Table 1. Inhibition of Human and Mouse 17β-HSD2 by 2,5-Thiophene Amide, 1,3-Phenyl Amide and 1,4-Phenyl Amide Derivatives in a Cell-Free Assay.

			IC50 (nM) a or % inh. at 1 μM a , d
Cmpd	R1	R2	h17β-HSD2 b	m17β-HSD2 c
1a	3-OMe	3-OMe	68	29%
1b	3-Me	3-Me	52	42%
1c	3-Me	3-OMe	58	30%
1d	2-OMe	3-OMe	490	19%
1e	3-OH	3-OH	33%	n.i.
1f	2-OH	3-OH	410	18%
1g	3-N(Me)2	3-OMe	170	40%
1h	3-F	3-OMe	510	n.i.
1i	4-CN	3-OMe	48%	n.i.
1j	2-F, 3-OMe	3-OMe	62	26%
1k	2-F, 3-OMe	3-Me	62	45%
2a	2-F, 3-OMe	3-OH	61	65%
2b	3-OMe	3-OMe	370	16%
2c	3-OH	3-OH	390	26%
2d	4-OH	3-OH	330	35%
2e	3-Me	3-OH	160	45%
2f	3-F	3-OH	330	37%
2g	4-CN	3-OH	n.i.	n.i.
3a	3-Me	3-Me	1100	50%
4a	3-OMe	3-OMe	520	25%
4b	4-OMe	3-OMe	1200	11%
4c	3-OH	3-OH	35%	n.i.
4d	3-OMe	3-OMe	11%	n.i.
4e	3-OH	3-OH	640	29%
4f	4-OH	3-OH	480	22%

^aMean value of at least two determinations, standard deviation less than 20%.

^bHuman placental microsomal fraction, substrate E2 [500 nM], cofactor NAD⁺ [1500 μM].

^cMouse liver microsomal fraction, substrate E2 [500 nM], cofactor NAD⁺ [1500 μM].

^dn.i.: no inhibition, i.e., inhibition ≤10%.