Table 1.

Inhibition of [³⁵S]TBPS Binding by Steroids 1-9 and Steroid Enantiomers ent-1-ent-3 and ent-7-ent-12^a

compd	IC50(nM)	nHill
1 b	414 ± 127	0.89 ± 0.20
ent-1 b	311 ± 36	1.00 ± 0.10
2	2,190 ± 420	1.26 ± 0.24
ent-2	6,490 ± 3,330	1.10 ± 0.33
3	>30,000c	–
ent-3	198 ± 25	0.98 ± 0.11
4 d	128 ± 11	1.44 ± 0.15
5 e	74 ± 7	0.89 ± 0.06
6f	226 ± 24	1.10 ± 0.11
7	895 ± 49	1.03 ± 0.05
ent-7	81 ± 8	0.92 ± 0.07
8	1,270 ± 162	1.13 ± 0.14
ent-8	3,030 ± 430	1.12 ± 0.13
9 g	6,680 ± 2,180	1.56 ± 0.51
ent-9	83 ± 11	1.15 ± 0.15
ent-10	1,520 ± 230	1.06 ± 0.14
ent-11	238 ± 21	0.86 ± 0.06
ent-12 h	2,020 ± 550	1.05 ± 0.23

^aThe results presented are from duplicate experiments performed in triplicate. Error limits are calculated as the standard error of the mean. Unless noted otherwise, compounds inhibited binding of [³⁵ S]TBPS by ≥ 95%.

^bLiterature values.⁹

^cA binding curve could not be calculated. Maximum displacement at 30 μM was 45%.

^dLiterature values.¹⁵

^eLiterature values.⁴⁶

^fLiterature values.⁴⁸

^gInhibition was partial at 30 μM. Maximal displacement for the calculated binding curve was 65%.

^hInhibition was partial at 30 μM. Maximal displacement for the calculated binding curve was 88%.