Expanding the Family of Monosubstituted 15-Membered Pyridine-Based Macrocyclic Ligands for Mn(II) Complexation in the Context of MRI

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F25%3A73633968" target="_blank" >RIV/61989592:15310/25:73633968 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.acs.org/doi/10.1021/acs.inorgchem.5c00452" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.inorgchem.5c00452</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.inorgchem.5c00452" target="_blank" >10.1021/acs.inorgchem.5c00452</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Expanding the Family of Monosubstituted 15-Membered Pyridine-Based Macrocyclic Ligands for Mn(II) Complexation in the Context of MRI

Popis výsledku v původním jazyce

As Mn(II) complexes attract continuous interest as alternatives to Gd-based contrast agents (CAs) in clinical magnetic resonance imaging (MRI), we synthesized two monosubstituted derivatives of the 15-membered pyridine-based macrocycle 15-pyN3O2 bearing either a 2-pyridylmethyl (L2) or a 2-benzimidazolylmethyl pendant arm (L3) and characterized their Mn(II) complexes MnL2 and MnL3 in the context of MRI contrast agent development. Their X-ray molecular structures confirmed a coordination number of seven and a pentagonal bipyramidal geometry with one coordination site available for inner-sphere water. Protonation constants of L2 and L3, and stability constants with selected divalent metal ions were determined using potentiometry. MnL2 and MnL3 complexes are fully formed at pH 7.4; however, they both display low kinetic inertness due to a significant spontaneous dissociation of the nonprotonated complex. The presence of one inner-sphere water molecule in the Mn(II) complexes was confirmed by 17O NMR and 1H NMRD measurements. The water exchange rate constants are very low (k ex 298 = 0.46 x 107 and 0.23 x 107 s-1 for MnL2 and MnL3, respectively), but typical for Mn(II) complexes of 15-pyN3O2 derivatives. The relaxivities are in good agreement with monohydrated small-molecular-weight Mn(II) chelates (r 1 = 2.49 and 2.77 mM-1 s-1 at 20 MHz, 25 degrees C, for MnL2 and MnL3, respectively).

Název v anglickém jazyce

Expanding the Family of Monosubstituted 15-Membered Pyridine-Based Macrocyclic Ligands for Mn(II) Complexation in the Context of MRI

Popis výsledku anglicky

As Mn(II) complexes attract continuous interest as alternatives to Gd-based contrast agents (CAs) in clinical magnetic resonance imaging (MRI), we synthesized two monosubstituted derivatives of the 15-membered pyridine-based macrocycle 15-pyN3O2 bearing either a 2-pyridylmethyl (L2) or a 2-benzimidazolylmethyl pendant arm (L3) and characterized their Mn(II) complexes MnL2 and MnL3 in the context of MRI contrast agent development. Their X-ray molecular structures confirmed a coordination number of seven and a pentagonal bipyramidal geometry with one coordination site available for inner-sphere water. Protonation constants of L2 and L3, and stability constants with selected divalent metal ions were determined using potentiometry. MnL2 and MnL3 complexes are fully formed at pH 7.4; however, they both display low kinetic inertness due to a significant spontaneous dissociation of the nonprotonated complex. The presence of one inner-sphere water molecule in the Mn(II) complexes was confirmed by 17O NMR and 1H NMRD measurements. The water exchange rate constants are very low (k ex 298 = 0.46 x 107 and 0.23 x 107 s-1 for MnL2 and MnL3, respectively), but typical for Mn(II) complexes of 15-pyN3O2 derivatives. The relaxivities are in good agreement with monohydrated small-molecular-weight Mn(II) chelates (r 1 = 2.49 and 2.77 mM-1 s-1 at 20 MHz, 25 degrees C, for MnL2 and MnL3, respectively).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

<a href="/cs/project/EF18_053%2F0016919" target="_blank" >EF18_053/0016919: Podpora mobility na UP II.</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

INORGANIC CHEMISTRY

ISSN

0020-1669

e-ISSN

1520-510X

Svazek periodika

64

Číslo periodika v rámci svazku

16

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

17

Strana od-do

8205-8221

Kód UT WoS článku

001469596800001

EID výsledku v databázi Scopus

2-s2.0-105003772636