The Synthesis and Screening of Nonionic Gadolinium (III) DTPA-Bisamide Complexes as Magnetic Resonance Imaging Contrast Agents

Periasamy, M.; White, David; deLearie, Lynn; Moore, Dennis A.; Wallace, Rebecca; Lin, Wei-Ming; Dunn, Jeff F.; Hirth, Walter; Cacheris, William P.; Pilcher, Gary D.; Galen, Karen P.; Hynes, Michael R.; Bosworth, Mark E; Lin, Huawen; Adams, Max

doi:10.1097/00004424-199111001-00074

Cited by 19 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Periasamy et al replaced two carboxylate pendant arms of DTPA with amide functionality. 23 The study sought effective structural alternatives for DTPA as MRI contrast agents. The authors demonstrated that mono-substituted amides of DTPA increased physiological toxicity, presumably due to enhanced rate of Gd 3+ exchange by calcium ions inside the body.…”

Section: Introductionsupporting

confidence: 78%

See 1 more Smart Citation

Thermodynamic and Spectroscopic Studies of Trivalentf-element Complexation with Ethylenediamine-N,N′-di(acetylglycine)-N,N′-diacetic Acid

2016

View full text Add to dashboard Cite

The coordination behavior and thermodynamic features of complexation of trivalent lanthanides and americium by ethylenediamine-N,N'-di(acetylglycine)-N,N'-diacetic acid (EDDAG-DA) (bisamide-substituted-EDTA) were investigated by potentiometric and spectroscopic techniques. Acid dissociation constants (K(a)) and complexation constants (β) of lanthanides (except Pm) were determined by potentiometric analysis. Absorption spectroscopy was used to determine stability constants for the binding of trivalent americium and neodymium by EDDAG-DA under similar conditions. The potentiometry revealed 5 discernible protonation constants and 3 distinct metal-ligand complexes (identified as ML(-), MHL, and MH2L(+)). Time-resolved fluorescence studies of Eu-(EDDAG-DA) solutions (at varying pH) identified a constant inner-sphere hydration number of 3, suggesting that glycine functionalities contained in the amide pendant arms are not involved in metal complexation and are protonated under more acidic conditions. The thermodynamic studies identified that f-element coordination by EDDAG-DA is similar to that observed for ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA). However, coordination via two amidic oxygens of EDDAG-DA lowers its trivalent f-element complex stability by roughly 3 orders of magnitude relative to EDTA.

show abstract

Section: Introductionsupporting

confidence: 78%

“…Periasamy et al replaced two carboxylate pendant arms of DTPA with amide functionality . The study sought effective structural alternatives for DTPA as MRI contrast agents.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic and Spectroscopic Studies of Trivalentf-element Complexation with Ethylenediamine-N,N′-di(acetylglycine)-N,N′-diacetic Acid

2016

View full text Add to dashboard Cite

show abstract

“…Wang et al discussed this decrease in the complex stability in terms of the overall weakening of the Lewis base donor capacity of the amide groups, coupled with the lower basicity of the terminal amines . The overall 10 6 -fold decrease in the stability of the complexes observed here for DTTA-DAG throughout the lanthanide series has been consistently observed for different diamide-substituted reagents. ,,− …”

Section: Discussionmentioning

confidence: 52%

Coordination Chemistry and f-Element Complexation by Diethylenetriamine-N,N″-bis(acetylglycine)-N,N′,N″-triacetic Acid

2016

View full text Add to dashboard Cite

Potentiometric and spectroscopic techniques were used to evaluate the coordination behavior and thermodynamic features of trivalent f-element complexation by diethylenetriamine-N,N″-bis(acetylglycine)-N,N',N″-triacetic acid (DTTA-DAG) and its di(acetylglycine ethyl ester) analogue [diethylenetriamine-N,N″-bis(acetylglycine ethyl ester)-N,N',N″-triacetic acid (DTTA-DAGEE)]. Protonation constants and stability constants of trivalent lanthanide complexes (except Pm) were determined by potentiometry. Six protonation sites and three metal-ligand complexes [ML, MHL, and MHL(aq)] were quantified for DTTA-DAG. Four protonation sites and one metal-ligand complex [ML(aq)] were observed for DTTA-DAGEE, consistent with the presence of two ester groups. Absorption spectroscopy was utilized to measure the stability constants for complexation of trivalent neodymium and americium by DTTA-DAG and trivalent neodymium by DTTA-DAGEE. The coordination environment of trivalent europium in the presence of DTTA-DAG was investigated at various acidities by luminescence lifetime measurements. Decay constants indicate one water molecule in the inner coordination sphere across the 1.0 < pH < 5.5 range, presumably due to octadentate coordination by DTTA-DAG. A trans-lanthanide pattern of complex stabilities for DTTA-DAG was found to be analogous to that observed for DTPA, with a ∼10 reduction of the complex stability. The lessened strength of complexation, relative to DTPA, was attributed to significant reduction of the total ligand basicity for DTTA-DAG due to the electronic influence of amide functionalization. When DTTA-DAG is used as an aqueous holdback complexant in liquid-liquid distribution experiments, the preferential coordination of Am in the aqueous environment offers efficient An/Ln differentiation. The separation extends to pH 2 conditions, where the kinetics of phase transfer in such liquid-liquid systems are aided by the acid-catalyzed dissociation of a metal/aminopolycarboxylate complex.

show abstract

“…As noted in the previous section, electronic relaxation can influence low field (<1 MHz) relaxivities; however, the similarity in relaxivity at 20 MHz for [Gd(DOTA)(H 2 O)] - , [Gd(DTPA)(H 2 O)] 2- , and [Gd(DTPA-BMA)(H 2 O)] can be attributed to the similar rotational correlation times of the three complexes. In Tables and , relaxivities are collected for a variety of gadolinium(III) chelates. ,,− ,,,,,,,,,,,,,,,,− ,,,− Tweedle and co-workers have shown that relaxivity per gadolinium(III) correlates well with molecular weight for a series of monomeric and multimeric gadolinium(III) chelates (Charts −19) and this is shown in Figure (data in Table ). For spheroidal molecules, increases in relaxivity increase approximately with increasing molecular weight.…”

Section: Relaxivitymentioning

confidence: 97%

Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications

et al. 1999

View full text Add to dashboard Cite

show abstract

The Synthesis and Screening of Nonionic Gadolinium (III) DTPA-Bisamide Complexes as Magnetic Resonance Imaging Contrast Agents

Cited by 19 publications

References 0 publications

Thermodynamic and Spectroscopic Studies of Trivalentf-element Complexation with Ethylenediamine-N,N′-di(acetylglycine)-N,N′-diacetic Acid

Thermodynamic and Spectroscopic Studies of Trivalentf-element Complexation with Ethylenediamine-N,N′-di(acetylglycine)-N,N′-diacetic Acid

Coordination Chemistry and f-Element Complexation by Diethylenetriamine-N,N″-bis(acetylglycine)-N,N′,N″-triacetic Acid

Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications

Contact Info

Product

Resources

About