Table 1.
Structure and antiviral activity of (-)-borneol-based esters.
| |||||
|---|---|---|---|---|---|
| Virus | n |
|
|
|
|
| I | II | III | IV | ||
| Filoviruses | 1 | a SIMarV-GP = 14 | a SIMarV-GP = 29 | a SIMarV-GP = 5 | a SIMarV-GP = 6 |
| 1 | b SIEboV-GP = 46 | b SIEboV-GP = 80 | b SIEboV-GP = 13 | NT | |
| 2 | a SIMarV-GP = 20 | a SIMarV-GP = 47 | a SIMarV-GP = 5 | a SIMarV-GP = 15 | |
| 2 | b SIEboV-GP = 870 | b SIEboV-GP = 170 | b SIEboV-GP = 36 | NT | |
| Influenza virus | 1 | c SIH1N1 = 23 | c SIH1N1 = 16 | c SIH1N1 = 82 | c SIH1N1 = 16 |
| 2 | c SIH1N1 = 25 | c SIH1N1 = 12 | c SIH1N1 = 45 | c SIH1N1 = 12 | |
| Vaccinia virus | 1 | NA | NA | d SIVACV = 56 | NA |
| 2 | NA | NA | d SIVACV = 48 | NA | |
| 3 | NA | NA | d SIVACV = 23 | NA | |
| Coronavirus | 1 | NA | NA | e SIpSARS-CoV-2-S = 5 | e SIpSARS-CoV-2-S = 10 |
| SISARS-CoV-2 = 11–40 * | |||||
| 2 | NA | NA | e SIpSARS-CoV-2-S = 18 | e SIpSARS-CoV-2-S = 29 | |
| SISARS-CoV-2 = 6–102 * | |||||
The selectivity index (SI, CC50/IC50 ratio) values of each compound were taken as the evaluation reference for antiviral potency. The antiviral activity against filoviruses and SARS-CoV-2 was studied using a “surrogate” system. This system included vesicular stomatitis virus (VSV) particles pseudotyped with Ebola virus GP (rVSV-ΔG-EboV-GP) or Marburg virus GP (rVSV-ΔG-MarV-GP), and lentiviral particles exhibiting the S protein of SARS-CoV-2 (pSARS-CoV-2-S). a SIMarV-GP = CC50/IC50MarV-GP, where IC50MarV-GP is the concentration of a compound required to inhibit rVSV-ΔG-MarV-GP infection of HEK293T cells by 50%. b SIEboV-GP = CC50/IC50EboV-GP, where IC50EboV-GP is the concentration of a compound required to inhibit rVSV-ΔG-EboV-GP infection of HEK293T cells by 50%. c SIH1N1 = CC50/IC50H1N1, where IC50H1N1: concentration resulting in a decrease in the A/Puerto Rico/8/34 (H1N1) virus titer by 50%. d SIVACV = CC50/IC50VACV, where IC50VACV: 50% inhibitory concentration, at which 50% of cells in infected monolayers are preserved. e SIpSARS-CoV-2-S = CC50/IC50pSARS-CoV-2-S, where IC50pSARS-CoV-2-S is the concentration of a compound required to inhibit SARS-CoV-2 pseudoviruses by 50%. SISARS-CoV-2 = CC50/IC50SARS-CoV-2, where IC50SARS-CoV-2 is the concentration leading to 50% inhibition of virus replication. * The data are presented against various SARS-CoV-2 virus strains. CC50 is the cytotoxic concentration, the concentration resulting in the death of 50% of cells.