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001-es BibID:	BIBFORM018844
Első szerző:	Aime, Silvio
Cím:	Properties, Solution State Behavior, and Crystal Structures of Chelates of DOTMA / Silvio Aime, Mauro Botta, Zoltán Garda, Benjamin E. Kucera, Gyula Tircso, Victor G. Young, Mark Woods
Dátum:	2011
ISSN:	0020-1669
Megjegyzések:	The chemistry of polyamino carboxylates and their use as ligands for Ln3+ ions is of considerable interest from the point of view of the development of new imaging agents. Of particular interest is the chemistry of the macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and its derivatives. Herein we report that the tetramethylated DOTA derivative, DOTMA, possess several properties that, from an imaging agent development point of view, are more advantageous than those of the parent DOTA. In particular, the Ln3+ chelates of DOTMA exhibit a marked preference for the monocapped twisted square antiprismatic coordination isomer which imparts more rapid water exchange kinetics on the chelates; ?M298 was determined to be 85 ns for GdDOTMA. Differential analysis of the 17O R2? temperature profiles of both GdDOTA and GdDOTMA afforded the ?M298 values for the square (SAP) and twisted square antiprismatic (TSAP) isomers of each chelate that were almost identical: 365 ns (SAP) and 52 ns (TSAP). The origin of this accelerated water exchange in the TSAP isomer appears to be the slightly longer Gd?OH2 bond distance (2.50 Å) that is observed in the crystal structure of GdDOTMA which crystallizes in the P2 space group as a TSAP isomer. The Ln3+ chelates of DOTMA also exhibit high thermodynamic stabilities ranging from log KML = 20.5 for CeDOTMA, 23.5 for EuDOTMA and YbDOTMA comparable to, but a shade lower than, those of DOTA.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Inorganic Chemistry. - 50 : 17 (2011), p. 7955-7965. -
További szerzők:	Botta, Mauro Garda Zoltán (1989-) (vegyész) Kucera, Benjamin E. Tircsó Gyula (1977-) (vegyész, kémia tanár) Young, Victor G. Woods, Mark
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM038094
Első szerző:	Rojas-Quijano, Federico A.
Cím:	Synthesis and Characterization of a Hypoxia-Sensitive MRI Probe / Federico A. Rojas-Quijano, Gyula Tircsó, Enikő Tircsóné Benyó, Zsolt Baranyai, Huan Tran Hoang, Ferenc K. Kálmán, Praveen K. Gulaka, Vikram D. Kodibagkar, Silvio Aime, Zoltán Kovács, A. Dean Sherry
Dátum:	2012
ISSN:	0947-6539
Megjegyzések:	Tissue hypoxia occurs in pathologic conditions, such as cancer, ischemic heart disease and stroke when oxygen demand is greater than oxygen supply. An imaging method that can differentiate hypoxic versus normoxic tissue could have an immediate impact on therapy choices. In this work, the gadolinium complex of 1,4,7,10-tetraaza-1,4,7,10-tetraacetate (DOTA) with a 2-nitroimidazole attached to one carboxyl group via an amide linkage was prepared, characterized and tested as a hypoxia-sensitive MRI agent. A control complex, Gd(DO3A-monobutylamide), was also prepared in order to test whether the nitroimidazole sidechain alters either the water proton T1 relaxivity or the thermodynamic stability of the complex. The stabilities of these complexes were lower than thatof Gd(DOTA)- as expected for monoamide derivatives. The water proton T1 relaxivity (r1), bound water residence lifetime (tM) and rotational correlation time (tR) of both complexes was determined by relaxivity measurements, variable temperature 17O NMR spectroscopy and proton nuclear magnetic relaxation dispersion (NMRD) studies. The resulting parameters (r1=6.38 mM-1 s-1 at 20 MHz, tM=0.71 ms, tR=141 ps) determined for the nitroimidazole derivative closely parallel those of other Gd(DO3A-monoamide) complexes of similar molecular size. In vitro MR imaging experiments with 9L rat glioma cells maintained under nitrogen (hypoxic) versus oxygen (normoxic) gas showed that both agents enter cells but only the nitroimidazole derivative was trapped in cells maintained under N2 as evidenced by an approximately twofold decrease in T1 measured for hypoxic cells versus normoxic cells exposed to this agent. These results suggest that the nitroimidazole derivative might serve as a molecular reporter for discriminating hypoxic versus normoxic tissues by MRI.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban Molekulatudomány
Megjelenés:	Chemistry-A European Journal. - 18 : 31 (2012), p. 9669-9676. -
További szerzők:	Tircsó Gyula (1977-) (vegyész, kémia tanár) Tircsóné Benyó Enikő (1977-) (vegyész, kémia tanár) Baranyai Zsolt (1977-) (vegyész) Tran-Hoang, Huan Kálmán Ferenc K. (1978-) (vegyész) Gulaka, Praveen K. Kodibagkar, Vikram D. Aime, Silvio Kovács Zoltán (1963-) (vegyész, angol szakfordító) Sherry, A. Dean
Pályázati támogatás:	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 K84291 OTKA PD83253 OTKA
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001-es BibID:	BIBFORM010537
Első szerző:	Rojas-Quijano, Federico A.
Cím:	Lanthanide(III) Complexes of Tris(amide) PCTA Derivatives as Potential Bimodal Magnetic Resonance and Optical Imaging Agents / Federico A. Rojas-Quijano, Enikő Tircsóné Benyó, Gyula Tircsó, Ferenc K. Kálmán, Zsolt Baranyai, Silvio Aime, A. Dean Sherry, Zoltán Kovács
Dátum:	2009
ISSN:	0947-6539
Megjegyzések:	Lanthanide complexes of two tris(amide) derivatives of PCTA were synthesized and characterized. The relaxometric and luminescence properties of their lanthanide complexes were investigated as bimodal magnetic resonance (MR) and optical imaging agents. Luminescence studies show that one of the Tb-III complexes dimerizes in solution at low millimolar concentrations, whereas the other may have a higher than expected coordination number in solution. The corresponding Gd-III complexes display unusually high T-1 relaxivities and enhanced kinetic inertness compared to GdPCTA. These features suggest that these new chelates may be suitable for in vivo applications. The fast water-exchange rates observed for these complexes make them unsuitable as paramagnetic chemical exchange saturation transfer (PAR-ACEST) agents.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Chemistry-a European Journal. - 15 : 47 (2009), p. 13188-13200. -
További szerzők:	Tircsóné Benyó Enikő (1977-) (vegyész, kémia tanár) Tircsó Gyula (1977-) (vegyész, kémia tanár) Kálmán Ferenc K. (1978-) (vegyész) Baranyai Zsolt (1977-) (vegyész) Aime, Silvio Sherry, A. Dean Kovács Zoltán
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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