1,2-Hydroxypyridonates as Contrast Agents for Magnetic Resonance Imaging:  TREN-1,2-HOPO

Jocher, Christoph J.; Moore, Evan G.; Xu, Jide; Avedano, Stefano; Botta, Maurizio; Aime, Silvio; Raymond, Kenneth N.

doi:10.1021/ic700985j

Cited by 57 publications

(73 citation statements)

References 34 publications

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“…The higher acidity of the 1,2-HOPO group versus the maltol is reflected by an average decrease of ca . 0.5 pK a units, and this agrees with the trend observed for the analogous hexadentate ligands TREN-1,2-HOPO 9 and TREN-MAM 7 (log β 014 = 20.7 and 21.9 respectively). The hexadentate ligands have very similar stability constants for Gd(III) binding resulting in identical conditional stability constants pGd = 19.3.…”

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confidence: 87%

Aqueous Ln(III) Luminescence Agents Derived from a Tasty Precursor

et al. 2008

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The synthesis, aqueous stability and photophysical properties are reported for a novel tetradentate ligand derived from maltol, a commonly used flavor enhancer. In aqueous solution, this chelate forms stable complexes with Ln(III) cations, and sensitized emission was observed from Eu(III), Yb(III), and Nd(III). A comparison with recently reported and structurally analogous ligands reveals a slightly higher basicity but lower complex stability with Eu(III) [pEu = 14.7 (1)]. A very poor metal centered quantum yield with Eu(III) was observed (Φtot = 0.04 %), which can be rationalized by the similar energy of the ligand triplet state and the Eu(III) 5D0 emissive level. Instead, sensitized emission from the Yb(III) and Nd(III) cations was observed, which emit in the Near Infra-Red (NIR).

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confidence: 87%

Aqueous Ln(III) Luminescence Agents Derived from a Tasty Precursor

et al. 2008

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“…No phosphate binding, however, could be detected for this ligand. [69] Octadentate H(2,2)-1,2-HOPO (19) does not show any anion binding at neutral pH in which the neutral, monoprotonated complex GdLH complex dominates. [65] Thus, the HOPO-based ligands examined do not have any appreciable anion binding for the physiologically relevant anions that could affect the in vivo performance of these ligands.…”

Section: Selectivitymentioning

confidence: 97%

High‐Relaxivity MRI Contrast Agents: Where Coordination Chemistry Meets Medical Imaging

et al. 2008

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“…This suggests a possible effect of the 1,2-HOPO isomer on electron spin relaxation of the metal center. A follow-up study was recently published which further probed the stability properties of the parent Gd-TREN-1,2-HOPO complex 15. Such detailed stability and selectivity studies, as well as the recent communication reporting an octadentate derivative,16 reveal the promise demonstrated by 1,2-HOPO-based ligands as MRI contrast agent precursors.…”

Section: Introductionmentioning

confidence: 95%

1,2-Hydroxypyridonate/Terephthalamide Complexes of Gadolinium(III): Synthesis, Stability, Relaxivity, and Water Exchange Properties

et al. 2008

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Four new Gd(III) complexes based on the 1,2-hydroxypyridinone chelator have been synthesized and evaluated as potential MRI contrast agents. Previously reported work examining Gd-TREN-1,2-HOPO (3) suggests that the 1,2-HOPO unit binds strongly and selectively to Gd(III), encouraging further study of the stability and relaxivity properties of this class of compounds. Among the new complexes presented in this paper are the homopodal Gd-Ser-TREN-1,2-HOPO (Gd-5) and three heteropodal bis-1,2-HOPO-TAM complexes (Gd-6, Gd-7, and Gd-8). Conditional stability constants were determined and all pGd values are in the range of 18.5 − 19.7, comparable to other analogous HOPO complexes and currently used commercial contrast agents. Relaxivities for all complexes are about twice those of commercial agents, ranging from 7.8 − 10.5 mM −1 s −1 (20 MHz; 25 °C), and suggest two inner-sphere water molecules in fast exchange. Luminescent measurements were used to verify the number of coordinated waters for Gd-5, and VT 17 O NMR experiments were employed for the highly soluble Gd-TREN-bis-1,2-HOPO-TAM-N3 (Gd-8) complex to measure a fast water exchange rate, 298 k ex = 1/τ M , of 5.1(±0.4) × 10 8 s −1 ( 298 τ M ∼ 2 ns).

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1,2-Hydroxypyridonates as Contrast Agents for Magnetic Resonance Imaging: TREN-1,2-HOPO

Abstract: ABSTRACT. 1,2-Hydroxypyridinones (1,2-HOPO) form very stable lanthanide complexes that may be useful as contrast agents for Magnetic Resonance Imaging (MRI). X-ray diffraction of single crystals

Cited by 57 publications

References 34 publications

Aqueous Ln(III) Luminescence Agents Derived from a Tasty Precursor

Aqueous Ln(III) Luminescence Agents Derived from a Tasty Precursor

High‐Relaxivity MRI Contrast Agents: Where Coordination Chemistry Meets Medical Imaging

1,2-Hydroxypyridonate/Terephthalamide Complexes of Gadolinium(III): Synthesis, Stability, Relaxivity, and Water Exchange Properties

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