Synthesis, biological evaluation and docking study of 3-aroyl-1-(4- sulfamoylphenyl)thiourea derivatives as 15-lipoxygenase inhibitors

Article abstract of DOI:10.1016/j.ejmech.2014.05.054

A series of 3-aroyl-1-(4-sulfamoylphenyl)thiourea derivatives containing sulfonamide moiety were designed and synthesized as 15-lipoxygenase (15-LOX) inhibitors. Most synthesized compounds showed potent activity against soybean 15-LOX with IC₅₀

Full text of DOI:10.1016/j.ejmech.2014.05.054

European Journal of Medicinal Chemistry 82 (2014) 308e313
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis, biological evaluation and docking study of
3-aroyl-1-(4-sulfamoylphenyl)thiourea derivatives as
15-lipoxygenase inhibitors
Mohammad Mahdavi a, Maryam Shahzad Shirazi a, Raana Taherkhani b, Mina Saeedi a,
,
, d
Eskandar Alipour b, Farshad Homayouni Moghadam c, Alireza Moradi c d, Hamid Nadri c
,
Saeed Emami e, Loghman Firoozpour f, Abbas Shafiee a, Alireza Foroumadi a
, f, *
a Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences,
Tehran, Iran
b Department of Chemistry, Islamic Azad University, Tehran-North Branch, Zafar St, Tehran, Iran
c Neurobiomedical Research Center, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
d Department of Medicinal Chemistry, Faculty of Pharmacy, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
e Department of Medicinal Chemistry and Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari,
Iran
f Drug Design and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of 3-aroyl-1-(4-sulfamoylphenyl)thiourea derivatives containing sulfonamide moiety were
designed and synthesized as 15-lipoxygenase (15-LOX) inhibitors. Most synthesized compounds showed
Received 10 March 2014
Received in revised form
21 May 2014
Accepted 23 May 2014
Available online 24 May 2014
potent activity against soybean 15-LOX with IC50 values less than 25
mM. The most potent compound 4c
(3-methylbenzoyl derivative) with IC50 value of 1.8 M was 10-fold more potent than quercetin. Inter-
m
estingly, compound 4c also showed the highest antioxidant activity, as determined by ferric reducing
antioxidant power (FRAP) assay. Its capacity for reducing ferric ion was more than ascorbic acid. The
viability assay of the selected compound 4c against oxidative stress-induced cell death in differentiated
PC12 cells revealed that compound 4c significantly protected neurons against cell death in low
concentrations.
Keywords:
Thiourea
Sulfonamides
Enzyme inhibitors
15-Lipoxygenase
Antioxidant activity
Docking study
© 2014 Elsevier Masson SAS. All rights reserved.
1. Introduction
intervention [3]. Among them, 15-LOX has been implicated in car-
diovascular complications (such as atherosclerosis), progression of
Mammalian lipoxygenases (LOXs) belong to a family of non-
heme iron-containing dioxygenases, which catalyze the hydro-
peroxidation of polyunsaturated fatty acids such as arachidonic and
linoleic acids to related hydroperoxides [1]. A heterogeneous family
of LOXs was found as 5-LOX, 12-LOX and 15-LOX isoforms which
oxidize different position of the key substrate, arachidonic acid [2].
The LOX isoforms have been shown to be involved in the
physiopathology and progression of several diseases in human thus
would be emerged as an attractive target for therapeutic
certain cancers and chronic obstructive pulmonary disease (COPD)
[4,5]. Moreover, oxidation of arachidonic and linoleic acids by 15-
LOX resulted in metabolites which have been shown to be pro-
inflammatory [6] and pro-thrombotic [7]. Accordingly, the finding
of new 15-LOX inhibitors has been interesting field in medicinal
chemistry and drug discovery.
Thiourea and sulfonamide derivatives have continuously
absorbed attention of the medicinal chemists in view of their
intense range of biological activities [8e10]. Thiourea derivatives
have been employed as anti-inflammatory and antimicrobial [11],
antimalarial [12], antitumoral [13], pesticidal [14], and anticancer
agents [15]. Also sulfonamides comprise a significant class of drugs
with diverse biological properties such as antimicrobial [16,17],
anticancer [18,19], anti-inflammatory [20], and antiviral activities
* Corresponding author. Drug Design and Development Research Center, Tehran
University of Medical Sciences, Tehran, Iran.
E-mail
addresses:
aforoumadi@tums.ac.ir,
aforoumadi@yahoo.com
(A. Foroumadi).
http://dx.doi.org/10.1016/j.ejmech.2014.05.054
0223-5234/© 2014 Elsevier Masson SAS. All rights reserved.

M. Mahdavi et al. / European Journal of Medicinal Chemistry 82 (2014) 308e313
309
Table 1
as well as HIV protease inhibitors [21]. Previously, several
sulfonamide-based compounds have been reported as 15-LOX in-
hibitors [22e24]. Considering the above mentioned findings about
importance of thiourea derivatives especially as anti-inflammatory
and lipoxygenase inhibitory compounds, we designed novel
phenylthiourea derivatives containing sulfonamide moiety as 15-
LOX inhibitors. Since there is a polar cavity in the active site of
lipoxygenase enzyme, thus the hydrophilic sulfonamide group as a
proton acceptor or donor was connected to the phenylthiourea
scaffold to combine their beneficial effects.
15-LOX inhibitory activity (IC50
,
m
M) and antioxidant potential of compounds 4aeo.
O
S
NH2
O
S
O
Ar
N
N
H
H
Compound
Ar
Ph
Soybean 15-LOXa
FRAP valueb
4a
4b
4c
4d
4e
4f
4g
4h
4i
4j
4k
4l
4m
4n
4o
6.0 1.0
8.1 0.4
1.8 0.2
28.0 2.3
22.7 1.5
NDc
190
214
554
370
285
ND
2-CH3-Ph
3-CH3-Ph
4-CH3-Ph
4-CH3O-Ph
4-NO2-Ph
3-F-Ph
2,3,4,5-F4-Ph
2-Cl-Ph
3-Cl-Ph
4-Cl-Ph
2,4-Cl2-Ph
2-Naphthyl
2-Furyl
In this paper, we described synthesis, biological evaluation and
docking study of 3-aroyl-1-(4-sulfamoylphenyl)thiourea de-
rivatives 4aeo as 15-lipoxygenase inhibitors.
8.7 0.2
12.6 0.9
18.7 1.2
6.7 0.8
25.0 2.2
23.6 2.2
NAd
45.0 3.7
36.0 1.8
18.0 1.6
e
282
69
2. Results and discussion
242.5
150
410
468
290
<150
<150
e
2.1. Chemistry
The synthetic route to target compounds namely 3-aroyl-1-(4-
sulfamoylphenyl)thiourea derivatives 4aeo is illustrated in
Scheme 1. Firstly, aroyl isothiocyanate derivatives 2 were conve-
niently synthesized using different aroyl chlorides 1 and ammo-
nium thiocyanate. Then, compounds 2aeo were reacted with 4-
sulfamoylaniline 3 to afford final compounds 4aeo. Compounds
4aed, 4f, 4g, 4j, 4k, and 4n have been previously reported by Saeed
et al. [25]. All final compounds 4aeo were characterized by IR, 1H
NMR, 13C NMR, MS spectral data as well as elemental analyses.
2-Thienyl
e
Quercetin
Ascorbic acid
e
546
a
IC50 values are expressed as Mean SD of three experiments.
FRAP value is expressed as mmol Fe(II)/g.
Not dissolved.
b
c
d
No activity.
4c had superior activity. Thus at both positions (ortho and meta),
the better results were obtained by methyl substituent.
2.2. Biological activity
2.2.1. In vitro 15-lipoxygenase inhibitory activity
The inhibitory activity of compounds 4aeo against soybean 15-
LOX was expressed as IC50 values in Table 1. Most of benzoylth-
iourea derivatives 4ael showed potent activity (IC50 values
2.2.2. Ferric reducing antioxidant power (FRAP)
Ferric reducing antioxidant power (FRAP) assay was used to
determine the total antioxidant potential of the target compounds
4aeo. In this method, the ferric tripyridyl triazine complex is
reduced by the test compound to ferrous form which has a deep
blue color [26]. The change of absorbance is measured at 585 nm.
Results are expressed in mmole ferrous/g dry mass of compounds
according to the plotted standard curve of ferrous sulfate (Table 1).
Ascorbic acid was used as references drug. Compound 4c showed
the highest antioxidant activity, as determined by FRAP assay. Its
capacity for reducing ferric ion was more than ascorbic acid.
Nevertheless, compounds 4k and 4l also showed high potency for
ferric reduction. The comparison of obtained FRAP values for the
unsubstituted compound 4a and substituted analogs 4bel,
revealed that the antioxidant potential was occasionally increased
by substitution on benzoyl moiety.
<25
1.8
m
M). The 3-methylbenzoyl derivative 4c with IC50 value of
m
M was the most potent compound. Its activity was 10-fold
more than that of standard anti-LOX agent quercetin. Moreover,
compounds 4a, 4b, 4g, 4h, and 4j were more active than quercetin.
Also, compound 4i with IC50 value of 18.7 mM was as potent as
quercetin.
As seen from data, the 3-methyl substituent on benzoyl moiety
could significantly increase the inhibitory activity against 15-LOX,
but other substituent on different position of benzoyl group could
not improve the activity. Indeed, 2-methyl, 3-fluoro, 3-chloro de-
rivatives (compounds 4b, 4g, and 4j, respectively) were as potent as
unsubstituted analog 4a. By comparing the activity of compounds
containing substituent at ortho-, meta-, or para-position of benzoyl
group, it revealed that the substitution at meta-position is well
tolerated. The replacement of phenyl with 2-naphthyl, 2-furyl and
2-thienyl dramatically diminished the activity (compounds 4meo
vs. 4a). In the case of 2-substituted compounds (4b and 4i), the
methyl substituent was better than chloro group. In addition,
among the 3-substituted compounds (4c, 4g, 4j), the methyl analog
2.2.3. Protection against H2O2-induced cell death in PC12 neurons
The neuroprotective activity of the selected compound 4c
against oxidative stress-induced cell death in differentiated PC12
cells was evaluated. The differentiated PC12 cells were incubated
with different concentrations (1, 5 and 10
3 h prior to treatment with H2O2. Moreover, quercetin was used as
reference drug at the concentration of 5 M. The cell viability was
mM) of the compound for
m
measured after 24 h by using the MTT assay. The data are shown in
Fig. 1 in which the cell viability was calculated in comparison with
H2O2-treated group. It should be noted that compound 4c did not
show any toxicity at the tested concentrations. Based on the results,
compound 4c remarkably increased the viability of H2O2-treated
cells from about 50% to 83% at 10 mM concentrations. In general,
compound 4c significantly protected neurons against cell death in
all used concentrations (P value <0.001) (see Fig. 2).
Scheme 1. Synthesis of compounds 4aeo: (a) NH4SCN, acetone, reflux, 10e20 min; (b)
acetone, reflux, 40e60 min.

310
M. Mahdavi et al. / European Journal of Medicinal Chemistry 82 (2014) 308e313
showed the highest antioxidant activity, as determined by FRAP
assay. The viability assay of the selected compound 4c against
oxidative stress-induced cell death in differentiated PC12 cells
revealed that compound 4c significantly protected neurons against
cell death in low concentrations.
The inhibitors of 15-LOX, such as compound 4c prototype maybe
useful for preventing and treating inflammatory diseases such as
asthma, psoriasis, osteoarthritis, rheumatoid arthritis, and athero-
sclerosis. Particularly, the ability of compound 4c to prevent
oxidative stress-induced cell death in neurons revealed that it may
be applicable to neuroprotection in a variety of neurodegenerative
diseases such as stroke where oxidative stress is a major cause of
injury. Future studies of this novel neuroprotective inhibitor of 15-
LOX, including investigation of their ADMET properties and in vivo
efficacy are required to demonstrate the usefulness of the agent to
combat neurodegenerative diseases.
Fig. 1. Protective activity of compound 4c against H2O2-induced cell death in differ-
entiated PC12 cells (***P < 0.001).
2.3. Docking study
4. Experimental
In order to investigate the orientation of compounds in the
active site pocket of target enzyme, docking study was performed
using Autodock Vina. To attain this aim, the potent 15-LOX inhibi-
tor, 4c was docked into the LOX active site pocket. Analysis of
docking results revealed that the hydrophilic sulfonamide moiety
was oriented toward polar cavity in the active site in such a way
that amino group could form a hydrogen bonds with Ser510 and
Melting points were taken on a Kofler hot stage apparatus and
are uncorrected. 1H- and 13C NMR spectra were recorded on Bruker
FT-400 using TMS as an internal standard. The IR spectra were
obtained on a Nicolet Magna FTIR 550 spectrometer (KBr disks).
Mass spectra were recorded with an Agilent Technology (HP) mass
spectrometer operating at an ionization potential of 70 eV. The
elemental analysis was performed with an Elementar Analy-
sensystem GmbH VarioEL CHNS mode.
Gly720. The T-shape pep interaction between adjacent phenyl ring
and Phe576 could assist the formation of hydrogen bond. In this
orientation, the more lipophilic phenyl group was laid to a hydro-
phobic pocket and stabilized by a p
-cation interaction with Fe3þ in
4.1. General procedure for the synthesis of compounds 4aeo
the active site. Meanwhile the carbonyl group hydrogen bonded
with His518 at the vicinity of catalytic Fe3þ
.
A solution of aroyl chloride 1 (1 mmol) and ammonium thio-
cyanate (1 mmol) in acetone (8 mL) was heated under reflux for
10e20 min. After completion of reaction (checked by TLC), the re-
action mixture was cooled to room temperature and the formed
precipitate (NH4Cl) was filtered off. To the freshly prepared solution
of benzoyl isothiocyanate derivative 2, sulfanilamide 3 (1 mmol)
was added and the mixture was stirred under reflux for 40e60 min.
Upon completion of reaction (checked by TLC), the resulting pre-
cipitate was collected by filtration and recrystallized from EtOH to
give the pure product 4.
3. Conclusion
We designed and synthesized a novel of thiourea derivatives
containing phenylsulfonamide moiety as 15-LOX inhibitors. Most
synthesized compounds showed potent activity with IC50 values
less than 25
mM. Among them, the 3-methylbenzoyl derivative 4c
was the most potent compound (IC50 value of 1.8
mM), being 10-fold
more potent than quercetin. Interestingly, compound 4c also
4.1.1. N-((4-Sulfamoylphenyl)carbamothioyl)benzamide (4a)
Yield: 75%, mp 205e207 ꢀC. IR (KBr): 3369, 3340, 3264, 1663,
1602, 1336, 1157 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.72 (s, 1H,
NH), 11.71 (s, 1H, NH), 7.99 (dd, J ¼ 7.7, 1.2 Hz, 2H, H2, H6), 7.91 (d,
J ¼ 8.5 Hz, 2H, sulfamoylphenyl), 7.86 (d, J ¼ 8.5 Hz, 2H, sulfa-
moylphenyl), 7.66 (t, J ¼ 7.7 Hz, 1H, H4), 7.55 (t, J ¼ 7.7 Hz, 2H, H3,
H5), 7.42 (s, 2H, NH2). 13C NMR (100 MHz, DMSO-d6): 179.9, 168.7,
141.4, 133.7, 132.5, 129.2, 128.9, 126.7, 124.9, 120.3. MS (70 eV): m/
ꢂ
z ¼ 335.04 [Mþ ]. Anal. Calcd for C14H13N3O3S2: C, 50.14; H, 3.91; N,
12.53. Found: C, 50.30; H, 4.21; N, 12.36.
4.1.2. 2-Methyl-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4b)
Yield: 70%, mp 203e205 ꢀC. IR (KBr): 3406, 3292, 1687, 1586,
1522, 1330, 1152 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.66 (s, 1H,
NH), 11.85 (s, 1H, NH), 7.93 (d, J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.85
(d, J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.52 (d, J ¼ 7.6 Hz, 1H, H6), 7.45
(dt, J ¼ 7.6, 1.2 Hz, 1H, H4), 7.42 (s, 2H, NH2), 7.31 (m, 2H, H3, H5),
2.43 (s, 3H, CH3). 13C NMR (100 MHz, DMSO-d6): 179.7, 170.9, 141.7,
141.3, 136.6, 134.3, 131.5, 131.1, 128.7, 126.7, 126.0, 124.8, 20.0. MS
Fig. 2. Representation of compound 4c interactions with soybean 15-lipoxygenase
active site. Hydrogen bond was shown as red dotted line. (For interpretation of the
references to color in this figure legend, the reader is referred to the web version of this
article.)
ꢂ
(70 eV): m/z ¼ 349.06 [Mþ ]. Anal. Calcd for C15H15N3O3S2: C, 51.56;
H, 4.33; N, 12.03. Found: C, 51.38; H, 4.49; N, 11.87.

M. Mahdavi et al. / European Journal of Medicinal Chemistry 82 (2014) 308e313
311
4.1.3. 3-Methyl-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4c)
sulfamoylphenyl), 7.81e7.79 (m, 1H, H6), 7.42 (s, 2H, NH2). 13C NMR
(100 MHz, DMSO-d6): 178.9, 162.5, 150.9, 147.7, 144.2, 142.0, 141.2,
139.0, 133.0, 126.7, 125.2, 112.9 (d, JC-F ¼ 21.5 Hz). MS (70 eV): m/
Yield: 77%, mp 209e211 ꢀC. IR (KBr): 3360, 3310, 3011, 1665,
1592,1524,1330,1154 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.74 (s,
1H, NH), 11.64 (s, 1H, NH), 7.91 (d, J ¼ 8.8 Hz, 2H, sulfamoylphenyl),
7.86 (d, J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.84 (d, J ¼ 3.2 Hz, 1H, H2),
7.78 (d, J ¼ 7.6 Hz, 1H, H6), 7.48 (d, J ¼ 7.6 Hz, 1H, H4), 7.44 (t,
J ¼ 7.6 Hz, 1H, H5), 7.42 (s, 2H, NH2), 2.40 (s, 3H, CH3). 13C NMR
(100 MHz, DMSO-d6): 179.7, 168.7, 141.8, 141.4, 138.3, 134.3, 132.4,
129.6, 128.9, 126.7, 126.4, 124.8, 21.3. MS (70 eV): m/z ¼ 349.06
ꢂ
z ¼ 407.00 [Mþ ]. Anal. Calcd for C14H9F4N3O3S2: C, 41.28; H, 2.23; N,
10.32. Found: C, 41.45; H, 2.10; N, 10.56.
4.1.9. 2-Chloro-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4i)
Yield: 70%, mp 210e212 ꢀC. IR (KBr): 3344, 3261, 3162, 3042,
1690, 1605, 1528, 1337, 1157 cmꢁ1. 1H NMR (400 MHz, DMSO-d6):
12.46 (s, 1H, NH), 12.14 (s, 1H, NH), 7.91 (d, J ¼ 8.8 Hz, 2H, sulfa-
moylphenyl), 7.86 (d, J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.65 (dd,
J ¼ 7.6, 0.8 Hz, 1H, H6), 7.59e7.53 (m, 2H, H3, H4), 7.47 (dt, J ¼ 7.6,
2.2 Hz, 1H, H5), 7.45 (s, 2H, NH2). 13C NMR (100 MHz, DMSO-d6):
ꢂ
[Mþ ]. Anal. Calcd for C15H15N3O3S2: C, 51.56; H, 4.33; N, 12.03.
Found: C, 51.72; H, 4.53; N, 11.81.
4.1.4. 4-Methyl-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4d)
179.4, 168.1, 141.9, 141.2, 134.7, 132.7, 130.5, 130.1, 129.8, 127.6, 126.7,
Yield: 77%, mp 215e217 ꢀC. IR (KBr): 3354, 3255, 2995, 1669,
1598,1525,1330,1154 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.76 (s,
1H, NH), 11.56 (s, 1H, NH), 7.93e7.90 (m, 4H, sulfamoylphenyl), 7.85
(d, J ¼ 8.4 Hz, 2H, H2, H6), 7.42 (s, 2H, NH2), 7.36 (d, J ¼ 8.4 Hz, 2H,
H3, H5), 2.40 (s, 3H, CH3). 13C NMR (100 MHz, DMSO-d6): 179.9,
168.5, 141.7, 141.4, 129.5, 129.3, 128.3, 126.7, 124.8, 120.2, 21.6. MS
ꢂ
125.0. MS (70 eV): m/z
C
¼
369.00 [Mþ ]. Anal. Calcd for
14H12ClN3O3S2: C, 45.47; H, 3.27; N, 11.36. Found: C, 45.22; H, 3.10;
N, 11.18.
4.1.10. 3-Chloro-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4j)
ꢂ
(70 eV): m/z ¼ 349.06 [Mþ ]. Anal. Calcd for C15H15N3O3S2: C, 51.56;
Yield: 70%, mp 184e186 ꢀC. IR (KBr): 3350, 3269, 3199, 3026,
1697, 1590, 1529, 1329, 1154 cmꢁ1. 1H NMR (400 MHz, DMSO-d6):
12.58 (s, 1H, NH), 11.85 (s, 1H, NH), 8.04 (s, 1H, H2), 7.93e7.89 (m,
5H, H6, sulfamoylphenyl), 7.73 (d, J ¼ 8.0 Hz, 1H, H4), 7.58 (t,
J ¼ 8.0 Hz, 1H, H5), 7.42 (s, 2H, NH2). 13C NMR (100 MHz, DMSO-d6):
H, 4.33; N, 12.03. Found: C, 51.41; H, 4.19; N, 12.20.
4.1.5. 4-Methoxy-N-((4-sulfamoylphenyl)carbamothioyl)
benzamide (4e)
Yield: 75%, mp 202e204 ꢀC. IR (KBr): 3369, 3345, 3193, 1673,
1599,1531,1340,1159 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.85 (s,
1H, NH), 11.53 (s, 1H, NH), 8.03 (d, J ¼ 8.8 Hz, 2H, H2, H6), 7.91 (d,
J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.86 (d, J ¼ 8.8 Hz, 2H, sulfa-
moylphenyl), 7.41 (s, 2H, NH2), 7.08 (d, J ¼ 8.8 Hz, 2H, H3, H5), 3.86
(s, 3H, OCH3). 13C NMR (100 MHz, DMSO-d6): 180.0, 167.9, 163.8,
141.7, 141.4, 131.5, 126.7, 124.8, 124.2, 114.3, 56.1. MS (70 eV): m/
179.7,167.2,141.8,141.3,134.6,133.6,133.3,130.9,129.0,127.9,126.8,
ꢂ
124.7. MS (70 eV): m/z
C
¼
369.00 [Mþ ]. Anal. Calcd for
14H12ClN3O3S2: C, 45.47; H, 3.27; N, 11.36. Found: C, 45.66; H, 3.13;
N, 11.14.
4.1.11. 4-Chloro-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4k)
ꢂ
z ¼ 365.05 [Mþ ]. Anal. Calcd for C15H15N3O4S2: C, 49.30; H, 4.14; N,
Yield: 70%, mp 209e211 ꢀC. IR (KBr): 3313, 3032, 1662, 1592,
1523, 1330, 1154 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.62 (s, 1H,
NH), 11.81 (s, 1H, NH), 8.00 (d, J ¼ 8.4 Hz, 2H, H2, H6), 7.90 (d,
J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.85 (d, J ¼ 8.8 Hz, 2H, sulfa-
11.50. Found: C, 49.18; H, 3.98; N, 11.28.
4.1.6. 4-Nitro-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4f)
moylphenyl), 7.63 (d, J ¼ 8.4 Hz, 2H, H3, H5), 7.42 (s, 2H, NH2). 13
C
Yield: 80%, mp 203e205 ꢀC. IR (KBr): 3350, 3267, 1682, 1593,
1529, 1339, 1157 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.49 (s, 1H,
NH), 12.07 (s, 1H, NH), 8.35 (d, J ¼ 8.8 Hz, 2H, H3, H5), 8.17 (d,
J ¼ 8.8 Hz, 2H, H2, H6), 7.91e7.85 (m, 4H, sulfamoylphenyl), 7.42 (s,
2H, NH2). 13C NMR (100 MHz, DMSO-d6): 179.6, 169.9, 150.3, 142.2,
141.9, 140.9, 130.8, 126.8, 124.9, 123.9. MS (70 eV): m/z ¼ 380.02
NMR (100 MHz, DMSO-d6): 179.8, 167.6, 141.8, 141.3, 138.5, 131.4,
ꢂ
131.2, 129.0, 126.7, 124.9. MS (70 eV): m/z ¼ 369.00 [Mþ ]. Anal.
Calcd for C14H12ClN3O3S2: C, 45.47; H, 3.27; N, 11.36. Found: C,
45.59; H, 3.41; N, 11.50.
ꢂ
[Mþ ]. Anal. Calcd for C14H12N4O5S2: C, 44.21; H, 3.18; N, 14.73.
4.1.12. 2,4-Dichloro-N-((4-sulfamoylphenyl)carbamothioyl)
benzamide (4l)
Found: C, 44.40; H, 3.33; N, 14.58.
Yield: 74%, mp 208e210 ꢀC. IR (KBr): 3295, 3199, 1667, 1590,
1529, 1331, 1158 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.58 (s, 1H,
NH), 11.80 (s, 1H, NH), 7.91e7.83 (m, 4H, sulfamoylphenyl), 7.81 (d,
J ¼ 2.0 Hz,1H, H3), 7.64e7.58 (m, 1H, H6), 7.56e7.52 (m,1H, H5), 7.42
(s, 2H, NH2). 13C NMR (100 MHz, DMSO-d6): 179.0, 168.2, 141.8,
141.3, 131.2, 131.1, 126.7, 125.4, 124.9, 120.6, 116.1, 115.9. MS (70 eV):
4.1.7. 3-Fluoro-N-((4-sulfamoylphenyl)carbamothioyl)benzamide
(4g)
Yield: 77%, mp 190e192 ꢀC. IR (KBr): 3417, 3322, 3244, 3030,
1676, 1605, 1559, 1327, 1155 cmꢁ1. 1H NMR (400 MHz, DMSO-d6):
12.45 (s, 1H, NH), 11.86 (s, 1H, NH), 7.90 (d, J ¼ 8.8 Hz, 2H, sulfa-
moylphenyl), 7.85 (d, J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.73e7.70
(m, 1H, H6), 7.68e7.63 (m, 1H, H2), 7.42 (s, 2H, NH2), 7.40e7.31 (m,
2H, H4, H5). 13C NMR (100 MHz, DMSO-d6): 179.3, 165.7, 159.8 (d,
JCeF ¼ 249.4 Hz), 141.9, 141.2, 134.7 (d, JCeF ¼ 8.6 Hz), 130.9, 126.7,
125.1, 122.5 (d, JCeF ¼ 13.3 Hz), 119.8, 116.7 (d, JCeF ¼ 21.6 Hz). MS
ꢂ
m/z ¼ 402.96 [Mþ ]. Anal. Calcd for C14H11Cl2N3O3S2: C, 41.59; H,
2.74; N, 10.39. Found: C, 41.38; H, 2.88; N, 10.21.
4.1.13. N-((4-Sulfamoylphenyl)carbamothioyl)-2-naphthamide
(4m)
ꢂ
(70 eV): m/z ¼ 353.03 [Mþ ]. Anal. Calcd for C14H12FN3O3S2: C,
Yield: 78%, mp 226e228 ꢀC. IR (KBr): 3375, 3273, 1672, 1558,
1516, 1314, 1158 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.78 (s, 1H,
NH), 11.87 (s, 1H, NH), 8.72 (s, 1H, H1), 8.12 (d, J ¼ 7.6 Hz, 1H, H3),
8.08e7.98 (m, 3H, H4, H5, H8), 7.94 (d, J ¼ 8.4 Hz, 2H, sulfamoyl-
phenyl), 7.87 (d, J ¼ 8.4 Hz, 2H, sulfamoylphenyl), 7.72e7.64 (m, 2H,
H6, H7), 7.43 (s, 2H, NH2). 13C NMR (100 MHz, DMSO-d6): 179.9,
168.7, 141.8, 141.4, 135.4, 132.2, 130.6, 129.9, 129.6, 129.2, 128.6,
47.58; H, 3.42; N, 11.89. Found: C, 47.77; H, 3.55; N, 12.05.
4.1.8. 2,3,4,5-Tetrafluoro-N-((4-sulfamoylphenyl)carbamothioyl)
benzamide (4h)
Yield: 72%, mp 172e174 ꢀC. IR (KBr): 3415, 3367, 3276, 3035,
1679, 1592, 1516, 1367, 1168 cmꢁ1. 1H NMR (400 MHz, DMSO-d6):
12.18 (s, 1H, NH), 12.07 (s, 1H, NH), 7.86e7.84 (m, 4H,
ꢂ
128.2, 127.6, 126.7, 125.0, 124.9. MS (70 eV): m/z ¼ 385.06 [Mþ ].

312
M. Mahdavi et al. / European Journal of Medicinal Chemistry 82 (2014) 308e313
Anal. Calcd for C18H15N3O3S2: C, 56.09; H, 3.92; N, 10.90. Found: C,
55.87; H, 4.15; N, 10.78.
measured at 585 nm and the concentration of the reduced Fe(II)
was calculated according to the calibration curve of ferrous sulfate
(FeSO4) as standard. The antioxidant activity was expressed as
mmol Fe(II) per gram of dry mass of compounds. Data are mean of
three independent experiments and are compared to ascorbic acid
as reference.
4.1.14. N-((4-Sulfamoylphenyl)carbamothioyl)furan-2-
carboxamide (4n)
Yield: 75%, mp 201e204 ꢀC. IR (KBr): 3381, 1676, 1595, 1532,
1336, 1168 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.57 (s, 1H, NH),
11.75 (s, 1H, NH), 8.40 (d, J ¼ 4.5 Hz, 1H, 4.5 Hz, furan), 8.07 (d,
J ¼ 4.5 Hz, 1H, 4.5 Hz, furan), 7.89 (d, J ¼ 8.8 Hz, 2H, sulfamoyl-
phenyl), 7.84 (d, J ¼ 8.8 Hz, 2H, sulfamoylphenyl), 7.41 (s, 2H, NH2),
7.27 (t, J ¼ 4.5 Hz, 1H, 4.5 Hz, furan). 13C NMR (100 MHz, DMSO-d6):
179.5, 162.4, 141.8, 141.4, 137.0, 136.0, 133.3, 129.3, 129.7, 124.9. MS
4.5. Molecular modeling study
All docking studies were performed using Autodock Vina (ver.
1.1.1) [30]. For this purpose, the crystal structure of soybean lip-
oxygenase complexed with 13(S)-hydroproxy-9(Z)-2,11(E)-octade-
cadienoic acid (code ID: 1IK3) were retrieved from protein data
bank. Then, the co-crystallized ligand and water molecules were
removed and the protein was converted to pdbqt format using
Autodock Tools (1.5.4) [31]. The 2D structures of ligands were
sketched using MarvinSketch 5.8.3, 2012, ChemAxon (http://www.
chemaxon.com) and then converted to 3D and pdbqt format by
Openbabel (ver. 2.3.1) [32]. The docking parameters were set as
follow: size_x ¼ 20; size_y ¼ 20; size_z ¼ 20; center_x ¼ 19.693;
center_y ¼ 0.054; center_z ¼ 17.628; exhaustiveness ¼ 100;
num_modes ¼ 15. The other parameters were left as default.
Finally, the conformations with the most favorable free energy of
binding were selected for analyzing the interactions between the
target enzyme and inhibitors. All the 3D models are generated
using the Chimera 1.6 software [33].
ꢂ
(70 eV): m/z ¼ 325.02 [Mþ ]. Anal. Calcd for C12H11N3O4S2: C, 44.30;
H, 3.41; N, 12.92. Found: C, 44.18; H, 3.28; N, 13.15.
4.1.15. N-((4-Sulfamoylphenyl)carbamothioyl)thiophene-2-
carboxamide (4o)
Yield: 72%, mp 217e219 ꢀC. IR (KBr): 3335, 3255, 1654, 1589,
1536, 1341, 1135 cmꢁ1. 1H NMR (400 MHz, DMSO-d6): 12.56 (s, 1H,
NH), 11.75 (s, 1H, NH), 8.40 (d, J ¼ 4.5 Hz, 1H, thiophene), 8.07 (d,
J ¼ 4.5 Hz, 1H, thiophene), 7.84 (d, J ¼ 8.4 Hz, 2H, sulfamoylphenyl),
7.89 (d, J ¼ 8.4 Hz, 2H, sulfamoylphenyl), 7.40 (s, 2H, NH2), 7.27 (t,
J ¼ 4.5 Hz, 1H, thiophene). 13C NMR (100 MHz, DMSO-d6): 179.5,
162.4,141.8, 141.4, 137.0, 136.0,133.3,129.3,126.7,124.9. MS (70 eV):
ꢂ
m/z ¼ 341.00 [Mþ ]. Anal. Calcd for C12H11N3O3S3: C, 42.22; H, 3.25;
N, 12.31. Found: C, 42.10; H, 3.40; N, 12.54.
4.2. 15-LOX inhibition assay
Acknowledgments
The stock solution of tested compounds was prepared in DMSO
(1 mL) and phosphate buffer (9 mL, 0.1 M, pH ¼ 8). This stock so-
lution was added to test solution containing enzyme (final con-
centration: 167 U/mL) and phosphate buffer (pH ¼ 8) to achieve the
final concentrations of 10ꢁ3 to 10ꢁ6. After incubation of test solu-
tion for 4 min, linoleic acid was added to reach the final concen-
This research was supported by grant from the Research Council
of Tehran University of Medical Sciences and Iran National Science
Foundation (INSF).
Appendix A. Supplementary data
tration of 134 mM. Then, changes in the absorbance were measured
by UV Unico Double Beam Spectrophotometer for 60 s at 234 nm.
The enzyme solution was kept in ice and controls were measured at
intervals throughout the experimental periods to ensure that the
enzyme activity was constant. All experiments performed at 25 ꢀC
in triplicate [27].
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.ejmech.2014.05.054.
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