Table 1. Structures and in vitro inhibitory potencies of compounds 38–47 against the β5i subunit of human iCP.

Compound	R	IC50 for β5i (nM)
38		227 ± 32
39		226 ± 21
40		351 ± 4
41		200 ± 13
42		141 ± 6
43		365 ± 5
44		174 ± 5
45		433 ± 13
46		264 ± 3
47		106 ± 4