Table 1.
Best binding energy (kcal mol–1) based on AutoDock scoring of the main constituents of the U. tomentosa into the RBD/ACE-2 interface and SARS-CoV-2 spike protein binding domain (RBD) (PDB ID: 6VYB).
| Main constituents of cat’s claw | Best binding energy RBD/ACE-2 interface (kcal mol–1) | Best binding energy SARS-CoV-2 RBD (kcal mol–1) |
|---|---|---|
| Spiroxindole alkaloids | ||
| Uncarine F | –7.1 | –6.1 |
| Speciophylline | –6.8 | –6.8 |
| Mitraphylline | –6.8 | –6.2 |
| Pteropodine | –6.7 | –6.2 |
| Isopteropodine | –6.7 | –6.3 |
| Isomitraphylline | –6.6 | –6.1 |
| Rynchophylline | –6.0 | –5.5 |
| Isorynchophyllin | –6.0 | –5.7 |
| Indole glycosides alkaloids | ||
| 3-isodihydrocadambine | –7.6 | –6.4 |
| Cadambine | –7.6 | –6.1 |
| 3-dihydrocadambine | –7.0 | –7.1 |
| Polyhydroxylated triterpenes | ||
| Uncaric acid | –7.0 | –5.5 |
| Floridic acid | –7.0 | –5.5 |
| PHT-1 | –6.9 | –5.6 |
| Quinovic acid glycosides | ||
| QAG-2 | –8.2 | –6.8 |
| QAG-5 | –8.0 | –6.1 |
| QAG-4 | –7.8 | –6.8 |
| QAG-6 | –7.8 | –6.8 |
| QAG-1 | –7.8 | –6.1 |
| QAG-3 | –7.3 | –6.2 |
| Proanthocyanidins | ||
| Proanthocyanidin C1 | –8.6 | –7.0 |
| Epiafzelechin-4β-8 | –7.7 | –6.2 |
| Proanthocyanidin B4 | –7.6 | –7.2 |
| Proanthocyanidin B2 | –7.5 | –7.2 |
| Epicatechin | –7.1 | –6.0 |
| Chlorogenic acid | –6.1 | –6.4 |
| Reference | ||
| HepOSa | –7.1 (–7.3)b | –7.1 (–7.3)b |
a
HepOS: Heparin octasaccharide taken from PDB 5UE2 was used as positive control.
b
Estimated by Kwon et al. (2020).