Table 2. Inhibition of SARS-CoV-2 M^pro by Alkyne Derivatives of Investigational COVID-19 Small-Molecule Therapeutics^a,^b.

^aInhibition assays were performed using SPE-MS as described employing SARS-CoV-2 M^pro (0.05 μM) and ALNDFSNSGSDVLYQPPQTSITSAVLQ/SGFRKMAFPS-NH₂ as a substrate (2.0 μM) in the presence of an internal standard (Supporting Figures S1 and S2).^43,62 The results are means of three independent repeats, each composed of technical duplicates (n = 3; mean ± SD). Representative dose–response curves are shown in Figure 3b.

^bRepresentative dose–response curves for cell-based assays are shown in Supporting Figure S3b. The results are means of three independent repeats (n = 3; mean ± SD). Cbz: −C(O)OCH₂C₆H₅.