Design, synthesis and biological evaluation of novel triaryl (Z)-olefins as tamoxifen analogues

Article abstract of DOI:10.1016/j.bmcl.2013.06.056

Tamoxifen (TAM) is used for the treatment and prevention of estrogen receptor positive breast cancer. However, the limited activity, toxicity and the development of resistance raised the current need for new potent nontoxic antiestrogen. Six novel TAM ana

Full text of DOI:10.1016/j.bmcl.2013.06.056

Bioorganic & Medicinal Chemistry Letters 23 (2013) 4960–4963
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Design, synthesis and biological evaluation of novel triaryl (Z)-olefins
as tamoxifen analogues
b
c
Khaled R. A. Abdellatif a, , Amany Belal , Hany A. Omar
⇑
a Department of Pharmaceutical Organic Chemistry, Beni-Suef University, Beni-Suef 62514, Egypt
b Department of Medicinal Chemistry, Beni-Suef University, Beni-Suef 62514, Egypt
c Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt
a r t i c l e i n f o
a b s t r a c t
Article history:
Tamoxifen (TAM) is used for the treatment and prevention of estrogen receptor positive breast cancer.
However, the limited activity, toxicity and the development of resistance raised the current need for
new potent nontoxic antiestrogen. Six novel TAM analogues 5a–f were synthesized using McMurry olef-
ination reaction. Replacement of the dimethylamino group in TAM by piperidino, piperazino or N-methyl
piperazino, substituting the phenyl ring with florine atom at p-position and changing the ethyl group by
methyl, afforded compounds showing comparable activity to TAM (1). Compounds 5c and 5e showed sig-
nificant increase in antiproliferative activity in two breast cancer cell lines (MCF-7 and MDA-MB-231)
compared to tamoxifen, while other compounds showed similar activity. The increased anticancer activ-
ity of compounds 5c and 5e was attributed to their ability to induce ER-independent cell death.
Ó 2013 Elsevier Ltd. All rights reserved.
Received 7 May 2013
Revised 13 June 2013
Accepted 17 June 2013
Available online 26 June 2013
Keywords:
Tamoxifen analogues
Triaryl (Z)-olefins
Breast cancer
Estrogen receptors
Breast cancer is the most leading cause of death and the most
frequent cancer in women. Estrogens are the most known stimula-
tor of breast cancer cell growth so antiestrogens are considered
good candidates for the treatment.1,2 Tamoxifen (TAM, 1), the non-
steroidal antiestrogenic drug is one of the most extensively used
drugs to treat hormone-responsive human breast cancers since
1970.3–6 The mode of action of TAM (1) in cancer therapy and in
preventing breast cancer in high risk women is believed to be par-
tially through competing with estrogens for binding to estrogen
receptors.7 High concentrations of TAM activates caspases and trig-
ger apoptotic cell death independently of its estrogen receptors
(ER) binding activity.8,9 Both ER-dependent and ER-independent
pathways for tamoxifen-induced programmed cell death are criti-
cal for successful therapy. The accumulative risk-benefit assess-
ment of TAM therapy and comparative studies with other new
types of drugs established its efficacy and safety.10 Therefore, the
development of new tamoxifen—type drugs are significantly
required.
site) is believed to diminish the binding interaction with Asp 351
(anionic carboxylate site) on the estrogen receptors.12 Although
replacement of the –CH2CH3 substituent in tamoxifen (1) by a –
CH3 substituent does not change the antiproliferative data for
MCF-7 human breast cancer cells.13,14 Accordingly, it was antici-
pated that replacement of the dimethylamino group of aminoalkyl-
oxy moiety with piperidino, piperazino and N-methylpiperazino to
elevate the basic characters of the amino group may provide a new
tamoxifen analogs of potential high antiproliferative activity.
Accordingly, here we describe the synthesis of novel TAM analogs,
molecular modeling studies, and their antiproliferative effect on
MCF-7 and MDA-MB-231 human breast cancer cells.
The synthetic pathways adopted for the preparation of the
desired new compounds are illustrated in Scheme 1. The (Z)-1-[4-
(2-chloroethoxy)phenyl]-1,2-diphenylprop-1-ene (4a) was synthe-
sized using a McMurry olefination reaction by Zn–TiCl4 catalzyed
reductive cross-coupling of 4-(2-chloroethoxy)benzophenone (2)
with acetophenone (3a) in 38% yield. The 4a product was the sole
The aminoalkyloxy moiety present in TAM (OCH2CH2NMe2,
Fig. 1) plays a major role in determining receptor binding affinity.11
Decreasing the basicity of the protonated amino group (cationic
Abbreviations: TAM, tamoxifen; ER, estrogen receptor; MOE, molecular operat-
ing environment; MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium
bromide; DMEM/F12, Dulbecco’s modified Eagle medium nutrient mixture F-12;
FBS, fetal bovine serum.
⇑
Corresponding author. Tel.: +20 100 2535444; fax: +20 82 2317958.
E-mail address: khaled.ahmed@pharm.bsu.edu.eg (K.R.A. Abdellatif).
Figure 1. Chemical structure of Tamoxifen (1).
0960-894X/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmcl.2013.06.056

K. R. A. Abdellatif et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4960–4963
4961
Scheme 1. Reagents and conditions: (a) Zn, TiCl4, THF, reflux 3.5 h; (b) piperidine, piperazine or N-methylpiperazine, EtOH, reflux 24 h.
stereoisomer obtained after silica gel column chromatography and
recrystallization from n-hexane. A similar cross-coupling reaction
of the benzophenone analog 2 with 4-floroacetophenone (3b)
afforded the (Z)-1-[4-(2-chloroethoxy)phenyl]-1-(4-florophenyl)-
2-phenylprop-1-ene (4b) (40%). Subsequent reaction of the chloro-
ethoxy 4a and 4b with piperidine, piperazine or N-methylpiperazine
in EtOH at reflux afforded the target compounds 5a–f in high yields
(72–85%). Stereoisomer assignments were made based on 1H NMR
chemical shifts from published information.15–19 4-(2-Chloroeth-
oxy)benzophenone (2) was prepared according to the reported
procedure.20
The rational for the design of the new tamoxifen analogs (5a–f)
was based on the expectation that replacement of a dimethyl ami-
no moiety in TAM (1) by other secondary amine moieties such as
piperidino, piperazino and N-methylpiperazino would furnish no-
vel tamoxifen analogs with high antiproliferative activity. Chang-
ing the ethyl group with methyl one and substituting the para
position of the phenyl ring with florine atom were also performed
to study its impact on activity. Docking experiments for the pre-
pared compounds 5a–f in the ligand binding domain (LBD), derived
from the structure of ER
all compounds showed score energy less than or closely similar
to tamoxifen (Table 1), docking tamoxifen into ER presented in
a crystallized with OH-Tam, showed that
Figure 2. Docking of Tamoxifen in the active site of ER
mol.
a
(3ERT), S = À30.12 kcal/
a
Figure 2. Furthermore, compounds 5c and 5e showed a hydrogen
bonding to Asp-351 amino acid (Figs. 3 and 4). The antiprolifera-
tive effect of increasing concentrations of the synthesized com-
pounds compared to tamoxifen in the presence and absence of
estradiol on MCF-7 and MDA-MB-231 cells was estimated using
MTT assay. Compounds 5c and 5e showed about twofold increase
in the antiproliferative activity compared to tamoxifen (Table 2),
while other compounds like 5a and 5f showed similar activities
like tamoxifen. To figure out if the increased antiproliferative activ-
ity of test compounds is ER-dependent or not, the antiproliferative
activity was estimated in an ER-negative breast cancer cell line,
MDA-MB-231 cells. In addition, the ability of these compounds
to antagonize estradiol-induced cell growth in MCF-7 cells was
tested. Both compounds 5c and 5e showed similar potency in
antagonizing estradiol-induced breast cancer cell growth and
Table 1
Docking energy score results. Tamoxifen (TAM) was docked in the active site of ER
a
receptor (3ERT.pdb) with S = À30.1209 kcal/mol (Fig. 2), the novel six tamoxifen
Figure 3. Docking of 5c (green colored) in the active site of 3ERT (S = À31.02 kcal/
analogs were docked against the same receptor using the same method
mol) exhibiting interaction with Asp-351, hydrogen bond 2.34 Å.
Compounds
Docking energy score (kcal/mol)
inhibiting the proliferation of MDA-MB-231 cells which indicates
that the increased anticancer activities is ER-independent (Table 2,
Fig. 5). To explain the increased anticancer activity of compounds
5c and 5e, their ability to induce ER-independent cell death was
tested. Both compounds showed relatively high ability to trigger
classic caspase-dependent apoptosis as indicated by increased cas-
pase 3/7 activities in MCF-7 treated cells compared to TAM (Fig. 6).
5a
5b
5c
5d
5e
5f
À31.8890
À31.7390
À31.0242
À31.1929
À28.9745
À31.4630
À30.1209
TAM

4962
K. R. A. Abdellatif et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4960–4963
Figure 6. Compounds 5c, 5e and tamoxifen increase caspases activities in MCF-7
cells. Apoptosis was assessed by analysis of activation of caspase-3 and -7 using
luminogenic substrate containing the DEVD sequence from Caspase-Glo™ 3/7 assay
kit. Results are expressed as the mean of relative light unit (RLU). Differences
among means were analyzed for statistical significance using one-way ANOVA
followed by the Dunnett’s test Columns, mean; bars, SD (n = 6). ⁄P < 0.05, ⁄⁄P < 0.01,
⁄⁄⁄P < 0.001 as compared to vehicle (DMSO)-treated cells.
Figure 4. Docking of 5e (green colored) in the active site of 3ERT (S = À28.97 kcal/
mol) exhibiting interaction with Asp-351, hydrogen bond 2.35 Å.
Table 2
Antiproliferative effect of test compounds and tamoxifen on MCF-7 and MDA-MB-231
cells. The reported IC50 values are concentrations at which cells death measures 50%
relative to DMSO control after 72 h exposure test compounds or tamoxifen (TAM) in
5% FBS-containing DMEM/F12 in 96-well plates. Cell viability was assessed by MTT
assay. Differences among means were analyzed for statistical significance using one-
way ANOVA followed by the Dunnett’s test. Values are means SD (n = 6)
New TAM analogs 5a–f were designed for evaluation as antipro-
liferative agents. Compounds 5c, 5d and 5e analogues exhibited
better activity than tamoxifen, whoever, 5a, 5b and 5f analogues
were less active than tamoxifen. The structure–activity data
acquired indicate that (i) some compounds exhibit better antipro-
liferative activity than tamoxifen when tested against MCF-7 and
MDA-MB-231 human breast cancer cells, (ii) replacement of a di-
methyl amino moiety in TAM (1) by more basic moieties such as
piperazino in 5c or N-methylpiperazino in 5e can be used as a tool
to prepare novel tamoxifen analogs with high antiproliferative
activity, (iii) addition of the florine atom on the p-position of the
phenyl ring resulted in more active analogues than tamoxifen 5c
and 5e except for compound 5f was less active than tamoxifen,
(iv) docking studies revealed that all the synthesized analogues
Compounds
IC50 (lM)
MCF-7
MDA-MB-231
5a
5b
5c
5d
5e
5f
55.46 4.21*
>100
73.54 5.03*
>100
6.75 1.34*
16.55 2.56*
5.58 1.76*
86.28 3.98*
27.96 2.64
10.53 1.98*
42.97 3.27*
13.04 2.40*
>100
TAM
64.85 4.09
*
P < 0.01as compared to tamoxifen (TAM)-treated cells.
have low docking score energy with ERa. Moreover, compounds
5c and 5e exhibited a hydrogen bond interaction with Asp-831
amino acid, (v) pharmacological screening revealed the ability of
some of the synthesized analogues to target breast cancer cells
not only via ER receptor binding but also via ER receptor-indepen-
dent mechanisms.
Titanium tetrachloride (0.99 mL, 9 mmol) was added drop wise
to a stirred suspension of Zn powder (1.18 g, 18 mmol) in dry THF
(15 mL) under an argon atmosphere at À10 °C, and this mixture
was heated under reflux for 1.5 h to produce the titanium reagent.
A cooled suspension of this titanium reagent was added to a
solution of 4-(2-chloroethoxy)benzophenone (2, 0.78 g, 3.0 mmol)
andacetophenone (3a, 0.36 g, 3.0 mmol) in THF (20 mL) at 0 °C, and
the reaction was allowed to proceed at reflux for 2 h. After cooling
to 25 °C, the reaction mixture was poured into a 10% aqueous
K2CO3 solution (45 mL), this mixture was stirred vigorously for
5 min, and the dispersed insoluble material was removed by
vacuum filtration. The organic fraction was separated, the aqueous
layer was extracted with EtOAc (3 Â 25 mL), and the combined
organic fractions were dried (Na2SO4). Removal of the solvent in
vacuum afforded a residue which was purified by silica gel column
chromatography using EtOAc–hexane (1:4, v/v) as eluent followed
by recrystallization of the product from n-hexane to give (Z)-4a as
white crystals. Compound 4b was synthesized using the same
procedure described for the preparation of 4a, by reaction of
Figure 5. Antiproliferative effect of test compounds and tamoxifen at
5 lM
concentration in the presence and absence of 1 nmol/L estradiol on MCF-7 cells.
Cell proliferation is expressed as the percentage of the cells compared with the
control wells. Differences among means were analyzed for statistical significance
using one-way ANOVA followed by the Dunnett’s test. Columns, mean of two
experiments, each with six replicates; bars, SD. ⁄P < 0.01 as compared to control
(estradiol)-treated cells.

K. R. A. Abdellatif et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4960–4963
4963
Compound
5b:
(Z)-1-{2-[4-(1,2-diphenyl-propenyl)-phenoxy]-
(4-chloroethoxyphenyl)benzophenone (2) with the 4-floroace-
tophenone (3b). The product obtained as white crystals.
ethyl}piperazine. 72% yield; mp 134–136 °C; IR: 3130 (NH), 3044 (CH
aromatic), 2939 (CH aliphatic) cmÀ1 1H NMR (CDCl3) d 2.13 (s, 3H, CH3),
;
A mixture of 4a or 4b (2 mmol) and an appropriate secondary
amine (100 mmol) in absolute ethanol (30 ml) was refluxed for
24 h, the solvent was removed under vacuum and the residue was
crystallized from ethanol to produce the pure compounds 5a–f as
white crystals. The effect of test agents on cell viability was assessed
using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazo-
lium bromide (MTT) assay in six replicates as previously reported.21
Caspase-3/7 and caspase-8 activities in MCF-7 cells treated with test
agents were measured using a Caspase-Glo assay kit as mentioned
before22 and according to the manufacturer’s instructions. Results
were verified by docking study. 21-25
2.74 (t, J = 4.6 Hz, 4H, piperazinyl H-3, H-5), 2.78 (t, J = 6.1 Hz, 2H, OCH2CH2N),
3.09 (t, J = 4.6 Hz, 4H, piperazinyl H-2, H-6), 3.98 (t, J = 6.1 Hz, 2H, OCH2CH2N),
6.56 (dd, J = 6.6, 1.8 Hz, 2H, ethoxyphenyl H-3, H-5), 6.80 (dd, J = 6.6, 1.8 Hz,
2H, ethoxyphenyl H-2, H-6), 7.12–7.38 (m, 10H, phenyl hydrogens); 13C NMR
(CDCl3): d 23.1, 43.1, 53.9, 57.6, 67.6, 113.6, 126.2, 126.6, 127.9, 128.2, 129.5,
130.9, 131.4, 135.5, 136.3, 138.2, 143.2, 143.6, 156.0; MS m/z (ES+) 399.1,
C
27H31N2O (M+H) requires 399.55. Anal. Calcd. for C27H30N2O (398.54): C,
81.37; H, 7.59; N, 7.03. Found: C, 81.44; H, 7.63; N, 7.27.
Compound 5c: (Z)-1-{2-[4-(1,2-diphenyl-propenyl)-phenoxy]-ethyl}-4-
methylpiperazine. 85% yield; mp 115–117 °C; IR: 3054 (CH aromatic), 2936
(CH aliphatic) cmÀ1 1H NMR (CDCl3) d 2.13 (s, 3H, CH3), 2.37 (s, 3H, NCH3),
;
2.59–2.67 (m, 8H, piperazinyl H), 2.78 (t, J = 6.1 Hz, 2H, OCH2CH2N), 3.99 (t,
J = 6.1 Hz, 2H, OCH2CH2N), 6.57 (d, J = 8.5 Hz, 2H, ethoxyphenyl H-3, H-5), 6.79
(d, J = 8.5 Hz, 2H, ethoxyphenyl H-2, H-6), 7.12-7.39 (m, 10H, phenyl
hydrogens); 13C NMR (CDCl3):
d 23.4, 45.6, 53.0, 54.8, 57.0, 65.6, 113.5,
126.0, 126.5, 127.9, 128.0, 129.2, 130.0, 131.9, 134.8, 135.7, 138.7, 143.7, 144.2,
References and notes
156.7; MS m/z (ES+) 413.1, C28H32N2O (M+H) requires 413.57. Anal. Calcd. for
C
28H32N2O (412.57): C, 81.51; H, 7.82; N, 6.79. Found: C, 81.43; H, 7.76; N, 6.56.
Compound 5d: (Z)-1-(2-{4-[2-(4-fluoro-phenyl)-1-phenyl-propenyl ]-
phenoxy}-ethyl)piperidine. 73% yield; mp 106–108 °C; IR: 3050 (CH
aromatic), 2934 (CH aliphatic) cmÀ1 1H NMR (CDCl3) d 1.29–1.46 (m, 2H,
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Biochem. Pharmacol. 1998, 55, 841.
;
piperidinyl H-4), 1.64–1.66 (m, 4H, piperidinyl H-3, H-5), 2.13 (s, 3H, CH3),
2.56–2.58 (m, 4H, piperidinyl H-2, H-6), 2.80 (t, J = 5.5 Hz, 2H, OCH2CH2N), 4.06
(t, J = 5.5 Hz, 2H, OCH2CH2N), 6.58 (dd, J = 6.6, 2.4 Hz, 2H, ethoxyphenyl H-3, H-
5), 6.77 (dd, J = 6.6, 2.4 Hz, 2H, ethoxyphenyl H-2, H-6), 6.84–6.90 (m, 2H,
fluorophenyl H-3, H-5), 7.09–7.14 (m, 2H, fluorophenyl H-2, H-6), 7.24–7.38
(m, 5H, phenyl hydrogens); 13C NMR (CDCl3): d 23.3, 23.9, 25.5, 54.9, 57.7, 65.3,
113.6, 114.6, 126.6, 128.1, 129.9, 130.8, 131.9, 133.7, 135.5, 139.1, 140.1, 143.6,
156.7, 162.7; MS m/z (ES+) 416.1, C28H31FNO (M+H) requires 416.54. Anal.
Calcd. for C28H30FNO (415.54): C, 80.93; H, 7.28; N, 3.37. Found: C, 80.84; H,
7.24; N, 3.35.
Compound
phenoxy}-ethyl) piperazine. 74% yield; mp 115–117 °C; IR: 3133 (NH), 3055
(CH aromatic), 2942 (CH aliphatic) cmÀ1 1H NMR (CDCl3) d 2.11 (s, 3H, CH3),
5e:
(Z)-1-(2-{4-[2-(4-fluoro-phenyl)-1-phenyl-propenyl]-
;
2.61 (t, J = 4.5 Hz, 4H, piperazinyl H-3, H-5), 2.76 (t, J = 5.5 Hz, 2H, OCH2CH2N),
3.00 (t, J = 4.5 Hz, 4H, piperazinyl H-2, H-6), 4.00 (t, J = 5.5 Hz, 2H, OCH2CH2N),
6.59 (dd, J = 6.6, 1.8 Hz, 2H, ethoxyphenyl H-3, H-5), 6.78 (dd, J = 6.6, 1.8 Hz,
2H, ethoxyphenyl H-2, H-6), 6.84–6.91 (m, 2H, fluorophenyl H-3, H-5), 7.09–
14. Zheng, L.; Wei, Q.; Zhou, B.; Yang, L.; Liu, Z. L. Anticancer Drugs 2007, 18, 1039.
15. Robertson, D. W.; Katzenellenbogen, J. A.; Hayes, J. R.; Katzenellenbogen, B. S. J.
Med. Chem. 1982, 25, 167.
7.14 (m, 2H, fluorophenyl H-2, H-6), 7.22–7.36 (m, 5H, phenyl hydrogens); 13
C
16. Yang, D. J.; Wallace, S.; Tansey, W.; Wright, K. C.; Kuang, L. R.; Tilbury, R. S.;
Diego, I.; Lim, J. L.; Emran, A. M.; Kim, E. E. Pharm. Res. 1991, 8, 174.
17. Foster, A. B.; Jarman, M.; Leung, O. T.; McCague, R.; Leclercq, G.;
Devleeschouwer, N. J. Med. Chem. 1985, 28, 1491.
18. McCague, R.; Leclercq, G.; Jordan, V. C. J. Med. Chem. 1988, 31, 1285.
19. McCague, R.; Leclercq, G.; Legros, N.; Goodman, J.; Blackburn, G. M.; Jarman,
M.; Foster, A. B. J. Med. Chem. 1989, 32, 2527.
20. Coe, P. L.; Scriven, C. E. J. Chem. Soc., Perkin Trans. 1 1986, 475.
21. Omar, H. A.; Sargeant, A. M.; Weng, J. R.; Wang, D.; Kulp, S. K.; Patel, T.; Chen, C.
S. Mol. Pharmacol. 2009, 76, 957.
22. Omar, H. A.; Chou, C. C.; Berman-Booty, L. D.; Ma, Y.; Hung, J. H.; Wang, D.;
Kogure, T.; Patel, T.; Terracciano, L.; Muthusamy, N.; Byrd, J. C.; Kulp, S. K.;
Chen, C. S. Hepatology 2011, 53, 1943.
NMR (CDCl3): d 23.3, 45.5, 53.7, 57.6, 65.6, 113.6, 114.9, 126.6, 128.1, 129.9,
130.8, 131.9, 133.7, 135.5, 139.1, 140.1, 143.6, 156.8, 162.7; MS m/z (ES+)
417.1,
(416.53): C, 77.85; H, 7.02; N, 6.73. Found: C, 77.90; H, 7.13; N, 6.69.
Compound 5f: (Z)-1-(2-{4-[2-(4-fluoro-phenyl)-1-phenyl-propenyl]-
phenoxy}-ethyl)-4-methylpiperazine. 82% yield; mp 127–129 °C; IR: 3047
(CH aromatic), 2937 (CH aliphatic) cmÀ1 1H NMR (CDCl3) d 2.09 (s, 3H, CH3),
C27H30FN2O (M+H) requires 417.53. Anal. Calcd. for C27H29FN2O
;
2.38 (s, 3H, NCH3), 2.52–2.75 (m, 8H, piperazinyl H), 2.78 (t, J = 6.1 Hz, 2H,
OCH2CH2N), 4.00 (t, J = 6.1 Hz, 2H, OCH2CH2N), 6.57 (dd, J = 6.6, 1.8 Hz, 2H,
ethoxyphenyl H-3, H-5), 6.76 (dd, J = 6.6, 1.8 Hz, 2H, ethoxyphenyl H-2, H-6),
6.83–6.89 (m, 2H, fluorophenyl H-3, H-5), 7.08–7.13 (m, 2H, fluorophenyl H-2,
H-6), 7.20–7.37 (m, 5H, phenyl hydrogens); 13C NMR (CDCl3): d 23.3, 45.7, 53.1,
54.8, 57.0, 65.7, 113.6, 114.9, 126.6, 128.1, 129.9, 130.8, 131.9, 133.7, 135.5,
139.1, 140.1, 143.6, 156.8, 162.7; MS m/z (ES+) 431.2, C28H32FN2O (M+H)
requires 431.56. Anal. Calcd. for C28H31FN2O (430.56): C, 78.11; H, 7.26; N,
6.51. Found: C, 77.99; H, 7.23; N, 6.38.
23. Spectral data for compounds 4a, 4b and 5a–f. Compound 4a: (Z)-1-[4-(2-
chloroethoxy)phenyl]-1,2-diphenyl-prop-1-ene. 38% yield; mp 128–130 °C; IR:
3053 (CH aromatic), 2909 (CH aliphatic) cmÀ1 1H NMR (CDCl3) d 2.12 (s, 3H,
;
CH3), 3.74 (t, J = 5.7 Hz, 2H, OCH2CH2Cl), 4.11 (t, J = 5.7 Hz, 2H, OCH2CH2Cl),
6.56 (dd, J = 6.6, 1.8 Hz, 2H, chloroethoxyphenyl H-3, H-5), 6.79 (dd, J = 6.6,
1.8 Hz, 2H, chloroethoxyphenyl H-2, H-6), 7.16–7.38 (m, 10H, phenyl
hydrogens); 13C NMR (CDCl3): d 23.3, 41.8, 67.7, 113.6, 126.0, 126.5, 127.8,
128.0, 129.2, 130.8, 131.9, 135.0, 136.2, 138.5, 143.6, 144.1, 156.1; MS m/z
(ES+) 349.1, C23H22ClO (M+H) requires 348.86.
24. Docking studies were achieved by Molecular Operating Environment (MOE,
Version 2005.06, Chemical Computing Group Inc., Montreal, Quebec, Canada)
using 3ERT.pdb file, which is a co-crystallized 4-hydroxytamoxifen with the
human ER-alpha. The top score docking energy value for each ligand was
recorded after performing 100 docking interactions for each one of these
ligands.
25. MCF-7 human breast cancer cells were obtained from the American Type
Culture Collection (Manassas, VA) and cultured in Dulbecco’s modified Eagle’s
medium/F12 medium (DMEM/F-12, Gibco, Grand Island, NY) supplemented
with 10% fetal bovine serum (FBS; Gibco). All cells were cultured at 37 °C in a
humidified incubator containing 5% CO2. Cells were seeded in 96-well flat-
bottomed plates for 24 h, and treated with test agents in 5% FBS-supplemented
DMEM/F-12 for 72 h in the presence and absence of 0.1 nM estradiol. Controls
received DMSO vehicle at a concentration equal to that in drug-treated cells.
After treatment, cells were incubated in the same medium containing 0.5 mg/
Compound
phenylprop-1-ene. 40% yield; mp 125–127 °C; IR: 3050 (CH aromatic), 2918
(CH aliphatic) cmÀ1 1H NMR (CDCl3) d 2.10 (s, 3H, CH3), 3.75 (t, J = 5.7 Hz, 2H,
4b:
(Z)-1-[4-(2-chloroethoxy)phenyl]-1-(4-florophenyl)-2-
;
OCH2CH2Cl), 4.12 (t, J = 5.7 Hz, 2H, OCH2CH2Cl), 6.58 (dd, J = 6.6, 1.8 Hz, 2H,
chloroethoxyphenyl H-3, H-5), 6.77 (dd, J = 6.6, 1.8 Hz, 2H, chloroethoxyphenyl
H-2, H-6), 6.84–6.89 (m, 2H, fluorophenyl H-3, H-5); 7.08–7.13 (m, 2H,
fluorophenyl H-2, H-6); 7.21–7.38 (m, 5H, phenyl hydrogens); 13C NMR
(CDCl3): d 23.3, 41.8, 67.9, 113.6, 114.9, 126.6, 128.1, 129.8, 130.8, 131.9, 133.9,
136.1, 139.0, 140.0, 143.5, 156.2, 162.8; MS m/z (ES+) 367.1, C23H21ClFO (M+H)
requires 367.86.
ml MTT at 37 °C for 2 h. Reduced MTT was solubilized in DMSO (200 lL/well)
for determination of absorbance at 570 nm using a microplate reader. Cells
Compound
ethyl}piperidine. 78% yield; mp 132–133 °C; IR: 3056 (CH aromatic), 2937
(CH aliphatic) cmÀ1 1H NMR (CDCl3) d 1.34–1.43 (m, 2H, piperidinyl H-4),
5a:
(Z)-1-{2-[4-(1,2-diphenyl-propenyl)-phenoxy]-
were plated at 1 Â 104 (100
l
l/well) into clear bottom, opaque wall 96-well
;
tissue culture plates and incubated for 24 h. The medium was removed and the
cells were then treated with test compounds for 72 h. Caspase-3/7 activity
were then calculated according to the instructions included in the kit. The
activity of caspase-3 and -7 was measured indirectly by assessing the product
of its reaction with luminogenic substrate containing the DEVD sequence.
Results are expressed as the mean of relative light unit (RLU). The
luminescence of plates was read using an illuminometer.
1.56–1.64 (m, 4H, piperidinyl H-3, H-5), 2.13 (s, 3H, CH3), 2.46–2.48 (m, 4H,
piperidinyl H-2, H-6), 2.71 (t, J = 6.1 Hz, 2H, OCH2CH2N), 4.00 (t, J = 6.1 Hz, 2H,
OCH2CH2N), 6.58 (dd, J = 6.6, 1.8 Hz, 2H, ethoxyphenyl H-3, H-5), 6.80 (dd,
J = 6.6, 1.8 Hz, 2H, ethoxyphenyl H-2, H-6), 7.10–7.32 (m, 10H, phenyl
hydrogens); 13C NMR (CDCl3):
d 23.1, 23.7, 25.2, 54.9, 57.7, 65.1, 113.8,
126.2, 126.8, 127.8, 128.1, 129.2, 130.9, 131.9, 135.0, 136.3, 138.7, 143.6, 144.2,
156.0; MS m/z (ES+) 398.1, C28H32NO (M+H) requires 398.55. Anal. Calcd. for
C
28H31NO (397.55): C, 84.59; H, 7.86; N, 3.52. Found: C, 84.67; H, 7.94; N, 3.81.