Penicillin derivatives inhibit the SARS-CoV-2 main protease by reaction with its nucleophilic cysteine - Malla, TR; Brewitz, L; Muntean, D-G; Aslam, H; Owen, CD; Salah, E; Tumber, A; Lukacik, P; Strain-Damerell, C; Mikolajek, H; Walsh, MA; Schofield, CJ (Journal of Medicinal Chemistry, 2022)