L)), deprotonated (LnL) and ternary hydroxo Ln(H-1L) complexes, but for both ligands dinuclear complexes of low stability were also detected. The stability constants for the Ln(HDFB)+ complexes are 11.95 (NdIII), 13.16 (GdIII) and 14.67 (YbIII), while these values of the Ln(DFC) complexes are considerably higher (14.42 (NdIII), 15.14 (GdIII) and 16.49 (YbIII)). The stability constants of the complexes of DFB and DFC are much lower than those of the Ln(L)3 complexes formed with some aromatic hydroxamic acids indicating that the relatively long spacer between the hydroxamic acid moieties in DFB and DFC is unfavorable for LnIII complexation. The relaxometric study conducted for the Gd(HDFB)+ species revealed an interesting pH dependence of the relaxivity associated with a large hydration number (bishydrated complex) and fast water exchange (kex=(29.9±0.4)x106s-1), which would be favorable for CA use. However the dissociation of Gd(HDFB)+ is fairly fast (<2ms) under all conditions employed in the present work thus the kinetically labile Gd(HDFB)+ is not suitable for in vivo CA applications. Some low stability ternary complexes were also detected with K(Gd(HDFB)(HCO3))=17.5±1.9 and K(Gd(HDFB)(Lactate))=8.4±3.2 but in the presence of citrate and phosphate ions the Gd(HDFB)+ complex was found to dissociate.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Equilibrium
Kinetic inertness
Ln(III) complexes
Natural siderophores
Relaxivity
Water exchange rate
Megjelenés:Journal of Inorganic Biochemistry. - 127 (2013), p. 53-61. -
További szerzők:Garda Zoltán (1989-) (vegyész) Kálmán Ferenc K. (1978-) (vegyész) Baranyai Zsolt (1977-) (vegyész) Pócsi István (1961-) (vegyész) Balla György (1953-) (csecsemő és gyermekgyógyász, neonatológus) Tóth Imre (1950-) (vegyész)
Pályázati támogatás:TÁMOP-4.2.2.A-11/1/KONV-2012-0045
TÁMOP
Gyermekgyógyászat Kutatócsoport
OTKA-K75883
OTKA
MTA-DE
MTA-DE Vascularis Biológia, Thrombosis- Haemostasis Kutatócsoport 11003
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