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Description
| - The kinetics of transmetallation of [Mn(nota)](-) and [Mn(dota)](2-) was investigated in the presence of Zn(2+) (5-50-fold excess) at variable pH (3.5-5.6) by (1)H relaxometry. The dissociation is much faster for [Mn(nota)](-) than for [Mn(dota)](2-) under both experimental and physiologically relevant conditions (t(1/2) = 74 h and 1037 h for [Mn(nota)](-) and [Mn(dota)](2-), respectively, at pH 7.4, c(Zn(2+)) = 10(-5) M, 25 degrees C). The dissociation of the complexes proceeds mainly via spontaneous ([Mn(nota)](-) k(0) = (2.6 +/- 0.5) x 10 (6) s (1); [Mn(dota)](2) k(0) = (1.8 +/- 0.6) x 10 (7) s (1)) and proton-assisted pathways ([Mn(nota)] k(1) = (7.8 +/- 0.1) x 10(-1) M(-1) s(-1); [Mn(dota)](2-) k(1) = (4.0 +/- 0.6) 10(-2) M(-1) s(-1), k(2) = (1.6 +/- 0.1) 10(3) M(-2) s(-1)). The observed suppression of the reaction rates with increasing Zn(2+) concentration is explained by the formation of a dinuclear Mn(2+)-L-Zn(2+) complex which is about 20-times more stable for [Mn(dota)](2-) than for [Mn(nota)](-) (K(MnLZn) = 68 and 3.6, respectively), and which dissociates very slowly (k(3) similar to 10(-5) M(-1) s(-1)). These data provide the first experimental proof that not all Mn(2+) complexes are kinetically labile. The absence of coordinated water makes both [Mn(nota)](-) and [Mn(dota)](2-) complexes inefficient for MRI applications. Nevertheless, the higher kinetic inertness of [Mn(dota)](2-) indicates a promising direction in designing ligands for Mn(2+) complexation.
- The kinetics of transmetallation of [Mn(nota)](-) and [Mn(dota)](2-) was investigated in the presence of Zn(2+) (5-50-fold excess) at variable pH (3.5-5.6) by (1)H relaxometry. The dissociation is much faster for [Mn(nota)](-) than for [Mn(dota)](2-) under both experimental and physiologically relevant conditions (t(1/2) = 74 h and 1037 h for [Mn(nota)](-) and [Mn(dota)](2-), respectively, at pH 7.4, c(Zn(2+)) = 10(-5) M, 25 degrees C). The dissociation of the complexes proceeds mainly via spontaneous ([Mn(nota)](-) k(0) = (2.6 +/- 0.5) x 10 (6) s (1); [Mn(dota)](2) k(0) = (1.8 +/- 0.6) x 10 (7) s (1)) and proton-assisted pathways ([Mn(nota)] k(1) = (7.8 +/- 0.1) x 10(-1) M(-1) s(-1); [Mn(dota)](2-) k(1) = (4.0 +/- 0.6) 10(-2) M(-1) s(-1), k(2) = (1.6 +/- 0.1) 10(3) M(-2) s(-1)). The observed suppression of the reaction rates with increasing Zn(2+) concentration is explained by the formation of a dinuclear Mn(2+)-L-Zn(2+) complex which is about 20-times more stable for [Mn(dota)](2-) than for [Mn(nota)](-) (K(MnLZn) = 68 and 3.6, respectively), and which dissociates very slowly (k(3) similar to 10(-5) M(-1) s(-1)). These data provide the first experimental proof that not all Mn(2+) complexes are kinetically labile. The absence of coordinated water makes both [Mn(nota)](-) and [Mn(dota)](2-) complexes inefficient for MRI applications. Nevertheless, the higher kinetic inertness of [Mn(dota)](2-) indicates a promising direction in designing ligands for Mn(2+) complexation. (en)
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Title
| - Dissociation kinetics of Mn(2+) complexes of NOTA and DOTA
- Dissociation kinetics of Mn(2+) complexes of NOTA and DOTA (en)
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skos:prefLabel
| - Dissociation kinetics of Mn(2+) complexes of NOTA and DOTA
- Dissociation kinetics of Mn(2+) complexes of NOTA and DOTA (en)
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skos:notation
| - RIV/00216208:11310/11:10105355!RIV12-GA0-11310___
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http://linked.open...avai/predkladatel
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http://linked.open...avai/riv/aktivita
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http://linked.open...avai/riv/aktivity
| - P(GAP207/11/1437), P(KAN201110651), P(OC 179), S, Z(MSM0021620857)
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http://linked.open...iv/cisloPeriodika
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http://linked.open...vai/riv/dodaniDat
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http://linked.open...aciTvurceVysledku
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http://linked.open.../riv/druhVysledku
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http://linked.open...iv/duvernostUdaju
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http://linked.open...titaPredkladatele
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http://linked.open...dnocenehoVysledku
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http://linked.open...ai/riv/idVysledku
| - RIV/00216208:11310/11:10105355
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http://linked.open...riv/jazykVysledku
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http://linked.open.../riv/klicovaSlova
| - metal; stability; resonance; pendant-arm; macrocyclic ligands; manganese(II) complexes; gadolinium(III) complexes; lanthanide(III) complexes; MRI contrast agents (en)
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http://linked.open.../riv/klicoveSlovo
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http://linked.open...odStatuVydavatele
| - GB - Spojené království Velké Británie a Severního Irska
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http://linked.open...ontrolniKodProRIV
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http://linked.open...i/riv/nazevZdroje
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http://linked.open...in/vavai/riv/obor
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http://linked.open...ichTvurcuVysledku
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http://linked.open...cetTvurcuVysledku
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http://linked.open...vavai/riv/projekt
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http://linked.open...UplatneniVysledku
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http://linked.open...v/svazekPeriodika
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http://linked.open...iv/tvurceVysledku
| - Hermann, Petr
- Kubíček, Vojtěch
- Lukeš, Ivan
- Bonnet, Celia S.
- Drahoš, Bohuslav
- Tóth, Éva
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http://linked.open...ain/vavai/riv/wos
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http://linked.open...n/vavai/riv/zamer
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issn
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number of pages
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http://bibframe.org/vocab/doi
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http://localhost/t...ganizacniJednotka
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is http://linked.open...avai/riv/vysledek
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