C[C@H](CS)C(=O)N1CCC[C@H]1C(=O)O
Potential for S-S disulphide formation (as with Plavix, omeprazole, proton pump inhibitors).... One representative ACE inhibitor. Studies show no contraindications in covid-19 for patients. x0874 by eye, similar size.
If covalent trapping of a cys protease is unprecedented in drugs (only Ph III) then maybe we could go back to medicinal chemistry and look to other ways of trapping the Cys? Might be a more subtle approach and fragment like?