Diols for Hormone Binding Domain
Journal of Medicinal Chemistry, 2005, Vol. 48, No. 13 4309
acetone/hexane afforded an off-white powder (0.020 g, 55 %):
Rf ) 0.03 (hexane/ethyl acetate 4:1); mp 133-136 °C; 1H NMR
in acetone-d6 δ 0.96 (s, 3H, 18-CH3), 1.2-2.9 (m, 15H, steroid
nucleus), 5.83 (d, 1H, J20-21 ) 12.93 Hz, 20-H), 6.35 (d, 1H,
J21-20 ) 12.93 Hz, 21-H), 6.55 (s, 1H, J4-2 ) 2.34 Hz), 6.60
(dd, 1H, J2-1 )8.4 Hz and J2-4 ) 2.43 Hz, 2-H), 6.77 (d, 2H,
J23-24 ) 8.64 Hz, 23-H and 27-H), 7.11 (d, 1H, J1-2 ) 8.31 Hz,
1-H), 7.53 (d, 2H, J24-23 ) 8.61 Hz, 24-H and 26-H), 8.01 (s,
1H, 3-OH), 8.43 (s, 1H, 25-OH); 13C NMR in acetone-d6 δ 14.27
(C-18) 23.52 (C-15), 28.11 (C-11), 28.16 (C-7), ∼29 under
acetone peak (C-6), 32.39 (C-12), 38.00 (C-16), 40.58 (C-8),
44.57 (C-9), 48.62 (C-13), 50.14 (C-14), 83.36 (C-17), 113.31
(C-2), 114.95 (C-24 and C-26), 115.66 (C-4), 126.80 (C-23 and
C-27), 127.82 (C-1), 129.20 (C-21), 131.32 (C-22), 132.32
(C-10), 134.22 (C-20), 138.16 (C-5), 153.65 (C-25), 154.00
(C-3).
acetone/chloroform to yield a light-orange powder (0.31 g,
68%): Rf ) 0.47 (1:1 hexane/ethyl acetate); mp 140-142 °C;
1H NMR in CDCl3 δ 0.91 (s, 3H, 18-CH3), 1.2-2.9 (m, 15H,
steroid nucleus), 3.8 (s, b, 2H, -NH2), 4.6 (s, b, 17-OH), 5.79
(d, 1H, J20-21 ) 12.90 Hz, 20-H), 6.40 (d, 1H, J21-20 ) 12.60
Hz, 20-H), 6.56 (d, 1H, J4-2 ) 2.7 Hz, 4-H), 6.64 (m, 4H, 2-H,
4-H, 24-H and 26-H), 7.16 (d, 1H, J1-2 ) 8.4 Hz, 1-H), 7.26 (s,
CDCl3), 7.32 (d, 2H, J ) 8.4 Hz, 23-H and 27-H); 13C NMR in
acetone-d6 δ 15.04 (C-18), 24.17 (C-15), 27.79 (C-11), 28.66
(C-7), under acetone peak (C-6), 32.94 (C-12), 38.51 (C-16),
41.25 (C-8), 45.03 (C-9), 49.12(C-13), 50.12 (C-14), 83.99
(C-17), 113.90 (C-2), 114.58 (C-24 and C-26), 116.25 (C-4),
127.41 (C-1), 131.14 (C-21), 132.33 (C-10), 132.66 (C-23 and
C-27), 133.03 (C-20), 138.76 (C-5), 150.02 (C-25), 156.29
(C-3).
(17R,20Z)-21-[(4-Acetyl)phenyl]-19-norpregna-1,3,5(10),-
20-tetraene-3,17â-diol (6i). Compound 5i (0.012 g,
0.026 mmol) was hydrolyzed using the general procedure to
yield 6i (0.0056 g, 51%): Rf ) 0.12 (hexane/ethyl acetate 5:1);
1H NMR in CDCl3 δ 0.91 (s, 3H, 18-CH3), 1.2-2.8 (m, 18H,
steroid nucleus), 6.01 (d, 1H, J20-21 ) 12.99 Hz, 20-H), 6.51
(d, 1H, J21-20 ) 12.81 Hz, 21-H), 6.57 (d, 1H, J4-2 ) 2.7 Hz,
(17R,20Z)-21-[(4-Cyano)phenyl]-19-norpregna-1,3,5(10),-
20-tetraene-3,17â-diol (5d). Compound 5d (0.005g) was
hydrolyzed to yield 6d (0.004 g, 90%): Rf ) 0.22 (hexane/ethyl
1
acetate 3:1); mp 99-105 °C; H NMR in acetone-d6 δ 0.90 (s,
3H, 18-CH3), 1.2-2.8 (m, 15H, steroid nucleus), 6.15 (d, 1H,
J20-21 ) 13.20 Hz, 20-H), 6.48 (d, 1H, J21-20 ) 13.20 Hz,
21-H), 6.54 (d, 1H, J4-2 ) 2.79, 4-H), 6.60 (dd, 1H, J2-4 ) 2.8
Hz, J2-1 ) 8.32 Hz, 2-H), 7.11 (d, 1H, J1-2 ) 8.31 Hz, 1-H), (d,
2H, J23-24 and J27-26 ) 8.58 Hz, 23-H and 27-H) (d, 2H, J24-23
4-H), 6.64 (dd, 1H, J2-1 ) 8.3 Hz, 2-H), 7.16 (d, 1H, J1-2
)
8.31 Hz, 1-H), 7.55 (d, 2H, J23-24 and J27-26 ) 8.46 Hz, 23-H,
27-H), 7.90 (d, 2H, J24-23 and J26-27 ) 8.37 Hz, 24-H and 26-
H); 13C NMR in CDCl3 δ 14.04 (C-18), 23.31 (C-15), 26.43
(-COCH3), 26.62 (C-11), 27.43 (C-7), 29.63 (C-6), 32.45 (C-12),
38.69 (C-16), 39.59 (C-8), 43.75 (C-9), 48.10 (C-13), 49.68
(C-14), 85.07 (C-17), 112.71 (C-2), 115.26 (C-4), 126.55 (C-21),
127.31 (C-1), 127.91 (C-23 and C-27), 129.52 (C-24 and C-26),
132.53 (C-10), 135.50 (C-25), 137.77 (C-20), 138.27 (C-5), 142.69
(C-22), 153.37 (C-3), 197.71 (-COCH3).
and J26-27 ) 8.55 Hz, 24-H and 26-H), 7.96 (s, 1H, 3-OH); 13
C
NMR in acetone-d6 δ 14.42 (C-18), 23.81 (C-15), 27.23 (C-11),
28.16 (C-7), ∼29 under acetone peak (C-6), 32.93 (C-12), 38.91
(C-16), 40.67 (C-8), 44.46 (C-9), 48.87 (C-13), 50.17 (C-14),
84.51 (C-17), 110.23 (C-25), 113.46 (C-2), 115.80 (C-4), 119.52
(-CN), 126.91 (C-24 and C-26), 127.80 (C-1), 131.58 (C-21),
131.71 (C-23 and 27), 131.85 (C-10), 138.27 (C-5), 140.41
(C-20), 143.61 (C-22), 155.82 (C-3).
Molecular Modeling and Dynamics. We initially evalu-
ated the conformations of our ligands 6a-i using the Builder
module from Insight II. Potentials for each atom were assigned
automatically or manually, when necessary. Low-energy con-
formations were generated using the molecular mechanics
method (Discover program, 100 steps, 0.001 final convergence)
and compared to solution conformations determined by NMR.39
The ERR-HBD used in our study was obtained from the
Protein Data Bank (PDB code 1G50, wild-type ERR-HBD
cocrystallized with estradiol). From the available monomers
(A, B), monomer A from the A/C homodimer was selected for
the docking and molecular dynamics studies. All water mol-
ecules present in the crystal structure were deleted. The
monomer contains all the amino acid residues between ASN
304 and HIS 550. All manipulations were performed using the
Builder module in Insight II. The complex of the ERR-HBD
monomer and estradiol bound within the binding cavity was
minimized using the molecular mechanics method with re-
straints applied to the backbone atoms of the protein (Dis-
cover_3 module, CVFF force field, dielectric constant 2.0,
conjugate gradient minimization 10 000 steps or until 0.001
final convergence). All ligands used in this study were con-
structed using the Builder module from Insight II. Potentials
for each atom were assigned automatically or manually when
necessary. Each ligand was optimized using the molecular
mechanics method as done with the receptor. Partial charges
for each atom were calculated using the Mopac program from
the Ampac/Mopac module in the Insight II package. In
addition, ligands were further optimized using the semi-
emperical method (calculation method. PM3; calculation type,
optimization; optimizer type, native).
(17R,20Z)-21-[(4-Methyl)phenyl]-19-norpregna-1,3,5-
(10),20-tetraene-3,17â-diol (6e). Compound 5e (0.14 g,
0.32 mmol) was hydrolyzed to yield 6e (0.060 g, 48%). Recrys-
tallization in chloroform afforded a white powder (0.055 g,
44%): Rf ) 0.38 (hexane/ethyl acetate 4:1); mp 95-96 °C;
1H NMR in CDCl3 δ 0.90 (s, 3H, 18-CH3), 1.2-2.8 (m, 18H,
steroid nucleus), 5.89 (d, 1H, J20-21 ) 12.81 Hz, 20-H), 6.50
(d, 1H, J21-20 ) 12.75 Hz, 21-H), 6.56 (d, 1H, J4-2 ) 2.46 Hz,
4-H), 6.62 (dd, 1H, J2-1 ) 8.40 Hz, J2-4 ) 2.82 Hz, 2-H), 7.15
(m, 3H, 1-H, 23-H, 27-H), 7.34 (d, 2H, J24-23 and J26-27
)
8.19 Hz, 24-H and 26-H); 13C NMR in CDCl3-d6 δ 14.07
(C-18), 21.18 (C-28), 23.26 (C-15), 26.48 (C-11), 27.44 (C-7),
29.68 (C-6), 32.49 (C-12), 38.49 (C-16), 39.61 (C-8), 43.79
(C-9), 47.99 (C-13), 49.58 (C-14), 85.08 (C-17), 112.70 (C-2),
115.26 (C-4), 126.55 (C-24 and C-26), 127.91 (C-1), 128.87
(C-21), 129.01 (C-23 and C-27),132.66 (C-10), 134.31 (C-22),
135.46 (C-25), 136.95 (C-20), 138.30 (C-5), 153.38 (C-3).
(17R,20Z)-21-[(4-Methoxy)phenyl]-19-norpregna-1,3,5-
(10),20-tetraene-3,17â-diol (6g). Compound 5g (0.14 g,
0.314 mmol) was hydrolyzed using the general procedure to
yield 6g (0.125 g, 98%), and recrystallization in acetone/hexane
afforded white crystalline needles (0.120 g, 94%): Rf ) 0.21
(hexane/ethyl acetate 4:1); mp 164-165 °C; 1H NMR in
acetone-d6 δ 0.97 (s, 3H 18-CH3), 1.2-2.9 (m, b, 15H, steroid
nucleus), 3.79 (s, 3H, OCH3), 5.87 (d, 1H, J20-21 ) 12.96 Hz,
20-H), 6.38 (d, 1H, J21-20 ) 12.96 Hz, 21-H), 6.53 (d, 1H, J4-2
) 2.55 Hz, 4-H), 6.62 (dd, 1H, J2-4 ) 2.43 Hz, J2-1 ) 8.43 Hz,
2-H), 6.86 (d, 2H, J24-23 and J26-27 ) 8.91 Hz, 24-H and 26-H),
7.11 (d, 1H, J1-2 ) 8.26 Hz, 1-H), 7.62 (d, 2H, J23-24 and J27-26
) 8.64 Hz, 23-H and 27-H), 7.95 (s, 1H, 3-OH); 13C NMR in
acetone-d6 δ 14.50 (C-18), 23.71 (C-15), 27.27 (C-11), 26.16
(C-7), ∼29 under acetone peak (C-6), 32.60 (C-12), 38.26
(C-16), 40.73 (C-8), 44.52 (C-9), 48.70 (C-13), 49.87 (C-14),
55.29 (-OCH3), 83.78 (C-17), 113.46 (C-2), 113.58 (C-24 and
C-26), 115.81 (C-4), 126.95 (C-1), 129.67 (C-21), 130.52 (C-22),
131.89 (C-10), 132.37 (C-23 and C-27), 135.06 (C-20), 138.32
(C-5), 155.80 (C-3), 159.41 (C-25).
The Affinity program within the Docking module in In-
sightII was used to perform the docking studies of the ligands
with the ERR-HBD.55 This module includes elements from
Monte Carlo, simulated annealing, and minimization for
automatically docking and finding the best structures of the
ligand complexed to the receptor based on the energy of the
ligand-receptor complex. The ligand was superimposed on the
estradiol molecule (A-ring over A-ring), and the estradiol was
then deleted. The complex was subjected to energy minimiza-
tion to obtain a starting structure in which bad steric contacts
are removed and internal energies are relieved. During the
(17R,20Z)-21-[(4-Amino)phenyl]-19-norpregna-1,3,5(10),-
20-tetraene-3,17â-diol (6h). The crude acetylated product 5h
(∼0.5 g) was deprotected to yield a dark-orange solid 6h
(0.34 g, 75.3%) followed by three recrystalizations from