Synthesis, enzyme inhibition and anticancer investigations of unsymmetrical 1,3-disubstituted ureas

Article abstract of DOI:10.2298/JSC121212076M

In this study, seventeen urea derivatives, including the five new derivatives N-mesityl-N'-(3-methylphenyl)urea (2), N-(3-methoxyphenyl)-N'- -(3-methylphenyl)urea (4), N-mesityl-N'-(4-methylphenyl)urea (6), N-(1,3-benzothiazol- 2-yl)-N'-(3-methylphenyl)ur

Full text of DOI:10.2298/JSC121212076M

J. Serb. Chem. Soc. 79 (1) 1–10 (2014)
UDC 577.15+66.097.8+547.495.2:615.277
JSCS–4560
Original scientific paper
Synthesis, enzyme inhibition and anticancer investigations of
unsymmetrical 1,3-disubstituted ureas
3
4
SANA MUSTAFA1,2 , SHAHNAZ PERVEEN and AJMAL KHAN
*
1Department of Chemistry, University of Karachi, Karachi-75270, Pakistan, 2Department of
Chemistry, Federal Urdu University for Arts, Science and Technology, Gulshan-e-Iqbal
Campus, Karachi-75300, Pakistan, 3PCSIR, Laboratories Complex, Karachi, Shahrah-e-Dr.
Salimuzzaman Siddiqui, Karachi-75280, Pakistan and 4HEJ Research Institute of Chemistry,
International Center for Chemical and Biological Sciences, University of Karachi,
Karachi-75270, Pakistan
(Received 12 December 2012, revised 11 July 2013)
Abstract: In this study, seventeen urea derivatives, including the five new
derivatives N-mesityl-N′-(3-methylphenyl)urea (2), N-(3-methoxyphenyl)-N′-
-(3-methylphenyl)urea (4), N-mesityl-N′-(4-methylphenyl)urea (6), N-(1,3-ben-
zothiazol-2-yl)-N′-(3-methylphenyl)urea (9) and N-(2-methylphenyl)-2-oxo-1-
-pyrrolidinecarboxamide (15), were synthesized by reacting ortho-, meta- and
para-tolyl isocyanate with primary and secondary amines using a previously
reported method. All the series 1–17 were subjected to urease, β-glucuronidase
and snake venom phosphodiesterase enzyme inhibition assays. The ranges of
inhibition of urease, β-glucuronidase and phosphodiesterase enzymes were
0.30–45.3, 4.9–44.9 and 1.2–46.4 %, respectively. Moreover, an effect of these
compounds on a prostate cancer cell line was observed. The new compound
N-(1,3-benzothiazol-2-yl)-N′-(3-methylphenyl)urea (9) showed in vitro antican-
cer activity with an IC50 value of 78.28±1.2 μM. All the compounds were
characterized by state of art spectroscopic techniques.
Keywords: amine; β-glucuronidase; disubstituted ureas; isocyanate; phospho-
diesterase; urease.
INTRODUCTION
Nitrogen-containing heterocyclic compounds play a significant role not only
in the life science industry, but also in many other industrial fields related to
special and fine chemistry. Among them, ureas represent an extensively used
1
tremendous class of compounds with multi-focal applications in several fields.
A number of these compounds are reported to exhibit a wide spectrum of bio-
logical and pharmacological activities. In the last decade, much attention has
2,3
been paid to the synthesis and application of such substituted urea derivatives.
*Corresponding author. E-mail: sanachemana@yahoo.com
doi: 10.2298/JSC121212076M
1
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

MUSTAFA, PERVEEN and KHAN
2
Ureas have been synthesized by a number of methodologies basically
employing substances such as phosgene. However, due to the harsh reaction
conditions and the hazardous nature of phosgene, it has been promisingly
substituted by safer compounds. Thus numerous substitutes of phosgene are well
4
documented in the literature. Additionally, their syntheses have been achieved
by simpler and much more economical chemical substances such as carbon
5,6
dioxide and carbon monoxide by the catalytic carbonation of amines. Other
methods involved the use of carbonates such as organic carbonate esters and
7,8
ethylene carbonate for the mass scale production of N,N′-disubstituted ureas.
Disubstituted ureas possess wide therapeutic activities, such as potent inhi-
bitors of interleukin-8, anthelmintics, antimalarial, anti-HIV, diuretic, analgesic,
9–12
antibacterial, antifungal, antimicrobial, algaecidal or antiperiphytic agents.
N,N′-Disubstituted ureas, amides and carbamates are reported as new powerful
13
and stable inhibitors of soluble epoxide hydrolase, both in vivo and in vitro.
They were determined to be useful for the treatment of hypertension, Raynaud
syndrome, respiratory distress syndrome, inflammation, diabetic complications,
14
arthritis and renal diseases.
A urease is an enzyme that decomposes urea to ammonia and carbonic acid
15,16
and provides nitrogen to an organism.
On the other hand, bacterial ureases
cause different pharmacological problems, ranging from the development of
infectious stones, pathogenesis of encephalopathy, pyelonephritis, urinary cathe-
15–20
ter encrustation and hepatic coma to peptic ulceration.
β-Glucuronidase is an exoglycosidase enzyme and its activity reflects liver
21,22
enzyme loss during cell turnover in humans.
In the cell, it is present in
lysosomes, although high levels are present in necrotic areas of large tumours.
Sly syndrome is an inherited disease characterized by a deficiency of glucuro-
23
nidase. It was reported that in certain diseases, e.g., cancer, hepatic diseases,
21
inflammatory joint and AIDS, the activity of β-glucuronidase is increased.
A phosphdiesterase (PDE) is an enzyme that participates in cell functions to
maintain intracellular levels of cyclic adenosine and cyclic guanosine monophos-
24
phate by hydrolyzing cyclic nucleotides. Nucleotide pyrophosphatase/phospho-
diesterase (NPP) is a class of enzyme comprised of seven isoforms among them
three are well known ectoenzymes as NPP-1 (PC-1), NPP-2 (autotaxin) and NPP-3
(B10; gp130 (RB13-6)) in mammalian. They are widely distributed in mam-
malian intestinal mucosa, liver cells and serum, snake venom and in various
25
plants. The calcification of bones and tissues is regulated by the NPP-1
enzyme. In humans, chondrocalcinosis and idiopathic infantile arterial calci-
26,27
fication result from an over or under expression of NPP-1, respectively.
The
potent phosphodiesterase (PDE) inhibitor drug sildenafil therapeutically obtained
great world-wide success for the treatment of erectile dysfunction. Selective PDE
inhibitors are highly beneficial in the treatment of various diseases, e.g., PDE-II
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

UNSYMMETRICAL 1,3-DISUBSTITUTED UREAS
3
inhibitors in sepsis; PDE-IV inhibitors in allergic rhinitis, asthma, psoriasis, mul-
tiple sclerosis, chronic obstructive pulmonary disease (COPD), Alzheimer dis-
ease, schizophrenia and depression and PDE-V inhibitors in cardiovascular dis-
24
ease, female sexual dysfunction and pulmonary hypertension.
Therefore approaches based on inhibition of these enzymes always remain a
need of world for the treatment of diseases arising from disturbed level of these
enzymes.
The huge volume of research on the synthesis and anticancer activities of
urea derivatives was previously reviewed. Many aromatic urea and thiourea deri-
vatives, such as benzoylureas, N-(2-chloroethyl)-N′-phenylureas, primaquine
derivatives, 3-(haloacylamino)benzoylurea and N-(benzothiazol-2-yl)-N-morpho-
linourea were synthesized and considered extensively for anticancer activity
against murine leukaemia, colon carcinoma, haematoma, lymphoma, melanoma,
28–31
breast cancer and prostate cancer cell lines of patients.
In view of the large volume of literature, it is clear that the discovery of
novel biologically active compounds for the treatment of malignancy is very
important. A challenge still exists to design even better inhibitors with improved
therapeutic effects. In continuation of ongoing studies on the discovery of new
enzyme inhibitors and anticancer agents, the synthesis of 1,3-disubstituted ureas
by a simple one pot reaction of tolyl isocyanates with selective amines is des-
cribed herein. The resulting compounds were evaluated for their inhibitory acti-
vities on urease, β-glucuronidase and snake venom phosphodiesterase enzymes
and their cytotoxicity against prostate cancer cell lines.
EXPERIMENTAL
Melting points were taken on Gallenkamp melting point apparatus. Thin layer chroma-
tograpy was performed on pre-coated silica gel plates (Kieselgel 60 F254, Merk, Germany) and
the spots were visualized under UV radiation (Dual range, Merk Millipore, UK) at 254 and
365 nm. The IR spectra were taken on a Thermo Nicolet Avatar 370 DTGS FT-IR spectro-
meter. The EI-MS measurements were performed on a MAT-312 and a JEOLJMS-HX 110
1
instrument. The H-NMR spectra were recorded on a Bruker Avance 400 MHz instrument, δ
in ppm related to SiMe4 (0 ppm) as internal standard. The 13C-NMR spectra were taken on a
Bruker Avance 125 MHz instrument. Elemental analyses were realized on a Perkin Elmer
2400 CHN elemental analyzer. All used solvents were of reagent grade. Yields, physical,
analytical and spectral data for the prepared ureas are given in the Supplementary material to
this paper.
General procedure for the synthesis of the 1,3-disubstituted ureas 1–17
The respective amine (3.18 mmol) was taken in 5–10 mL of 1,4-dioxane and then
approximately 1.60 mmol of ortho-, meta- or para-tolyl isocyanate was added dropwise. The
reactions are completed in 30–60 min. After completion of the reaction, the mixture was
cooled with ice to afford white crystals of the title compound.32
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

MUSTAFA, PERVEEN and KHAN
4
Urease inhibition assay
Reaction mixtures containing 1 unit of urease enzyme isolated from jack-bean and 55 μL
of buffers containing 100 mM urea were incubated with 5 μL of 1 mM test compound for 15
min in 96-well plates at 30 °C. The ammonia production, which in turn quantifies the urease
activity, was measured by the indophenol method. For this purpose, 70 μL of alkali (0.5 %
w/v NaOH and 0.1 % active chloride NaOCl) and 45 μL of phenol reagent (1 % w/v phenol
and 0.005 % w/v sodium nitroprusside) were poured into each well. After 50 min, the increase
in absorbance at a wavelength of 630 nm was measured by a microplate reader (Molecular
Device, USA). All reactions were run in triplicate in a total volume of 200 μL and the change
in absorbance per min were processed using Soft-Max Pro software (Molecular Device,
USA).33
β-Glucuronidase assay
The β-glucuronidase activity was determined by a spectrophotometric method that
involved the measurement of the absorbance of p-nitrophenol formed from the substrate at
405 nm. The reaction mixture consisting of 185 μL of 0.1 M acetate buffer (pH 7.00), 10 μL
of enzyme solution and 5 μL of test compound (0.4 mM) solution was incubated for 30 min at
37 °C. The plates were read on a multiplate reader SpectraMax plus 384 (Molecular Devices,
U.S.A.) after the addition of 50 μL of 0.4 mM p-nitrophenyl-β-D-glucuronide at 405 nm. All
assays were performed in triplicate.34
Phosphodiesterase-I inhibition assay
Phosphodiesterase I inhibition assay was performed using snake venom according to a
previously reported method with minute variations. Briefly, 33 mM Tris–HC1 buffer of pH
8.8 (97 µL), 30 mM Mg acetate with an enzyme concentration of 0.000742 U well-1 and 0.33
mM bis-(p-nitrophenyl) phosphate (Sigma N-3002, 60 µL) as substrate were taken. EDTA
with an IC50±SD of 274 0.007 μM was used as the positive control.
After a pre-incubation period of 30 min, the enzyme with the test samples was observed
spectrophotometrically for enzyme activity on a microtitre plate reader at 37 °C by following
the rate of change in OD min-1 at 410 nm of the p-nitrophenol released from p-nitrophenyl
phosphate. All assays were processed in triplicate.35
Anticancer assay
Anticancer activity of compounds was evaluated in 96-well flat-bottomed micro plates
by using the standard reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
bromide) colorimetric assay. For this purpose, PC3 cells (prostate cancer) were cultured in
Dulbecco-modified Eagle medium, containing 5 % of foetal bovine serum (FBS), 100 µg mL-
of streptomycin and 100 IU mL-1 of penicillin in 25 cm3 flasks, in an incubator at 37 °C
1
under a 5 % carbon dioxide atmosphere. The exponentially growing cells were counted with a
haemocytometer and diluted to a concentration of 1×105 cells mL-1. The diluted culture was
then introduced into 96-well plates (100 µL well-1) and incubated overnight. After incubation,
medium was separated and 200 µL of fresh medium was added with various concentrations of
the compounds in the range 1–100 µM. After 72 h, 50 µL MTT (2 mg mL-1) was added to
each well and incubated further for 4 h. Subsequently, 100 µL of DMSO was added to each
well. The MTT was reduced to formazan within viable cells and its absorbance was measured
at 570 nm using a microplate ELISA reader (Spectra Max plus, Molecular Devices, CA,
USA).36
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

UNSYMMETRICAL 1,3-DISUBSTITUTED UREAS
5
RESULTS AND DISCUSSION
Chemistry
In a typical reaction ortho-, meta- or para-tolyl isocyanate was treated with a
primary or secondary amine in 1,4-dioxane at room temperature (Scheme 1). The
product formation and progress of reaction was observed by TLC. The difference
in retardation factor (R ) values of the reaction mixture and the starting pure
f
reactants indicated completion of the reaction. After completion of reaction, the
mixture was cooled by the addition of a few cubes of crushed ice. As a result, the
solid product precipitated. The obtained solid was filtered and washed several
times with cold distilled water to remove excess amine and to obtain the pure
34
product (Table I).
Scheme 1. Synthetic route for 1,3-disubstituted ureas.
TABLE I. Synthesis of 1,3-disubstituted urea derivatives (1–17)
Cmpd.
1
–R
m-CH3
–R′
O
–R″ Cmpd.
–R
m-CH3
–R′
O
–R″
H
–
10
CH
N
3
CH
N
3
2
3
m-CH3
m-CH3
H
11
p-CH3
o-CH3
H
H
CH
S
3
H C
3
CH
CH3
CH
3
H
12
CH
3
H C
3
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

MUSTAFA, PERVEEN and KHAN
6
TABLE I. Continued
Cmpd.
4
–R
m-CH3
–R′
–R″ Cmpd.
–R
o-CH3
–R′
CH
–R″
H
CH3
H
13
OCH
3
O
N
5
6
p-CH3
p-CH3
–
14
15
o-CH3
o-CH3
H
–
OCH
3
CH
3
H
O
N
CH
3
H C
3
CH3
N
S
CH
7
p-CH3
H
16
17
o-CH3
p-CH3
H
H
O
8
9
p-CH3
m-CH3
H
H
CH
3
OCH
3
N
S
The structures of the compounds were confirmed by mass, NMR and IR
spectroscopy, and CHN elemental analysis. Their melting points were also
recorded. The compounds were evaluated for their inhibition of different enzy-
mes and anticancer activities.
Biology
Enzyme inhibition screening. In vitro screening is one of the initial phases in
drug discovery and many drug molecules are enzyme inhibitors; hence, their
discovery and improvement is an active area of research in biochemistry and
pharmacology. Thus in this study, compounds 1–17 were synthesized and ran-
domly checked in three enzyme-inhibition assays (urease, β-glucoranidase and
phosphodiestrase-I). All compounds showed various range of % inhibition against
these enzymes (Table II).
In the series, compounds 1–4, 9 and 10 are m-tolyl urea derivatives having
various R′ groups. It was found that compound 4 with an m-methoxy group in the
phenyl ring of R′ exhibited 53.2 % urease inhibition and was the most potent of
these compounds, which exhibited an activity of less than 50 %. For compounds
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

UNSYMMETRICAL 1,3-DISUBSTITUTED UREAS
7
5–8, 11 and 17, a similar result was observed, i.e., that the para tolyl compound 8
having an m-methoxy group in phenyl ring of R′ was the most potent with a 59.1
% urease inhibition. Compound 6 with a 2,4,6-trimethylphenyl group was also
active (45.3 % inhibition). Of the o-tolyl derivatives 12–16, again compound 14
with an m-methoxy in the phenyl group of R′ exhibited the greatest inhibition
(47.5 %). The other compounds had an activity in the range of 0.3 to 45.3 %
inhibition. Comparing compounds 4, 8 and 14 with same R′ group, compound 8,
which is a p-tolyl urea, exhibited the highest urease inhibition.
TABLE II. Enzyme inhibitions (±SD, %) and anticancer activities (IC50±SD, μM) of synthe-
sized urea derivatives (1–17); PC3 = prostate cancer cell lines; – = no inhibition; SD =
= standard deviation; IC50 = concentration at 50 % inhibition
Cmpd.
Urease
β-Glucuronidase
Phosphodiesterase Anticancer (PC3)
1
2
3
4
5
6
7
8
37.70±0.09
21.70±0.04
0.30±0.05
53.20±0.03
19.90±0.04
45.30±0.02
32.50±0.01
59.10±0.01
40.70±0.01
6.90±0.04
12.20±0.02
4.00±0.03
30.20±0.02
47.50±0.02
23.70±0.01
12.90±0.02
–
26.90±0.02
4.90±0.01
–
40.30±0.01
2.30±0.02
20.40±0.01
–
46.40±0.02
>100
>100
>100
>100
>100
>100
>100
>100
78.3±1.2
>100
>100
>100
>100
>100
>100
>100
>100
–
32.00±0.01
4.80±0.01
–
–
–
–
–
37.80±0.01
16.50±0.01
28.70±0.02
20.60±0.01
8.50±0.01
6.00±0.03
44.90±0.01
19.60±0.01
7.20±0.02
24.50±0.02
D-Sacchuric acid,
1,4-lactone, 97.1±1.2
9
10
11
12
13
14
15
16
17
37.80±0.01
–
–
–
2.10±0.01
1.20±0.01
6.50±0.01
9.800±0.003
EDTA
90.10±0.01
Standard Thiourea
98.20±0.01
Doxorubicin
0.91±0.12
The high activity of the m-methoxyphenyl moiety-containing compounds
may arise because of the mutual effect of the electronegative oxygen of the
methoxy group and the nitrogens and oxygen of the carbamide residue, which
may increase the ligand–chelator ability of the compounds to form octahedral
complexes with the nickel ions of urease enzyme. Moreover, the presence of
bulky groups around the active nitrogen in other compounds decreased the acti-
vity of enzyme and the m-methoxyphenyl was the least bulky group in this series,
which makes it easier for the urease to enter the active substrate binding site. In
contrast, certain urea derivatives with m-methyl- and m-methoxyphenyl groups
37,38
were previously reported in the literature as potent inhibitor of urease.
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

MUSTAFA, PERVEEN and KHAN
8
However, in the inhibition studies of β-glucuronidase, compounds 1, 2, 4–6
and 8–17 showed % inhibition in the range 4.9 to 44.9 %, i.e., no significant
activity, while the other compounds gave negative results towards β-glucuro-
nidase in the enzyme inhibition assay.
In the phosphodiestrase enzyme inhibition studies, the range of % inhibition
was 1.2 to 46.4 %, i.e., none of the prepared urea derivatives showed significant
activity, except compound 1, N-(3-methylphenyl)-2-oxo-1-pyrrolidinecarbox-
amide, that exhibited low activity with a percentage inhibition value of 46.4 %,
while its ortho and meta derivatives were nearly inactive towards phosphodieste-
rase-I (Table II).
Anticancer screening against PC3 cell lines. To explore further their biolo-
gical activity against prostate cancer cell lines (PC3), all the compounds were
tested. Unfortunately, only one urea derivative, N-(1,3-benzothiazol-2-yl)-N′-(3-
-methylphenyl)urea (9) showed better cytotoxicity activity with an IC value of
50
78.3, as compared to our standard doxorubicin having an IC ±SD value of
50
0.91±0.12 μM (Table II).
CONCLUSIONS
In this study, attention was focused on the synthesis and biological activities
of 1,3-disubstitued ureas. Thus, seventeen urea derivatives, including five new
derivatives 2, 4, 6, 9 and 15, were synthesized. The % inhibition for urease,
β-glucuronidase and phosphodiesterase enzymes were in the range 0.3–45.3, 4.9–
–44.9 and 1.2–46.4 %, respectively. In the in vitro anticancer study, the new
compound N-(1,3-benzothiazol-2-yl)-N′-(3-methylphenyl)urea showed significant
anticancer activity with an IC value of 78.28±1.2 μM against PC3 cell lines.
50
SUPPLEMENTARY MATERIAL
Yields, physical, analytical and spectral data for the prepared ureas are available
electronically from http://www.shd.org.rs/JSCS/, or from the corresponding author on request.
Acknowledgement. This work was supported by the Higher Education Commission
(HEC), Pakistan, under the Indigenous 5000 PhD Fellowship Program.
И З В О Д
СИНТЕЗА, ЕНЗИМСКА ИНХИБИЦИЈА И ИСПИТИВАЊЕ АНТИТУМОРСКЕ
АКТИВНОСТИ НЕСИМЕТРИЧНИХ 1,3-ДИСУПСТИТУИСАНИХ УРЕА
1,2
3
4
SANA MUSTAFA , SHAHNAZ PERVEEN и AJMAL KHAN
1Department of Chemistry, University of Karachi, Karachi-75270, Pakistan, 2Department of Chemistry,
Federal Urdu University for Arts, Science and Technology, Gulshan-e-Iqbal Campus, Karachi-75300,
Pakistan, 3PCSIR, Laboratories Complex, Karachi, Shahrah-e-Dr. Salimuzzaman Siddiqui, Karachi-
75280, Pakistan и 4HEJ Research Institute of Chemistry, International Center for Chemical and
Biological Sciences, University of Karachi, Karachi-75270, Pakistan
Током истраживања синтетисано је седамнаест деривата, укључујући и нова једи-
њења: N-мезитил-N′-(3-метилфенил)уреа (2), N-(3-метилфенил)-N′-(3-метоксифенил)-
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

UNSYMMETRICAL 1,3-DISUBSTITUTED UREAS
9
уреа (4), N-мезитил-N′-(4-метилфенил)уреа (6), N-(1,3-бензотиазол-2-ил)-N′-(3-метил
-фенил)уреа (9) и N-(2-метилфенил)-2-оксо-1-пиролидинкарбоксамид (15) реакцијом
орто-, мета- и пара-толил-изоцијаната са примарним и секундарним аминима. Испи-
тана је инхибиторна активност добијених деривати према уреази, β-глукуронидази и
фосфодиестерази змијског отрова. Утрвђено је да је опсег инхибиције према уреази,
β-глукуронидази и фосфодиестерази ѕмијског отрова. 0,3–45,3, 4,9–44,9 и 1,2–46,4 %,
редом. Осим тога, испатан је и ефекат синтетисаних једињења према ћелијској линији
рака простате. Нов дериват N-(1,3-бензотиазол-2-ил)-N′-(3-метилфенил)уреа (9) пока-
зује in vitro активност IC50 од 78,3±1,2 μM. Сва синтетисана једињења окаратактерисана
су стандардним спектроскопским техникама.
(Примљено 12. децембра 2012, ревидирано 11. јула 2013)
REFERENCES
1. I. L. Finar, Organic Chemistry, Vol. 1, 6th ed., Pearson Education Asia Ltd., Hong Kong,
2003, p. 460
2. P. Y. S. Lam, P. K. Jadhav, C. J. Eyermann, C. N. Hodge, Y. Ru, L. T. Bacheler, J. L.
Meek, M. J. Otto, M. M. Rayner, Y. N. Wong, C. H. Chang, P. C. Weber, D. A. Jackson,
T. R. Sharpe, S. Erickson-Viitanen, Science 263 (1994) 380
3. J. L. Castro, R. G. Ball, H. B. Broughton, M. G. N. Russell, D. Rathbone, A. P. Watt, R.
Baker, K. L. Chapman, A. E. Fletcher, S. Patel, A. J. Smith, G. R. Marshall, W. Ryecroft,
V. G. Matassa, J. Med. Chem. 39 (1996) 842
4. F. Bigi, R. Maggi, G. Sartori, Green Chem. 2 (2000) 140
5. N. Sonoda, T. Yasuhara, K. Konodo, T. Ikeda, S. Tsutsumi, J. Am. Chem. Soc. 93 (1971)
691
6. J. D. Diaz, K. A. Darko, L. McElwee-White, Eur. J. Org. Chem. 27 (2007) 4453
7. S. Fujita, B. M. Bhanage, H. Kanamaru, M. Arai, J. Mol. Catal. A: Chem. 230 (2005) 43
8. S. Franceso, R. Bruno, Tetrahedron Lett. 51 (2010) 6301
9. B. Olga, B. Chiara, F. Bondavalli, S. Schenone, A. Ranise, N. Arduino, M. B. Bertolotto,
F. Montecucco, L. Ottonello, F. Dallegri, M. Tognolini, V. Ballabeni, S. Bertoni, E.
Barocelli, J. Med. Chem. 50 (2007) 3618
10. J. N. Dominguez, C. Leon, J. Rodrigues, N. G. Dominguez, J. Gut, P. J. Rosenthal, J.
Med. Chem. 48 (2005) 3654
11. C. Sahlberg, R. Norren, P. Engelhardt, M. Hogberg, J. Kangasmetsa, L. Vrang, H. Zang,
Bioorg. Med. Chem. Lett. 8 (1998) 1511
12. S. Igarashi, M. Futagawa, N. Tanaka, Y. Kawamura, K. Morimoto, W. O. Patent No.
039289 (1998)
13. I. H. Kim, C. Morisseau, T. Watanabe, B. D. Hammock, J. Med. Chem. 47 (2004) 2110
14. B. D. Hammock, P. D. Jones, C. Morisseau, H. Huang, H. Tsai, R. J. Gless, W. O. Patent
No. 106525 (2007)
15. H. L. Mobley, M. D. Island, R. P. Hausinger, Microbiol. Rev. 59 (1995) 451
16. H. L. Mobley, R. P. Hausinger, Microbiol. Rev. 53 (1989) 85
17. S. Perveen, K. M. Khan, M. A. Lodhi, M. I. Choudhary, Atta-ur-Rahman, W. Voelter,
Lett. Drug Des. Discov. 5 (2008) 401
18. J. C. Polacco, M. A. Holland, Int. Rev. Cytol. 145 (1993) 65
19. S. Perveen, UK Patent Publication No. GB 2443892 A (2008)
20. J. M. Bremner, Nutr. Cycl. Agroecosys. 42 (1995) 321
21. B. Sperker, J. T. Backman, H. K. Kroemer, Clin. Pharmacokinet. 33 (1997) 18
22. W. L. Johanna, S. S. Li, J. D. Potter, I. B. King, J. Nutr. 132 (2002) 1341
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

MUSTAFA, PERVEEN and KHAN
10
23. M. Graaf, E. Boven, H. W. Scheeren, H. J. Haisma, H. M. Pinedo, Curr. Pharm. Desig. 8
(2002) 1391
24. V. Boswell-Smith, D. Spina, C. P. Page, Br J. Pharmacol. 147 (2006) S252
25. J. W. Goding, R. Terkeltaub, M. Maurice, P. Deterre, A. Sali, S. A. Belli, Immunol. Rev.
161 (1998) 11
26. K. Johnson, S. Hashimoto, M. Lotz, K. Pritzker, J. Goding, R. Terkeltaub, Arthr. Rheum.
44 (2001) 1071
27. F. Rutsch, S. Vaingankar, K. Johnson, I. Goldfine, B. Maddux, P. Schauerte, H. Kalhoff,
K. Sano, W. A. Boisvert, A. Superti-Furga, R. Terkeltaub, Am. J. Pathol. 158 (2001) 543
28. H. Q. Li, P. C. Lv, T. Yan, H. L. Zhu, Anticancer Agents Med. Chem. 9 (2009) 471
29. G. Dzimbeg, B. Zorc, M. Kralj, K. Ester, K. Pavelic, G. Andrei, R. Snoeck, J. Balzarini,
E. D. Clercq, M. Mintas, Eur. J. Med. Chem. 43 (2008) 1180
30. D. Q. Song, Y. Wang, L. Z. Wu, P. Yang, Y. M. Wang, L. M. Gao, Y. Li, J. R. Qu, Y. H.
Wang, Y. H. Li, N. N. Du, Y. X. Han, Z. P. Zhang, J. D. Jiang, J. Med. Chem. 51 (2008)
3094
31. M. A. R. Hamdy, M. A. Morsy, J. Enzyme Inhib. Med. Chem. 22 (2007) 57
32. S. Perveen, S. Mustafa, M. A. Khan, A. Dar, K. M. Khan, W. Voelter, Med. Chem. 8
(2012) 330
33. K. M. Khan, S. Iqbal, M. A. Lodhi, G. M. Maharvi, Zia-Ullah, M. I. Choudhary, Atta-ur-
Rahman, S. Perveen, Bioorg. Med. Chem. 12 (2004) 1963
34. N. Riaz, I. Anis, Aziz-ur-Rahman, A. Malik, Z. Ahmad, P. Muhammad, S. Shujaat, Atta-
-ur-Rahman, Nat. Prod. Res. 17 (2003) 247
35. V. U. Ahmad, M. A. Abbasi, H. Hussain, M. N. Akhtar, U. Farooq, N. Fatima, M. I.
Choudhary, Phytochemistry 63 (2003) 217
36. T. Mosmann, J. Immunol. Meth. 65 (1983) 55
37. S. Uesato, Y. Hashimoto, M. Nishino, Y. Nagaoka, H. Kuwajima, Chem. Pharm. Bull. 50
(2002) 1280
38. Z. Amtul, A. U. Rahman, R. A. Siddiqui, M. I. Choudhary, Curr. Med. Chem. 9 (2002)
1323.
Available online at www.shd.org.rs/JSCS/
_______________________________________________________________________________________________________________________
Copyright (C)2014 SCS

Copyright of Journal of the Serbian Chemical Society is the property of National Library of
Serbia and its content may not be copied or emailed to multiple sites or posted to a listserv
without the copyright holder's express written permission. However, users may print,
download, or email articles for individual use.