Table 2.
pKa Values and compound solubilities in PBS at pH 5, pH 6, and pH 7.4 at 37 °C.
| Compds | pKa Values1 | PBS pH 5 | PBS pH 6 | PBS pH 7.4 |
|---|---|---|---|---|
| 1 | - | 0.003–0.005 g/L | 0.003–0.005 g/L | 0.003–0.005 g/L |
| 2 | - | 0.007–0.01 g/L | 0.007–0.01 g/L | 0.007–0.01 g/L |
| 4 | 1.90, 7.47 & 9.432 | 72.70 ± 0.40 g/L | 13.43 ± 0.26 g/L | 1.91 ± 0.06 g/L |
| 12 | ~ 7.85 | 26.30 ± 0.90 g/L | 3.70 ± 0.31 g/L | 1.31 ± 0.05 g/L |
| 15 | ~ 7.30 | 10.99 ± 0.20 g/L | 2.06 ± 0.11 g/L | 0.19 ± 0.01 g/L |
| 18 | ~ 2.20 & ~ 9.25 | 1.16 ± 0.04 g/L | 1.13 ± 0.06 g/L | 1.77 ± 0.08 g/L |
| 21 | ~7.30 | 11.18 ± 0.21 g/L | 3.60 ± 0.12 g/L | 0.62 ± 0.03 g/L |
Standard deviations are based on three experiments;
1
The pKa values for 12, 15, 18, and 21 are estimated based on calculations using Advanced Chemistry Development (ACD/Labs) software within ScifinderScholar® for the corresponding benzyl esters;
2
Measured values from reference[36].