Table 1. Characterization of PR-Targeted Contrast Agents.
| agent | r1a | r2a | logP | toxicity LC50b | competitive PR binding IC50c |
|---|---|---|---|---|---|
| 1 | 5.2 ± 0.3 | 5.7 ± 0.3 | –1.06 ± 0.02 | 2.65 | 122 ± 26 |
| 2 | 6.9 ± 0.1 | 7.9 ± 0.1 | –0.08 ± 0.06 | 1.23 | 0.80 ± 0.06 |
| 3 | 6.7 ± 0.3 | 7.6 ± 0.3 | 0.11 ± 0.01 | 1.00 | 1.80 ± 0.44 |
| 4 | 6.4 ± 0.1 | 7.4 ± 0.1 | 1.40 ± 0.08 | 0.88 | 0.95 ± 0.34 |
| P4 | N.D. | N.D. | 2.88d | 0.002241 | 0.001632 |
a
r1 and r2 measured in mM–1 s–1 at 1.41 T, 37°.
b
LC50 measured in mM and determined by sinusoidal curve fitting of a dose response curve in GraphPad Prism in T47D PR(+) cells.
c
IC50 measure in μM and determined by the equation mP100% + (mP0% – mP100%)/(1 + 10 log (IC50 – X)), where Y = mP, X = Log [compound], mP100% = 100% inhibition, and mP0% = 0% inhibition.
d
Measured by shake flask method/mass.42