Table 2.

KIRAs Containing 4-aminophenol R₂ Groups^a

compd	R1	R2	R3	IRE1β RNase IC50 (nM)	IRE1α RNase IC50 (nM)	IRE1β RNase Selectivity (Fold)
8				4.4 ± 0.7	22 ± 9	5.0
9				120 ± 40	120 ± 10	1.0
10				50 ± 2	6.0 ± 1.7	0.12
11				99 ± 56	57 ± 11	0.57
12				150 ± 30	130 ± 70	0.87
13				3.9 ± 1.1	240 ± 50	60
14				13 ± 2	110 ± 10	8.1
15				3.5 ± 1.4	390 ± 270	110
16				430 ± 70	2000 ± 100	4.5
17				74 ± 14	270 ± 70	3.6
18				17 ± 2	83 ± 8	5.8

^aRNase IC₅₀ data are shown as mean ± SEM, n=3. RNase selectivity was determined by dividing the IRE1α RNase IC₅₀ by the IRE1β RNase IC₅₀ value for each inhibitor (individual IC₅₀ curves provided in Supp. Figure 2).