2,3-Diarylpropenoic acids as selective non-steroidal inhibitors of type-5 17β-hydroxysteroid dehydrogenase (AKR1C3)

Article abstract of DOI:10.1016/j.ejmech.2012.12.045

The aldo-keto reductase AKR1C3 is an important target for the development of new drugs. Selective inhibitors of this enzyme are needed because they should not inhibit other, structurally closely related AKR1C isoforms. A comprehensive series of 2,3-diarylpropenoic acids was synthesized and evaluated for the inhibition of AKR1C1-AKR1C3. We found that the 4-methylsulfonylphenyl substituent at position 2 of these acids is required to exhibit the selective inhibition of AKR1C3. The best results were obtained for the compounds that fulfill the above requirement and possess a 4-bromophenyl, 4-methylthiophenyl, 4-methylphenyl or 4-ethylphenyl substituent at position 3 of the substituted propenoic acids (i.e., acids 28, 29, 37, and 39, respectively). These compounds represent an important step toward the development of drug candidates for a treatment of the hormone-dependent and hormone-independent forms of prostate and breast cancers.

Full text of DOI:10.1016/j.ejmech.2012.12.045

Accepted Manuscript
2,3-Diarylpropenoic acids as selective non-steroidal inhibitors of type-5 17β-
hydroxysteroid dehydrogenase (AKR1C3)
Martin Gazvoda, Nataša Beranič, Samo Turk, Bojan Burja, Marijan Kočevar, Tea
Lanišnik Rižner, Stanislav Gobec, Slovenko Polanc
PII:
S0223-5234(12)00767-2
10.1016/j.ejmech.2012.12.045
EJMECH 5916
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 14 September 2012
Revised Date: 24 December 2012
Accepted Date: 26 December 2012
Please cite this article as: M. Gazvoda, N. Beranič, S. Turk, B. Burja, M. Kočevar, T.L. Rižner, S.
Gobec, S. Polanc, 2,3-Diarylpropenoic acids as selective non-steroidal inhibitors of type-5 17β-
hydroxysteroid dehydrogenase (AKR1C3), European Journal of Medicinal Chemistry (2013), doi:
10.1016/j.ejmech.2012.12.045.
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ACCEPTED MANUSCRIPT
G R A P H I C A L A B S T R A C T

ACCEPTED MANUSCRIPT
2
,3-Diarylpropenoic acids as selective non-steroidal inhibitors of type-5 17β-
hydroxysteroid dehydrogenase (AKR1C3)
a,&
b,&
c
a
a
Martin Gazvoda , Nataša Beranič , Samo Turk , Bojan Burja , Marijan Kočevar , Tea
b
,c
,a
Lanišnik Rižner, Stanislav Gobec** , Slovenko Polanc*
a
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-
1
000, Ljubljana, Slovenia
b
Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-
1
000, Ljubljana, Slovenia
c
Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI-1000, Ljubljana, Slovenia
G R A P H I C A L A B S T R A C T
Abbreviations: DMF, N,N-dimethylformamide; DMSO, dimethyl sulfoxide; ESI, electrospray
ionization; HPLC, high-performance liquid chromatography; HRMS, high-resolution mass
spectrometry; IR, infrared; LC-MS liquid chromatography-mass spectrometry; NADPH,
reduced nicotinamide adenine dinucleotide phosphate; NMR, nuclear magnetic resonance;
NSAID, non-steroidal anti-inflammatory drug.
&
Both authors contributed equally to the manuscript.
*
*
Corresponding author. Tel.: +386-1-24-19-236; fax: +386-1-24-19-220.
* Corresponding author. Tel.: +386-1-47-69-585; fax: +386-1-42-58-031.
E-mail addresses: slovenko.polanc@fkkt.uni-lj.si (S. Polanc), stanislav.gobec@ffa.uni-lj.si
S. Gobec).
(
1

ACCEPTED MANUSCRIPT
A B S T R A C T
The aldo-keto reductase AKR1C3 is an important target for the development of new drugs.
Selective inhibitors of this enzyme are needed because they should not inhibit other,
structurally closely related AKR1C isoforms. A comprehensive series of 2,3-diarylpropenoic
acids was synthesized and evaluated for the inhibition of AKR1C1–AKR1C3. We found that
the 4-methylsulfonylphenyl substituent at position 2 of these acids is required to exhibit the
selective inhibition of AKR1C3. The best results were obtained for the compounds that fulfill
the above requirement and possess a 4-bromophenyl, 4-methylthiophenyl, 4-methylphenyl or
4
-ethylphenyl substituent at position 3 of the substituted propenoic acids (i.e., acids 28, 29,
7, and 39, respectively). These compounds represent an important step towards the
3
development of drug candidates for a treatment of the hormone-dependent and hormone-
independent forms of prostate and breast cancers.
Keywords: Aldo-keto reductase; AKR1C3; Selective inhibitors; 2,3-Diarylpropenoic acids;
Cancer
1
. Introduction
The enzymes AKR1C1–AKR1C4, members of the aldo-keto reductase superfamily, catalyze
the interconversions of 3-, 17- and 20-ketosteroids with the corresponding 3α/β-, 17β-, 20α-
hydroxysteroids to varying extents, using NADPH as a cofactor [1,2]. In this way they can
control the ligand occupancy and trans-activation of androgen, estrogen and progesterone
receptors by modulating the concentrations of the active steroids [3]. The AKR1C enzymes
are also involved in the prostaglandin and neurosteroid production and inactivation, and in the
metabolism of xenobiotics [2].
Among the AKR1C enzymes, AKR1C3 preferentially acts as a 17-ketosteroid reductase and
converts a weak androgen 4-androstene-3,17-dione to a potent androgen testosterone and
estrone to a potent estrogen 17β-estradiol. As a 20-ketosteroid reductase, AKR1C3 inactivates
progesterone by forming its metabolite 20α-hydroxyprogesterone, which has a lower affinity
towards the progesterone receptor [1,4]. AKR1C3 also acts as a 3-ketosteroid reductase by
converting 5α-dihydrotestosterone into an estrogen receptor β ligand 3β-androstandiol, and
inactive androgen 3α-androstandiol [1]. Catalyzing these reactions AKR1C3 represents an
important target enzyme for the development of potential drugs for a treatment of the
hormone-dependent forms of cancer. Finally, AKR1C3 catalyzes the reduction of
prostaglandin H2 (PGH2) into PGF2α, and PGD2 into 11β-PGF2, thereby diverting the
2

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biosynthesis of prostanoids away from the antiproliferative J-series [2]. This makes AKR1C3
an interesting target enzyme also for the development of the hormone-independent forms of
cancer.
The products of AKR1C3-catalyzed reactions stimulate tumor growth, so an imbalance in the
AKR1C3 expression and action can be related to the different hormone-dependent and
hormone-independent cancers like breast [5], prostate [6], endometrial [7], and also other
diseases, such as endometriosis [8], benign prostatic hyperplasia and dysmenorrhea [9,10].
AKR1C3 thus represents an interesting therapeutic target for the development of new drugs.
Since AKR1C3 shares at least an 84% sequence homology and overlapping catalytic
properties with other human members of the AKR1C superfamily (AKR1C1, AKR1C2 and
AKR1C4) that are, with the exception of the liver-specific AKR1C4, expressed in different
tissues [1], selective AKR1C3 inhibition is crucial and remains a great challenge. To date
several structurally different classes of compounds have been reported to possess AKR1C3-
inhibitory activity. The structural analogues of AKR1C3 substrates with a steroidal backbone,
such as progestins [11] and estrogen lactones [12], have been shown to inhibit AKR1C3 in the
low-µM or even the low-nM range, respectively. Inhibitors of AKR1C3 also comprise other
classes of compounds, like cyclopentane derivatives [13], benzodiazepines [14], flavonoids
[
15], cinnamic acid derivatives [16] jasmonates [17] or NSAIDs [18]. All these compounds
inhibit AKR1C3 with µM IC50 values, but most of these inhibitors have low selectivity over
AKR1C3. To date only a few compounds that act as selective AKR1C3 inhibitors have been
reported (e.g., an indole derivative known as CBM, and an indomethacin analogue that
belongs to the group of NSAIDs). Unfortunately, CBM possesses poor bioavailability relative
to its potency [10], so the search for a selective AKR1C3 inhibitor continues.
From the above facts it is evident that the desired inhibitor of AKR1C3 should not inhibit the
closely related isoforms AKR1C1 and AKR1C2, which play distinct roles in the metabolism
of steroidal hormones. Recently described N-phenylaminobenzoates were found to fulfill this
requirement and can serve as potent and selective inhibitors of AKR1C3 [19]. On the other
hand, the already-mentioned cinnamic acid and derivatives are also promising inhibitors of
AKR1C3 [16].
Here we report on the effectiveness and the selectivity of inhibition of AKR1C3 by the related
2
,3-diarylpropenoic acids (α-arylcinnamic acids, Table 1). Although a half of the examined
compounds have been previously described in the literature, their inhibition of AKR1C3 and
other isoforms has not been studied so far. These acids have been used in our study, together
3

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with a set of new compounds, to get the information concerning an effect of the substituents,
attached to the aromatic rings, on AKR1C3 selectivity and inhibitory activity.
[Table 1]
2
2
. Results and discussion
.1. Design of new AKR1C3 inhibitors based on a cinnamic acid scaffold
In 2006, some of us discovered that cinnamic acid and several of its simple, substituted
derivatives inhibited AKR1C3 with micromolar IC50 values [16a]. Among them, α-
methylcinnamic acid was the most promising inhibitor. This prompted us to design the
synthesis of a series of cinnamic acids with bulky aryl substituents on the position α (α-
arylcinnamic acids) and to evaluate their AKR1C1–AKR1C3 inhibitory activities (Figure 1).
[Fig. 1]
2
.2. Chemistry
Several acids were synthesized as described before (1 [20], 2 [21], 3 [21], 5 [21], 6 [21], 7
21], 8 [21], 9 [21], 10 [21], 11 [21], 12 [21], 16 [22] and 26 [22]). Most of them were
[
recently applied by us as a precursor to pyrazolo-fused combretastatins [21]. Some acids have
also been mentioned in the literature (13 [23], 15 [24], 19 [25], 20 [24], 30 [26], 31 [25], 36
[
27], and 40 [28]), but the synthesis and characterization details were not available. For this
reason they were prepared following our general synthesis and all the missing data are
provided (see Supporting information). The latter acids as well as the new ones were available
with the Perkin reaction between substituted benzaldehydes and properly functionalized
arylacetic acids in acetic anhydride using either potassium acetate or triethylamine as a base
that led to the desired 2,3-diarylpropenoic acids as the final products (Scheme 1). Reaction
conditions were optimized in all cases. The experiments indicated that the yield of the isolated
product depend mainly on the nature of an aromatic aldehyde employed in a particular
reaction. Namely, benzaldehydes bearing electron withdrawing groups (e.g., halogen,
trifluoromethyl, methylsulfonyl) led to 2,3-diarylpropenoic acids 17, 18, 22, 25, 27, 35−38 in
higher yields (63−89%) than those possessing electron donating substituents (e.g., alkyl,
methoxy, hydroxy, methylthio) that gave the acids 28−34 and 39 in 21−76% yield. Similar
results were reported for the synthesis of various cinnamic acids from substituted
benzaldehydes and acetic anhydride [29].
4

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[Scheme 1]
The synthesis of acetoxy-substituted acid 4 required an acetylation of the initially formed
2E)-3-(3-hydroxyphenyl)-2-(3,4,5-trimethoxyphenyl)prop-2-enoic acid applying acetic
(
anhydride in the presence of catalytic amounts of 4-dimethylaminopyridine in DMF as a
solvent. The methylsulfonyl- substituted acids 21, 24, and 40 were prepared from their
methylthio analogues 20, 23 and 39 using the appropriate reaction conditions to keep an
olefinic C=C bond intact. The best results for such selective oxidation of the sulfur atom
were obtained employing hydrogen peroxide in acetic acid (Scheme 2). Furthermore, the acid
4
2 resulted from the Suzuki coupling of 37 with 4-(methylthio)phenylboronic acid (Scheme
3
).
[
[
Scheme 2]
Scheme 3]
2
.3. Biological Activity
The compounds shown in Table 1 were assayed for the inhibition of the enzymes AKR1C1–
AKR1C3. These enzymes catalyze the oxidation of an artificial substrate 1-acenaphthenol
+
with NAD as a coenzyme, in the presence and absence of individual compounds. The
enzymatic activity was followed spectrophotometrically (Table 2). The results are given as a
percentage of the inhibition of the enzyme in the presence of 100 µM of each acid. For the
compounds that showed more than 50% inhibition the IC50 values were determined.
Medroxyprogesterone acetate, previously described inhibitor of AKR1C enzymes [14], was
assayed on our test as a reference and a positive control. The IC50 values were 1.8 µM
(AKR1C1), 4.1 µM (AKR1C2), and 0.3 µM (AKR1C3), respectively.
[Table 2]
A non-substituted 2,3-diphenylpropenoic acid (1) inhibits AKR1C1. Several acids with two or
more methoxy groups in the molecule are either not active (2–5, 7–12) or slightly active
against AKR1C2 or AKR1C3 (6, 13, 14). We noticed that the introduction of the sulfur-
containing substituent increased the inhibitory activity. Thus, out of the four acids 15–18,
three of them inhibit at least two enzymes. The acid 19 having the MeSO substituent on the
2
5

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1
fragment Ar (i.e., at the position adjacent to the carboxylic functionality) revealed the
selective inhibition of AKR1C3. In addition, 20 and 21 inhibit all three enzymes, but the acid
2
2 is a selective inhibitor of AKR1C3. These results indicate the influence of the sulfur-
containing group. Comparing the activity of the acids 21 and 22 it is evident that the acid 22
containing the 4-MeSO group is a selective inhibitor of AKR1C3 but 21, possessing the 4-
2
chloro substituent, is not. So, they differ only in the presence of the chlorine or the MeSO2
functionalities. Similar results were obtained in the case of the acids 23–27. Namely, the
2
molecules with a sulfur substituent as a part of the Ar moiety are not selective inhibitors (23,
1
2
4 and 26), while the acids possessing the MeSO group at the para position of the Ar inhibit
2
AKR1C3 selectively (25 and 27). Having the above results in hand we focused exclusively on
the activity of the 2-(4-methylsulfonyl)phenylpropenoic acids 28–39 that differ only in the
2
Ar moiety. Most of them are indeed selective inhibitors of AKR1C3, with the exception of
the non-active 31, 32, and 34, as well as 36 that is not a selective inhibitor. The most efficient
and selective inhibitors are the 4-bromo-substituted acid 37 and 4-methylthio analogue 39.
The structure of the latter compound was further modified. The introduction of the
methylsulfonyl functionality in the place of the methylthio group leads to a considerable drop
of activity (an acid 40), although the selectivity is retained. On the other hand, 41, bearing the
2
acetylaminosulfonyl moiety at the para position of the Ar , is not active at all. The same is
true if the para-phenylen linker is introduced to connect the methylthio group and the benzene
2
ring of Ar (an acid 42). It is also interesting to note that acids 28 and 29, although they
exhibit a lower activity against AKR1C3 compared to the above-mentioned 37 and 39, are the
most selective inhibitors of this enzyme. Namely, they practically do not inhibit AKR1C1 and
AKR1C2 at a 100 µM concentration.
2
Several important conclusions can be drawn from these results. Firstly, the 4-MeSO group on
1
Ar seems to be crucial for AKR1C3 selectivity as shown by the activities of the compounds
1
9, 22, 25, 27–30, 33 and 35–40 with only compound 36 possessing also a weak AKR1C2
activity. This is consistent with the docking study (see below) predicting that MeSO
2
functionality forms interactions with the SP1 sub-pocket, and with previous studies which
reported that the binding to the SP1 sub-pocket was responsible for the isoform selectivity
2
[
10]. Secondly, a group on Ar seems to regulate the activity. The nature of the substituents
and their positions are of course important. Here, the bulky hydrophobic substituents seem to
be the most appropriate. This can be concluded from a series of halogenated analogs. Namely,
the activity is increased with the size of the substituent and is also dependent on a position of
the substituent on the aromatic ring. Thus, the fluorine bearing acids 27 and 35 have
6

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inhibitory activities of 43.1 and 38.9 µM, respectively. Furthermore, the chlorophenyl acids
2
2 and 25 possess the activities of 10.8 and 16.8 µM, respectively, and finally with the bromo
analogs 36 and 37, which are the most active and have activities of 13.6 and 4.9 µM,
respectively. An enzyme inhibitory potency is therefore increased with the bulk of the
substituent and is generally higher in the case of the para substituted analogues. A positive
influence of the para substituent is particularly pronounced with its size. Thus, both
fluorinated analogs possess almost the same activities, the para substituted chloro analog has
5
0% better activity as the meta one, while the para substituted bromo acid has almost 3-fold
better activity than the meta compound. In addition, the need for a lipophilic substituent is
3
indicated by a good activity of the acids 28, 29, 38 and 39 containing 4-Me, 4-Et, 4-CF or 4-
2
MeS functionality attached to the Ar ring. On the other hand, and the lack of activity
obtained for the compounds 31, 32, and 34, or weak activity in the case of 40, seems to be
2
attributed to the more hydrophilic substituents on the Ar ring (4-OH, 3-OH, 3,4,5-OMe and
2
MeSO ).
2
.4. Molecular docking
To gain an additional insight into the binding mode and selectivity of the 2,3-diarylpropenoic
acids, the compounds with the best AKR1C1 (compound 1) or AKR1C3 (compounds 20, 22,
2
8, 29, 36, 37, 39) inhibitory activities were docked to the crystal structures of both isoforms.
For the docking, the AKR1C1 crystal structure with co-crystallized 3,5-dichlorosalicylic acid
(
PDB code 3C3U) [30] and the AKR1C3 crystal structure with co-crystallized indomethacin
PDB code 1S2A) [31] were used.
(
The docking results are in good correlation with the results of the inhibition assays. In the
case of the AKR1C1 docking, compound 1 has the highest score, closely followed by
1
compound 20. In both cases the Ar is aligned with the co-crystallized 3,5-dichlorosalicylic
2
1
acid, with Ar extending into the steroid-binding channel. The Ar containing a bulky MeSO
2
1
substituent are unfavorable since they prevent the binding of Ar in the same way as the 3,5-
dichlorosalicylic acid, explaining the lack of AKR1C1 activity in those compounds (see
Supporting information).
In the case of AKR1C3, the docked poses of the compounds 22, 28, 29, 36, 37 and 39 occupy
1
a similar position of the active site as the co-crystallized indomethacin, with the Ar
2
overlapping with the p-chlorobenzoyl moiety of the indomethacin and the Ar overlapping
with an indole part of the indomethacin. A typical docking pose is presented in Figure 2
(docking pose for the compound 37). Due to the nature of AKR1C3, which has a large
7

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number of aromatic residues in a steroid-binding channel, the dominating interactions are
1
predicted to be pi interactions. Ar forms pi interactions with the Phe306 of the SP1 sub-
2
pocket and the Trp227 of the SP2 sub-pocket, while the Ar forms pi interactions with the
Phe306 of the SP1. Additional pi interactions are also possible between the propenoic acid
2
double bond and Tyr24, a part of the SP3 sub-pocket. The MeSO group on the para position
1
of the Ar seems to be crucial for selectivity and forms important H-bonds with the amino
acid residues Ser118 and Asn167 of the SP1 sub-pocket. The differences in the SP1 sub-
pockets between the AKR1C isoforms have previously been noted and suggested to be
exploited in the design of AKR1C3 selective inhibitors [10].
[Fig. 2]
3
. Conclusions
The aldo-keto reductases AKR1C1–AKR1C3 play an important role in the production and
inactivation of neurosteroids and prostaglandins as well as in the metabolism of xenobiotics
and lipid aldehydes. They can regulate the occupancy and trans-activation of the androgen,
estrogen and progesterone receptors. These facts make them important drug targets for the
treatment of the hormone-dependent and hormone-independent forms of cancer and other
diseases. Several 2,3-diarylpropenoic acids were synthesized by the Perkin reaction between
the substituted benzaldehydes and the properly functionalized arylacetic acids. They were
evaluated as inhibitors of AKR1C1–AKR1C3. A modification of the structure revealed that
the 4-methylsulfonylphenyl substituent at the position 2 of the 2,3-diarylpropenoic acid is an
appropriate one to obtain a selective inhibition of AKR1C3. We found that the compounds 37
and 39 are the best inhibitors of AKR1C3 and also show very good selectivity. On the other
hand, their 4-methylphenyl and 4-ethylphenyl analogues (28 and 29, respectively), which
exhibit a slightly lower activity against AKR1C3, are the most selective ones. Namely, they
practically do not inhibit AKR1C1 and AKR1C2 at a 100 µM concentration. Our data suggest
that 2,3-diarylpropenoic acids represent a new class of selective inhibitors of AKR1C3 and
may serve as a good starting point for the development of new antitumor agents for the
treatment of the hormone-dependent and hormone-independent forms of prostate and breast
cancers.
4
4
. Experimental protocols
.1. Chemistry
8

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Starting materials for the synthesis of the examined compounds were used as obtained from
the commercial source (Aldrich). Melting points were determined on a Kofler micro hot stage
and are uncorrected. NMR spectra were recorded at 29 °C with a Bruker Avance DPX 300
1
13
spectrometer ( H NMR spectra at 300 MHz; C NMR spectra at 75.5 MHz) and with a
1
13
Bruker Avance III spectrometer ( H NMR spectra at 500 MHz; C NMR spectra at 125.8
MHz). Proton spectra are referenced to TMS as an internal standard; the carbon shifts are
given against the central line of the solvent signal (DMSO-d
6 3
at δ = 39.5 ppm; CDCl at δ =
7
7.1 ppm). IR spectra were obtained with a Bio-Rad FTS 3000MX (KBr pellets) and a
Perkin–Elmer Spectrum 100, equipped with a Specac Golden Gate Diamond ATR as a solid
sample support. MS spectra were recorded with a VG-Analytical AutoSpec Q instrument and
an Agilent 62224 Accurate Mass TOF LC/MS spectrometer. Elemental analyses (C, H, N)
were performed with Perkin Elmer 2400 Series II CHNS/O Analyzer. TLC was carried out on
Fluka silica-gel TLC-cards.
1
A purity of all tested compounds was checked by HPLC (see Supporting information), H
1
3
NMR and C NMR spectroscopy as well as with elemental microanalysis. The figures
obtained for the C, H, N analyses were always within ±0.35% of the calculated values.
4
.1.1. General procedure for the synthesis of acids
Potassium acetate (982 mg, 10 mmol) or triethylamine (1.5 mL, 10.75 mmol; for the synthesis
of 13, 14, 15, 18, 20, 22, 23, and 25) was added to a stirred mixture of the appropriate
arylacetic acid (7.5 mmol), aromatic aldehyde (7.5 mmol) and acetic anhydride (3 mL, 32
mmol). The reaction mixture was stirred at 100–140 °C for 3.5–70 h. Then it was cooled to rt,
water was added (40 mL) and the mixture was treated with a solution of 10 M NaOH until pH
1
2 was reached, followed by conc. HCl (to pH 1). The resulting mixture was extracted with
CH Cl (3 x 80 mL). Organic phases were extracted with 2 M NaOH (3 x 80 mL) and water
80 mL). The combined aqueous solutions were washed with CH Cl (100 mL) to remove the
2
2
(
2
2
impurities and traces of starting materials, then acidified with conc. HCl (until pH was 1), and
finally extracted with CH Cl (4 x 50 mL). The methylene chloride phase was washed with
2
2
brine (100 mL), dried over anhydrous sodium sulfate, evaporated to dryness and the residue
was crystallized from a suitable solvent.
4
.1.1.1 (2E)-3-(3,4-Dimetoxyphenyl)-2-(naphthalen-2-yl)prop-2-enoic acid (14). Reaction
time: 48 h; temperature: 100 °C; yield 22%; mp 220–222 °C (EtOAc); IR (KBr) 2955, 1677,
–
1 1
1
6
595, 1512, 1421, 1259, 1143, 1026 cm ; H NMR (DMSO-d
6
) δ 3.07 (3H, s), 3.66 (3H, s),
.50 (1H, d, J = 1.5 Hz), 6.73−6.81 (2H, m), 7.36 (1H, dd, J
1
= 1.5 Hz, J
2
= 8.4 Hz),
9

ACCEPTED MANUSCRIPT
13
7
.47−7.55 (2H, m), 7.78−7.80 (1H, m), 7.82−7.99 (4H, m), 12.62 (1H, broad s); C NMR
(DMSO-d
6
) δ 54.3, 55.4, 111.3, 112.9, 124.7, 126.2, 126.9, 127.5, 127.7, 128.00, 128.04,
-
1
2
28.2, 130.6, 132.2, 133.2, 134.5, 139.5, 147.9, 149.8, 168.6; MS (ESI–) m/z 333 ([M - H] ,
-
2); HRMS for C21
H
17
O
4
([M - H] ): calcd 333.1127; found 333.1130. Anal. for C21
H
18
O
4
:
calcd C, 75.43; H, 5.43; found C, 75.31; H, 5.33.
.1.1.2 (2E)-2-[1,3-Benzodixol-5-yl]-3-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (17).
Reaction time: 19 h; temperature: 100 °C; yield 89%; mp 231–232 °C (EtOAc); IR 3021,
4
–1
1
2
925, 1677, 1618, 1592, 1493, 1441, 1308, 1239, 1146 cm ; H NMR (DMSO-d
6
) δ 3.19
(
(
3H, s), 6.05 (2H, s), 6.58 (1H, dd, J = 7.9 Hz, J = 1.6 Hz), 6.77 (1H, d, J = 1.6 Hz), 6.89
1
2
1H, d, J = 7.9 Hz), 7.35 (2H, d, J = 8.4 Hz), 7.74 (1H, s), 7.77 (2H, d, J = 8.4 Hz), 12.94 (1H,
1
3
broad s); C NMR (DMSO-d
6
) δ 43.1, 101.1, 108.5, 109.9, 123.0, 126.8, 128.9, 130.6, 135.9,
+
1
36.8, 139.8, 140.3, 146.9, 147.4, 168.0; MS (ESI+) m/z 347 ([M + H] ); HRMS for
+
C
17 15 6 14 6
H O S ([M + H] ): calcd 347.0584; found 347.0576. Anal. for C17H O S: calcd C, 58.95;
H, 4.07; found C, 58.66; H, 3.96.
4
3
1
.1.1.3 (2E)-3-[4-(Acetylsulfamoyl)phenyl]-2-phenylprop-2-enoic acid (18). Reaction time:
.5 h; temperature: 100 °C; yield 63%; mp 238–241 °C (H O); IR 3259, 2988, 2901, 1731,
722, 1659, 1594, 1423, 1348, 1273 cm ; H NMR (DMSO-d ) δ 1.90 (3H, s), 7.16−7.20
2
–
1 1
6
(2H, m), 7.25 (2H, d, J = 8.4 Hz), 7.36−7.42 (3H, m), 7.69 (2H, d, J = 8.4 Hz), 7.81 (1H, s),
1
3
1
1
1
4
2.07 (1H, broad s), 13.1 (1H, broad s); C NMR (DMSO-d
6
) δ 23.3, 127.3, 128.0, 128.6,
+
29.4, 130.4, 135.5, 136.4, 137.0, 138.9, 139.7, 168.0, 168.9; MS (ESI–) m/z 346 ([M + H] ,
00 %); Anal. for C17
5
H15NO S: C, 59.12; H, 4.38; N, 4.06; found C, 59.36; H, 4.35; N, 3.97.
.1.1.4 (2E)-3-(4-Chlorophenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (22).
Reaction time: 70 h; temperature: 140 °C; yield 63%; mp 263–264 °C (EtOAc); IR 2970,
–1
1
2
879, 1667, 1610, 1592, 1564, 1492, 1414, 1393, 1311 cm ; H NMR (DMSO-d
6
) δ 3.27
(3H, s), 7.07 (2H, d, J = 8.8 Hz), 7.32 (2H, d, J = 8.8 Hz), 7.46 (2H, d, J = 8.5 Hz), 7.86 (1H,
13
s), 7.93 (2H, d, J = 8.5 Hz), 13.05 (1H, broad s); C NMR (DMSO-d ) δ 43.5, 127.2, 128.6,
6
1
30.7, 131.8, 132.6, 132.9, 133.9, 138.9, 140.0, 141.4, 167.5; MS (ESI+) m/z 354 ([M +
+
+
4 4
NH ] ); HRMS for C16H14ClO S ([M + H] ): calcd 337.0296; found 337.0288. Anal. for
C H ClO S: calcd C, 57.06; H, 3.89; found C, 56.96; H, 3.74.
16
13
4
4
.1.1.5 (2E)-2-(3-Chlorophenyl)-3-[4-(methylsulfanyl)phenyl]prop-2-enoic acid (23).
Reaction time: 6 h; temperature: 100 °C; yield 49%; mp 213–215 °C (EtOAc/n-heptane); IR
–1 1
(
KBr) 3418, 1668, 1609, 1589, 1426, 1287, 1272, 1191 cm ; H NMR (DMSO-d
6
) δ 2.42
(3H, s), 7.00 and 7.09 (4H, AA′BB′, J = 8.7 Hz), 7.11−7.18 (1H, m), 7.27 (1H, broad s),
13
7
6
.38−7.46 (2H, m), 7.77 (1H, s), 12.77 (1H, broad s); C NMR (DMSO-d ) δ 14.0, 125.1,
1
0

ACCEPTED MANUSCRIPT
1
27.6, 128.3, 129.3, 130.2, 130.4, 130.6, 130.8, 133.1, 138.7, 139.3, 140.6, 167.8; MS (ESI–)
-
-
m/z 303.0 ([M – H] ); HRMS for C16
2
H12ClO S ([M – H] ): calcd 303.0247; found 303.0253.
Anal. for C H ClO S: calcd C, 63.05; H, 4.30; found C, 53.23; H, 4.23.
16
13
2
4
.1.1.6 (2E)-3-(3-Chlorophenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (25).
Reaction time: 41 h; temperature: 100 °C; yield 68%; mp 210–212 °C (EtOAc); IR 2979,
–1
1
2
942, 1674, 1618, 1560, 1478, 1424, 1288, 1211, 1144 cm ; H NMR (DMSO-d ) δ 3.25
6
(3H, s), 6.98 (1H, d, J = 8.0 Hz), 7.08−7.10 (1H, m), 7.25 (1H, t, J = 7.8 Hz), 7.33 (1H, dd, J
1
=
8.0 Hz, J
2
= 1.5 Hz), 7.47 (2H, d, J = 8.3 Hz), 7.85 (1H, s), 7.94 (2H, d, J = 8.3 Hz), 13.11
13
(
1H, broad s); C NMR (DMSO-d ) δ 43.5, 127.2, 128.6, 129.0, 129.7, 130.2, 130.7, 133.1,
6
+
1
33.5, 136.2, 138.6, 140.1, 141.4, 167.3; MS (ESI+) m/z 354 ([M + NH] ); HRMS for
+
C
16
H
14ClO
4
S ([M + H] ): calcd 337.0296; found 337.0285. Anal. for C16
H
13ClO
4
S: calcd C,
5
7.06; H, 3.89; found C, 57.21; H, 3.96.
.1.1.7 (2E)-3-(4-Fluorophenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (27).
4
Reaction time: 48 h; temperature: 140 °C; yield 65%; mp 224–226 °C (EtOAc/n-hexane); IR
–
1 1
3
3
024, 1667, 1599, 1586, 1508, 1414, 1392, 1304, 1264, 1147 cm ; H NMR (DMSO-d
6
) δ
.26 (3H, s), 7.08−7.13 (4H, m), 7.46 (2H, d, J = 8.4 Hz), 7.86 (1H, s), 7.93 (2H, d, J = 8.4
1
3
Hz), 12.94 (1H, broad s); C NMR (DMSO-d
6
) δ 43.5, 115.6 (d, J = 21.8 Hz), 127.2, 130.5
(d, J = 3.2 Hz), 130.7, 131.7, 132.5 (d, J = 8.6 Hz), 139.1, 140.0, 141.7, 162.3 (d, J = 249.0
+
+
4 4
Hz), 167.6; MS (ESI+) m/z 338 ([M + NH ] ); HRMS for C16H14FO S ([M + H] ): calcd
3
3
4
21.0591; found 321.0596. Anal. for C H FO S: calcd C, 59.99; H, 4.09; found C, 59.74; H,
16 13 4
.98.
.1.1.8 (2E)-3-(4-Methylphenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (28).
Reaction time: 22 h; temperature: 120 °C; yield 59%; mp 256–258 °C (EtOAc); IR 2976,
–1
1
2
927, 1684, 1602, 1593, 1563, 1510, 1420, 1275, 1148 cm ; H NMR (DMSO-d
6
) δ 2.22
(3H, s), 3.26 (3H, s), 6.93 (2H, d, J = 8.3 Hz), 7.03 (2H, d, J = 8.3 Hz), 7.45 (2H, d, J = 8.3
1
3
Hz), 7.84 (1H, s), 7.93 (2H, d, J = 8.3 Hz), 12.92 (1H, broad s); C NMR (DMSO-d ) δ 20.9,
6
4
3.6, 127.2, 129.2, 130.3, 130.8, 130.9, 131.1, 139.4, 139.8, 140.3, 142.2, 167.8; MS (ESI+)
+
+
m/z 317 ([M + H] ); HRMS for C17
16 4
H O S ([M + H] ): calcd 317.0842; found 317.0837.
Anal. for C H O S: calcd C, 64.54; H, 5.10; found C, 64.52.; H, 5.13.
17
16
4
4
.1.1.9 (2E)-3-(4-Ethylphenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (29).
Reaction time: 20 h; temperature: 120 °C; yield 59%; mp 227–229 °C (EtOAc); IR 3026,
–1
1
2
961, 2868, 1687, 1617, 1603, 1592, 1419, 1274, 1141 cm ; H NMR (DMSO-d
6
) δ 1.10
(3H, t, J = 7.8 Hz), 2.52 (2H, q, J = 7.8 Hz), 6.96 (2H, d, J = 8.5 Hz), 7.08 (2H, d, J = 8.5 Hz),
13
7
.46 (2H, d, J = 8.3 Hz), 7.83 (1H, s), 7.93 (2H, d, J = 8.3 Hz), 12.88 (1H, broad s); C NMR
1
1

ACCEPTED MANUSCRIPT
(DMSO-d
6
) δ 15.1, 27.9, 43.5, 127.2, 128.0, 130.4, 130.7, 130.9, 131.3, 139.9, 140.2, 142.2,
+
+
1
3
5
4
45.6, 167.8; MS (ESI+) m/z 331 ([M + H] ); HRMS for C18
19 4
H O S ([M + H] ): calcd
31.0999; found 331.0993. Anal. for C H O S: calcd C, 65.43; H, 5.49; found C, 65.24; H,
1
8
18
4
.46.
.1.1.10 (2E)-3-(3-Hydroxyphenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (32).
Reaction time: 23 h; temperature: 120 °C; yield 64%; mp 236–238 °C (H O/EtOH); IR 3371,
2
–1
1
2
988, 2901, 1667, 1578, 1470, 1394, 1266, 1137, 1066 cm ; H NMR (DMSO-d
3H, s), 6.42−6.44 (1H, m), 6.48 (1H, d, J = 7.5 Hz), 6.65−6.69 (1H, m), 7.02 (1H, t, J = 8.0
Hz), 7.45 (2H, d, J = 8.5 Hz), 7.75 (1H, s), 7.92 (2H, d, J = 8.5 Hz), 9.48 (1H, broad s), 12.94
6
) δ 3.25
(
13
(
1H, broad s); C NMR (DMSO-d
6
) δ 43.6, 116.6, 116.8, 121.3, 127.1, 129.5, 130.7, 131.8,
+
1
35.1, 139.8, 140.4, 142.0, 157.2, 167.8; MS m/z 336 ([M + NH
4
] ); HRMS for C16
H
15
O
5
S
+
(
[M + H] ): calcd 319.0635; found 319.0637. Anal. for C H O S: calcd C, 60.37; H, 4.43;
16 14 5
found C, 60.12; H, 4.33.
4
.1.1.11 (2E)-3-(3,4-Dihydroxyphenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid
33). Reaction time: 50 h; temperature: 120 °C; yield 44%; mp 229–231 °C (H O/EtOH); IR
429, 2937, 1663, 1598, 1524, 1443, 1425, 1262, 1172, 1133 cm ; H NMR (DMSO-d ) δ
= 2.0 Hz), 6.59 (1H, d, J =
(
2
–1 1
3
3
8
9
1
+
C
6
1 2
.26 (3H, s), 6.39 (1H, d, J = 2.0 Hz), 6.44 (1H, dd, J = 8.0 Hz, J
.0 Hz), 7.44 (2H, d, J = 8.5 Hz) 7.67 (1H, s), 7.93 (2H, d, J = 8.5 Hz), 8.98 (1H, broad s),
1
3
6
.50 (1H, broad s), 12.61 (1H, broad s); C NMR (DMSO-d ) δ 43.6, 115.4, 117.4, 123.6,
25.1, 127.2, 127.9, 130.8, 139.6, 140.8, 142.6, 145.0, 147.5, 168.1; MS (ESI+) m/z 335 ([M
+
+
H] ); HRMS for C16
S: calcd C, 57.48; H, 4.22; found C, 57.41; H, 4.08.
.1.1.12 (2E)-2-[4-(Methylsulfonyl)phenyl]-3-(3,4,5-trimethoxyphenyl)prop-2-enoic acid
34). Reaction time: 19.5 h; temperature: 130 °C; yield 76%; mp 218–220 °C (EtOH); IR
15 6
H O S ([M + H] ): calcd 335.0584; found 335.0579. Anal. for
16
14 6
H O
4
(
–
1 1
2
3
7
1
+
C
6
988, 2842, 1677, 1604, 1578, 1505, 1451, 1417, 1308, 1252 cm ; H NMR (DMSO-d ) δ
.24 (3H, s), 3.44 (6H, s), 3.61 (3H, s), 6.35 (2H, s), 7.51 (2H, d, J = 8.5 Hz), 7.80 (1H, s),
1
3
6
.99 (2H, d, J = 8.5 Hz), 12.88 (1H, broad s); C NMR (DMSO-d ) δ 43.3, 55.3, 60.1, 108.1,
27.4, 129.0, 130.8, 130.9, 138.5, 140.0, 140.2, 142.5, 152.4, 167.6; MS (ESI+) m/z 393 ([M
+
+
H] ); HRMS for C19
S: calcd C, 58.15; H, 5.14; found C, 58.31; H, 5.21.
.1.1.13 (2E)-3-(3-Fluorophenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (35).
Reaction time: 19 h; temperature: 100 °C; yield 75%; mp 201–203 °C (EtOAc); IR 3187,
21 7
H O S ([M + H] ): calcd 393.1003; found 393.1004. Anal. for
19
20 7
H O
4
–1
1
3
002, 1705, 1624, 1582, 1481, 1447, 1393, 1275, 1134 cm ; H NMR (DMSO-d
6
) δ 3.26
(
3H, s), 6.84−6.89 (2H, m), 7.12 (1H, dt, J = 8.5 Hz, J = 2.5 Hz), 7.25−7.30 (1H, m), 7.47
1
2
1
2

ACCEPTED MANUSCRIPT
1
3
(
2H, d, J = 8.5 Hz), 7.86 (1H, s), 7.94 (2H, d, J = 8.5 Hz), 13.10 (1H, broad s); C NMR
DMSO-d ) δ 43.5, 116.1 (d, J = 21.3 Hz), 116.5 (d, J = 22.4 Hz), 126.3 (d, J = 2.6 Hz),
27.2, 130.5 (d, J = 8.4 Hz), 130.7, 133.4, 136.4 (d, J = 8.1 Hz), 138.7, 140.1, 141.5, 161.7 (d,
(
6
1
-
-
J = 244.2 Hz), 167.4; MS ESI–) m/z 319 ([M - H] ); HRMS for C16
H
12FO
4
S ([M - H] ): calcd
3
3
4
19.0446; found 319.0447. Anal. for C16
.82.
H13FO S: calcd C, 59.99; H, 4.09; found C, 59.70; H,
4
.1.1.14 (2E)-3-(4-Bromophenyl)-2-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (37).
O); IR 2971,
672, 1609, 1583, 1489, 1406, 1311, 1274, 1259, 1147 cm ; H NMR (DMSO-d ) δ 3.27
Reaction time: 19.5 h; temperature: 120 °C; yield 68%; mp 261–262 °C (H
2
–1
1
1
6
(3H, s), 6.99 (2H, d, J = 8.5 Hz), 7.44–7.48 (4H, m), 7.46 (2H, d, J = 8.3 Hz), 7.83 (1H, s),
1
3
7
1
.93 (2H, d, J = 8.3 Hz), 13.03 (1H, broad s); C NMR (DMSO-d
6
) δ 43.5, 122.8, 127.2,
+
30.7, 131.5, 132.0, 132.7, 133.2, 139.0, 140.0, 131.4, 167.5; MS (ESI+) m/z 381 ([M + H] );
+
HRMS for C16
H
14BrO
4
S ([M + H] ): calcd 380.9791; found 380.9791. Anal. for
C
16
H13BrO
4
S: calcd C, 50.41; H, 3.44; found C, 50.26; H, 3.19.
4
.1.1.15
(2E)-2-[4-(Methylsulfonyl)phenyl]-3-[4-(trifluoromethyl)phenyl]prop-2-enoic
acid (38). Reaction time: 18.5 h; temperature: 120 °C; yield 66%; mp 218–221 °C (EtOAc);
–1 1
IR 2988, 1682, 1620, 1595, 1416, 1394, 1323, 1307, 1271, 1148 cm ; H NMR (DMSO-d
6
) δ
3
7
1
.26 (3H, s), 7.26 (2H, d, J = 8.5 Hz), 7.48 (2H, d, J = 8.3 Hz), 7.61 (2H, d, J = 8.5 Hz), 7.93–
13
6
.95 (3H, m), 13.20 (1H, broad s); C NMR (DMSO-d ) δ 43.5, 123.9 (q, J = 272.7 Hz),
25.3 (q, J = 3.7 Hz), 127.2, 129.0 (q, J = 32.0 Hz), 130.69, 130.71, 134.4, 138.2 (q, J = 1.0
+
Hz), 138.6, 140.1, 141.1, 167.3; MS (ESI+) m/z 388 ([M + NH
4
] ); HRMS for C17
H
14
F
3
O
4
S
+
(
[M + H] ): calcd 371.0559; found 371.0559. Anal. for C17
H
13
F
3
O
4
S: calcd C, 55.13; H, 3.54;
found C, 55.15; H, 3.43.
.1.1.16 (2E)-3-[4-(Methylsulfanyl)phenyl]-2-[4-(methylsulfonyl)phenyl]prop-2-enoic
acid (39). Reaction time: 20 h; temperature: 120 °C; yield 53%; mp 238–240 °C (EtOAc/n-
4
–1 1
heptane); IR (KBr) 3416, 2927, 1665, 1586, 1410, 1309, 1251, 1190, 1146, 1088 cm ; H
NMR (DMSO-d ) δ 2.42 (3H, s), 3.26 (3H, s), 6.98 (2H, d, J = 8.7 Hz), 7.10 (2H, d, J = 8.7
Hz), 7.47 (2H, d, J = 8.4 Hz), 7.81 (1H, s), 7.94 (2H, d, J = 8.4 Hz), 12.83 (1H, broad s); C
NMR (DMSO-d ) δ 14.0, 43.5, 125.1, 127.2, 130.0, 130.68, 130.69, 130.72, 139.7, 139.9,
6
1
3
6
+
+
1
3
4
4
40.8, 142.1, 167.7; MS (ESI+) m/z 349 ([M + H] ); HRMS for C17
H
17
O
4
S
2
([M + H] ): calcd
49.0568; found 349.0555. Anal. for C17
.79.
H O S : calcd C, 58.60; H, 4.63; found C, 58.83; H,
16 4 2
.1.1.17
(2E)-3-[4-(Acetylsulfamoyl)phenyl]-2-[4-(methylsulfonyl)phenyl]prop-2-enoic
acid (41). Reaction time: 4.5 h; temperature: 110 °C; yield 25% (column chromatography);
1
3

ACCEPTED MANUSCRIPT
mp 177.5–179.0 °C (H
2
O/EtOH); IR 3342, 2988, 2901, 1721, 1689, 1607, 1470, 1406, 1287,
–1 1
1
145 cm ; H NMR (DMSO-d
6
) δ 1.91 (3H, s), 3.27 (3H, s), 7.28 (2H, d, J = 8.5 Hz), 7.47
(7H, d, J = 8.5 Hz), 7.74 (2H, d, J = 8.5 Hz), 7.92 (1H, s) 7.93 (2H, d, J = 8.5 Hz), 12.12 (1H,
1
3
broad s), 13.20 (1H, broad s); C NMR (DMSO-d
6
) δ 23.2, 43.5, 127.2, 127.5, 130.5, 130.6,
+
1
34.7, 138.3, 139.0, 139.2, 140.2, 140.9, 167.3, 168.9; MS (ESI+) m/z 424 ([M + H] );
+
HRMS for C H NO S ([M + H] ): calcd 424.0519; found 424.0515. Anal. for C H NO S
7 2
18
18
7
2
18 17
2
3 2
x / H O: calcd C, 49.65; H, 4.24; N, 3.22; found C, 49.34.; H, 4.08.; N, 3.18.
4
.1.2. Synthesis of (2E)-3-(3-acetoxyphenyl)-2-(3,4,5-trimethoxyphenyl)prop-2-enoic acid
(4). Applying a general method described above, (2E)-3-(3-hydroxyphenyl)-2-(3,4,5-
trimethoxyphenyl)prop-2-enoic acid was obtained from 3-hydroxybenzaldehyde and (3,4,5-
trimethoxyphenyl)acetic acid using triethylamine as a base; reaction time: 45 h; temperature:
1
1
00 °C; yield 42%; mp 220−225 °C (EtOAc); IR (KBr) 3447, 2941, 1678, 1587, 1413, 1310,
–
1 1
6
271, 1127 cm ; H NMR (DMSO-d ) δ 3.68 (6H, s), 3.71 (3H, s), 6.46 (2H, s), 6.53−6.59
(2H, m), 6.67−6.70 (1H, m), 7.02−7.05 (1H, m), 7.64 (1H, s), 9.40 (1H, s), 12.60 (1H, broad
13
s); C NMR (DMSO-d
6
) δ 56.0, 60.1, 106.9, 116.3, 116.9, 121.3, 129.2, 131.7, 133.0, 135.7,
-
1
37.1, 139.1, 153.0, 157.1, 168.4; MS (ESI–) m/z 329 ([M - H] , 68); HRMS for C18
H
17
O
6
:
calcd 329.1025; found 329.1028. Anal. for C18
H, 5.51.
18 6
H O : calcd C, 65.45; H, 5.49; found C, 65.33;
To the solution of (2E)-3-(3-hydroxyphenyl)-2-(3,4,5-trimethoxyphenyl)prop-2-enoic acid
3.96 g, 12 mmol) in DMF (12 mL) were added 4-dimethylaminopyridine (30 mg, 0.245
(
mmol) and acetic anhydride (1.73 mL, 18 mmol). The reaction mixture was stirred at rt for 48
h, treated with water (36 mL) and extracted with EtOAc:THF 3:1 (3 x 60 mL). The combined
organic phases were washed with 5% HCl, dried over anhydrous sodium sulfate and
evaporated to dryness to give the acid 4. Yield 64%; mp 186.9−189.7 °C (EtOAc); IR 2946,
−1 1
1
683, 1582, 1412, 1289, 1240, 1211, 1128 cm ; H NMR (DMSO-d ) δ 2.18 (3H, s), 3.67
6
(6H, s), 3.71 (3H, s), 6.46 (2H, s), 6.77−6.79 (1H, m), 7.01−7.05 (2H, m), 7.26−7.31 (1H, m),
1
3
7
1
.72 (1H, s), 12.73 (1H, broad s); C NMR (DMSO-d
6
) δ 20.6, 55.9, 60.1, 106.8, 122.5,
23.1, 127.7, 129.3, 131.3, 134.3, 135.9, 137.3, 137.7, 150.2, 153.1, 168.1, 168.8; MS (ESI–)
-
-
m/z 371 ([M - H] , 10); HRMS for C20
19 7
H O ([M - H] ): calcd 371.1131; found 371.1123.
Anal. for C20 : calcd C, 64.51; H, 5.41; found C, 64.34; H, 5.39.
20 7
H O
4
.1.3. Oxidation of the methylthio moiety into methylsulfonyl group
1
4

ACCEPTED MANUSCRIPT
Hydrogen peroxide (30%, 30 mmol, 3.1 mL) was added to a stirred suspension of the
propenoic acid 20 or 23 (6 mmol) in acetic acid (60 mL) at 0 °C and the reaction mixture was
stirred at rt for 48 h. Then, it was poured into cold water (300 mL) and the precipitate was
filtered off to give the product 21 or 24.
4
.1.3.1. (2E)-2-(4-Chlorophenyl)-3-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (21).
Yield 73%; mp 231−234 °C (AcOH/H O); IR (KBr) 3414, 2928, 1688, 1433, 1312, 1303,
2
−1 1
1
271, 1152 cm ; H NMR (DMSO-d
6
) δ 3.19 (3H, s), 7.22 and 7.44 (4H, AA'XX', J = 8.4
1
3
Hz), 7.33 and 7.79 (4H, AA'XX', J = 8.4 Hz), 7.88 (1H, s), 13.03 (1H, broad s); C NMR
(
DMSO-d ) δ 43.2, 126.8, 128.6, 130.6, 131.5, 132.8, 134.3, 135.1, 137.6, 139.4, 140.5,
6
-
-
1
3
67.6; MS (ESI–) m/z 335.0 ([M - H] , 30); HRMS for C16
4
H12ClO S ([M - H] ): calcd
35.0145; found 335.0150. Anal. for C16 S: calcd C, 57.06; H, 3.89; found C, 57.32;
H
13ClO
4
H, 3.66.
.1.3.2. (2E)-2-(3-Chlorophenyl)-3-[4-(methylsulfonyl)phenyl]prop-2-enoic acid (24).
Yield 74%; mp 205–207 °C (AcOH/H O); IR (KBr) 3418, 1668, 1609, 1589, 1426, 1287,
) δ 3.19 (3H, s), 7.12−7.16 (1H, m), 7.30−7.47 (5H, m),
4
2
–1 1
1
7
1
272, 1191 cm ; H NMR (DMSO-d
.77−7.80 (2H, m), 7.89 (1H, s), 13.06 (1H, broad s); C NMR (DMSO-d
28.0, 128.3, 129.3, 130.4, 130.7, 133.1, 134.8, 137.6, 137.9, 139.3, 140.6, 167.4; MS (ESI–)
6
13
6
) δ 43.2, 126.8,
-
-
m/z 335.0 ([M - H] ); HRMS for C16
4
H12ClO S ([M - H] ): calcd 335.0145; found 335.0141.
Anal. for C16 S: calcd C, 57.06; H, 3.89; found C, 57.17; H, 3.76.
H
13ClO
4
4
.1.4. Suzuki coupling to obtain (2E)-3-[4'-(methylsulfanyl)biphenyl-4-yl]-2-[4-
(methylsulfonyl)phenyl]prop-2-enoic acid (42). An aqueous solution of 2 M potassium
carbonate (4.0 mL), triphenylphosphine (32 mg, 0.12 mmol) and Pd(OAc) (7 mg, 0.03
2
mmol) were added to a solution of (2E)-3-(4-bromophenyl)-2-[4-(methylsulfonyl)-
phenyl]prop-2-enoic acid (37; 381 mg, 1.0 mmol) and 4-(methylthio)phenylboronic acid (252
mg, 1.5 mmol) in dimethoxyethane (10 mL) under an argon atmosphere. The reaction mixture
was heated at 100 °C for 17 h, cooled to rt and the solvent was removed under reduced
pressure. Dichloromethane (30 mL) and water (20 mL) were added and the mixture was
acidified with 1 M aqueous HCl to pH 3. Layers were separated and the water phase was
additionally extracted with dichloromethane (3 x 20 mL). The combined organic layers were
washed with brine (2 x 30 mL), dried over anhydrous sodium sulfate and evaporated to
dryness giving the acid 42. Yield 72%; mp 291–293 °C (EtOAc); IR 2988, 2923, 1666, 1590,
–
1 1
1
7
486, 1425, 1396, 1307, 1275, 1150 cm ; H NMR (DMSO-d
6
) δ 2.49 (3H, s), 3.28 (3H, s),
.13 (2H, d, J = 8.5 Hz), 7.30 (2H, d, J = 8.5 Hz), 7.51 (2H, d, J = 8.3 Hz), 7.56 (2H, d, J =
1
5

ACCEPTED MANUSCRIPT
1
3
8
.5 Hz), 7.61 (2H, d, J = 8.5), 7.90 (1H, s), 7.96 (2H, d, J = 8.3 Hz), 12.98 (1H, broad s); C
NMR (DMSO-d
6
) δ 14.5, 43.5, 126.2, 127.0, 127.2, 130.7, 131.0, 131.6, 132.7, 135.2, 138.3,
+
1
39.7, 139.9, 140.1, 142.0, 167.7 (one signal missing); MS (ESI+) m/z 423 ([M + H] );
+
21 4 2 20 4 2
HRMS for C23H O S ([M + H] ): calcd 425.0876; found 425.0876. Anal. for C23H O S x
0
2
.5 H O: calcd C, 63.72; H, 4.88; found C, 63.56; H, 4.66.
4
.2. Molecular docking
A multi-conformer library of 3D structures of the compounds 1, 20, 22, 28, 29, 36, 37 and 39
was prepared with the program Omega (OpenEye Scientific Software Inc.). For the
preparation of 3D conformations the default parameters were used, except that the maximum
number of conformations per compound was increased to 300. Active sites of AKR1C1 (PDB
code 3C3U) [30] and AKR1C3 (PDB code 1S2A) [31] were prepared with the program
fred_receptor (OpenEye Scientific Software Inc.). Co-crystallized cofactors were retained in
the structures. An active site was in both cases defined as a box around co-crystallized
inhibitor, 3,5-dichlorosalicylic acid in the case of AKR1C1 and indomethacin in the case of
AKR1C3. A docking protocol was validated by re-docking of co-crystallized inhibitors.
Subsequently, the multi-conformer library of the compounds 1, 20, 22, 28, 29, 36, 37 and 39
was docked with FRED [32] in both enzymes using chemgauss3 as a scoring function.
4
.3. Inhibition Assays
Recombinant enzymes AKR1C1-AKR1C3 were prepared as described before [33]. These
enzymes in vitro catalyze the oxidation of the 1-acenaphthenol in the presence of the
+
coenzyme NAD and this reaction was followed spectrophotometrically by measuring the
−
1
−1
increase in NADH absorbance (ελ340 = 6220 M .cm ) in the presence and absence of each of
the compounds. The assays were carried out in a 0.3 mL volume that included a 100 mM
phosphate buffer (pH 9.0), 0.005% triton X-114 and 5% DMSO as a co-solvent. A substrate
m m m
concentration of 30 µM (K ), 50 µM (K ) and 100 µM (< K ) and an enzyme concentration
of 0.3 µM, 0.2 µM, and 1.5 µM were used for assays with AKR1C1, AKR1C2 and AKR1C3,
respectively, in the presence of 2.3 mM coenzyme. Screening was performed for 100 ꢀM
compounds. For the compounds that showed more than 50% inhibition, the IC50 values were
determined. The measurements were performed on Biotek PowerWave XS microplate readers
with initial velocities calculated, and the IC50 values were determined graphically from plots
of log10 [inhibitor concentration] versus % inhibition, using GraphPad Prism Version 4.00
1
6

ACCEPTED MANUSCRIPT
(GraphPad Software, Inc.). Ki values were then calculated using the Cheng-Prusoff equation
for competitive inhibition.
Acknowledgements
Slovenian Research Agency is gratefully acknowledged for the financial support (projects P1-
0
230, J3-4135). We thank Dr. Bogdan Kralj and Dr. Dušan Žigon (Mass Spectrometry
Centre, Jožef Stefan Institute, Ljubljana, Slovenia) for recording the mass spectra. This work
was supported with the infrastructure of the EN-FIST Centre of Excellence, Dunajska 156, SI-
1
000 Ljubljana, Slovenia. We thank OpenEye Scientific Software, Inc. for free academic
licenses of their software. The authors thank Dr. Trevor M. Penning (University of
Pennsylvania, School of Medicine, Philadelphia, PA, USA) for the pcDNA3-AKR1C1 and
pcDNA3-AKR1C2 constructs and Dr. Jerzy Adamski (Helmholtz Zentrum Munchen,
Germany) for the pGex-AKR1C3 construct. This study was partially supported by Young
Researcher grants to M.G. and N.B. from the Slovenian Research Agency.
Appendix A. Supporting information
Supplementary material associated with this article can be found, in the online version, at
http://........ It includes the characterization data of the compounds 13, 15, 19, 20, 30, 31, 36,
and 40 as well as the predicted binding pose of the compound 1 in the AKR1C1 active site
and the data about a purity of all tested acids checked by HPLC .
References
[
1] T.M. Penning, M.E. Burczynski, J.M. Jez, C.F. Hung, H.K. Lin, H. Ma, M. Moore, N.
Palackal, K. Ratnam, Human 3α-hydroxysteroid dehydrogenase isoforms (AKR1C1–
AKR1C4) of the aldo-keto reductase superfamily: functional plasticity and tissue
distribution reveals roles in the inactivation and formation of male and female sex
hormones, Biochem. J. 351 (2000) 67–77.
[
[
2] T.M. Penning, M.C. Byrns, Steroid hormone transforming aldo-keto reductases and
cancer, Ann. N. Y. Acad. Sci. 1155 (2009) 33–42.
3] T.M. Penning, J.E. Drury, Human aldo-keto reductases: function, gene regulation, and
single nucleotide polymorphisms, Arch. Biochem. Biophys. 464 (2007) 241–250.
1
7

ACCEPTED MANUSCRIPT
[
[
4] I. Dufort, P. Rheault, X.F. Huang, P. Soucy, V. Luu-The, Characteristics of a highly
labile human type 5 17β-hydroxysteroid dehydrogenase, Endocrinology 140 (1999) 568–
5
74.
5] M.C. Byrns, L. Duan, S.H. Lee, I.A. Blair, T.M. Penning, Aldo-keto reductase 1C3
expression in MCF-7 cells reveals roles in steroid hormone and prostaglandin
metabolism that may explain its over-expression in breast cancer, J. Steroid Biochem.
Mol. Biol. 118 (2010) 177–187.
[
6] R.B. Montgomery, E.A. Mostaghel, R. Vessella, D.L. Hess, T.F. Kalhorn, C.S. Higano,
L.D. True, P.S. Nelson, Maintenance of intratumoral androgens in metastatic prostate
cancer: a mechanism for castration-resistant tumor growth, Cancer Res. 68 (2008) 4447–
4
454.
[
[
7] T. Lanišnik-Rižner, T. Šmuc, R. Rupreht, J. Šinkovec, T.M. Penning, AKR1C1 and
AKR1C3 may determine progesterone and estrogen ratios in endometrial cancer, Mol.
Cell. Endocrinol. 248 (2006) 126–135.
8] T. Šmuc, N. Hevir, M. Ribič-Pucelj, B. Husen, H. Thole, T.L. Rižner, Disturbed
estrogen and progesterone action in ovarian endometriosis, Mol. Cell. Endocrinol. 301
(2009) 59–64.
[
[
9] P. Brožič, S. Turk, T.L. Rižner, S. Gobec, Inhibitors of Aldo-Keto reductases AKR1C1–
AKR1C4, Curr. Med. Chem. 18 (2011) 2554–2565.
10] M.C. Byrns, Y. Jin, M.P. Penning, Inhibitors of type 5 17β-hydroxysteroid
dehydrogenase (AKR1C3): Overview and structural insights, J. Steroid Biochem. Mol.
Biol. 125 (2011) 95–104.
[
[
11] N. Beranič, S. Gobec, T.L. Rižner, Progestins as inhibitors of the human 20-ketosteroid
reductases, AKR1C1 and AKR1C3, Chem. Biol. Interact. 191 (2011) 227–233.
12] P. Bydal, V. Luu-The, F. Labrie, D. Poirier, Steroidal lactones as inhibitors of 17β-
hydroxysteroid dehydrogenase type 5: chemical synthesis, enzyme inhibitory activity,
and assessment of estrogenic and androgenic activities, Eur. J. Med. Chem. 44 (2009)
6
32–644.
[
[
13] B. Štefane, P. Brožič, M. Vehovc, T.L. Rižner, S. Gobec, New cyclopentane derivatives
as inhibitors of steroid metabolizing enzymes AKR1C1 and AKR1C3, Eur. J. Med.
Chem. 44 (2009) 2563–2571.
14] Y. Higaki, N. Usami, S. Shintani, S. Ishikura, O. El-Kabbani, A. Hara, Selective and
potent inhibitors of human 20α-hydroxysteroid dehydrogenase (AKR1C1) that
1
8

ACCEPTED MANUSCRIPT
metabolizes neurosteroids derived from progesterone, Chem. Biol. Interact. 143–144
(2003) 503–513.
[
[
15] L. Skarydova, L. Zivna, G. Xiong, E. Maser, V. Wsol, AKR1C3 as a potential target for
the inhibitory effect of dietary flavonoids, Chem. Biol. Interact. 178 (2009) 138–144.
16] (a) P. Brožič, B. Golob, N. Gomboc, T. Lanišnik-Rižner, S. Gobec, Cinnamic acids as
new inhibitors of 17β-hydroxysteroid dehydrogenase type 5 (AKR1C3), Mol. Cell.
Endocrinol. 248 (2006) 233–235;
(b) S. Endo, T. Matsunaga, A. Kanamori, Y. Otsuji, H. Nagai, K. Sundaram, O. El-
Kabbani, N. Toyooka, S. Ohta, A. Hara, Selective inhibition of human type-5 17β-
hydroxysteroid dehydrogenase (AKR1C3) by baccharin, a component of brazilian
propolis, J. Nat. Prod. 75 (2012) 716−721.
[
[
17] N.J. Davies, R.E. Hayden, P.J. Simpson, J. Birtwistle, K. Mayer, J.P. Ride, C.M. Bunce,
AKR1C isoforms represent a novel cellular target for jasmonates alongside their
mitochondrial-mediated effects, Cancer Res. 69 (2009) 4769–4775.
18] M.C. Byrns, S. Steckelbroeck, T.M. Penning, An indomethacin analogue, N-(4-
chlorobenzoyl)-melatonin, is a selective inhibitor of aldo-keto reductase 1C3 (type 2 3α-
HSD, type 5 17β-HSD, and prostaglandin F synthase), a potential target for the treatment
of hormone dependent and hormone independent malignancies, Biochem. Pharmacol. 75
(2008) 484–493.
[
19] (a) A.O. Adeniji, B.M. Twenter, M.C. Byrns, Y. Jin, J.D. Winkler, T.M. Penning,
Discovery of substituted 3-(phenylamino)benzoic acids as potent and selective inhibitors
of type 5 17β-hydroxysteroid dehydrogenase (AKR1C3), Bioorg. Med. Chem. Lett. 21
(2011) 1464–1468;
(b) A.O. Adeniji, B.M. Twenter, M.C. Byrns, Y. Jin, M. Chen, J.D. Winkler, T.M.
Penning, Development of potent and selective inhibitors of aldo−keto reductase 1C3
type 5 17β-hydroxysteroid dehydrogenase) based on N-phenyl-aminobenzoates and
(
their structure−activity relationships, J. Med. Chem. 55 (2012) 2311–2323.
20] S. Li, W. Yuan, S. Ma, Highly regio- and stereoselective three-component nickel-
catalyzed syn-hydrocarboxylation of alkynes with diethyl zinc and carbon dioxide,
Angew. Chem. Int. Ed. 50 (2011) 2578–2582.
[
[
21] B. Burja, T. Čimbora-Zovko, S. Tomić, T. Jelušić, M. Kočevar, S. Polanc, M. Osmak,
Pyrazolone-fused combretastatins and their precursors: synthesis, cytotoxicity,
antitubulin activity and molecular modeling studies, Bioorg. Med. Chem. 18 (2010)
2
375–2387.
1
9

ACCEPTED MANUSCRIPT
[
[
22] A. Moreau, O.-H. Chen, P.N.P. Rao, E.E. Knaus, Design, synthesis, and biological
evaluation of (E)-3-(4-methanesulfonylphenyl)-2-(aryl)acrylic acids as dual inhibitors of
cyclooxygenases and lipoxygenases, Bioorg. Med. Chem. 14 (2006) 7716–7727.
23] C. Zhu, Y. Zhang, G. Cao, S. Peng, W. Wang, J. Zheng, Studies on the nonsteroidal
antifertility agents. II. Synthesis and antifertility activity of some p-coumaric acid
derivatives, Nanjing Yaoxueyuan Xuebao (1982) 50−56. Chem. Abstr. 99 (1983)
2
12230.
[
[
[
24] J. J. Talley, J. S. Carter, P. W. Collins, S.W. Kramer, T. D. Penning, D.J. Rogier Jr., R.S.
Rogers, Substituted thiazoles for the treatment of inflammation, WO 9603392 A1;
Chem. Abstr. 125 (1996) 33628.
25] J.-L. Mao, X.-K. Ran, J.-Z. Tian, B. Jiao, H.-L. Zhou, L. Chen, Z.-G. Wang, Design,
synthesis and biological evaluation of novel 4-hydroxybenzeneacrylic acid derivatives,
Bioorg. Med. Chem. Lett. 21 (2011) 1549–1553.
26] X. Ran, J. Mao, H. Pang, L. Chen, B. Jiao, Preparation of 3-phenyl-2-(4-
mesylphenyl)acrylates as cyclooxygenase-2 inhibitors for treatment of inflammation and
pain, Faming Zhuanli Shenqing Gongkai Shuomingshu, Patent CN 1762994 (April 26,
2
006); Chem. Abstr. 145 (2006) 62680.
[
27] D. Macdonald, A. Mastracchio, H. Perrier, D. Dube, M. Gallant, C. Li, L.A. Trimble, S.
Day, N. Chauret, D.A. Nicoll-Griffith, J.M. Silva, Z. Huang, F. Laliberte, S. Liu, D.
Ethier, D. Pon, E. Muise, L. Boulet, C.C. Chan, A. Styhler, S. Charleson, J. Mancini, P.
Masson, D. Claveau, D. Nicholson, M. Turner, R.N. Young, Y. Girard, Discovery of a
substituted 8-arylquinoline series of PDE4 inhibitors: structure-activity relationship,
optimization, and identification of a highly potent, well tolerated, PDE4 inhibitor,
Bioorg. Med. Chem. Lett. 15 (2005) 5241–5246.
[
28] F. Wang, S. Li, W. Feng, Anti-inflammatory structure-activity relationships of a new
series of open-loop COX-2 inhibitors derived from rofecoxib, Beijing Huagong Daxue
Xuebao, Ziran Kexueban 31 (2004) 84–87, Chem. Abstr. 142 (2005) 385056.
29] T. Rosen, The Perkin reaction, in: B. Trost, I. Fleming (Eds.), Comprehensive Organic
Synthesis, vol. 2, Pergamon Press, Oxford, 1991, pp. 395–408.
[
[
30] U. Dhagat, S. Endo, R. Sumii, A. Hara, O. El-Kabbani, Selectivity determinants of
inhibitor binding to human 20α-hydroxysteroid dehydrogenase: crystal structure of the
enzyme in ternary complex with coenzyme and the potent inhibitor 3,5-dichlorosalicylic
acid, J. Med. Chem. 51 (2008) 4844–4848.
2
0

ACCEPTED MANUSCRIPT
[
31] A.L. Lovering, J.P. Ride, C.M. Bunce, J.C. Desmond, S.M. Cummings, S.A. White,
Crystal structures of prostaglandin D2 11-ketoreductase (AKR1C3) in complex with the
nonsteroidal anti-inflammatory drugs flufenamic acid and indomethacin, Cancer Res. 64
(
2004) 1802–1810.
32] M. McGann, FRED pose prediction and virtual screening accuracy, J. Chem. Inf. Model.
1 (2011) 578–596.
[
[
5
33] P. Brožič, T. Šmuc, S. Gobec, T. Lanišnik-Rižner, Phytoestrogens as inhibitors of the
human progesterone metabolizing enzyme AKR1C1, Mol. Cell. Endocrinol. 259 (2006)
3
0–42.
List of captions
Fig. 1. Design of 2,3-diarylpropenoic acids.
Fig. 2. Predicted binding pose of the compound 37 (blue) in the AKR1C3 active site (green).
Scheme 1. Synthesis of 2,3-diarylpropenoic acids employing the Perkin reaction.
Scheme 2. Selective oxidation of the methylthio groups of the acids 20, 23 and 39.
Scheme 3. Synthesis of the acid 42.
Table 1. Structures of 2,3-diarylpropenoic acids 1–42.
Table 2. Effect of 2,3-diarylpropenoic acids 1–42 on the inhibition of AKR1C1–AKR1C3.
2
1

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Fig. 1. Design of 2,3-diarylpropenoic acids.
Fig. 2. Predicted binding pose of the compound 37 (blue) in the AKR1C3 active site (green).
Only relevant amino acid residues are shown and labeled. The co-crystallized indomethacin is
shown as magenta sticks and the cofactor as orange sticks. The H-bonds are shown as yellow
dashes.
2
2

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Reagents and conditions: arylacetic acid (7.5 mmol), aromatic aldehyde (7.5 mmol), acetic
anhydride (32 mmol), potassium acetate (10 mmol) or triethylamine (10.75 mmol), 100–140 ºC, 3.5–70
h.
Scheme 1. Synthesis of 2,3-diarylpropenoic acids employing the Perkin reaction.
Reagents and conditions: 2,3-diarylpropenoic acid (6 mmol), hydrogen peroxide (30%, 30 mmol, 3.1
mL), acetic acid (60 mL), rt, 48 h.
Scheme 2. Selective oxidation of the methylthio groups of the acids 20, 23 and 39.
2
3

ACCEPTED MANUSCRIPT
Reagents and conditions: acid 37 (1 mmol), 4-(methylthio)phenylboronic acid (1.5 mmol), potassium
3 2
carbonate (4 mL of 2 M aqueous solution), Ph P (0.12 mmol), Pd(OAc) (0.03 mmol), DME (10 mL),
argon, 100 ºC, 17 h.
Scheme 3. Synthesis of the acid 42.
2
4

ACCEPTED MANUSCRIPT
Table 1
Structures of 2,3-diarylpropenoic acids 1–42.
1
2
1
2
Acid
Ar
Ar
Acid
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
Ar
Ar
1
2
3
4
5
6
7
8
9
C
6
H
5
C
6
H
5
4-MeSO -C
2
6
6
H
4
4
4-Cl-C
4-MeS-C
4-MeSO
3-Cl-C
4-MeSO
4-F-C
4-Me-C
4-Et-C
4-MeO-C
6
H
4
3,4,5-MeO-C
3,4,5-MeO-C
3,4,5-MeO-C
3,4,5-MeO-C
3,4,5-MeO-C
3,4,5-MeO-C
3,4,5-MeO-C
3,4,5-MeO-C
3,4,5-MeO-C
6
6
6
6
6
6
6
6
6
H
H
H
H
H
H
H
H
H
2
2
2
2
2
2
2
2
2
3-OH,4-MeO-C
3-OAc,4-MeO-C
3-OAc-C
3-F,4-MeO-C
3-F-C
3,4-MeO-C
4-MeO-C
6
H
3
3-Cl-C
6
6
H
4
6
H
4
6
H
3
3-Cl-C
H
4
2
-C
6
H
H
4
4
H
4-MeSO
-C
H
H
6
6
4
2
4
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
4
6
H
3
4-F-C
6
H
2
4
-C
6
6
H
4
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
4-MeSO
-C
-C
-C
-C
-C
-C
-C
-C
-C
-C
-C
-C
-C
-C
-C
-C
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
6
H
H
H
6 4
6
3
6
H
4
6 4
H
1-naphthyl
2-naphthyl
6 4
H
10
11
12
13
14
15
16
17
18
19
20
21
4-HO-C
6
6
H
4
4
3,4-MeO-C
3,4-MeO-C
1-naphthyl
2-naphthyl
6
6
H
H
3
3
3,4,5-MeO-C
6
6
H
2
3-HO-C
H
2,4,5-MeO-C
H
2
3,4-HO-C
6 3
H
3,4-MeO-C
6
6
H
3
3
3,4,5-MeO-C
6
H
2
3,4-MeO-C
H
3-F-C
6
H
4
C
C
6
6
H
5
5
4-MeS-C
6
H
4
3-Br-C
6
6
H
4
H
4-MeSO
2
2
-C
-C
6
6
H
H
4
4
4-Br-C
H
4
3,4-OCH
2
O-C
6
H
3
4-MeSO
4-CF
4-MeS-C
4-MeSO
3
-C
6
H
4
C
H
5
4-MeCONHSO
-C
H
H
6
6
2
6
4
4
6
4-MeSO
2
-C
6
H
4
C
6
H
5
2
-C
H
4
4-Cl-C
4-Cl-C
6
6
H
H
4
4
4-MeS-C
4-MeSO
6
H
4
6
4-MeCONHSO
2
-C
6
6
H
4
4
-C
H
4-(4-MeS-C )-C
H
6 4
H
2
4
2
5

ACCEPTED MANUSCRIPT
Table 2
Effect of 2,3-diarylpropenoic acids 1–42 on the inhibition of AKR1C1–AKR1C3.
Inhibition of
AKR1C1
Inhibition of
AKR1C2
Inhibition of
AKR1C3
a
a
a
IC50
µM
IC50
µM
IC50
µM
Acid
%
%
%
1
2
3
4
5
6
7
8
9
90.1 ± 1.3
14.4 ± 8.1
8.0 ± 0.2
40.0 ± 14.8
−5.2 ± 6.4
7.8 ± 3.7
6.1 ± 0.1
15.1 ± 1.1
6.4 ± 8.3
9.6 ± 8.6
7.1 ± 1.7
22.2 ± 6.8
29.4 ± 6.8
9.7 ± 1.5
87.0 ± 8.5
77.6 ± 2.0
45.2 ± 5.4
97.8 ± 0.3
26.3 ± 3.7
88.1 ± 0.7
89.6 ± 0.6
34.7 ± 16.2
7.9 ± 0.9
47.5 ± 4.0
20.6 ± 4.5
3.2 ± 2.2
27.0 ± 22.3
9.9 ± 1.1
55.9 ± 3.1
0.6 ± 4.4
4.3 ± 0.3
13.8 ± 0.8
15.9 ± 2.2
4.2 ± 5.6
9.4 ± 5.6
77.8 ± 0.4
39.6 ± 9.5
59.1 ± 3.4
61.4 ± 0.3
24.2 ± 9.4
87.3 ± 7.6
27.3 ± 3.5
75.2 ± 1.1
63.4 ± 7.4
24,3 ± 10,4
78.3 ± 3.0
66.4 ± 0.0
43.0 ± 1.0
69.7 ± 3.6
9.2 ± 6.6
1.1 ± 14.9
n.i.
29.1 ± 2.8
51.7 ± 4.3
8.8 ± 2.0
42.6 ± 2.3
10.3 ± 0.4
12.2 ± 2.4
4.2 ± 0
10.3 ± 0.4
14.8 ± 3.5
30.8 ± 2.6
16.1 ± 4.6
7.0 ± 0
59.7 ± 6.2
78.3 ± 1.3
92.8 ± 4.9
52.3 ± 3.2
35.8 ± 6.8
34.8 ± 1.5
55.5 ± 0.2
86.0 ± 5.3
61.1 ± 3.2
90,6 ± 3,3
84.7 ± 0.3
57.4 ± 0.4
81.6 ± 0.4
43.8 ± 1.2
86.2 ± 0.0
92.7 ± 4.0
89.1 ± 2.3
71.2 ± 1.5
39.9 ± 0.5
43.8 ± 3.0
71.8 ± 0.4
5.7 ± 0.1
121.1 ± 0.3
77.0 ± 0.3
24.2 ± 0.1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
127.8 ± 0.3
38.7 ± 0.2
30.2 ± 0.2
139.2 ± 0.3
12.3 ± 0.0
30.8 ± 0.2
41.2 ± 0.2
34.4 ± 0.2
8.7 ± 0.0
25.2 ± 0.1
69.8 ± 0.3
8.3 ±0.0
6.6 ± 0.1
15.7 ± 0.1
27.3 ± 0.2
26.9 ± 0.2
86.6 ± 0.3
10.8 ± 0.0
17.0 ± 0.1
76.7 ± 0.3
16.8 ± 0.1
81.7 ± 10.8 19.1 ± 0.1
20.8 ± 0.1
23.1 ± 0.1
75.9 ± 2.5
44.5 ± 1.9
86.1 ± 7.2
21.0 ± 0.2
19.3 ± 0.1
23.3 ± 0.1
44.6 ± 0.2
43.1 ± 0.2
13.4 ± 1.1
13.6 ± 1.1
36.9 ± 1.1
b
n.i.
n.i.
n.i.
n.i.
n.i.
46.5 ± 11.6
n.i.
15.4 ± 5.8
34.8 ± 3.2
28.7 ± 13.4
3.5 ± 4.7
43.8 ± 13.1
n.i.
n.i.
n.i.
n.i.
27.2 ± 9.8
n.i.
27.0 ± 2.8
58.3 ± 4.2
19.2 ± 5.2
18.4 ± 16.6
14.4 ± 2.1
n.i.
33.1 ± 1.1
78.3 ± 0.0
93.3 ± 1.8
93.2 ± 0.4
90.6 ± 1.5
93.5 ± 0.5
63.7 ± 1.3
26.1 ± 5.5
72.2 ± 8.1
38.9 ± 1.1
13.6 ± 1.1
4.9 ± 1.1
23.3 ± 1.1
5.8 ± 0.1
51.0 ± 1.1
74.3 ± 1.1
5.9 ± 8.8
64.7 ± 3.8
10.6 ± 2.6
57.4 ± 5.8
a
The values represent % inhibition at 100 µM inhibitor.
No inhibition.
b
2
6

ACCEPTED MANUSCRIPT
Highlights
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ꢀ
ꢀ
ꢀ
A series of new 2,3-diarylpropenoic acids were prepared.
The compounds were evaluated for their inhibition of aldo-keto reductases.
Selective inhibitors of AKR1C3 were identified.
Substituents on benzene rings play a crucial role in selective inhibition of AKR1C3.

ACCEPTED MANUSCRIPT
Appendix A. Supporting information
S1
2
,3-Diarylpropenoic acids as selective non-steroidal inhibitors of type 5 17β-
hydroxysteroid dehydrogenase (AKR1C3)
Martin Gazvoda, Nataša Beranič, Samo Turk, Bojan Burja, Marijan Kočevar, Tea Lanišnik Rižner,
Stanislav Gobec, Slovenko Polanc
Table of contents
Characterization data of the acid 13
S2
S2
S2
S2
S3
S3
S3
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
Characterization data of the acid 15
Characterization data of the acid 19
Characterization data of the acid 20
Characterization data of the acid 30
Characterization data of the acid 31
Characterization data of the acid 36
Characterization data of the acid 40
Predicted binding pose of the compound 1 (blue) in AKR1C1 active site
1
1
1
1
1
1
1
13
H NMR and C NMR of the acid 22
13
H NMR and C NMR of the acid 25
13
H NMR and C NMR of the acid 28
13
H NMR and C NMR of the acid 29
13
H NMR and C NMR of the acid 37
13
H NMR and C NMR of the acid 38
13
H NMR and C NMR of the acid 39
Purity of acids 1−42 determined by HPLC