MS-325 / Angiography / MRI contrast agent / NMR spectroscopy / Interaction with HSA / Gadolimium
The physicochemical characterization of MS-325 [trisodium {4-distance (r) between the protons of the coordinated water molecule and the gadolinium ion. The kinetic and (R)-[(4,4-diphenylcyclohexyl)phosphanooxymethyl]-3,6,9-triaza-3,6,9-tris(methoxycarbonyl)undecanedioato}gadolinium-thermodynamic stability of MS-325 in solutions containing phosphorylated metabolites (ATP, phosphocreatine and (III)], a new derivative of Gd-DTPA {Magnevist ® : dimeglumin [{3,6,9-triaza3,6,9-tris(methoxycarbonyl)undecanedi-inorganic phosphate) were measured by 31 P relaxation rate analysis and found to be higher than for Gd-DTPA. Similarly, oato}gadolinium(III)], presented as a potentially useful angiographic contrast agent, was carried out in various the Zn 2+ transmetallation process studied by proton relaxometry is slower than for the same reference compound. media. Water solution, protein-containing solution, phosphorylated metabolites solution, and Zn 2+ -containing
Finally, an analysis of the noncovalent binding of MS-325 to serum proteins by proton relaxometry showed that MS-325 solution were investigated using different NMR techniques such as water 1 H nuclear magnetic relaxation rates, water interacts with human serum albumin (HSA) and that the association constant of this interaction is equal to 6100 ± 2130 17 O transverse relaxation rates, and 31 P longitudinal relaxation rates of phosphorylated metabolites. The proton M -1 . A peak relaxivity of approx. 50 s -1 mM -1 was determined at 25 MHz for the protein-bound paramagnetic complex. This relaxivity of MS-325 in water was found to be higher than that of the parent compound Gd-DTPA; this can be attributed value is lower than the maximal relaxivity predicted for a paramagnetic center totally immobilized at the surface of to the longer rotational correlation time (τ R ) of the hydrated complex, and possibly to an apparently shorter mean the protein.