Table 2 Comparison of IC50 values of 10 most active compounds on SARS-CoV nsp14 and human RNMT activities.
Compounds SARS-CoV nsp14 IC50a (μM) hRNMTIC50 (μM)
Sinefunginb 0.36 <0.05
2 40.6 ± 3.2 10.9 ± 1.0
6 55.5 ± 5.1 >500
9 2.6 ± 0.2 >500
10 3.9 ± 0.4 >500
11 70.4 ± 4.9 169.3 ± 30.4
12 5.7 ± 0.5 275.9 ± 28.7
13 0.6 ± 0.1 247.5 ± 14.9
14 1.5 ± 0.1 n.d
15 2.4 ± 0.2 n.i
16 9.9 ± 0.9 n.d
a Concentration inhibiting MTase activity by 50%; mean value from three independent experiments.
b values from the literature [11]. The MTase activity for IC50 determinations was measured using a filter binding assay as described above. n.i: no inhibition detected at 50 μM; n.d: not determined due to inhibition lower than 50% at 50 μM.