Thiophene-fused γ-lactams inhibit isolated recombinant SARS-CoV-2 M^pro.

	γ-Lactam	aIC50 [μM]
i		8.5 ± 1.4
ii		8.4 ± 0.5
iii		>100
iv		>100
v		>100

^aAssays were performed as reported using SPE-MS, employing SARS-CoV-2 M^pro (0.05 μM) and substrate peptide (2.0 μM).⁴² Results are means of two independent runs each composed of technical duplicates (n = 2; mean ± standard deviation, SD). Representative dose–response curves of selected γ-lactams are shown in Fig. 2.