TY - JOUR
T1 - Some new DTPA-N,N″-bis(amides) functionalized by alkyl carboxylates
T2 - Synthesis, complexation and stability properties
AU - Dutta, Sujit
AU - Kim, Suk Kyung
AU - Patel, Daksha B.
AU - Kim, Tae Jeong
AU - Chang, Yongmin
PY - 2007/8/31
Y1 - 2007/8/31
N2 - A new series of DTPA-N,N″-bis(amide) ligands functionalized by alkyl carboxylates on the amide side-arms (1a-1l) and their Gd(III) complexes of the type [Gd(1)(H2O)] · xH2O (2a-2l) were synthesized and characterized by analytical and spectroscopic techniques. Potentiality of 2a-2l as contrast agent for magnetic resonance imaging (MRI CA) was investigated by measuring some relevant physicochemical properties such as (i) the protonation constants of 1a-1l, (ii) thermodynamic and conditional stability constants of 2a-2l, (iii) the selectivity (pGd) of 1a-1l for the Gd(III) ion over the endogenous metal ions such as Zn(II), Ca(II), and Cu(II), and (iv) the relaxivities (R1 and R2) of 2a-2l in aqueous and aqueous HP-β-CD solutions. Comparative studies reveal that most of new Gd(III) complexes show enhanced thermodynamic stability and selectivity as compared with those of [Gd(DTPA-BMA)(H2O)] (DTPA-BMA = N,N″-di(methylcarbamoylmethyl)diethylenetriamine-N,N′,N″-triacetate). Also enhanced with 1a-1l (except 1f and 1h) is affinity for Gd(III) as compared with [DTPA-BMA]3- under physiological conditions. The relaxivities (R1 and R2) of aqueous solutions of 2a-2l, on the other hand, drop significantly as compared with [Gd(DTPA-BMA)(H2O)] although they increase dramatically (6-10 fold) in aqueous hydroxypropyl-β-cyclodextrin (HP-β-CD) solutions.
AB - A new series of DTPA-N,N″-bis(amide) ligands functionalized by alkyl carboxylates on the amide side-arms (1a-1l) and their Gd(III) complexes of the type [Gd(1)(H2O)] · xH2O (2a-2l) were synthesized and characterized by analytical and spectroscopic techniques. Potentiality of 2a-2l as contrast agent for magnetic resonance imaging (MRI CA) was investigated by measuring some relevant physicochemical properties such as (i) the protonation constants of 1a-1l, (ii) thermodynamic and conditional stability constants of 2a-2l, (iii) the selectivity (pGd) of 1a-1l for the Gd(III) ion over the endogenous metal ions such as Zn(II), Ca(II), and Cu(II), and (iv) the relaxivities (R1 and R2) of 2a-2l in aqueous and aqueous HP-β-CD solutions. Comparative studies reveal that most of new Gd(III) complexes show enhanced thermodynamic stability and selectivity as compared with those of [Gd(DTPA-BMA)(H2O)] (DTPA-BMA = N,N″-di(methylcarbamoylmethyl)diethylenetriamine-N,N′,N″-triacetate). Also enhanced with 1a-1l (except 1f and 1h) is affinity for Gd(III) as compared with [DTPA-BMA]3- under physiological conditions. The relaxivities (R1 and R2) of aqueous solutions of 2a-2l, on the other hand, drop significantly as compared with [Gd(DTPA-BMA)(H2O)] although they increase dramatically (6-10 fold) in aqueous hydroxypropyl-β-cyclodextrin (HP-β-CD) solutions.
KW - DTPA-bis(amide) ligands
KW - Gadolinium
KW - Hydroxypropyl-β-cyclodextrin
KW - MRI contrast agents
KW - Poly(aminocarboxylate) ligands
KW - Thermodynamic stability
UR - http://www.scopus.com/inward/record.url?scp=34547763673&partnerID=8YFLogxK
U2 - 10.1016/j.poly.2007.04.027
DO - 10.1016/j.poly.2007.04.027
M3 - Article
AN - SCOPUS:34547763673
SN - 0277-5387
VL - 26
SP - 3799
EP - 3809
JO - Polyhedron
JF - Polyhedron
IS - 14
ER -