Synthesis and cytotoxic activity evaluation of 2,3-thiazolidin-4-one derivatives on human breast cancer cell lines

Article abstract of DOI:10.1016/j.bmcl.2013.06.051

It is well known that resveratrol (RSV) displayed cancer-preventing and anticancer properties but its clinical application is limited because of a low bioavailability and a rapid clearance from the circulation. Aim of this work was to synthesize pharmacol

Full text of DOI:10.1016/j.bmcl.2013.06.051

Bioorganic & Medicinal Chemistry Letters xxx (2013) xxx–xxx
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis and cytotoxic activity evaluation of 2,3-thiazolidin-4-one
derivatives on human breast cancer cell lines
Marina Sala a, , Adele Chimento b, , Carmela Saturnino a, Isabel M. Gomez-Monterrey c, Simona Musella d,
Alessia Bertamino a, Ciro Milite a, Maria Stefania Sinicropi b, Anna Caruso b, Rosa Sirianni b, Paolo Tortorella e,
b,
Ettore Novellino c, Pietro Campiglia a, , Vincenzo Pezzi
⇑
⇑
a Department of Pharmaceutical Science, Division of Biomedicine, University of Salerno, Fisciano, SA 84084, Italy
b Department of Pharmacy, Health and Nutrition Sciences, University of Calabria, Arcavacata di Rende, Cosenza 87036, Italy
c Department of Pharmaceutical and Toxicological Chemistry, University of Naples ‘‘Federico II’’, Naples 8013, Italy
d Department Pharmaco-Biological, University of Messina, 98168 Messina, Italy
e Department Pharmaceutical Chemistry, University of Bari ‘‘Aldo Moro’’, 70125 Bari, Italy
a r t i c l e i n f o
a b s t r a c t
Article history:
It is well known that resveratrol (RSV) displayed cancer-preventing and anticancer properties but its clin-
ical application is limited because of a low bioavailability and a rapid clearance from the circulation. Aim
of this work was to synthesize pharmacologically active resveratrol analogs with an enhanced structural
rigidity and bioavailability. In particular, we have synthesized a library of 2,3-thiazolidin-4-one deriva-
tives in which a thiazolidinone nucleus connects two aromatic rings. Some of these compounds showed
strong inhibitory effects on breast cancer cell growth. Our results indicate that some of thiazolidin-based
resveratrol derivatives may become a new potent alternative tool for the treatment of human breast
cancer.
Received 24 April 2013
Revised 11 June 2013
Accepted 16 June 2013
Available online xxxx
Keywords:
Resveratrol analogs anticancer drugs
2,3-Thiazolidin-4-one derivatives
Polyphenol
Breast cancer cells
MCF-7
Ó 2013 Published by Elsevier Ltd.
SKBR3
Epidemiological and current laboratory studies suggest that
consumption of certain types of fruits and vegetables, containing
phytochemicals, is associated with reduced cancer risk.1
Furthermore, it is postulated that dietary phytochemicals can func-
tion as chemopreventive and/or adjuvant chemotherapeutic
agents. One such phytochemical is resveratrol (3,5,40-trihydroxy-
trans-stilbene) (RSV), (Fig. 1) a naturally occurring phytoalexin,
readily available in the diet and a lot of health-promoting effects
have been ascribed to it.
Resveratrol, first identified as a bioactive compound in 1992, is
found in several plants, particularly in the skin of red grapes.2
This compound has elicited much attention in recent years, as a
potential anticancer agent, since its inhibitory effect on carcino-
genic processes (initiation, promotion, and progression) was first
reported in 1997.3 Thereafter extensive studies have verified the
cancer-preventing and anticancer properties of resveratrol in vari-
ous murine models of human cancer, including skin cancer (both
chemically and ultraviolet B-induced), gastric and colorectal can-
cer, lung cancer, breast cancer, ovarian and prostate cancer, hepa-
toma, neuroblastoma, fibrosarcoma, pancreatic cancer, and
leukemia.4 Several studies, using both in vitro and in vivo model
systems, have illustrated resveratrol’s capacity to modulate a mul-
titude of signaling pathways associated with cellular growth and
division, apoptosis, angiogenesis, invasion, and metastasis.5
In particular, it exhibits an action in both hormone-sensitive
and hormone-resistant breast cancer cells and shows cytostatic
activity and determines cell growth arrest; these properties seem
to be related to regulation of xenobiotic carcinogen metabolism
and antiinflammatory, antiproliferative, and pro-apoptotic effects.6
The phytoestrogenic character of RSV was confirmed by its capac-
ity to bind and activate a- and b-estrogen receptors (ERs) regulat-
ing transcription of estrogen-responsive target genes. However,
OH
HO
⇑
Corresponding authors. Fax: +39 089 969353 (P.C.); fax: +39 0984 493271
(V.P.).
OH
E-mail addresses: pcampigl@unisa.it (P. Campiglia), v.pezzi@unical.it (V. Pezzi).
These authors equally contributed to this work.
Figure 1. Resveratrol (3,5,40-trihydroxy-trans-stilbene) (RSV).
0960-894X/$ - see front matter Ó 2013 Published by Elsevier Ltd.
http://dx.doi.org/10.1016/j.bmcl.2013.06.051
Please cite this article in press as: Sala, M.; et al. Bioorg. Med. Chem. Lett. (2013), http://dx.doi.org/10.1016/j.bmcl.2013.06.051

2
M. Sala et al. / Bioorg. Med. Chem. Lett. xxx (2013) xxx–xxx
in culture, Gehm et al.7 showed that RSV (3–10
ist when combined with estradiol (E2), while Lu and Serrero8 re-
ported ER antagonism of RSV (5 M) in the presence of E2 and
partial agonism in its absence.8 Bowers et al.9 observed partial to
full agonism in CHO-K1 cells transfected with ER or ERb and re-
porter genes based on various estrogen receptor element (EREs).
The authors showed that RSV (100 M) acts as a mixed agonist/
antagonist in cells transiently transfected with ER and mediates
higher transcriptional activity when bound to ERb than to ER
lM) is a superagon-
S
R
HO
O
N
l
OH
a
R1
cis-like conformation
OH
I
l
Figure 2. Structure of cis-resveratrol (I) and
resveratrol containing an thiazolidin-4-one moiety.
a cis-conformation mimetic of
a.
Moreover, RSV showed antagonist activity with ERa, but not with
ERb.9 Based on these reports, it appears that the ability of RSV to
act as an ER agonist varies between different cell types and dosage.
Resveratrol acts as an estrogen-agonist or antagonist that depends
although a number of studies have been conducted, the effects of
RSV on ERs remain controversial. For example, with MCF-7 cells
Table 1
Library of synthesized 2,3-thiazolidin-4-one (3–14)
Entry
Arylamine
Aryl-aldehyde
2,3-Thiazolidin-4-one derivative
Yield (%)
H
O
S
HO
NH2
OH
OH
N
O
1a
2a
1
93
HO
OH
3
OH
O
O
S
S
HO
HO
NH2
NH2
H
O
N
N
1a
1a
2
3
47
63
OH
OH
2b
HO
HO
4
OH
H
O
OH
OH
2c
HO
HO
5
S
O
O
O
HO
HO
HO
NH2
NH2
NH2
H
O
OH
N
N
N
1a
1a
1a
4
5
80
85
OH
2d
HO
HO
HO
OH
6
S
S
O
O
H
O
O
2e
O
O
7
O
O
H
O
O
O
O
O
6
90
2f
O
S
8
O
O
HO
NH2
H
O
N
1a
7
90
2g
HO
O
9
Please cite this article in press as: Sala, M.; et al. Bioorg. Med. Chem. Lett. (2013), http://dx.doi.org/10.1016/j.bmcl.2013.06.051

M. Sala et al. / Bioorg. Med. Chem. Lett. xxx (2013) xxx–xxx
3
Table 1 (continued)
Entry
Arylamine
Aryl-aldehyde
2,3-Thiazolidin-4-one derivative
Yield (%)
H
O
S
HO
NH2
Cl
Cl
N
O
1a
2h
8
9
90
HO
Cl
10
H
O
S
H3C
NH2
N
O
1b
2h
56
H3C
O
Cl
11
H
S
NH2
N
O
1c
10
11
80
48
2i
12
O
S
H3C
H3C
NH2
NH2
N
H
1b
1b
O
2j
13
O
O
S
H
N
O
O
O
2f
O
12
85
H3C
O
O
14
upon the relative abundance of ER-
a
and -b and the cis-regulatory
replacement of the alkene linker between the two aromatic rings
with a heterocyclic system. This approach keeps the geometry of
these rings relatively unchanged and close to that of the cis stilbene
template. Now, we prepared a library of 2,3-diaryl-4-thiazolidi-
none derivatives in which a thiazolidin-4-one nucleus connects
two aromatic rings (Fig. 2).
This design results in an increase in the structural rigidity of the
new analogs, fixing the cis-conformation of resveratrol. Modifica-
tions on both aryl moieties have been also considered in order to
define which functional groups are critical for cell proliferation
control. These variations could lead to new restricted conformation
analogs of resveratrol with higher cytotoxic activity that this and,
hence, higher ability to inhibit the growth of cancer cells in vitro.
The synthesis of designed compounds16 (3–14, Table 1) was car-
ried out by condensation of anilines (1) and aldehydes (2) with
thioglycolic acid in THF using N,N-dicyclohexylcarbodiimide
(DCC) as a dehydrating agent (Scheme 1). This protocol, described
by Srivastava et al.17 has the advantage of mild reaction conditions,
sequences they target.10 Furthermore, resveratrol was also shown
to inhibit the proliferation of the estrogen-receptor negative hu-
man breast carcinoma cell line, MDA-MB-468, by inhibiting the
levels of autocrine growth stimulators.11
Although the anticancer effects of resveratrol have been dem-
onstrated, its clinical application is limited because of a low bio-
availability and a rapid clearance from the circulation.12 In fact,
in humans, three metabolic pathways have been identified, that
is, sulfate and glucuronic acid conjugation of the phenolic groups
and hydrogenation of the aliphatic double bond, the latter likely
produced by the intestinal microflora.13 Extremely rapid sulfate
conjugation by the intestine/liver appears to be the rate-limiting
step in resveratrol’s bioavailability. Virtually no unconjugated res-
veratrol was detected in urine or serum samples, which could have
implications regarding the significance of in vitro studies that used
only unconjugated resveratrol.
The structural alteration of the stilbene moiety of resveratrol
has been found to be a promising strategy for generation of several
synthetic analogs with improved pharmacokinetic parameters.
Moreover, the structure-activity studies have shown that methoxy
groups added to the trihydroxystilbene scaffold of resveratrol, sig-
nificantly potentiated its cytotoxic activity.14 In view of the signif-
icant biological and anticancer potential of RSV, we considered its
structure as lead compound for the design and synthesis of small
molecules with structural rigidity, enhance bioavailability and
antitumoral activity. Recently, Mayhoub et al.15 described a series
of 2,3-thiadiazol analogs of resveratrol using a strategy by the
5
1
4
O
2 S
O
H
NH2
R2
3
N
R2
R3
HSCH2CO2H, DCC
THF, 0°C rt
R3
+
R5
R1
R4
R1
1
R5
R4
2
3-14
Scheme 1. Synthesis of 2,3-thiazolidin-4-one derivates (3–14).
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4
M. Sala et al. / Bioorg. Med. Chem. Lett. xxx (2013) xxx–xxx
a very short reaction time (1 h) and product formation in high
yields (47–93%).
We evaluated the effects on cell proliferation of these new
derivatives against estrogen receptor positive (ER+) MCF-7
(Fig. 3) and estrogen receptor negative (ERꢀ) SKBR3 (Fig. 4) human
breast cancer cell line at different concentrations (0.1, 1, 10
using the MTT assay.18
lM)
Therefore, we treated for 72 h MCF-7 and SKBR3 cells with each
compounds and also with RSV in order to compare the anticancer
effects of the chemicals used to this well-known anticancer agent.
In MCF7 cells, 5, 7–8 (Fig. 3a), 9–12 (Fig. 3b) determined a clear
dose-response inhibitory effect on cell growth. Low doses of4
(Fig. 3a) and 13 (Fig. 3b) elicited an inhibition while higher doses
do not favor it. 14 (Fig. 3b) decreased cell viability only at 1 and
10 lM concentrations. As showed in Figure 3b, the compounds 9
and 10 are more active.
In fact, the most interesting results were obtained for 9 and 10
characterized by the presence of –OMe groups in R3 and R4 and of
an chlorine atom on the aromatic ring bonded at C-2 position, of
the thiazolidinone moiety, respectively, as evidenced by half-
maximal inhibitory concentration (IC50) values (Table 2).
In particular, the thiazolidin-4-one derivative 9 showed the best
pattern of dose-dependent inhibition among substance tested with
an IC50 of 2.58
(IC50 = 28.07 M).
In SKBR3 cells, 3–8 (Fig. 4a) and 9–11 (Fig. 4b) did not change
cell proliferative behavior while only 10 M of 5, 8–11 decreased
lM, value much more relevant respect to RSV
l
l
Figure 4. Effects of different doses of 2,3-thiazolidin-4-one derivatives on SKBR3
cell proliferation. Cells treated for 72 h with the indicated concentrations of
compounds 3–8 (a), 9–14 (a) and RSV (a and b). Cell viability was evaluated by MTT
assay. Statistically significant differences are indicated. Columns, mean of three
independent experiments each performed with triplicate samples expressed as
percent of basal; bars, SD. (⁄P < 0.01 compared with basal).
significantly cell viability. Among all tested compounds in SKBR3
cells particularly 12–14 (Fig. 4b) determined a significant inhibi-
tion starting from the lowest dose. As showed in Figure 4 the pres-
ence of
a phenyl unsubstituted (12), a naphthyl (13) or a
trimethoxy-phenyl groups (14) at C2 position of the thiazolidinon-
ic core were important for the inhibitory activity as indicated by
IC50 values (Table 3).
In particular, the derivative 14 showed the best pattern of dose-
dependent inhibition among tested substances with an IC50 of
Table 2
IC50 of resveratrol and its derivatives 9–10 for MCF-7 cells on cell viability
Compounds
IC50
(
lM)
95% Confidence interval
9
10
RSV
2.58
5
28.07
1.85–3.6
2.14–11.73
23.85–33.04
Table 3
IC50 of resveratrol and its derivatives 12–14 for SKBR-3 cells on cell viability
Compounds
IC50
(
lM)
95% Confidence interval
Figure 3. Effects of different doses of 2,3-thiazolidin-4-one derivatives on MCF-7
cell proliferation. Cells treated for 72 h with the indicated concentrations of
compounds 3–8 (a), 9–14 (b) and RSV (a and b). Cell viability was evaluated by MTT
assay. Statistically significant differences are indicated. Columns, mean of three
independent experiments each performed with triplicate samples expressed as
percent of basal; bars, SD. (⁄,⁄⁄P < 0.01 compared with basal).
12
13
14
RSV
0.81
0.25
0.23
0.19–3.53
0.06–1.1
0.06–0.94
34.59–49.61
41.42
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M. Sala et al. / Bioorg. Med. Chem. Lett. xxx (2013) xxx–xxx
5
10. Gougelet, A.; Mueller, S. O.; Korach, K. S.; Renoir, J. M. J. Steroid Biochem. Mol.
Biol. 2007, 104, 110.
11. Serrero, G.; Lu, R. Antioxid. Redox Signal. 2001, 3, 969.
12. Walle, T.; Hsieh, F.; DeLegge, M. H.; Oatis, J. E., Jr.; Walle, U. K. Drug Metab.
Dispos. 2004, 32, 1377.
13. (a) De Santi, C.; Pietrabissa, A.; Mosca, F.; Pacifici, G. M. Xenobiotica 2000, 30,
1047; (b) De Santi, C.; Pietrabissa, A.; Spisni, R.; Mosca, F.; Pacifici, G. M.
Xenobiotica 2000, 30, 609; (c) Yu, C. W.; Shin, Y. G.; Chow, A.; Li, Y. M.;
Kosmeder, J. W.; Lee, Y. S.; Hirschelman, W. H.; Pezzuto, J. M.; Mehta, R. G.; Van
Breemen, R. B. Pharm. Res. 1907, 2002, 19.
14. (a) Lee, S. K.; Nam, K. A.; Hoe, Y. H.; Min, H. Y.; Kim, E. Y.; Ko, H.; Song, S.; Lee,
T.; Kim, S. Arch. Pharm. Res. 2003, 26, 253; (b) Roberti, M.; Pizzirani, D.; Simoni,
D.; Rondanin, R.; Baruchello, R.; Bonora, C.; Buscemi, F.; Grimaudo, S.; Tolomeo,
M. J. Med. Chem. 2003, 46, 3546.
0.23
(41.42
It is evident that the dose at which RSV shows antiproliferative
l
M, a value much more relevant respect to IC50 value of RSV
lM).
effects on MCF7 and SKBR3 cells is relatively higher (>10 lM) (Ta-
bles 2 and 3)23 compared to that of the tested compounds.
In addition, a control experiment using 3T3 mouse embryonic
fibroblast cells has been performed; no effects on cell viability
was obtained using all thiazolidin-based resveratrol derivatives
of 0.1 lM from to 10 lM after 72 h of treatment (data not shown),
suggesting that these compounds have specific inhibitory effect on
breast cancer cells.
15. Mayhoub, A. S.; Marler, L.; Kondratyuk, T. P.; Park, E. J.; Pezzuto, J. M.;
Cushman, M. Bioorg. Med. Chem. 2012, 20, 510.
Because of the widespread chemopreventive and chemothera-
peutic applications of resveratrol, a strong demand exists to search
for other pharmacologically active resveratrol analogs with en-
hanced potency and selectivity. The findings arising from the stud-
ies described in this work could open a possible approach to the
design and development of new restricted resveratrol analogs,
such as 2,3-thiazolidin-4-one derivatives,24 as anticancer agents
for the treatment of human breast cancer. In this effort, we have
identified 9–10 compounds as potent anticancer agents against
MCF-7 breast cancer cells and 12–14 compounds with cytotoxic
activity on SKBR3 cells. It was demonstrated that changes in the
structure of the RSV derivatives may be responsible for the differ-
16. Experimental section: Reagents, starting material and solvents were purchased
from Sigma–Aldrich (Milano, Italy) and used as received. Analytical TLC was
performed on plates coated with a 0.25 mm layer of silica gel 60 F254 Merck
and preparative TLC on 20 ꢁ 20 cm glass plates coated with a 2 mm layer of
silica gel PF254 Merck. Silica gel 60 (300–400 mesh, Merck) was used for flash
chromatography. Melting points were measured with a Köfler apparatus and
are uncorrected. 1H and 13C NMR spectra were recorded with a Bruker 300
spectrometer operating at 300 and 100 MHz, respectively. Chemical shifts are
reported in d values (ppm) relative to internal Me4Si and J values are reported
in Hz. Mass spectra were obtained using a ESI mass spectrometer: Finnigan
LCQ Advantage max (Thermo Finnigan;San Jose, CA, USA).
General Procedure for the synthesis of 2,3-diaryl-thiazolidin-4-ones.
Arylamine (1 mmol) and arylaldehyde (2 equiv) appropriately substituted
were stirred in THF at 0 °C for 5 min, then thioglycolic acid (3 equiv) was
added. After 5 min N,N-dicyclohexylcarbodiimide (DCC) (1.3 equiv) was added
to the reaction mixture at 0 °C and it was stirred for additional 50 min at room
temperature. DCC was removed by filtration and the filtrate was concentrated
to dryness under reduced pressure and the residue was taken up in ethyl
acetate. The organic layer was successively washed with 10% aq. citric acid,
water, 10% aq. sodium hydrogen carbonate and finally with brine. Finally, the
organic layer was dried over sodium sulphate anhydrous and the solvent was
removed under reduced pressure to get a crude product that was purified by
column chromatography on silica gel using n-hexane/ethyl acetate 4:1 as
eluent.
2,3-Bis-(4-hydroxy-phenyl)-thiazolidin-4-one (3). White solid. Yield 93%. Mp
230–231 °C. 1H NMR (300 MHz, CD3OD): d 3.87 (d, J = 12.3 Hz, 1H), 3.95 (d,
J = 12.3 Hz, 1H), 6.08 (s, 1H), 6.70-6.73 (m, 4H), 6.93 (d, J = 6.6 Hz, 2H), 7.20 (d,
J = 6.4 Hz, 2H). 13C NMR (75 MHz, CD3OD): d 33.5, 72.6, 115.8, 116.3, 123.0,
129.8, 132.0, 134.3, 154.1, 156.9, 171.2. ESI m/z calcd for C15H13NO3S: 287.06;
found: 286.10.
ent ERa-mediates biological responses observed in estrogen-
sensitive cancer cells.25 Moreover, the different inhibitory effects
of the 9, 10, 12, 13 and 14 compounds in the two breast tumor cell
lines may suggest that the biological action of these molecules
could be also influenced by the different estrogenic receptor pat-
tern. In particular, in ER positive MCF-7 cells 9–10 compounds
could interfere with ERa-dependent pathway, while in ER negative
and GPER positive SKBR3 cells 12, 13 and 14 compounds could
antagonize with GPER-dependent pathway that is involved in E2
dependent SKBR3 cell growth.26,27 This last aspect is currently
under investigation in our laboratory.
Our data outline a promising perspective: these thiazolidin-
based resveratrol derivatives may become an alternative tool to
modulate complex signal transduction pathways and interfere
with their activation in cancer. Modifications of the two structural
aromatic domains on the thiazolidin-4-one core aimed to identify
more potent and selective antitumor agents are currently under-
way. Further experiments are needed to clarify the molecular
mechanism involved in the growth responses to the tested com-
pounds and to evaluate in vivo bioavailability and chemotherapeu-
tic potential.
2-(3,4-Dihydroxyphenyl)-3-(4-hydroxyphenyl)thiazolidin-4-one (4). White
solid. Yield 47%. Mp 214–215 °C. 1H NMR (300 MHz, CD3OD):
d 3.77 (d,
J = 15.7 Hz, 1H), 3.87 (d, J = 15.7 Hz, 1H), 6.00 (s, 1H), 6.19–6.21 (m, 2H), 6,90 (s,
1H) 6.93 (d, J = 6.6 Hz, 2H), 7.20 (d, J = 6.4 Hz, 2H). 13C NMR (75 MHz, CD3OD): d
33.5, 72.9, 115.6, 115.8, 116.1, 123.1, 133.2, 134.3, 146.0, 154.1, 171.2. ESI m/z
calcd for C15H13NO4S: 303.06; found 304.31.
2-(3,5-Dihydroxyphenyl)-3-(4-hydroxyphenyl)thiazolidin-4-one (5). White
solid. Yield 63%. Mp. 214–215 °C. 1H NMR (300 MHz, CD3OD): d 3.80 (d,
J = 15.7 Hz, 1H), 3.94 (d, J = 15.7 Hz, 1H), 5.96 (s, 1H) 6.00 (s, 1H), 6.26–6.29 (m,
2H), 6.73–6.76 (m, 2H), 6.97–6.99 (m, 2H). 13C NMR (75 MHz, CD3OD): d 33.5,
73.2, 102.0, 107.1, 116.1, 123.2, 134.3, 142.0, 155.1, 158.4, 171.2. ESI m/z calcd
for C15H13NO4S: 303.06; found 304.12.
2-(2,4-Dihydroxy-phenyl)-3-(4-hydroxy-phenyl)-thiazolidin-4-one (6). White
solid. Yield 80%. Mp 214–215 °C. 1H NMR (300 MHz, CD3OD):
d 3.84 (d,
Acknowledgments
J = 15.6 Hz, 1H), 3.97 (d, J = 15.7, 1H), 6.00 (s, 1H), 6.39–6.67 (m, 3H), 6,82–6,93
(m, 4H). 13C NMR (75 MHz, CD3OD): d 33.5, 72.9, 102.0, 107.1, 116.1, 123.2,
134.3, 145.6, 154.1, 171.2. ESI m/z calcd for C15H13NO4S: 303.06; found 304.09.
3-(4-Hydroxyphenyl)2-(2,4-dimethoxyphenyl)thiazolidin-4-one (7). White
solid. Yield 85%, Mp. 234–235 °C. 1H NMR (300 MHz, DMSO): d 3.76 (s, 3H),
3.82 (s, 3H), 3.93 (d, J = 14.47 Hz, 1H) 3.99 (d, J = 15.39 Hz, 1H), 6.45 (s, 1H),
This work was supported by grants from the Italian Ministry of
Education (MIUR) (PRIN n° 20098SJX4F) and by Associazione Itali-
ana per la Ricerca sul Cancro (AIRC) project n. IG10344.
6.63–6.65 (m, 1H) 6.66–6.69 (m, 2H), 6.98–6.95 (m, 2H), 7.15–7.12 (m, 2H). 13
C
NMR (75 MHz, DMSO): d 33.5, 55.8, 56.1, 66.7, 101.0, 107.1, 108.8, 116.1, 123.2,
134.3, 154.1, 160.2, 171.2. ESI m/z calcd for C17H17NO4S: 331.09; found 332.12.
3-(4-Hydroxyphenyl)-2-(3,4,5-trimethoxyphenyl)thiazolidin-4-one (8). White
solid. Yield 90%. Mp. 240–241 °C. 1H NMR (300 MHz, DMSO): d 3.78 (s, 9H),
3.96 (d, J = 15.39, 1H), 4.01 (d, J = 15.47, 1H), 5.89 (s, 1H), 6.49–6.56 (m, 4H),
6.82 (s, 2H). 13C NMR (75 MHz, DMSO): d 33.5, 56.1, 60.8, 73.2, 106.1, 116.1,
123.2, 133.1, 134.3, 137.6, 152.8, 154.1, 171.2. ESI m/z calcd for C18H19NO5S:
361.10; found 362.10.
3-(4-Hydroxyphenyl)-2-(3,4-dimethoxyphenyl)thiazolidin-4-one (9). White
solid. Yield 90%. Mp. 240–241 °C. 1H NMR (300 MHz, DMSO): d 3.79 (s, 6H),
3.93 (d, J = 15,39, 1H), 3.95 (d, J = 15.47, 1H), 6.16 (s, 1H), 6.70–6.78 (m, 2H),
6.82–6.97 (m, 5H). 13C NMR (75 MHz, DMSO): d 33.5, 56.1, 72.9, 112.3, 113.8,
116.1, 122.3, 123.2, 132.5, 134.3, 148.2, 198.7, 154.1, 171.2. ESI m/z calcd for
References and notes
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3. Jang, M.; Cai, L.; Udeani, G. O.; Slowing, K. V.; Thomas, C. F.; Beecher, C. W.;
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5. (a) Kundu, J. K.; Surh, Y. J. Cancer Lett. 2008, 269, 243; (b) Athar, M.; Back, J. H.;
Kopelovich, L.; Bickers, D. R.; Kim, A. L. Arch. Biochem. Biophys. 2009, 486, 95.
6. Le Corre, L.; Chalabi, N.; Delort, L.; Bignon, Y. J.; Bernard-Gallon, D. J. Mol. Nutr.
Food Res. 2005, 49, 462.
7. Gehm, B. D.; McAndrews, J. M.; Chien, P. Y.; Jameson, J. L. Proc. Natl. Acad. Sci.
U.S.A. 1997, 94, 14138.
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C17H17NO4S: 331.09; found 332.30.
2-(4-Chlorophenyl)-3-(4-hydroxyphenyl)thiazolidin-4-one (10). White solid.
Yield 90%. Mp. 244–245 °C. 1H NMR (300 MHz, DMSO): d 3.88 (d, J = 15.39, 1H),
3.99(d,J = 15.47, 1H),6.20(s, 1H), 6.69–6.70(m, 2H), 6.95–6.97(m,2H),7.29–7.39
(m, 4H). 13C NMR (75 MHz, DMSO): d 33.5, 72.6, 116.1, 123.2, 128.7, 130.1, 132.7,
134.3, 137.0, 154.1, 171.2. ESI m/z calcd for C15H12ClNO2S: 305.03; found 306.10.
Please cite this article in press as: Sala, M.; et al. Bioorg. Med. Chem. Lett. (2013), http://dx.doi.org/10.1016/j.bmcl.2013.06.051

6
M. Sala et al. / Bioorg. Med. Chem. Lett. xxx (2013) xxx–xxx
2-(4-Chlorophenyl)-3-p-tolylthiazolidin-4-one (11). White solid. Yield 56%. Mp.
four well plates (0.2 ꢁ 105 cells/well) and grown for 48 h in complete medium.
Before being treated, cells were starved in DMEM/F12 (for MCF-7 cells) or in
RPMI (for SKBR3 cells) serum free medium for 24 h to the purpose of cell cycle
synchronization. The effect of the different doses of compounds on cell
viability was measured using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl
tetrazolium bromide) (MTT) assay as previously described.20–22 Seventy two
hours after treatments, fresh MTT (Sigma), re-suspended in PBS, was added to
each well (final concentration (0.33 mg/ml). After 3 h incubation, cells were
lysed with 1 ml of DMSO. Each experiment was performed in triplicate and the
optical density was measured at 570 nm in a spectrophotometer.
Statistical analyses. All experiments were conducted at least three times and
the results were from representative experiments. Data were expressed as
mean values standard deviation (SD), and the statistical significance between
control (basal) and treated samples was analyzed using the GraphPad Prism 5
software program. The unpaired Student’s t-test was used to compare two
groups. P < 0.05 was considered statistically significant.
215–217 °C. 1H NMR (300 MHz, DMSO): d 2.28 (s, 3H), 3.86 (d, J = 15.7 Hz, 1H),
4.01 (d, J = 15.7 Hz, 1H), 6.05 (s, 1H), 7.01–7.03 (d, J = 8.8 Hz, 2H), 7.09–7.12 (d,
J = 8.6 Hz, 2H), 7.26–7.28 (m, 4H). 13C NMR (75 MHz, DMSO): d 21.4, 33.8, 65.3,
126.0, 128.9, 129.4, 130.1, 134.9, 135.0, 137.7, 138.5, 171.2. ESI m/z calcd for
C
16H14ClNOS: 303.05; found 304.16.
2,3-Diphenylthiazolidin-4-one (12). White solid. Yield 80%. Mp. 250–251 °C. 1
H
NMR (300 MHz, CDCl3): d 3.86 (d, J = 15.7 Hz, 1H), 4.00 (d, J = 15.7 Hz, 1H), 6.11 (s,
1H), 7.27–7.15 (m, 6H), 7.32–7.29 (m, 4H). 13C NMR (75 MHz, DMSO): d 33.5, 72.6,
126.9, 127.1, 127.5, 128.0, 128.6, 128.9, 139.2, 141.7, 171.2. ESI m/z calcd for
C15H13NOS: 255.07; found: 256.20.
2-(Naphthalen-1-yl)-3-p-tolylthiazolidin-4-one (13). White solid. Yield 48%. Mp.
240–241 °C. 1H NMR (300 MHz, CDCl3): d 2.23(s, 3H), 3.90 (d J = 15.7 Hz, 1H), 4.05
(d, J = 15.7 Hz, 1H), 6.23 (s, 1H), 7.05–7.11 (m, 3H), 7.48 (s, 1H) 7.65–7.77 (m, 3H),
7.80 (s, 1H), 7.86–7.80 (m, 3H). 13C NMR (75 MHz, DMSO): d 21.3, 33.5, 56.1, 60.8,
73.2, 106.1, 116.1, 129.2, 133.4, 136.8, 137.6, 152.8, 171.2. ESI m/z calcd for
C
20H17NOS: 319.10; found 320.20.
19. Sirianni, R.; Capparelli, C.; Chimento, A.; Panza, S.; Catalano, S.; Lanzino, M.;
Pezzi, V.; Andò, S. Mol. Cell. Endocrinol. 2012, 363, 100.
20. Sirianni, R.; Zolea, F.; Chimento, A.; Ruggiero, C.; Cerquetti, L.; Fallo, F.; Pilon, C.;
Arnaldi, G.; Carpinelli, G.; Stigliano, A.; Pezzi, V. J. Clin. Endocrinol. Metab. 2012,
97, E2238.
21. Caruso, A.; Chimento, A.; El-Kashef, H.; Lancelot, J. C.; Panno, A.; Pezzi, V.;
Saturnino, C.; Sinicropi, M. S.; Sirianni, R.; Rault, S. J. Enzyme Inhib. Med. Chem.
2012, 27, 60.
2-(3,4,5-Trimethoxyphenyl)-3-p-tolylthiazolidin-4-one (14). White solid. Yield
85%. Mp. 244–245 °C. 1H NMR (300 MHz, CDCl3): d 2.29 (s, 3H), 3.80 (s, 9H), 3.89
(d, J = 15.7 Hz, 1H), 4.01 (d, J = 15.7 Hz, 1H), 6.01 (s, 1H), 6.50 (s, 2H), 7.07–7.10 (m,
4H). 13C NMR (75 MHz, DMSO): d 21.3, 33.5, 56.1, 60.8, 73.2, 106.1, 116.1, 129.2,
133.4, 136.8, 137.6, 152.8, 171.2. ESI m/z calcd for C19H21NO4S: 359.12; found
360.13.
17. Srivastava, T.; Haq, W.; Katti, S. B. Tetrahedron 2002, 58, 7619.
18. Cell culture and treatments. MCF-7 breast cancer cells (a ER positive breast
cancer cells, provided by Dr. E. Surmacz, Sbarro Institute for Cancer Research
and Molecular Medicine, Philadelphia, USA) were maintained as previously
described.19 SKBR3 breast cancer cells (a ER negative breast cancer cells,
obtained from American Type Culture Collection (ATCC), Manassas, VA, USA)
were maintained in RPMI1640 without phenol red supplemented with 10%
fetal bovine serum (FBS), 1% glutamine and 1% penicillin/streptomycin (Sigma–
Aldrich, Milano, Italy) (complete medium). Cells were maintained at 37 °C in a
humidified atmosphere of 95% air and 5% CO2 and were screened periodically
for Mycoplasma contamination. All compounds were dissolved in
22. Sinicropi, M. S.; Caruso, A.; Conforti, F.; Marrelli, M.; El Kashef, H.; Lancelot, J.
C.; Rault, S.; Statti, G. A.; Menichini, F. J. Enzyme Inhib. Med. Chem. 2009, 24,
1148.
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Navarro, S.; Santiago-Josefat, B.; Fernandez-Salguero, P. M. Biochem. Pharmacol.
2002, 64, 1375.
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L.; Stivala, L. A.; Iacopetta, D.; Dolce, V.; Andò, S.; Pezzi, V.; Maggiolini, M. Mol.
Nutr. Food Res. 2009, 53, 845.
dimethylsulfoxide (DMSO) (Sigma, St. Louis, Missouri, USA) at
a
concentration of 10 mM and diluted in DMEM/F12 (for MCF-7 cells) or in
RPMI (for SKBR3 cells) medium supplemented with 1% DCC-FBS (dextran-
coated charcoal-treated newborn calf serum) to obtain the working
concentration.
26. Vivacqua, A.; Romeo, E.; De Marco, P.; De Francesco, E. M.; Abonante, S.;
Maggiolini, M. Breast Cancer Res. Treat. 2012, 133(3), 1025.
27. Lappano, R.; De Marco, P.; De Francesco, E. M.; Chimento, A.; Pezzi, V.;
Maggiolini, M. J. Steroid Biochem. Mol. Biol. 2013 (Mar 28). pii: S0960-
0760(13)00054-X. 10.1016/j.jsbmb.2013.03.005 [Epub ahead of print].
Assessment of cell viability. MCF-7 and SKBR3 cells were seeded on twenty-
Please cite this article in press as: Sala, M.; et al. Bioorg. Med. Chem. Lett. (2013), http://dx.doi.org/10.1016/j.bmcl.2013.06.051