Table 2. K i values [nM] of the individually synthesized compounds for β-tryptase and the other two serine proteases trypsin and α-chymotrypsin (α-ChT).
| Compound | β-Tryptase | Trypsin | α-ChT |
| 5(A)3 | 12.5 ± 0.8 | ||
| 5(B)3 | 104.9 ± 31.0 | ||
| 5(C)3 | 22.5 ± 2.1 | ||
| 5(D)3 | 114/29.900 a | ||
| 5(E)3 | >100.000 | >100.000 | >100.000 |
| 3(A)2 | 65.6 ± 2.3 | ||
| 3(B)2 | 391.8 ± 24.4 | ||
| 3(C)2 | 78.0 ± 3.1 | ||
| 3(AC) | 120.8 ± 3.9 |
aA biphasic behaviour was observed with two binding modes, one with higher affinity (K i = 114.0 ± 19.3 nM) and one with lower affinity (K i = 29.93 ± 1.44 μM).