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Titolo:
PREPARATION, PHYSICOCHEMICAL CHARACTERIZATION, AND RELAXOMETRY STUDIES OF VARIOUS GADOLINIUM(III)-DTPA-BIS(AMIDE) DERIVATIVES AS POTENTIAL MAGNETIC-RESONANCE CONTRAST AGENTS
Autore:
GERALDES CFGC; URBANO AM; ALPOIM MC; SHERRY AD; KUAN KT; RAJAGOPALAN R; MATON F; MULLER RN;
Indirizzi:
UNIV COIMBRA,DEPT BIOCHEM P-3000 COIMBRA PORTUGAL
Titolo Testata:
Magnetic resonance imaging
fascicolo: 3, volume: 13, anno: 1995,
pagine: 401 - 420
SICI:
0730-725X(1995)13:3<401:PPCARS>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Keywords:
NUCLEAR MAGNETIC RELAXATION DISPERSION (NMRD); ELECTRON SPIN RESONANCE (ESR); GD(DTPA)(2-); GD3+ CHELATES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
NO
Recensione:
Indirizzi per estratti:
Citazione:
C.F.G.C. Geraldes et al., "PREPARATION, PHYSICOCHEMICAL CHARACTERIZATION, AND RELAXOMETRY STUDIES OF VARIOUS GADOLINIUM(III)-DTPA-BIS(AMIDE) DERIVATIVES AS POTENTIAL MAGNETIC-RESONANCE CONTRAST AGENTS", Magnetic resonance imaging, 13(3), 1995, pp. 401-420

Abstract

Macroscopic protonation constants were measured for a series of DTPA mono- and bis-amide ligands using potentiometric titrations. Proton NMR pH titrations yielded protonation populations of the various nitrogen and oxygen basic sites of the ligands for the different protonation stages. Amide formation decreased the basicity of the backbone nitrogens of the ligands and the thermodynamic stability of the correspondingGd3+ chelates. Nuclear magnetic relaxation dispersion (NMRD) profilesand ESR linewidths were measured for the Gd3+ chelates, Some of theseexhibited an elevated high field relaxivity relative to Gd(DTPA)(2-),in response to their high molecular weight. As opposed to Gd(DTPA)(2-), at 5 degrees C the chemical exchange process of the single inner-sphere water molecule of the bis-amide complexes becomes so slow that itgoverns the paramagnetic relaxation process, causing the observed NMRD profiles to be close to those expected for the outer-sphere contribution. The chelates containing long alkyl side chains, such as Gd(DTPA-HPA(2)), showed increased relaxivity values in the presence of human serum albumin (HSA), indicative of noncovalent interaction with the protein, These chelates could be useful as nonionic hepatobiliary contrast agents.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/11/20 alle ore 07:29:41