Table 3.
Thermodynamic stability constants for GBCAs and Mn2+ and Fe3+ complexes considered as T1-relaxation agents.
| logKa,b | logKcond pH 7.4 | |
|---|---|---|
| Gd-DTPA1 | 22.5 | 18.4 |
| Gd-DTPA-BMA1 | 16.9 | 14.8 |
| GD-DTPA-BMEA1 | 16.6 | 15.0 |
| Gd-BOPTA1 | 22.6 | 18.4 |
| Gd-EOB-DTPA1 | 23.5 | 18.7 |
| MS-3251 | 22.1 | 18.9 |
| Gd-DOTA1 | 24.7 | 17.2 |
| Gd-HP-DO3A1 | 23.8 | 17.1 |
| Gd-DO3A-butrol1 | 21.8 | 14.7 |
| Mn-EDTA | 12.6,213 13.9231 | 10.7,213 11.0231 |
| Mn-EDTA-BOM231 | 13.5 | 10.6 |
| Mn-EDTA-BOM2231 | 13.9 | 11.0 |
| Mn-CyDTA213 | 14.3 | 12.3 |
| Mn-PyC3A79 | 13.9 | 11.3 |
| Mn-DPAAA234 | 13.19 | 13.0 |
| Mn-PAADA233 | 9.59 | 8.8 |
| Mn-DPAMA237 | 10.13 | 10.1 |
| Mn-PMPA240 | 14.3 | 11.1 |
| Mn-12-PyN4A83 | 11.5 | 7.1 |
| Mn-12-PyN4P83 | 14.1 | 7.4 |
| Mn-15-PyN584 | 10.9 | 7.7 |
| Mn-15-PyN3O284 | 7.2 | 5.2 |
| Mn-PC2A-EA78 | 19.0 | 12.7 |
| Mn-1,4-DO2A241 | 16.1 | 10.1 |
| Mn-1,7-DO2A241 | 14.5 | 8.2 |
| Mn-1,4-DO2AM77 | 12.64 | 8.9 |
| Fe-CyDTA | 30.1 | 28.0 |
| Fe-PyC3A110 | N/D | 23.2 |
| Fe-EHPG212 | >30 | N/D |
a
K = [metal-ligand complex]/[metal][ligand].
b
logK may vary depending on measurement conditions (typically within logK +/− 1).