Table 1.
Structures and inhibition data of compounds for protease enzyme activity and VSV pseudotype and chimera SARS-CoV-2 viral entry into human Calu-3 lung epithelial cells
| Name/structure | TMPRSS2 IC50 (nM) | HGFA IC50 (nM) | Matriptase IC50 (nM) | Hepsin IC50 (nM) | Thrombin IC50 (nM) | Factor Xa IC50 (nM) | VSV-SARS-CoV-2 Calu-3 EC50 (nM) | VSV-SARS-CoV-2 Chimera Calu-3 EC50 (nM) | SARS-CoV-2 Wild-type Calu-3 IC50 (nM) |
| Remdesivir | NA | NA | NA | NA | NA | NA | ND | ND | 1,271 |
| Camostat | 1.5 | >20,000 | 7.0 | 7.0 | >20,000 | >20,000 | 83 | 21 | ND |
| Nafamostat | 0.14 | 158 | 0.05 | 0.9 | 5,020 | 4,570 | ND | ND | 220* |
| Ac-SKLR-kbt-V (1) | 74 | 23 | 14 | 1.0 | 7530 | 514 | 307 | 489 | ND |
| Cyclo(DLK)R-kbt (2) | 2.6 | 8520 | 2.6 | 19 | 8140 | 2,050 | 104 | 197 | 660 |
| Cyclo(DMK)R-kbt (19) | 19 | 3240 | 1.0 | 5.9 | 18,500 | 1,390 | 119 | ND | ND |
| Cyclo(aGLY)R-kbt (21) | 197 | >20,000 | 14 | 20 | >20,000 | 8,810 | 565 | ND | ND |
| Cyclo(DQK)R-kbt (20) | ND | 16,100 | 7.7 | 22 | >20,000 | >20,000 | 138 | ND | ND |
| Ac-WFR-kbt (8) | 9.4 | 329 | 5.7 | 7.6 | >20,000 | 22 | ND | 1,377 | ND |
| Ac-SKFR-kt (9) | 7.9 | 114 | 6.1 | 17 | >20,000 | 1,060 | ND | 1,157 | ND |
| Ac-KQFR-kt (10) | 29 | 116 | 1.4 | 1.2 | >20,000 | 158 | ND | 262 | ND |
| Ac-SQLR-kt (11) | 16 | 364 | 18 | 0.68 | ND | ND | ND | 1,320 | ND |
| Ac-LLR-kt (18) | 54 | 506 | 56 | 4.6 | ND | ND | 349 | 1,838 | ND |
| Ac-SKLR-kbt (3) | 39 | 66 | 6.1 | 0.32 | >20,000 | 3,800 | ND | 4,272 | ND |
| Ac-FLFR-kbt (12) | 3.0 | 228 | 7.2 | 2.9 | >20,000 | 26 | ND | 101 | ND |
| Ac-dWFR-kbt (13) | 1.1 | 27 | 2.6 | 1.1 | 3,700 | 98 | 32 | ND | ND |
| dWFR-kbt (14) | 39 | ND | ND | ND | ND | ND | ND | 357 | ND |
| dWFR-kbt-CO2H (15) | 42 | ND | ND | ND | ND | ND | ND | 105 | ND |
| Ac-WLFR-kbt (16) | 6.3 | 266 | 12 | 0.79 | >20,000 | 2.0 | 150 | ND | ND |
| Ac-KQLR-kbt (17) | ND | 60 | 1.1 | 0.17 | >20,000 | 258 | 78 | 572 | ND |
| Ac-IQFR-kbt (7) | 0.25 | 30 | 0.92 | 0.14 | >20,000 | 792 | ND | 3.6 | 102 |
| Ac-QFR-kbt (6) | 0.31 | 14 | 0.13 | 0.08 | >20,000 | 1.4 | ND | 0.53 | 105 |
| Ac-PQFR-kbt (5) | 0.28 | 75 | 0.32 | 0.13 | >20,000 | 199 | ND | 0.86 | 52 |
| Ac-GQFR-kbt (4) | 0.34 | 32 | 0.31 | 0.19 | >20,000 | 700 | ND | 0.43 | 74 |
ND, not determined; NA, not applicable.
*
Here, n = 1.