Synthesis and biological evaluation of some pyrazoline derivatives bearing a dithiocarbamate moiety as new cholinesterase inhibitors

Article abstract of DOI:10.1002/ardp.201200384

In the present study, new pyrazoline derivatives were synthesized via the reaction of 1-(chloroacetyl)-3-(2-furyl)-5-aryl-2-pyrazolines with sodium salts of N,N-disubstituted dithiocarbamic acids. Each derivative was evaluated for its ability to inhibit a

Full text of DOI:10.1002/ardp.201200384

Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
189
Full Paper
Synthesis and Biological Evaluation of Some Pyrazoline
Derivatives Bearing a Dithiocarbamate Moiety as New
Cholinesterase Inhibitors
1
Mehlika D. Altintop , Ahmet Ozdemir , Zafer A. Kaplancikli , Gu¨lhan Turan-Zitouni ,
1
1
1
¨
Halide E. Temel2, and Gu¨ls¸en A. C¸ iftc¸i2
1 Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Anadolu University, Eskis¸ehir,
Turkey
2 Faculty of Pharmacy, Department of Biochemistry, Anadolu University, Eskis¸ehir, Turkey
In the present study, new pyrazoline derivatives were synthesized via the reaction of 1-(chloroacetyl)-
3-(2-furyl)-5-aryl-2-pyrazolines with sodium salts of N,N-disubstituted dithiocarbamic acids.
Each derivative was evaluated for its ability to inhibit acetylcholinesterase (AChE) and
butyrylcholinesterase (BuChE) using a modification of Ellman’s spectrophotometric method. The
compounds were also investigated for their cytotoxic properties using the MTT assay. The most potent
AChE inhibitor was found as compound 7 followed by compounds 27 and 17, when compared with
eserine. Compounds effective on AChE carry the 2-dimethylaminoethyl moiety, which resembles the
trimethylammonium group and the ethylene bridge of acetylcholine. Among all compounds,
compound 7 bearing 2-dimethylaminoethyl and 3,4-methylenedioxyphenyl moieties was also
found to be the most effective inhibitor of BuChE. The MTT assay indicated that the effective
concentration of compound 7 was lower than its cytotoxic concentration.
Keywords: Acetylcholinesterase / Anticholinesterase activity / Butyrylcholinesterase / Dithiocarbamate / Pyrazoline
Received: October 8, 2012; Revised: December 5, 2012; Accepted: December 21, 2012
DOI 10.1002/ardp.201200384
Introduction
esterase (AChE), which selectively hydrolyses acetylcholine,
and butyrylcholinesterase (BuChE), which hydrolyses acetyl-
choline and other choline esters as a non-specific cholinester-
ase. The difference between the two types of cholinesterase
is the respective preference for substrates: the former
hydrolyses acetylcholine more quickly; whereas the latter
hydrolyses butyrylcholine more quickly. The main function
of AChE is the termination of cholinergic neurotransmission,
but the function of BuChE is not so clear [4–7].
Enzymes have attracted a great deal of interest as targets for
drug discovery due to their essential roles in life processes
and pathophysiology. Inhibition of disease-associated
enzymes is a promising approach for pharmacologic inter-
vention in human diseases. Among oral therapeutic agents in
clinical use today, nearly half of them exert their therapeutic
action by inhibiting specific enzymes. Likewise, current drug
discovery efforts in pharmaceutical industry are focused on
the identification and optimization of drug candidates that
act as specific enzyme inhibitors [1–3].
The role of the cholinergic system in cognition and
the identification of cholinergic deficits in Alzheimer’s
disease has led to the development of cholinesterase
inhibitors as the first-line treatment for symptoms of this
disease [4–11].
Cholinesterases have been the subject of intense investi-
gation in medicinal chemistry as important drug targets.
Two cholinesterases are present in humans: acetylcholin-
Carbamates are the most widely studied class of anti-
cholinesterase agents and considerable research on them
in relation to Alzheimer’s disease has been accomplished.
Rivastigmine possesses a carbamate moiety that resembles
the ester linkage of acetylcholine. It is one of the most
widely used anticholinesterase agents for the treatment of
Alzheimer’s disease [5–12].
Correspondence: Mehlika D. Altintop, Faculty of Pharmacy, Department
of Pharmaceutical Chemistry, Anadolu University, 26470 Eskis¸ehir, Turkey.
E-mail: mdaltintop@anadolu.edu.tr
Fax: þ90 222 3350750
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190
M. D. Altintop et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Dithiocarbamates are important pharmacophores owing to
their lipophilicity, which is crucial for the delivery of central
nervous system drugs to their site of action through the blood-
brain barrier. Medicinal chemists have studied dithiocarba-
mates extensively due to the fact that new effective compounds
can be obtained by the bioisosteric replacement of a carba-
mate moiety with a dithiocarbamate moiety [13–20].
The CH proton appeared as doublet of doublets at d 5.45–
5.49 ppm due to the vicinal coupling with two magnetically
non-equivalent protons of the methylene group at position 4
of the pyrazoline ring. The CH2 protons of the acetyl group
were observed at 4.54–4.76 ppm as double doublets. This
geminal coupling resulted from the steric structure of the
compound. These geminal protons were observed as double
doublet due to two different possible conformations since
rigid protons occurred. All the other aromatic and aliphatic
protons were observed in the expected regions.
Pyrazolines have also received considerable attention as
privileged scaffolds due to their synthetic and biological
importance in medicinal chemistry. Pyrazoline derivatives
have been reported to exhibit a wide spectrum of biological
effects including anticholinesterase activity [21–26]. Ucar
et al. [26] synthesized N-substituted pyrazoline derivatives
and evaluated these compounds as MAO-B and cholinesterase
inhibitors which may have promising features in the treat-
ment of Alzheimer’s and Parkinson’s diseases.
In the mass spectra of the compounds (1–30), the Mþ1 peak
was observed. All compounds gave satisfactory elemental
analysis results.
The anticholinesterase effects of the compounds (1–30) on
AChE and BuChE were determined by a modification of
Ellman’s spectrophotometric method (Table 2).
On the basis of these findings and in the continuation of
our ongoing research program in the field of synthesis and
biological evaluation of heterocyclic compounds as cholin-
esterase inhibitors [27, 28], herein we report the synthesis
and biological evaluation of some pyrazoline derivatives
bearing a dithiocarbamate moiety as new anticholinesterase
agents. The compounds were also investigated for their cyto-
toxic effects.
Among these compounds (1–30), compound 7 can be
identified as the most promising anticholinesterase agent
due to its inhibitory effect on AChE with an IC50 value
of 0.72 ꢁ 0.06 mg/mL when compared with eserine
(IC50 ¼ 0.0013 ꢁ 0.0001 mg/mL) (Fig. 1). Compounds 27 and
17 exhibited AChE inhibitory activity with IC50 values
of 2.32 ꢁ 0.76 mg/mL and 7.2 ꢁ 1.04 mg/mL, respectively.
Effective compounds on AChE carry the 2-dimethylaminoethyl
moiety. It is apparent that there is a positive correlation
between AChE inhibitory activity and the 2-dimethyl-
aminoethyl moiety. It can be attributed to the similarity of
the 2-dimethylaminoethyl group and the trimethylammo-
nium and the ethylene groups of acetylcholine (Scheme 2).
Compounds 5, 1, and 6 exhibited AChE inhibitory activity with
IC50 values of 48 ꢁ 5.64 mg/mL, 50.68 ꢁ 2.72 mg/mL, and
62 ꢁ 8.48 mg/mL, respectively. Compounds 14 and 25 were
inactive against AChE, whereas other derivatives showed weak
inhibition on AChE (IC50 > 80 mg/mL).
Results and discussion
The synthesis of pyrazoline derivatives (1–30) was carried out
according to the steps shown in Scheme 1. In the initial step,
1-(2-furyl)-3-aryl-2-propen-1-ones were synthesized via the
base-catalyzed Claisen-Schmidt condensation of 2-acetyl-
furan with appropriate aldehydes. The ring closure reaction
of chalcones with hydrazine hydrate afforded 5-aryl-3-(2-
furyl)-2-pyrazolines. 1-(Chloroacetyl)-3-(2-furyl)-5-aryl-2-pyra-
zolines were obtained by the reaction of 5-aryl-3-(2-furyl)-2-
pyrazolines with chloroacetyl chloride in the presence of
triethylamine. Sodium salts of N,N-disubstituted dithiocarba-
mic acids were prepared by the reaction of a secondary amine
with carbon disulfide in the presence of sodium hydroxide.
The reaction of 1-(chloroacetyl)-3-(2-furyl)-5-aryl-2-pyrazo-
lines with sodium salts of N,N-disubstituted dithiocarbamic
acids afforded 1-[(N,N-disubstituted thiocarbamoylthio)-
acetyl]-3-(2-furyl)-5-aryl-2-pyrazoline derivatives (1–30). Some
properties of the compounds were given in Table 1.
Compound 7 also exhibited the highest inhibitory effect
on BuChE with an IC50 value of 7.46 ꢁ 0.83 mg/mL when
compared with eserine (IC50 ¼ 0.012 ꢁ 0.005 mg/mL;
Fig. 2). Compound 27 exhibited BuChE inhibitory activity
with an IC50 value of 26.93 ꢁ 2.54 mg/mL. Although com-
pound 17 carries the 2-dimethylaminoethyl group, it exhibits
weak inhibition on BuChE (IC50 > 80 mg/mL). This outcome
confirms that functional groups at the fifth position of the
pyrazoline ring may have a considerable influence on BuChE
inhibitory activity. Compounds 1, 6, and 5 exhibited BuChE
inhibitory activity with IC50 values of 36 ꢁ 5.66 mg/mL,
57.33 ꢁ 2.31 mg/mL, and 65.33 ꢁ 2.31 mg/mL, respectively.
Compounds 3, 4, 10, 13, 14, 18, 19, 21, 22, and 28 were
inactive against BuChE, whereas other derivatives showed
weak inhibition on BuChE (IC50 > 80 mg/mL).
The structures of all compounds (1–30) were confirmed by
1
IR, H NMR, mass spectral data, and elemental analyses. In
the IR spectra of all compounds (1–30), all derivatives have a
strong, characteristic band in the region 1684–1654 cmꢀ1
–
due to C O stretching vibration.
–
In the 500 MHz 1H NMR spectra of the compounds (1–30),
the CH2 protons of the pyrazoline ring resonated as a pair of
doublets of doublets at d 3.00–3.25 ppm and 3.76–3.82 ppm.
The compounds were also evaluated for their cytotoxic
properties using the MTT assay (Table 3). The biological study
indicated that compounds 4, 8, and 9 possessed the highest
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Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Pyrazoline Derivatives as New Cholinesterase Inhibitors
191
R'
R'
NaOH
H
+
O
O
O
O
O
NH2NH2.H2O
ClCH2COCl
N(C2H5)3
O
O
N
O
N
N
N
R'
R'
H
Cl
S
CS2
R
H
NaS
R
NaOH
O
N
N
R'
O
R
S
S
Scheme 1. The synthesis of the compounds (1–30).
cytotoxicity with an IC50 value of <7.8 mg/mL, whereas com-
pound 22 exhibited the lowest cytotoxicity with an IC50 value
of 206.7 ꢁ 47.3 mg/mL against mouse fibroblast (NIH/3T3)
cell lines.
In the present paper, we synthesized a series of pyrazoline
derivatives bearing a dithiocarbamate moiety and evaluated
their anticholinesterase effects and cytotoxicity.
The biological results indicate that compound 7 is the
most potent inhibitor of AChE and BuChE with IC50
values of 0.72 ꢁ 0.06 mg/mL and 7.46 ꢁ 0.83 mg/mL,
respectively. This outcome confirms that the 2-dimethyl-
aminoethyl and 3,4-methylenedioxyphenyl moieties may have
a considerable influence on the anticholinesterase activity.
In addition, the cytotoxic concentration (IC50 ¼ 9.2 ꢁ
Conclusion
Cholinesterase inhibitors (ChEIs) have attracted a great deal
of interest among researchers due to their importance in the
first-line treatment for symptoms of Alzheimer’s disease.
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192
M. D. Altintop et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Table 1. Some properties of the compounds (1–30).
Compound
R
R0
Yield
(%)
m.p.
(8C)
Molecular
formula
Molecular
weight
1
2
3
4
5
6
7
8
4-Ethylpiperazin-1-yl
Morpholin-4-yl
4-(4-Methoxyphenyl)piperazin-1-yl
4-Benzylpiperazin-1-yl
4-Methylpiperazin-1-yl
Thiomorpholin-4-yl
4-(2-Dimethylaminoethyl)piperazin-1-yl
4-Phenylpiperazin-1-yl
Pyrrolidin-1-yl
Piperidin-1-yl
4-Ethylpiperazin-1-yl
Morpholin-4-yl
4-(4-Methoxyphenyl)piperazin-1-yl
4-Benzylpiperazin-1-yl
4-Methylpiperazin-1-yl
Thiomorpholin-4-yl
4-(2-Dimethylaminoethyl)piperazin-1-yl
4-Phenylpiperazin-1-yl
Pyrrolidin-1-yl
Piperidin-1-yl
4-Ethylpiperazin-1-yl
Morpholin-4-yl
4-(4-Methoxyphenyl)piperazin-1-yl
4-Benzylpiperazin-1-yl
4-Methylpiperazin-1-yl
Thiomorpholin-4-yl
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
3,4-Methylenedioxy
4-Methyl
4-Methyl
4-Methyl
4-Methyl
4-Methyl
4-Methyl
4-Methyl
4-Methyl
4-Methyl
4-Methyl
4-Methoxy
4-Methoxy
4-Methoxy
4-Methoxy
4-Methoxy
4-Methoxy
4-Methoxy
78
77
48
75
86
88
69
73
91
93
84
77
80
87
84
92
90
92
94
93
52
78
68
78
72
67
71
69
57
64
82
165
47
98
118
85
63
95
81
89
86
91
67
94
106
101
98
108
102
121
75
C23H26N4O4S2
C21H21N3O5S2
C28H28N4O5S2
C28H28N4O4S2
486.61
459.54
564.68
548.68
472.58
475.60
529.67
534.65
443.54
457.57
456.62
429.56
534.69
518.69
442.60
445.62
499.69
504.67
413.56
427.58
472.62
445.56
550.69
534.69
458.60
461.62
515.69
520.67
429.56
443.58
C22H24N4O4S2
C21H21N3O4S3
C25H31N5O4S2
C27H26N4O4S2
C21H21N3O4S2
C22H23N3O4S2
C23H28N4O2S2
C21H23N3O3S2
C28H30N4O3S2
C28H30N4O2S2
C22H26N4O2S2
C21H23N3O2S3
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
C25H33N5O2S2
C27H28N4O2S2
C21H23N3O2S2
C22H25N3O2S2
C23H28N4O3S2
C21H23N3O4S2
C28H30N4O4S2
C28H30N4O3S2
C22H26N4O3S2
C21H23N3O3S3
C25H33N5O3S2
C27H28N4O3S2
C21H23N3O3S2
C22H25N3O3S2
87
125
120
132
55
137
65
4-(2-Dimethylaminoethyl)piperazin-1-yl
4-Phenylpiperazin-1-yl
Pyrrolidin-1-yl
4-Methoxy
4-Methoxy
4-Methoxy
59
67
Piperidin-1-yl
1.6 mg/mL) of compound 7 is higher than its effective con-
centration. In the view of this study, further research
can be carried out on the development of new effective
anticholinesterase agents by the modification of com-
pound 7.
General procedure for the synthesis of the compounds
1-(2-Furyl)-3-aryl-2-propen-1-ones
A
mixture of 2-acetylfuran (0.06 mol), aromatic aldehyde
(0.06 mol) and 10% aqueous sodium hydroxide (10 mL) in etha-
nol (30 mL) was stirred at room temperature for about 5 h. The
resulting solid was washed, dried, and crystallized from ethanol
[29, 30].
Experimental
5-Aryl-3-(2-furyl)-2-pyrazolines
Chemistry
A mixture of appropriate furyl chalcone (0.03 mol) and 80% hydra-
zine hydrate (0.06 mol) in ethanol (30 mL) was refluxed for 3 h.
The reaction mixture was cooled and kept at 08C overnight. The
resulting solid was recrystallized from ethanol [29, 30].
All reagents were purchased from commercial suppliers and
were used without further purification. Melting points (m.p.)
were determined on a Electrothermal 9100 melting point appar-
atus (Weiss-Gallenkamp, Loughborough, UK) and were uncor-
rected. Infrared spectra (IR) were recorded on a Shimadzu
8400 Fourier transform (FT)-IR spectrophotometer (Shimadzu,
Tokyo, Japan). Proton nuclear magnetic resonance (1H NMR)
spectra were recorded on Bruker a 500 MHz spectrometer
(Bruker, Billerica, MA, USA). Chemical shifts were expressed in
parts per million (ppm) and tetramethylsilane was used as an
internal standard. Mass spectra were recorded on a VG Quattro
Mass spectrometer (Agilent, Minnesota, USA). Elemental analyses
were performed on a Perkin Elmer EAL 240 elemental analyzer
(Perkin-Elmer, Norwalk, CT, USA).
1-(Chloroacetyl)-3-(2-furyl)-5-aryl-2-pyrazolines
5-Aryl-3-(2-furyl)-2-pyrazolines (0.02 mol) and triethylamine
(0.02 mol) were dissolved in dry acetone (30 mL) with constant
stirring. Later, the mixture was cooled in an ice bath, and
chloroacetyl chloride (0.02 mol) was added dropwise with stir-
ring. The reaction mixture thus obtained was further agitated for
2 h at room temperature. The precipitate was filtered, the sol-
vent was evaporated to dryness under reduced pressure, and the
products were recrystallized from ethanol [29].
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Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Pyrazoline Derivatives as New Cholinesterase Inhibitors
193
Table 2. The anticholinesterase activities of the compounds (1–30) as IC50 values (mg/mL).
Compound AChE % Inhibition
(80 mg/mL)
IC50 (mg/mL)
BuChE % Inhibition
(80 mg/mL)
IC50 (mg/mL)
1
2
3
4
5
6
7
8
96.92 ꢁ 0.92
47.66 ꢁ 2.65
21.51 ꢁ 3.70
9.44 ꢁ 1.84
68.78 ꢁ 3.93
57.69 ꢁ 4.80
96.22 ꢁ 1.65
25.45 ꢁ 2.40
45.30 ꢁ 2.40
16.04 ꢁ 3.73
28.01 ꢁ 2.74
27.30 ꢁ 2.69
5.60 ꢁ 1.26
na
19.49 ꢁ 2.93
15.76 ꢁ 4.23
89.74 ꢁ 3.62
14.51 ꢁ 3.05
15.18 ꢁ 0.32
29.14 ꢁ 0.83
31.02 ꢁ 3.49
9.24 ꢁ 1.05
15.92 ꢁ 1.69
20.01 ꢁ 2.74
na
50.68 ꢁ 2.72
>80
>80
86.39 ꢁ 7.91
46.04 ꢁ 0.96
na
36 ꢁ 5.66
>80
nt
>80
na
nt
65.33 ꢁ 2.31
48 ꢁ 5.64
62 ꢁ 8.48
0.72 ꢁ 0.06
>80
69.97 ꢁ 3.49
69.74 ꢁ 2.49
92.41 ꢁ 0.37
43.15 ꢁ 5.91
23.07 ꢁ 0.63
na
9.35 ꢁ 1.84
19.18 ꢁ 2.25
na
57.33 ꢁ 2.31
7.46 ꢁ 0.83
>80
>80
9
>80
>80
>80
>80
>80
nt
>80
>80
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Eserine
nt
>80
>80
nt
nt
>80
>80
>80
nt
nt
>80
nt
nt
>80
>80
>80
na
25.15 ꢁ 0.16
33.64 ꢁ 8.17
41.43 ꢁ 2.46
na
7.2 ꢁ 1.04
>80
>80
na
35.68 ꢁ 5.92
>80
>80
>80
>80
>80
nt
na
na
10.89 ꢁ 1.93
16.58 ꢁ 3.94
10.91 ꢁ 1.03
13.85 ꢁ 0.21
59.76 ꢁ 4.95
na
13.7 ꢁ 2.23
36.86 ꢁ 4.50
nt
28.44 ꢁ 1.79
90.25 ꢁ 0.78
13.36 ꢁ 3.58
27.30 ꢁ 2.24
35.15 ꢁ 3.52
nt
>80
2.32 ꢁ 0.76
>80
26.93 ꢁ 2.54
>80
>80
nt
>80
>80
0.0013 ꢁ 0.0001
>80
0.012 ꢁ 0.005
na, not active; nt, not tested.
solvent was evaporated under reduced pressure and then dry
ether was added until precipitation. The products were afforded
by filtration and recrystallized from ethanol [20].
1-[(N,N-Disubstituted thiocarbamoylthio)acetyl]-3-(2-furyl)-
5-aryl-2-pyrazolines (1–30)
A
mixture of 1-(chloroacetyl)-3-(2-furyl)-5-aryl-2-pyrazolines
(0.01 mol) and appropriate sodium salts of N,N-disubstituted
dithiocarbamic acid (0.01 mol) was treated in acetone at room
temperature for 3 h. The solvent was evaporated, the resulting
solid was washed with water and recrystallized from ethanol.
1-[((4-Ethylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-(2-
Figure 1. AChE inhibitory activity of compound 7.
furyl)-5-(3,4-methylenedioxyphenyl)-2-pyrazoline (1)
IR (KBr) nmax (cmꢀ1): 3112.89 (aromatic C–H), 2902.67 (aliphatic
C–H asymmetric), 2810.09 (aliphatic C–H symmetric), 1658.67
–
–
–
(C O), 1487.01, 1425.30 (C N and C C), 1382.87, 1236.29,
–
–
–
–
–
Sodium salts of N,N-disubstituted dithiocarbamic acids
Sodium hydroxide (10 mmol) was dissolved in ethanol (80 mL)
with constant stirring. After addition of the secondary amine
(10 mmol) the mixture was cooled in an ice bath and carbon
disulfide (100 mmol) was added dropwise with stirring. The
reaction mixture was stirred for 1 h at room temperature. The
1035.70, 1018.34 (C–N, C–O, and C S).
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.01 (3H, s), 2.35 (2H, m),
2.43 (4H, m), 3.02 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.77 (1H, dd, J ¼ 18.0,
11.5 Hz), 3.92–4.19 (4H, two br. s), 4.56 (1H, d, J ¼ 14.0 Hz), 4.73
(1H, d, J ¼ 13.5 Hz), 5.45 (1H, dd, J ¼ 11.5, 4.5 Hz), 5.97 (2H, s),
6.66–7.01 (5H, m), 7.91 (1H, s).
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194
M. D. Altintop et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Scheme 2. The similarity of acetylcholine and compounds 7, 17, and 27.
–
1234.36, 1224.71, 1031.85 (C–N, C–O and C S), 991.34, 867.91
–
(C–H out of plane deformation).
1H NMR (500 MHz, d ppm, DMSO-d6): 3.18 (1H, dd, J ¼ 18.0,
4.5 Hz), 3.67 (4H, m), 3.78 (1H, dd, J ¼ 18.0, 12.0 Hz), 3.95–4.20
(4H, two br), 4.58 (1H, d, J ¼ 14.0 Hz), 4.75 (1H, d, J ¼ 13.5 Hz),
5.45 (1H, dd, J ¼ 12.0, 4.5 Hz), 5.99 (2H, s), 6.67–6.87 (4H, m),
7.01 (1H, d, J ¼ 3.5 Hz), 7.92 (1H, s).
For C21H21N3O5S2, calculated: C, 54.89; H, 4.61; N, 9.14; found:
C, 54.90; H, 4.59; N, 9.17; MS (FAB) [Mþ1]þ: m/z 460.
1-[[(4-(4-Methoxyphenyl)piperazin-1-yl)-
thiocarbamoylthio]acetyl]-3-(2-furyl)-5-(3,4-methylene-
dioxyphenyl)-2-pyrazoline (3)
IR (KBr) nmax (cmꢀ1): 3114.82 (aromatic C–H), 2902.67 (aliphatic
C–H asymmetric), 2831.31 (aliphatic C–H symmetric), 1654.81
Figure 2. BuChE inhibitory activity of compound 7.
–
–
–
(C O), 1647.10, 1512.09, 1487.01, 1425.30 (C N and C C),
–
–
–
1386.72, 1240.14, 1220.86, 1035.70, 1004.84 (C–N, C–O and
For C23H26N4O4S2‘, calculated: C, 56.77; H, 5.39; N,
11.51; found: C, 56.78; H, 5.38; N, 11.49; MS (FAB) [Mþ1]þ:
m/z 487.
–
C S), 808.12 (C–H out of plane deformation).
–
1H NMR (500 MHz, DMSO-d6) d (ppm): 3.12 (4H, m), 3.25 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.69 (3H, s), 3.78 (1H, dd, J ¼ 18.0, 11.5 Hz),
3.96–4.22 (4H, m), 4.59 (1H, d, J ¼ 14.0 Hz), 4.76 (1H, d,
J ¼ 13.5 Hz), 5.46 (1H, m), 5.98 (2H, m), 6.64–7.03 (9H, m), 7.91
(1H, m).
1-[((Morpholin-4-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(3,4-methylenedioxyphenyl)-2-pyrazoline (2)
IR (KBr) nmax (cmꢀ1): 3109.04 (aromatic C–H), 2920.03 (aliphatic
C–H asymmetric), 2850.59 (aliphatic C–H symmetric), 1666.38
For C28H28N4O5S2, calculated: C, 59.56; H, 5.00; N, 9.92; found:
C, 59.54; H, 5.01; N, 9.90; MS (FAB) [Mþ1]þ: m/z 565.
–
–
–
(C O), 1485.09, 1429.15 (C N and C C), 1388.65, 1267.14,
–
–
–
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Pyrazoline Derivatives as New Cholinesterase Inhibitors
195
Table 3. In vitro cytotoxicity of the compounds (1–30) against NIH/
3T3 cells for 24 h.
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.20 (3H, s), 2.39 (4H, m),
3.03 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.78 (1H, dd, J ¼ 18.0, 11.5 Hz),
3.92–4.19 (4H, two br. s), 4.57 (1H, d, J ¼ 14.0 Hz), 4.73 (1H, d,
J ¼ 13.5 Hz), 5.45 (1H, dd, J ¼ 11.5, 4.5 Hz), 5.96 (2H, s), 6.65–7.03
(5H, m), 7.91 (1H, s).
Compound
IC50 value (mg/mL)a)
1
2
3
4
12.2 ꢁ 2.0
51.3 ꢁ 3.2
191.0 ꢁ 18.9
<7.8
For C22H24N4O4S2, calculated: C, 55.91; H, 5.12; N, 11.86;
found: C, 55.89; H, 5.10; N, 11.88; MS (FAB) [Mþ1]þ: m/z 473.
1-[((Thiomorpholin-4-yl)thiocarbamoylthio)acetyl]-3-(2-
furyl)-5-(3,4-methylenedioxyphenyl)-2-pyrazoline (6)
5
6
7
8
8.3 ꢁ 0.3
13.3 ꢁ 1.5
9.2 ꢁ 1.6
<7.8
IR (KBr) nmax (cmꢀ1): 3112.89 (aromatic C–H), 2910.38 (aliphatic
–
–
–
C–H), 1666.38 (C O), 1485.09, 1431.08 (C N and C C), 1388.65,
–
–
–
–
9
<7.8
1282.57, 1242.07, 1191.93, 1037.63 (C–N, C–O and C S), 935.41,
–
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
16.7 ꢁ 4.2
18.7 ꢁ 2.1
12.3 ꢁ 1.5
61.0 ꢁ 8.5
17.7 ꢁ 2.5
22.3 ꢁ 1.5
16.3 ꢁ 1.2
63.7 ꢁ 9.1
31.3 ꢁ 1.2
13.7 ꢁ 1.5
67.7 ꢁ 2.5
26.7 ꢁ 4.2
206.7 ꢁ 47.3
24.0 ꢁ 1.0
22.0 ꢁ 1.0
28.3 ꢁ 0.6
13.0 ꢁ 1.0
9.3 ꢁ 0.3
22.7 ꢁ 2.1
17.0 ꢁ 1.0
51.0 ꢁ 7.9
811.98 (C–H out of plane deformation).
1H NMR (500 MHz, d ppm, DMSO-d6): 2.73 (4H, m), 3.04 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.77 (1H, m), 4.20–4.52 (4H, two br), 4.59 (1H, d,
J ¼ 14.0 Hz), 4.74 (1H, d, J ¼ 13.5 Hz), 5.46 (1H, m), 5.98 (2H, s),
6.67–7.03 (5H, m), 7.91 (1H, s).
For C21H21N3O4S3, calculated: C, 53.03; H, 4.45; N, 8.84; found:
C, 53.05; H, 4.44; N, 8.87; MS (FAB) [Mþ1]þ: m/z 476.
1-[[(4-(2-Dimethylaminoethyl)piperazin-1-yl)-
thiocarbamoylthio]acetyl]-3-(2-furyl)-5-(3,4-methylene-
dioxyphenyl)-2-pyrazoline (7)
IR (KBr) nmax (cmꢀ1): 3112.89 (aromatic C–H), 2939.31 (aliphatic
C–H asymmetric), 2815.88 (aliphatic C–H symmetric), 1666.38
–
–
–
–
(C O), 1487.01, 1425.30 (C N and C C), 1236.29, 1130.21,
–
–
–
1035.70 (C–N, C–O and C S), 997.13, 808.12 (C–H out of plane
–
deformation).
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.12 (6H, s), 2.34 (2H, m),
2.41 (2H, m), 2.47 (4H, m), 3.02 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.76 (1H,
dd, J ¼ 18.0, 11.5 Hz), 3.90–4.19 (4H, two br. s), 4.56 (1H, d,
J ¼ 14.0 Hz), 4.72 (1H, d, J ¼ 13.5 Hz), 5.45 (1H, dd, J ¼ 11.5,
4.5 Hz), 5.97 (2H, s), 6.66–7.01 (5H, m), 7.91 (1H, s).
For C25H31N5O4S2, calculated: C, 56.69; H, 5.90; N, 13.22;
found: C, 56.69; H, 5.90; N, 13.22; MS (FAB) [Mþ1]þ: m/z 530.
a)
Cytotoxicity of compounds to mouse fibroblast (NIH/3T3) cell
line. Incubation for 24 h. IC50 is the drug concentration required
to inhibit 50% of the cell proliferation. The values represent
mean ꢁ standard deviation of triplicate determinations.
1-[(4-Phenylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
1-[((4-Benzylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(3,4-methylenedioxyphenyl)-2-pyrazoline (8)
IR (KBr) nmax (cmꢀ1): 3116.75 (aromatic C–H), 2935.46 (aliphatic
C–H asymmetric), 2854.45 (aliphatic C–H symmetric), 1658.67
(2-furyl)-5-(3,4-methylenedioxyphenyl)-2-pyrazoline (4)
IR (KBr) nmax (cmꢀ1): 3025.20 (aromatic C–H), 2916.17 (aliphatic
C–H asymmetric), 2810.09 (aliphatic C–H symmetric), 1662.50
–
–
–
(C O), 1500.52, 1485.09, 1425.30 (C N and C C), 1380.94,
–
–
–
–
–
–
–
(C O), 1647.10, 1454.03, 1423.37 (C N and C C), 1249.79,
–
–
–
–
1244.00, 1226.64, 1114.78, 1035.70 (C–N, C–O and C S),
–
1178.43, 1029.92 (C–N, C–O and C S), 814.90 (C–H out of plane
–
819.69 (C–H out of plane deformation).
deformation).
1H NMR (500 MHz, DMSO-d6) d (ppm): 3.03 (1H, dd, J ¼ 18.0,
4.5 Hz), 3.28 (4H, m), 3.79 (1H, dd, J ¼ 18.0, 11.5 Hz), 3.92–4.19
(4H, two br. s), 4.56 (1H, d, J ¼ 14.0 Hz), 4.71 (1H, d, J ¼ 13.5 Hz),
5.45 (1H, dd, J ¼ 11.5, 4.5 Hz), 5.98 (2H, s), 6.67–7.02 (5H, m),
7.23–7.34 (5H, m), 7.91 (1H, s).
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.45 (4H, m), 3.02 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.52 (2H, s), 3.77 (1H, dd, J ¼ 18.0, 11.5 Hz),
3.94–4.21 (4H, two br. s), 4.56 (1H, d, J ¼ 14.0 Hz), 4.72 (1H,
d, J ¼ 13.5 Hz), 5.45 (1H, dd, J ¼ 11.5, 4.5 Hz), 5.97 (2H, s),
6.65–7.01 (5H, m), 7.24–7.35 (5H, m), 7.91 (1H, s).
For C27H26N4O4S2, calculated: C, 60.65; H, 4.90; N, 10.48;
found: C, 60.63; H, 4.88; N, 10.47; MS (FAB) [Mþ1]þ: m/z 535.
For C28H28N4O4S2, calculated: C, 61.29; H, 5.14; N, 10.21;
found: C, 61.30; H, 5.12; N, 10.19; MS (FAB) [Mþ1]þ: m/z 549.
1-[((4-Methylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
1-[(Pyrrolidin-1-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(3,4-methylenedioxyphenyl)-2-pyrazoline (9)
(2-furyl)-5-(3,4-methylenedioxyphenyl)-2-pyrazoline (5)
IR (KBr) nmax (cmꢀ1): 3112.89 (aromatic C–H), 2906.53 (aliphatic
C–H asymmetric), 2790.80 (aliphatic C–H symmetric), 1672.17
IR (KBr) nmax (cmꢀ1): 3112.89 (aromatic C–H), 2968.24 (aliphatic
C–H asymmetric), 2894.95 (aliphatic C–H symmetric), 1666.38
–
–
–
–
–
–
(C O), 1485.09, 1427.23 (C N and C C), 1380.94, 1290.29,
–
(C O), 1488.94, 1436.87 (C N and C C), 1326.93, 1244.00,
–
–
–
–
–
–
–
1242.07, 1143.71, 1041.49 (C–N, C–O and C S), 810.05 (C–H
–
out of plane deformation).
1159.14, 1035.70, 1006.77 (C–N, C–O, and C S), 808.12 (C–H
–
out of plane deformation).
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

196
M. D. Altintop et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.88–2.06 (4H, m), 3.03
(1H, dd, J ¼ 18.0, 4.5 Hz), 3.63–3.75 (4H, m), 3.78 (1H, dd,
J ¼ 18.0, 11.5 Hz), 4.54 (1H, d, J ¼ 14.0 Hz), 4.72 (1H, d,
J ¼ 13.5 Hz), 5.45 (1H, dd, J ¼ 11.5, 4.5 Hz), 5.98 (2H, s), 6.67–
7.01 (5H, m), 7.91 (1H, s).
For C21H21N3O4S2, calculated: C, 56.87; H, 4.77; N, 9.47; found:
C, 56.85; H, 4.77; N, 9.49; MS (FAB) [Mþ1]þ: m/z 444.
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.24 (3H, s), 3.12 (4H, m),
3.25 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.69 (3H, s), 3.81 (1H, dd, J ¼ 18.0,
11.5 Hz), 4.09–4.35 (4H, two br.), 4.60 (1H, d, J ¼ 14.0 Hz), 4.75
(1H, d, J ¼ 13.5 Hz), 5.49 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.67 (1H, m),
6.84 (2H, d, J ¼ 8.6 Hz), 6.92 (2H, d, J ¼ 8.5 Hz), 6.99–7.13 (5H, m),
7.90 (1H, m).
For C28H30N4O3S2, calculated: C, 62.90; H, 5.66; N, 10.48;
found: C, 62.89; H, 5.65; N, 10.48; MS (FAB) [Mþ1]þ: m/z 535.
1-[(Piperidin-1-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(3,4-methylenedioxyphenyl)-2-pyrazoline (10)
1-[((4-Benzylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methylphenyl)-2-pyrazoline (14)
IR (KBr) nmax (cmꢀ1): 3112.89 (aromatic C–H), 2902.67 (aliphatic
C–H asymmetric), 2821.66 (aliphatic C–H symmetric), 1666.38
IR (KBr) nmax (cmꢀ1): 3024.18 (aromatic C–H), 2916.17 (aliphatic
C–H asymmetric), 2810.09 (aliphatic C–H symmetric), 1662.52
–
–
–
(C O), 1598.88, 1488.94, 1425.30 (C N and C C), 1386.72,
–
–
–
–
– –
(C O), 1454.03, 1423.37 (C N and C C), 1228.57, 1139.85 (C–N,
– –
–
1240.14, 1151.42, 1035.70, 1004.84 (C–N, C–O, and C S),
–
–
–
808.12 (C–H out of plane deformation).
C–O, and C S), 995.20, 813.90 (C–H out of plane deformation).
–
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.53 (6H, m), 3.02 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.78 (1H, dd, J ¼ 18.0, 11.5 Hz), 4.10–4.34 (4H,
m), 4.60 (1H, d, J ¼ 14.0 Hz), 4.76 (1H, d, J ¼ 13.5 Hz), 5.47 (1H,
dd, J ¼ 11.5, 4.5 Hz), 5.97 (2H, m), 6.65–7.25 (5H, m), 7.91 (1H, s).
For C22H23N3O4S2, calculated: C, 57.75; H, 5.07; N, 9.18; found:
C, 57.74; H, 5.07; N, 9.21; MS (FAB) [Mþ1]þ: m/z 458.
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.26 (3H, s), 2.45 (4H, m),
3.00 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.52 (2H, s), 3.80 (1H, dd, J ¼ 18.0,
11.5 Hz), 3.93–4.21 (4H, two br. s), 4.57 (1H, d, J ¼ 14.0 Hz), 4.71
(1H, d, J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.67 (1H, m),
7.00 (1H, d, J ¼ 3.5 Hz), 7.08–7.32 (9H, m), 7.91 (1H, s).
For C28H30N4O2S2, calculated: C, 64.84; H, 5.83; N, 10.80;
found: C, 64.84; H, 5.80; N, 10.82; MS (FAB) [Mþ1]þ: m/z 519.
1-[((4-Ethylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methylphenyl)-2-pyrazoline (11)
1-[((4-Methylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methylphenyl)-2-pyrazoline (15)
IR (KBr) nmax (cmꢀ1): 3114.82 (aromatic C–H), 2968.24 (aliphatic
C–H), 2918.10 (aliphatic C–H), 1666.38 (C O), 1467.73, 1445.62
–
IR (KBr) nmax (cmꢀ1): 3116.75 (aromatic C–H), 2937.38 (aliphatic
C–H asymmetric), 2792.73 (aliphatic C–H symmetric), 1662.52
–
–
–
(C N and C C), 1269.07, 1236.29, 1157.21, 1018.34 (C–N, C–O,
–
–
–
– –
(C O), 1461.94, 1425.30 (C N and C C), 1288.36, 1141.78 (C–N,
– –
–
and C S), 813.90 (C–H out of plane deformation).
–
–
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.01 (3H, s), 2.25 (3H, s),
2.35 (2H, m), 2.44 (4H, m), 3.01 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.80 (1H,
dd, J ¼ 18.0, 12.0 Hz), 3.92–4.19 (4H, two br s), 4.57 (1H, d,
J ¼ 14.0 Hz), 4.72 (1H, d, J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 12.0,
4.5 Hz), 6.67 (1H, m), 7.01 (1H, s), 7.08–7.12 (4H, m), 7.91 (1H, s).
For C23H28N4O2S2, calculated: C, 60.50; H, 6.18; N, 12.27;
found: C, 60.52; H, 6.17; N, 12.29; MS (FAB) [Mþ1]þ: m/z 457.
C–O, and C S), 995.20, 813.90 (C–H out of plane deformation).
–
–
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.20 (3H, s), 2.25 (3H, s),
2.39 (4H, m), 3.01 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.80 (1H, dd, J ¼ 18.0,
11.5 Hz), 3.92–4.19 (4H, two br. s), 4.58 (1H, d, J ¼ 14.0 Hz), 4.72
(1H, d, J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.66 (1H, m),
7.01 (1H, s), 7.08–7.18 (4H, m), 7.91 (1H, s).
For C22H26N4O2S2, calculated: C, 59.70; H, 5.92; N, 12.66;
found: C, 59.71; H, 5.90; N, 12.65; MS (FAB) [Mþ1]þ: m/z 443.
1-[((Morpholin-4-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(4-methylphenyl)-2-pyrazoline (12)
1-[((Thiomorpholin-4-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methylphenyl)-2-pyrazoline (16)
IR (KBr) nmax (cmꢀ1): 3114.82 (aromatic C–H), 2918.10 (aliphatic
C–H asymmetric), 2854.45 (aliphatic C–H symmetric), 1666.38
IR (KBr) nmax (cmꢀ1): 3116.75 (aromatic C–H), 2916.17 (aliphatic
–
–
–
– –
C–H), 1666.38 (C O), 1467.73, 1421.44 (C N and C C), 1282.57,
– –
–
(C O), 1514.02, 1423.37 (C N and C C), 1386.72, 1269.07,
–
–
–
–
–
–
1230.50, 1112.85, 1027.99, 1000.99 (C–N, C–O, and C S),
–
1215.07, 1143.71 (C–N, C–O, and C S), 813.90 (C–H out of plane
–
813.90 (C–H out of plane deformation).
deformation), 667.32 (C–S).
1H NMR (500 MHz, d ppm, DMSO-d6): 2.25 (3H, s), 3.01 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.70 (4H, m), 3.80 (1H, dd, J ¼ 18.0, 12.0 Hz),
3.95–4.20 (4H, two br.), 4.59 (1H, d, J ¼ 14.0 Hz), 4.74 (1H, d,
J ¼ 13.5 Hz), 5.49 (1H, dd, J ¼ 12.0, 4.5 Hz), 6.67 (1H, t, J ¼ 3.5,
2.0 Hz), 7.01 (1H, d, J ¼ 3.5 Hz), 7.08–7.20 (4H, m), 7.91 (1H, s).
For C21H23N3O3S2, calculated: C, 58.72; H, 5.40; N, 9.78; found:
C, 58.70; H, 5.41; N, 9.80; MS (FAB) [Mþ1]þ: m/z 430.
1H NMR (500 MHz, d ppm, DMSO-d6): 2.25 (3H, s), 2.72 (4H, m),
3.01 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.81 (1H, dd, J ¼ 18.0, 4.5 Hz),
4.22–4.51 (4H, two br), 4.60 (1H, d, J ¼ 14.0 Hz), 4.73 (1H, d,
J ¼ 13.5 Hz), 5.49 (1H, dd, J ¼ 12.0, 4.5 Hz), 6.66 (1H, m), 7.01
(1H, s), 7.06–7.12 (4H, m), 7.91 (1H, s).
For C21H23N3O2S3, calculated: C, 56.60; H, 5.20; N, 9.43; found:
C, 56.59; H, 5.19; N, 9.45; MS (FAB) [Mþ1]þ: m/z 446.
1-[[(4-(4-Methoxyphenyl)piperazin-1-yl)-
thiocarbamoylthio]acetyl]-3-(2-furyl)-5-(4-methylphenyl)-
1-[[(4-(2-Dimethylaminoethyl)piperazin-1-yl)-
thiocarbamoylthio]acetyl]-3-(2-furyl)-5-(4-methylphenyl)-
2-pyrazoline (13)
IR (KBr) nmax (cmꢀ1): 3116.75 (aromatic C–H), 2918.10 (aliphatic
C–H asymmetric), 2829.38 (aliphatic C–H symmetric), 1666.38
2-pyrazoline (17)
IR (KBr) nmax (cmꢀ1): 3097.47 (aromatic C–H), 2939.31 (aliphatic
C–H asymmetric), 2815.88 (aliphatic C–H symmetric), 1672.17
–
–
–
–
– –
(C O), 1465.54, 1425.30 (C N and C C), 1232.43, 1132.14,
– –
1013.25 (C–N, C–O, and C S), 813.90 (C–H out of plane
–
deformation).
–
(C O), 1512.09, 1425.30 (C N and C C), 1274.86, 1222.79,
–
–
–
–
–
1004.84 (C–N, C–O, and C S), 813.90 (C–H out of plane
–
deformation).
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www.archpharm.com

Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Pyrazoline Derivatives as New Cholinesterase Inhibitors
197
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.14 (6H, s), 2.25 (3H, s), 2.35
(2H, m), 2.42 (2H, m), 2.48 (4H, m), 3.01 (1H, dd, J ¼ 18.0, 4.5 Hz),
3.80 (1H, dd, J ¼ 18.0, 11.5 Hz), 3.91–4.18 (4H, two br. s), 4.56 (1H,
d, J ¼ 14.0 Hz), 4.72 (1H, d, J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 11.5,
4.5 Hz), 6.66 (1H, m), 7.01 (1H, s), 7.06–7.12 (4H, m), 7.91 (1H, s).
For C25H33N5O2S2, calculated: C, 60.09; H, 6.66; N, 14.02;
found: C, 60.11; H, 6.65; N, 14.03; MS (FAB) [Mþ1]þ: m/z 500.
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.01 (3H, s), 2.36 (2H, m),
2.44 (4H, m), 3.02 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.70 (3H, s), 3.78 (1H,
dd, J ¼ 18.0, 11.5 Hz), 3.92–4.20 (4H, two br. s), 4.58 (1H, d,
J ¼ 14.0 Hz), 4.71 (1H, d, J ¼ 13.5 Hz), 5.47 (1H, dd, J ¼ 11.5,
4.5 Hz), 6.61–7.14 (6H, m), 7.91 (1H, s).
For C23H28N4O3S2, calculated: C, 58.45; H, 5.97; N, 11.85;
found: C, 58.44; H, 5.97; N, 11.87; MS (FAB) [Mþ1]þ: m/z 473.
1-[((4-Phenylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methylphenyl)-2-pyrazoline (18)
1-[((Morpholin-4-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(4-methoxyphenyl)-2-pyrazoline (22)
IR (KBr) nmax (cmꢀ1): 3022.25 (aromatic C–H), 2914.24 (aliphatic
C–H asymmetric), 2821.66 (aliphatic C–H symmetric), 1658.67
IR (KBr) nmax (cmꢀ1): 3136.04 (aromatic C–H), 2958.60 (aliphatic
C–H asymmetric), 2852.52 (aliphatic C–H symmetric), 1664.45
–
–
–
(C O), 1598.88, 1502.44, 1425.30 (C N and C C), 1384.79,
–
–
–
–
–
–
–
(C O), 1610.45, 1512.09, 1463.87, 1421.44 (C N and C C),
–
–
–
–
1272.93, 1222.79, 1151.42, 1004.84 (C–N, C–O, and C S),
–
1247.86, 1178.43, 1029.92 (C–N, C–O, and C S), 829.33 (C–H
–
813.90 (C–H out of plane deformation).
out of plane deformation).
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.25 (3H, s), 3.00 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.29 (4H, m), 3.81 (1H, dd, J ¼ 18.0, 11.5 Hz),
3.09–4.34 (4H, two br. s), 4.61 (1H, d, J ¼ 14.0 Hz), 4.76 (1H, d,
J ¼ 13.5 Hz), 5.49 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.67 (1H, m), 6.75–
6.95 (4H, m), 7.01 (1H, s), 7.11–7.24 (5H, m), 7.92 (1H, m).
For C27H28N4O2S2, calculated: C, 64.26; H, 5.59; N, 11.10;
found: C, 64.26; H, 5.61; N, 11.09; MS (FAB) [Mþ1]þ: m/z 505.
1H NMR (500 MHz, d ppm, DMSO-d6): 3.02 (1H, dd, J ¼ 18.0,
4.5 Hz), 3.70 (4H, m), 3.72 (3H, s), 3.82 (1H, dd, J ¼ 18.0, 12.0 Hz),
3.96–4.19 (4H, two br.), 4.59 (1H, d, J ¼ 14.0 Hz), 4.72 (1H, d,
J ¼ 13.5 Hz), 5.47 (1H, dd, J ¼ 12.0, 4.5 Hz), 6.65–7.29 (6H, m),
7.91 (1H, s).
For C21H23N3O4S2, calculated: C, 56.61; H, 5.20; N, 9.43; found:
C, 56.59; H, 5.21; N, 9.44; MS (FAB) [Mþ1]þ: m/z 446.
1-[((Pyrrolidin-1-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(4-methylphenyl)-2-pyrazoline (19)
1-[[(4-(4-Methoxyphenyl)piperazin-1-yl)-
thiocarbamoylthio]acetyl]-3-(2-furyl)-5-(4-methoxyphenyl)-
IR (KBr) nmax (cmꢀ1): 3116.75 (aromatic C–H), 2947.03 (aliphatic
C–H asymmetric), 2869.88 (aliphatic C–H symmetric), 1662.52
2-pyrazoline (23)
IR (KBr) nmax (cmꢀ1): 3122.54 (aromatic C–H), 2931.60 (aliphatic
C–H asymmetric), 2833.24 (aliphatic C–H symmetric), 1658.67
–
–
–
–
(C O), 1450.15, 1433.01 (C N and C C), 1328.86, 1159.14,
–
–
–
1006.77 (C–N, C–O, and C S), 813.90 (C–H out of plane
–
–
–
–
(C O), 1610.45, 1512.09, 1423.37 (C N and C C), 1247.86,
–
–
–
–
deformation).
1029.92 (C–N, C–O, and C S), 827.41 (C–H out of plane
–
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.88–2.05 (4H, m), 2.26
(3H, s), 3.01 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.63–3.76 (4H, m), 3.80 (1H,
dd, J ¼ 18.0, 11.5 Hz), 4.56 (1H, d, J ¼ 14.0 Hz), 4.71 (1H, d,
J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.67 (1H, m), 7.01
(1H, m), 7.08–7.18 (4H, m), 7.91 (1H, s).
deformation).
1H NMR (500 MHz, DMSO-d6) d (ppm): 3.12 (4H, m), 3.25 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.70 (6H, s), 3.79 (1H, m), 4.10–4.34 (4H, two br),
4.60 (1H, d, J ¼ 14.0 Hz), 4.73 (1H, d, J ¼ 13.5 Hz), 5.48 (1H, dd,
J ¼ 11.5, 4.5 Hz), 6.61–7.15 (10H, m), 7.91 (1H, s).
For C28H30N4O4S2, calculated: C, 61.07; H, 5.49; N, 10.17;
found: C, 61.05; H, 5.50; N, 10.16; MS (FAB) [Mþ1]þ: m/z 551.
For C21H23N3O2S2, calculated: C, 60.99; H, 5.61; N, 10.16;
found: C, 60.98; H, 5.59; N, 10.17; MS (FAB) [Mþ1]þ: m/z 414.
1-[((Piperidin-1-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(4-methylphenyl)-2-pyrazoline (20)
1-[((4-Benzylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methoxyphenyl)-2-pyrazoline (24)
IR (KBr) nmax (cmꢀ1): 3116.75 (aromatic C–H), 2937.38 (aliphatic
C–H asymmetric), 2856.38 (aliphatic C–H symmetric), 1666.38
IR (KBr) nmax (cmꢀ1): 2916.17 (aliphatic C–H asymmetric), 2833.24
–
(aliphatic C–H symmetric), 1662.52 (C O), 1512.09, 1463.87,
–
–
–
–
–
1423.37 (C N and C C), 1249.79, 1178.43, 1029.92 (C–N, C–O,
(C O), 1481.23, 1427.23 (C N and C C), 1244.00, 1132.14,
–
–
–
–
–
–
–
1006.77 (C–N, C–O, and C S), 813.90 (C–H out of plane
–
–
and C S), 829.33 (C–H out of plane deformation).
–
deformation).
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.46 (4H, m), 3.02 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.52 (2H, s), 3.71 (3H, s), 3.79 (1H, dd, J ¼ 18.0,
11.5 Hz), 3.94–4.21 (4H, two br. s), 4.57 (1H, d, J ¼ 14.0 Hz), 4.70
(1H, d, J ¼ 13.5 Hz), 5.47 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.66–7.32
(11H, m), 7.91 (1H, s).
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.58 (6H, m), 2.26 (3H, s),
3.01 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.80 (1H, dd, J ¼ 18.0, 11.5 Hz),
3.91–4.19 (4H, m), 4.57 (1H, d, J ¼ 14.0 Hz), 4.70 (1H, d,
J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.67 (1H, m), 7.01
(1H, m), 7.06–7.20 (4H, m), 7.91 (1H, s).
For C28H30N4O3S2, calculated: C, 62.90; H, 5.66; N, 10.48;
found: C, 62.92; H, 5.65; N, 10.48; MS (FAB) [Mþ1]þ: m/z 535.
For C22H25N3O2S2, calculated: C, 61.80; H, 5.89; N, 9.83; found:
C, 61.79; H, 5.88; N, 9.84; MS (FAB) [Mþ1]þ: m/z 428.
1-[((4-Ethylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methoxyphenyl)-2-pyrazoline (21)
1-[((4-Methylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methoxyphenyl)-2-pyrazoline (25)
IR (KBr) nmax (cmꢀ1): 3124.47 (aromatic C–H), 2931.60 (aliphatic
C–H asymmetric), 2833.24 (aliphatic C–H symmetric), 1664.45
IR (KBr) nmax (cmꢀ1): 3122.54 (aromatic C–H), 2933.53 (aliphatic
C–H asymmetric), 2835.16 (aliphatic C–H symmetric), 1662.52
–
–
–
– –
(C O), 1512.09, 1463.87, 1425.30 (C N and C C), 1247.86,
– –
–
(C O), 1610.45, 1512.09, 1427.23 (C N and C C), 1247.86,
–
–
–
–
–
–
1178.43, 1029.92 (C–N, C–O, and C S), 829.33 (C–H out of plane
–
deformation).
1230.50, 1178.43, 1029.92 (C–N, C–O, and C S), 829.33 (C–H
–
out of plane deformation).
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

198
M. D. Altintop et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.20 (3H, s), 2.39 (4H, m),
3.02 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.74 (3H, s), 3.80 (1H, dd, J ¼ 18.0,
11.5 Hz), 3.92–4.19 (4H, two br.), 4.58 (1H, d, J ¼ 14.0 Hz), 4.70
(1H, d, J ¼ 13.5 Hz), 5.47 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.68–7.26 (6H,
m), 7.91 (1H, m).
For C22H26N4O3S2, calculated: C, 57.62; H, 5.71; N, 12.22;
found: C, 57.61; H, 5.69; N, 12.23; MS (FAB) [Mþ1]þ: m/z 459.
1178.43, 1029.92 (C–N, C–O and C S), 829.33 (C–H out of plane
–
deformation).
–
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.88–2.04 (4H, m), 3.03
(1H, dd, J ¼ 18.0, 4.5 Hz), 3.63–3.69 (4H, m), 3.71 (3H, s), 3.79 (1H,
dd, J ¼ 18.0, 11.5 Hz), 4.56 (1H, d, J ¼ 14.0 Hz), 4.70 (1H, d,
J ¼ 13.5 Hz), 5.47 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.66–7.14 (6H, m),
7.91 (1H, s).
For C21H23N3O3S2, calculated: C, 58.72; H, 5.40; N, 9.78; found:
C, 58.71; H, 5.39; N, 9.80; MS (FAB) [Mþ1]þ: m/z 430.
1-[((Thiomorpholin-4-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methoxyphenyl)-2-pyrazoline (26)
IR (KBr) nmax (cmꢀ1): 3114.82 (aromatic C–H), 2910.38 (aliphatic
C–H asymmetric), 2833.24 (aliphatic C–H symmetric), 1662.52
1-[((Piperidin-1-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(4-methoxyphenyl)-2-pyrazoline (30)
(C O), 1512.09, 1463.87, 1436.87 (C N and C C), 1247.86,
–
IR (KBr) nmax (cmꢀ1): 3120.61 (aromatic C–H), 2933.53 (aliphatic
C–H asymmetric), 2854.45 (aliphatic C–H symmetric), 1666.38
–
–
–
–
–
–
1178.43, 1029.92 (C–N, C–O, and C S), 829.33 (C–H out of plane
–
– –
(C O), 1610.45, 1512.09, 1431.08 (C N and C C), 1245.93,
– –
–
–
deformation).
1H NMR (500 MHz, d ppm, DMSO-d6): 2.72 (4H, m), 3.02 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.71 (3H, s), 3.79 (1H, dd, J ¼ 18.0, 4.5 Hz), 4.26–
4.49 (4H, two br), 4.60 (1H, d, J ¼ 14.0 Hz), 4.71 (1H, d,
J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 12.0, 4.5 Hz), 6.67–7.28 (6H, m),
7.92 (1H, s).
1178.43, 1027.99 (C–N, C–O and C S), 829.33 (C–H out of plane
–
–
deformation).
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.61 (6H, m), 3.02 (1H, dd,
J ¼ 18.0, 4.5 Hz), 3.71 (3H, s), 3.79 (1H, dd, J ¼ 18.0, 11.5 Hz),
3.91–4.19 (4H, m), 4.57 (1H, d, J ¼ 14.0 Hz), 4.69 (1H, d,
J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.66–7.14 (6H, m),
7.91 (1H, s).
For C22H25N3O3S2, calculated: C, 59.57; H, 5.68; N, 9.47; found:
C, 59.57; H, 5.66; N, 9.48; MS (FAB) [Mþ1]þ: m/z 444.
For C21H23N3O3S3, calculated: C, 54.64; H, 5.02; N, 9.10; found:
C, 54.63; H, 5.04; N, 9.09; MS (FAB) [Mþ1]þ: m/z 462.
1-[[(4-(2-Dimethylaminoethyl)piperazin-1-yl)-
thiocarbamoylthio]acetyl]-3-(2-furyl)-5-(4-methoxyphenyl)-
AChE and BuChE inhibitory activity
2-pyrazoline (27)
IR (KBr) nmax (cmꢀ1): 3122.54 (aromatic C–H), 2933.53 (aliphatic
C–H asymmetric), 2819.73 (aliphatic C–H symmetric), 1662.52
AChE and BuChE inhibitory activity was determined by Ellman’s
method with minor modifications (electric eel AChE enzyme was
used instead of bovine AChE enzyme and buffer was added at
2.4 mL instead of 3 mL) [31]. Compounds 1–30 were dissolved in
DMSO and tested in the final concentration range of 5–80 mg/mL.
Twenty microliter of enzyme (AChE or BuChE, 1 U/mL), 10 mL
sample added to 2.4 mL buffer, the mixture was incubated
at 378C for 15 min. After 15 min incubation, 50 mL of 0.01 M
5,50-dithio-bis(2-nitrobenzoic acid (DTNB) and 20 mL of 75 mM
acetylthiocholine iodide (ATCI) or 25 mM butyrylthiocholine
iodide (BTCI) were added, and the final mixture was incubated
at room temperature for 30 min. Blank was prepared using
10 mL of DMSO instead of the test sample, with all other pro-
cedures similar to those used in the case of the sample mixture.
Absorbances were measured at 412 nm and 378C using poly-
styrol cuvets with a spectrophotometer (Shimadzu, UV-1700).
Experiments were done in triplicate. Data are expressed as mean
ꢁ standard deviation (SD).
–
–
–
(C O), 1512.09, 1471.59 (C N and C C), 1247.86, 1178.43,
–
–
–
–
1031.85 (C–N, C–O, and C S), 829.33 (C–H out of plane
–
deformation).
1H NMR (500 MHz, DMSO-d6) d (ppm): 2.16 (6H, s), 2.39 (2H, m),
2.42 (2H, m), 2.48 (4H, m), 3.02 (1H, dd, J ¼ 18.0, 4.5 Hz), 3.71 (3H,
s), 3.80 (1H, dd, J ¼ 18.0, 11.5 Hz), 3.91–4.18 (4H, two br. s), 4.57
(1H, d, J ¼ 14.0 Hz), 4.70 (1H, d, J ¼ 13.5 Hz), 5.47 (1H, dd,
J ¼ 11.5, 4.5 Hz), 6.66–7.14 (6H, m), 7.91 (1H, s).
For C25H33N5O3S2, calculated: C, 58.23; H, 6.45; N, 13.58;
found: C, 58.22; H, 6.47; N, 13.55; MS (FAB) [Mþ1]þ: m/z 516.
1-[((4-Phenylpiperazin-1-yl)thiocarbamoylthio)acetyl]-3-
(2-furyl)-5-(4-methoxyphenyl)-2-pyrazoline (28)
IR (KBr) nmax (cmꢀ1): 3114.82 (aromatic C–H), 2927.74 (aliphatic
C–H asymmetric), 2833.24 (aliphatic C–H symmetric), 1674.10
–
–
–
(C O), 1512.09, 1423.37 (C N and C C), 1386.72, 1247.86,
–
The inhibition (percent) of AChE or BuChE was calculated
using the following equation.
–
–
–
1176.50, 1027.99 (C–N, C–O, and C S), 829.33 (C–H out of plane
–
deformation).
ꢀ
ꢁ
1H NMR (500 MHz, DMSO-d6) d (ppm): 3.03 (1H, dd, J ¼ 18.0,
4.5 Hz), 3.29 (4H, m), 3.71 (3H, s), 3.80 (1H, dd, J ¼ 18.0, 11.5 Hz),
4.10–4.34 (4H, two br. s), 4.61 (1H, d, J ¼ 14.0 Hz), 4.74 (1H, d,
J ¼ 13.5 Hz), 5.48 (1H, dd, J ¼ 11.5, 4.5 Hz), 6.67–7.25 (11H, m),
7.95 (1H, s).
OD sample
OD control
Ið%Þ ¼ 100-
ꢂ100
Toxicity
For C27H28N4O3S2, calculated: C, 62.28; H, 5.42; N, 10.76;
found: C, 62.30; H, 5.39; N, 10.76; MS (FAB) [Mþ1]þ: m/z 521.
The level of cellular MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphen-
yltetrazolium bromide) (Sigma) reduction was quantified as
previously described in the literature with small modifications
as represented below in detail [32, 33].
1-[((Pyrrolidin-1-yl)thiocarbamoylthio)acetyl]-3-(2-furyl)-5-
(4-methoxyphenyl)-2-pyrazoline (29)
IR (KBr) nmax (cmꢀ1): 3116.75 (aromatic C–H), 2952.81 (aliphatic
C–H asymmetric), 2871.81 (aliphatic C–H symmetric), 1683.74
Cell culture and drug treatment
NIH/3T3 cells were obtained from the American Type Culture
Collection (ATCC, USA). The cells were incubated in Dulbecco’s
–
–
–
–
–
(C O), 1564.16, 1512.09, 1436.87 (C N and C C), 1247.86,
–
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

Arch. Pharm. Chem. Life Sci. 2013, 346, 189–199
Pyrazoline Derivatives as New Cholinesterase Inhibitors
199
modified Eagle’s medium (DMEM) supplemented with 10% fetal
calf serum (Life Technologies, UK), 100 IU/mL penicillin
(Gibco, Paisley, Scotland) and 100 mg/mL streptomycin (Gibco)
at 378C in a humidified atmosphere of 95% air and 5% CO2.
Exponentially growing cells were plated at 2 ꢂ 104 cells/mL into
96-well microtiter tissue culture plates (Nunc, Denmark) and
incubated for 24 h before the addition of the drugs (the optimum
cell number for cytotoxicity assays was determined in prelimi-
nary experiments). Stock solutions of compounds were prepared
in DMSO (Sigma–Aldrich, Poole, UK) and further dilutions were
made with fresh culture medium (the concentration of DMSO in
the final culture medium was <0.1%, which had no effect on the
cell viability).
[11] G. Pepeu, M. G. Giovannini, Curr. Alzheimer Res. 2009, 6, 86–96.
[12] T. L. Lemke, D. A. Williams, Foye’s Principles of Medicinal
Chemistry, Lippincott Williams&Wilkins, Baltimore and
Philadelphia, USA 2008, chapter 12.
[13] P. M. Madalageri, O. Kotresh, J. Chem. Pharm. Res. 2012, 4 (5),
2697–2703.
[14] R. B. Silverman, The Organic Chemistry of Drug Design and Drug
Action, Elsevier Academic Press, Burlington, USA 2004,
chapter 2.
[15] H. Waterbeemd, R. Mannhold, in Lipophilicity Descriptors
for Structure–Property Correlation Studies: Overview of
Experimental and Theoretical Methods and a Benchmark
of Log P Calculations, Lipophilicity in Drug Action and
Toxicology. (R. Mannhold, H. Kubinyi, H. Timmerman,
MTT assay for cytotoxicity of the compounds
ˇ
Series, Eds., V. Pliska, B. Testa, H. Waterbeemd Vol, Eds.),
VCH Publishers, New York, USA 1996, chapter 23.
The MTT assay is widely used as a measure of cytotoxicity. After
24 h of preincubation, the tested compounds were added to give
final concentrations in the range of 7.8–500 mg/mL and the cells
were incubated for 24 h. At the end of this period, MTT was
dissolved in phosphate buffered saline (PBS) at 5 mg/mL and
filtered to sterilize. At the time indicated above, stock MTT
solution (20 mL/200 mL medium) was added to all assay wells,
and the plates were incubated for 4 h at 378C. After the medium
was removed, the formazan crystals formed by MTT metabolism
were solubilized by addition of 200 mL DMSO (instead of acid-
isopropanol) to each well and after a few minutes at room
temperature to ensure that all crystals were dissolved, absorb-
ance was read at 540 nm with a microtitre plate spectropho-
tometer (Bio-Tek plate reader). Each concentration was repeated
in three wells and IC50 values were defined as the drug concen-
trations that reduced absorbance to 50% of control values.
[16] R. Tokuyama, Y. Takahashi, Y. Tomita, M. Tsubouchi, T.
Yoshida, N. Iwasaki, N. Kado, E. Okezaki, O. Nagata, Chem.
Pharm. Bull. 2001, 49 (4), 353–360.
[17] G. A. Patani, E. J. LaVoie, Chem. Rev. 1996, 96, 3147–3176.
[18] X.-J. Wang, H.-W. Xu, L.-L. Guo, J.-X. Zheng, B. Xu, X. Guo, C.-X.
Zheng, H.-M. Liu, Bioorg. Med. Chem. Lett. 2011, 21, 3074–3077.
[19] K. Bacharaju, S. R. Jambula, S. Sivan, S. Jyostnatangeda, V.
Manga, Bioorg. Med. Chem. Lett. 2012, 22, 3274–3277.
¨
[20] G. Turan-Zitouni, A. Ozdemir, K. Gu¨ven, Arch. Pharm. Chem.
Life Sci. 2005, 338, 96–104.
[21] S. Kumar, S. Bawa, S. Drabu, R. Kumar, H. Gupta, Drug Discov.
2009, 4, 154–163.
[22] M. A. Rahman, A. A. Siddiqui, Int. J. Pharm. Sci. Drug Res. 2010,
2, 165–175.
The authors have declared no conflict of interest.
[23] M. R. Shaaban, A. S. Mayhoub, A. M. Farag, Expert Opin. Ther.
Patents 2012, 22 (3), 253–291.
[24] G. Holan, C. T. Virgona, K. G. Watson, B. L. Finkelstein, Bioorg.
Med. Chem. Lett. 1996, 6 (1), 77–80.
References
[25] V. Jayaprakash, S. Yabanoglu, B. N. Sinha, G. Ucar, Turk. J.
Biochem. 2010, 35 (2), 91–98.
[1] R. A. Copeland, Evaluation of Enzyme Inhibitors in Drug
Discovery: A Guide for Medicinal Chemists and Pharmacologists,
Wiley-Interscience, New Jersey, USA 2005, chapter 1.
[26] G. Ucar, N. Gokhan, A. Yesilada, A. A. Bilgin, Neurosci. Lett.
2005, 382, 327–331.
[2] R. A. Copeland, R. R. Gontarek, L. Luo, Enzyme Inhibitors:
Biostructure-Based and Mechanism-Based Designs, in:
Textbook of Drug Design and Discovery. (Eds.: P. Krogsgaard-
Larsen, K. Strømgaard, U. Madsen), CRC Press, Boca
Raton, USA 2010, chapter 11.
[27] M. D. Altintop, Z. A. Kaplancikli, A. Ozdemir, G. Turan-
ˇ
ˇ
Zitouni, H. E. Temel, G. Akalin, Arch. Pharm. Chem. Life Sci.
2012, 345 (2), 112–116.
[28] G. Turan-Zitouni, A. Ozdemir, Z. A. Kaplancikli, M. D.
Altintop, H. E. Temel, G. Akalin C¸iftc¸i, J. Enzyme Inhib. Med.
Chem. 2012, DOI: 10.3109/14756366.2011.653355.
[3] R. A. Copeland, M. R. Harpel, P. J. Tummino, Expert Opin. Ther.
Targets 2007, 11 (7), 967–978.
[29] A. A. Khalaf, R. A. Kabli, M. T. Zimaity, A. M. Khalil, A. M.
Kaddah, H. A. Al-Rifaie, Indian J. Chem. Sect. B 1993, 32, 1125–
1129.
[4] P. Anand, B. Singh, N. Singh, Bioorg. Med. Chem. 2012, 20,
1175–1180.
[5] A. Martinez, A. Castro, Expert Opin. Invest. Drugs 2006, 15, 1–12.
[30] R. A. Kabli, A. A. Khalaf, M. T. Zimaity, A. M. Khalil, A. M.
Kaddah, H. A. Al-Rifaie, J. Indian Chem. Soc. 1991, 68, 47–51.
[6] D. G. Wilkinson, P. T. Francis, E. Schwam, J. Payne-Parrish,
Drugs Aging 2004, 21, 453–478.
[31] G. L. Ellman, K. D. Courtney, V. Anders, R. M. Featherstone,
Biochem. Pharmacol. 1961, 7, 88–95.
[7] Z.-X. Shen, Med. Hypotheses 2004, 63, 298–307.
[8] E. Giacobini, Neurochem. Res. 2003, 28, 515–522.
[9] J. Grutzendler, J. C. Morris, Drugs 2001, 61, 41–52.
[10] G. T. Grossberg, Curr. Ther. Res. Clin. Exp. 2003, 64, 216–235.
[32] T. Mossmann, J. Immunol. Methods 1983, 65, 55–63.
[33] K. Keiser, C. C. Johnson, D. A. Tipton, J. Endod. 2000, 26, 288–
291.
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