Inhibition Assay: A rapid plate DNA synthesis assay was performed using optimized conditions. Briefly, a 1.2:1 ratio of a 20-mer oligonucleotide primer (5′-GCGAATGAATGACCGCTGAC-3′, SEQ ID No. 1) and a 5′-end biotinylated 100-mer oligonucleotide template (5′-Biotin-AGCACTATTGACATTACAGAGTCGCCTTGGCTCTCTGGCTGTTCGTTGCGGGCTCCGCG TGCGTTGGCTTCGGTCGTCCCGTCAGCGGTCATTCATTGGC-3′) were annealed and loaded into a 96-well microtiter streptavidin-coated plate (Streptawell plates, Roche Applied Science, Indianapolis, Ind., USA) at 5 pmol/well. The wells were incubated at 37 C for 90 min, and washed with 100 L PBS. The reaction was conducted in low salt buffer (20 mM Tris-HCl pH 7.4, 3 mM MgCl2, 0.1 mM EDTA, 0.5 mM DTT, 2% glycerol, 40 ug/mL BSA, 5 uM dNTPs, 1 uM digoxigenin-11-2′-deoxyuridine-5′-triphosphate (DIG-dUTP, Roche Applied Science) with 1 μL vaccinia infected cell lysate or 1 uL of in vitro translated E9 DNA polymerase. The reaction plates were incubated at 37° C
Antiviral activity determined as inhibition of SARS-CoV-2 induced cytotoxicity of VERO-6 cells at 10 uM after 48 hours exposure to 0.01 MOI SARS CoV-2 virus by high content imaging
Binding affinity to recombinant human BAX (1 to 92 residues) expressed in Escherichia coli BL21 (DE3) assessed as dissociation constant incubated for 10 mins by microscale thermophoresis analysis