Table 2. Half-Maximal Inhibitory Concentrations (IC50) of Metal Complexes 1–8 with Respect to the SARS-CoV-2-Associated Cysteine Proteases 3-Chymotrypsin-like Protease (3CLpro), Papain-like Protease (PLpro), Cathepsin B (CatB), and Cathepsin L (CatL)a.
| 3CLpro (μM) | PLpro (μM) | CatB (μM) | CatL (μM) | |
|---|---|---|---|---|
| 1 | 0.037 ± 0.008 | 19.6 ± 3.3 | 0.016 ± 0.003 | 0.026 ± 0.006 |
| 2 | 0.046 ± 0.009 | 22.4 ± 4.7 | 0.018 ± 0.005 | 0.051 ± 0.007 |
| 3 | 0.018 ± 0.006 | 7.6 ± 2.8 | 0.009 ± 0.003 | 0.019 ± 0.005 |
| 4 | 0.75 ± 0.17 | >100 | 9.3 ± 2.7 | 0.153 ± 0.007 |
| 5 | 1.43 ± 0.20 | >100 | >100 | 0.186 ± 0.009 |
| 6 | >100 | >100 | >100 | >100 |
| 7 | 0.84 ± 0.26 | >100 | >100 | 0.194 ± 0.007 |
| 8 | 59.4 ± 6.3 | >100 | >100 | >100 |
a
Values and standard deviations are derived from three independent experiments. Experimental details for all enzymatic assays can be found in the Experimental Section.