ArticleInorganic chemistry2013
Is macrocycle a synonym for kinetic inertness in Gd(III) Complexes? Effect of coordinating and noncoordinating substituents on inertness and relaxivity of Gd(III) chelates with DO3A-like ligands.
Article in Inorganic chemistry, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
15 citing papers in PubMed.
- Macrocyclic Chelators for Aqueous Lanthanide Separations via Precipitation: Toward Sustainable Recycling of Rare-Earths from NdFeB Magnets.Journal of the American Chemical Society · 2025Article
- pH-responsive i-motif-conjugated nanoparticles for MRI analysis.Sensors & diagnostics · 2024Article
- A DNA-Based MRI Contrast Agent for Quantitative pH Measurement.ACS sensors · 2021Article
- Coordination Behavior of 1,4-Disubstituted Cyclen Endowed with Phosphonate, Phosphonate Monoethylester, and H-Phosphinate Pendant Arms.Molecules (Basel, Switzerland) · 2019Article
- Chemistry of MRI Contrast Agents: Current Challenges and New Frontiers.Chemical reviews · 2019Review
- Removal of gadolinium-based contrast agents: adsorption on activated carbon.Environmental science and pollution research international · 2017Article
- Amplifying the sensitivity of zinc(II) responsive MRI contrast agents by altering water exchange rates.Journal of the American Chemical Society · 2015Article
- MR imaging probes: design and applications.Dalton transactions (Cambridge, England : 2003) · 2015Review
- Probing the structure-relaxivity relationship of bis-hydrated Gd(DOTAla) derivatives.Inorganic chemistry · 2015Article
- Rapid synthesis of 1,7-bis(Tetrahedron letters · 2014Article
- Enhancing magnetic resonance imaging with contrast agents for ultra-high field strengths.The Analyst · 2014Review
- Gd(DOTAlaP): exploring the boundaries of fast water exchange in gadolinium-based magnetic resonance imaging contrast agents.Inorganic chemistry · 2014Article
- Lanthanide(III) complexes of rhodamine-DO3A conjugates as agents for dual-modal imaging.Inorganic chemistry · 2013Article
- [Gd(CyPic3A)(H2O)2]-: a stable, bis(aquated) and high-relaxivity Gd(III) complex.Chemical communications (Cambridge, England) · 2013Article
- Strategies for optimizing water-exchange rates of lanthanide-based contrast agents for magnetic resonance imaging.Molecules (Basel, Switzerland) · 2013Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
Abstract
Gadolinium chelates with octadentate ligands are widely used as contrast agents for magnetic resonance imaging (MRI), with macrocyclic ligands based on DO3A being preferred for the high kinetic inertness of their Gd chelates. A major challenge in the design of new bifunctional MRI probes is the need to control the rotational motion of the chelate, which greatly affects its relaxivity. In this work we explored facile alkylation of a secondary amine in macrocyclic DO3A-like ligands to create a short, achiral linkage to limit the undesired internal motion of chelates within larger molecular constructs. The acetate moiety on the trans nitrogen was also replaced with either a bidentate (ethoxyacetate, L1 or methyl picolinate, L2) or bulky monodentate (methyl phosphonate, L3) donor arm to give octa- or heptadentate ligands, respectively. The resultant Gd(III) complexes were all monohydrated (q = 1) and exhibited water residency times that spanned 2 orders of magnitude (τM = 2190 ± 170, 3500 ± 90, and 12.7 ± 3.8 ns at 37 °C for GdL1, GdL2, and GdL3, respectively). Alkylation of the secondary amine with a noncoordinating biphenyl moiety resulted in coordinatively saturated q = 0 complexes of octadentate ligands L1 and L2. Relaxivities were limited by slow water exchange and/or lack of water coligand. All complexes showed decreased inertness compared to [Gd(DO3A)] despite higher ligand denticity, and inertness was further decreased upon N-alkylation. These results demonstrate that high kinetic inertness and in vivo safety of Gd chelates with macrocyclic ligands should not be generalized.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.