Table 1.

SAR of KIRAs Containing Naphthyl R₂ Groups^a

compd	R1	R2	R3	IRE1β RNase IC50 (nM)	IRE1α RNase IC50 (nM)	IRE1β RNase Selectivity (Fold)
1				55 ± 5	5.0 ± 2.3	0.09
3				15 ± 2	22 ± 9	1.4
4				100 ± 10	430 ± 230	4.2
5				490 ± 20	9.4 ± 1.0	0.02
6				>20000	10 ± 1	<0.0005
7				14000 ± 4000	42 ± 5	0.003

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