Practical Synthesis, Antidepressant, and Anticonvulsant Activity of 3-Phenyliminoindolin-2-one Derivatives

Article abstract of DOI:10.1111/cbdd.12668

Herein, a series of 3-phenyliminoindolin-2-one derivatives were designed, synthesized, and screened for their antidepressant and anticonvulsant activities. The IR spectra of the compounds afforded NH stretching (3340-3346 cm^-1) bands and C=O stretching (1731-1746 cm^-1). In the ¹H-NMR spectra of the compounds, N-H protons of indoline ring were observed at 10.65-10.89 ppm generally as broad bands, and ¹³C-NMR spectra of the compounds C=O were seen at 161.72-169.27 ppm. Interestingly, compounds 3o, 3p and 3r significantly shortened immobility time in the The forced swimming test (FST) and The tail suspension test (TST) at 50 mg/kg dose levels. In addition, compound 3r exhibited higher levels of efficacy than the reference standard fluoxetine but had no effect on locomotor activity in the open-field test. Compound 3r significantly increased serotonin and norepinephrine and the metabolite 5-hydroxyindoleacetic acid in mouse brain, suggesting that the effects of compound 3r may be mediated through these neurotransmitters. In the seizure screen, 15 compounds showed some degree against PTZ-induced seizure at a dose of 100 mg/kg, and the tested compounds did not show any neurotoxicity at a dose of 300 mg/kg in the rotarod test.

Full text of DOI:10.1111/cbdd.12668

Chem Biol Drug Des 2016; 87: 342–351
Research Article
Practical Synthesis, Antidepressant, and
Anticonvulsant Activity of 3-Phenyliminoindolin-2-one
Derivatives
Jian-Yin Ma1, Ying-Chun Quan2, Hong-Guo Jin3,
Received 20 April 2015, revised 16 July 2015 and accepted
for publication 29 August 2015
Xing-Hua Zhen1, Xue-Wu Zhang2,* and Li-Ping
Guan1,*
Depression and epilepsy are the commonly encountered
neurological disorders (1,2). Depression is a common
1Food and Pharmacy College, Zhejiang Ocean University
and Zhejiang Provincial Engineering Technology Research
comorbidity associated with epilepsy and an important
factor that affects quality of life in these individuals and
contributing considerably to the global burden of the dis-
ease (3,4). Patients with epilepsy are at high risk of devel-
oping depressive symptoms, and the suicide rates in
patients with epilepsy have been reported to be much
higher than in the general population (5). It has reported
that the rate of depression has been found to be 37% in a
community-based study of people with epilepsy, and the
rate of depression has been found to be 50% in patients
typically referred to epilepsy centers (Figure 1) (6,7).
Improvement of the quality of life of depression patients
with epilepsy is one of the most important therapeutic
goals. So, research on the ideal antidepressants for people
with epilepsy should be efficacious but with few adverse
effects is currently an area of considerable activity, and the
search for novel and increasingly effective drugs with
antidepressant and anticonvulsant effects represents an
important and challenging area of medicinal chemistry.
Center of Marine Biomedical Products, Zhoushan,
Zhejiang 316022, China
2College of Medicine, Yanbian University, Park street 977,
Yanji, Jilin 133002, China
3Department of Neurology, Zhoushan Hospital of Zhejiang
Province, Zhoushan 316021, China
*Corresponding authors: Xue-Wu Zhang,
zhangxuewu@ybu.edu.cn and Li-Ping Guan,
glp730@163.com
Herein, a series of 3-phenyliminoindolin-2-one deriva-
tives were designed, synthesized, and screened for
their antidepressant and anticonvulsant activities. The
IR spectra of the compounds afforded NH stretching
(3340–3346 cmÀ1) bands and C=O stretching (1731–
1746 cmÀ1). In the 1H-NMR spectra of the compounds,
N-H protons of indoline ring were observed at 10.65–
10.89 ppm generally as broad bands, and 13C-NMR
spectra of the compounds C=O were seen at 161.72–
169.27 ppm. Interestingly, compounds 3o, 3p and 3r
significantly shortened immobility time in the The
forced swimming test (FST) and The tail suspension
test (TST) at 50 mg/kg dose levels. In addition, com-
pound 3r exhibited higher levels of efficacy than the
reference standard fluoxetine but had no effect on
locomotor activity in the open-field test. Compound 3r
significantly increased serotonin and norepinephrine
and the metabolite 5-hydroxyindoleacetic acid in
mouse brain, suggesting that the effects of compound
3r may be mediated through these neurotransmitters.
In the seizure screen, 15 compounds showed some
Isatin is a heterocyclic moiety which can be used for the
synthesis of a large variety of heterocyclic compounds
such as quinolines, indoles, and as raw material for medic-
inal important drugs. Isatin and its derivatives were
reported to possess proconvulsant and anticonvulsant
activities (8–11). Isatin derivatives also displayed as potent
antidepressants activities and possess CNS-monoamine
oxidase (MAO) inhibition (12–14). A previous study from
our laboratory found that isatin-1-N-phenylacetamide
derivatives and 2-(6-bromo-2,3-dioxoindolin)-N-substituted
phenylacetamide derivatives showed the potent antide-
pressant-like and anticonvulsant activity against maximal
electroshock test and chemical-induced substances PTZ
(15,16). As part of our continuous efforts in this area, we
recently embarked on a program to combine isatin and
phenylamine through the preparation of a hybrid molecule
composed on the two individual units (Figure 2). Herein,
we describe our most recent work toward the design, syn-
thesis, and evaluated of seventeen 3-phenyliminoindolin-2-
degree against PTZ-induced seizure at
a dose of
100 mg/kg, and the tested compounds did not show
any neurotoxicity at
rotarod test.
a dose of 300 mg/kg in the
Key words: antidepressant, neuro-transmitters, pentylenete-
trazole, phenyliminoindolin-2-one
Abbreviations: 5-HIAA, 5-hydroxyindoleacetic acid; 5-HT,
serotonin; CNS, central nervous system; DA, dopamine; FLU,
fluoxetine; FST, forced swimming test; NE, noradrenaline;
PTZ, pentylenetetrazole; TST, tail suspension test.
342
ª 2015 John Wiley & Sons A/S. doi: 10.1111/cbdd.12668

3-Phenyliminoindolin-2-one Derivatives
one derivatives (3a–3r) for their antidepressant and anti-
convulsant activities.
5 mL water, the solution of hydroxylamine hydrochloride
(1.11 g, 16 mmol) in 10 mL water. The mixture was stirred
at 65 °C for 2 h, until the reaction was over which was
confirmed using TLC. During the heating period, some
crystals of compound 1 separate. Cooled the solution in
running water and the remainder crystallizes was filtered
with suction and then dried in infrared drying oven (15,16).
Methods and Materials
Chemistry
Melting points were determined in open capillary tubes. IR
spectra were recorded (in KBr) on a FT-IR1730 (Bruker,
Switzerland); 1H-NMR and 13C-NMR spectra were mea-
sured on an AV-300 (Bruker, Rheinstetten, Germany); and
all chemical shifts were given in ppm relative to tetram-
ethylsilane. High resolution mass spectra were measured
on an MALDI-TOF/TOF mass spectrometer (Bruker Dal-
tonik, Bremen, Germany). The major chemicals were pur-
chased from Aldrich Chemical Corporation (Shanghai,
China). All other chemicals were of the analytical grade.
The synthesis of indoline-2,3-dione (2)
In a 50-mL round-bottomed flask, concentrated sulfuric
acid 15 mL was warmed to 50 °C with an efficient
mechanical stirrer. Dry compound 1 (4 mmol) is added at
such a rate as to keep the temperature between 60 °C.
External cooling should be applied at this stage so that
the reaction can be carried out more rapidly. After the
addition of the isonitroso compound is finished, the solu-
tion is heated to 80 °C and kept at this temperature for
about 10 min to complete the reaction. Then, the reaction
mixture is cooled to room temperature and poured upon
ten times its volume of cracked ice. After standing for
about one and half an hour, the isatin is filtered with suc-
tion, washed several times with cold water to remove the
sulfuric acid, and then dried by infrared. This product is
pure enough for the next reaction (15,16).
The synthesis of 2-hydroxyimino-N-
phenylacetamide (1)
In a 100-mL round-bottomed flask, 4.26 g sodium sulfate
(30 mmol) and 15 mL water were placed and stirred with
an efficient mechanical, then controlled the temperature at
50 °C. This solution was added in the following order:
0.995 g of chloral hydrate (6 mmol), the solution of aniline
(5 mmol) and 0.6 mL of concentrated hydrochloric acid in
The synthesis of 3-phenyliminoindolin-2-one (3a–
3r)
The compound 2 (1.0 g, 4 mmol), substituted aniline
(8 mmol), and 30 mL 95% of EtOH were added in round-
bottomed flask, and the mixture was stirred at room tem-
perature. Then, 0.8 mL glacial acetic acid was added to
the mixture. The reaction system was stirred at 80 °C for
8–10 h. The reaction was monitored by TLC until the reac-
tion was over. Then, the product was filtered with suction,
and the crude product was separated and purified using
column chromatographic EtOAc/petroleum ether (1:6 V/V).
The yield, melting point, and spectral data of each com-
pound are given as below.
3-(4-phenylimino)indolin-2-one (3a)
Figure 1: Estimates of the prevalence of depression and
Yield 55.0%; m.p. 209.7–211.4 °C; IR (KBr) cmÀ1:3342,
1743, 1658, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.77
(1H, s, -NH), 7.27–8.10 (3H, m, -C6H3), 6.81–7.16 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.21, 156.20,
151.88, 147.56, 134.81, 131.09, 126.12, 124.87, 122.10,
117.71, 117.37, 116.14, 115.72, 111.87; ESI-HRMS calcd
for C14H10N2O+([M + H]+): 223.0739; found: 223.0744.
epilepsy.
3-(2-tolylimino)indolin-2-one (3b)
Yield 59.8%; m.p. 234.5–236.3 °C; IR (KBr) cmÀ1: 3344,
1745, 1648, 1249; 1H-NMR (CDCl3, 300 MHz): d 10.70
(1H, s, -NH), 7.33–7.69 (4H, m, -C6H4), 6.94–7.26 (4H, m,
-C6H4), 2.36 (3H, s, -CH3); 13C-NMR (CDCl3, 75 MHz): d
168.88, 155.45, 151.55, 144.20, 143.23, 138.64, 130.08,
Figure 2: Design of compounds 3a–3r.
Chem Biol Drug Des 2016; 87: 342–351
343

Ma et al.
129.91, 127.78, 126.85, 124.44, 122.01, 118.55, 116.41,
3-(4-fluorophenylimino)indolin-2-one (3h)
29.07. ESI-HRMS calcd for
237.0950; found: 237.0961.
C
15H12N2O+ ([M + H]+):
Yield 60.8%; m.p. 230.5–231.7 °C; IR (KBr) cmÀ1:3344,
1742, 1658, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.77
(1H, s, -NH), 7.27–8.10 (3H, m, -C6H3), 6.81–7.16 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.21, 156.20,
151.88, 147.56, 134.81, 131.09, 126.12, 124.87, 122.10,
117.71, 117.37, 116.14, 115.72, 111.87; ESI-HRMS calcd
for C14H9FN2O+([M + H]+): 241.0699; found: 241.0676.
3-(4-tolylimino)indolin-2-one (3c)
Yield 68.3%; m.p. 229.5–231.4 °C; IR (KBr) cmÀ1: 3344,
1742, 1648, 1249; 1H-NMR (CDCl3, 300 MHz): d 10.88
(1H, s, -NH), 7.20–80.9(4H, m, -C6H4), 6.51–6.84 (4H, m,
-C6H4), 2.35 (3H, s, -CH3); 13C-NMR (CDCl3, 75 MHz): d
169.27, 155.88, 151.85, 144.00, 143.29, 138.92, 134.06,
129.78, 127.85, 126.73, 122.85, 120.85, 119.35, 116.44,
3-(2-chlorophenylimino)indolin-2-one (3i)
Yield 76.3%; m.p. 219.5–220.5 °C; IR (KBr) cmÀ1: 3346,
1744, 1655, 1248; 1H-NMR (CDCl3, 300 MHz): d 10.97
(1H, s, -NH), 7.36–8.12 (4H, m, -C6H4), 6.31–7.01 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 163.73, 157.06,
147.50, 135.23, 130.41, 128.45, 126.36, 125.71, 122.73,
122.39, 121.86, 119.11, 116.30, 112.00; ESI-HRMS calcd
for C14H9ClN2O+([M + H]+): 257.0403; found: 257.0410.
26.07; ESI-HRMS calcd for
237.0950; found: 237.0942.
C
15H12N2O+ ([M + H]+):
3-(2-methoxyphenylimino)indolin-2-one (3d)
Yield 48.6%; m.p. 233.8–246.3 °C; IR (KBr) cmÀ1: 3340,
1745, 1648, 1249; 1H-NMR (CDCl3, 300 MHz): d 10.76
(1H, s, -NH), 7.15–7.44 (4H, m, -C6H4), 6.63–7.13 (4H, m,
-C6H4), 2.71 (3H, s, -OCH3); 13C-NMR (CDCl3, 75 MHz): d
161.87, 159.41, 155.55, 150.54, 144.20, 143.17, 138.29,
134.22, 133.68, 129.55, 126.71, 119.03, 116.09, 110.43,
3-(3-chlorophenylimino)indolin-2-one (3j)
Yield 71.2%; m.p. 221.1–223.8 °C; IR (KBr) cmÀ1: 3345,
1743, 1655, 1249; 1H-NMR (CDCl3, 300 MHz): d 10.86
(1H, s, -NH), 7.37–7.88 (4H, m, -C6H4), 6.48–6.96 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.10, 156.19,
151.88, 147.55, 134.82, 131.04, 126.11, 124.93, 122.14,
117.72, 117.37, 116.14, 115.74, 111.95; ESI-HRMS calcd
for C14H9ClN2O+([M + H]+): 257.0403; found: 257.0412.
+
60.21; ESI-HRMS calcd for C15H12N2O2 ([M + H]+):
253.0899; found: 253.0887.
3-(4-methoxyphenylimino)indolin-2-one (3e)
Yield 55.4%; m.p. 239.2–240.3 °C; IR (KBr) cmÀ1: 3341,
1743, 1647, 1250; 1H-NMR (CDCl3, 300 MHz): d 10.43
(1H, s, -NH), 7.26–7.66 (4H, m, -C6H4), 6.76–7.09 (4H, m,
-C6H4), 2.79 (3H, s, -OCH3); 13C-NMR (CDCl3, 75 MHz): d
161.72, 159.45, 155.68, 150.56, 144.15, 143.19, 138.26,
134.21, 133.68, 129.36, 126.70, 119.00, 116.05, 110.45,
3-(4-chlorophenylimino)indolin-2-one (3k)
Yield 79.8%; m.p. 232.3–233.1 °C; IR (KBr)cmÀ1: 3344,
1739, 1649, 1246; 1H-NMR (CDCl3, 300 MHz): d 10.89
(1H, s, -NH), 7.38–8.02 (4H, m, -C6H4), 6.50–7.12 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.21, 156.34,
151.48, 147.47, 134.73, 131.07, 126.31, 124.73, 122.10,
117.71, 117.92, 116.12, 115.74, 111.89; ESI-HRMS calcd
for C14H9ClN2O+([M + H]+): 257.0403; found: 257.0399.
+
60.22; ESI-HRMS calcd for C15H12N2O2 ([M + H]+):
253.0899; found: 253.0890.
3-(2-fluorophenylimino)indolin-2-one (3f)
Yield 70.8%; m.p. 198.3–199.6 °C; IR (KBr) cmÀ1: 3343,
1740, 1653, 1245; 1H-NMR (CDCl3, 300 MHz): d 10.78
(1H, s, -NH), 7.15–8.11 (4H, m, -C6H4), 6.91–7.07 (4H,
m, -C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.22, 155.88,
151.89, 147.50, 134.80, 131.11, 126.13, 124.90, 122.15,
117.70, 117.37, 116.19, 115.75, 111.92; ESI-HRMS
3-(2-bromophenylimino)indolin-2-one (3l)
Yield 69.3%; m.p. 219.8–220.6 °C; IR (KBr) cmÀ1: 3341,
1745, 1658, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.65
(1H, s, -NH), 7.26–7.89 (4H, m, -C6H4), 6.92–7.16 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.09, 152.10,
147.62, 138.53, 134.84, 131.35, 127.84, 126.12, 124.84,
112.87, 122.12, 120.47, 116.61, 111.77; ESI-HRMS calcd
for C14H9BrN2O+([M + H]+): 230.9898; found: 230.9887.
calcd for
241.0687.
C
14H9FN2O+([M + H]+): 241.0699; found:
3-(3-fluorophenylimino)indolin-2-one (3g)
Yield 69.0%; m.p. 209.5–211.0 °C; IR (KBr) cmÀ1: 3342,
1740, 1658, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.68
(1H, s, -NH), 7.37–7.89 (4H, m, -C6H4), 6.96–7.21 (4H,
m, -C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.33, 156.43,
151.68, 147.45, 134.81, 131.11, 126.16, 124.90, 122.17,
117.71, 117.33, 116.12, 115.70, 111.92; ESI-HRMS
calcd for C14H9FN2O+([M + H]+): 241.0699; found:
241.0673.
3-(3-bromophenylimino)indolin-2-one (3m)
Yield 67.5%; m.p. 219.1–220.2 °C; IR (KBr) cmÀ1: 3340,
1745, 1658, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.84
(1H, s, -NH), 7.31–7.88 (4H, m, -C6H4), 6.92–7.07 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.03, 152.03,
147.61, 138.55, 134.86, 131.34, 127.84, 126.10, 124.84,
112.89, 122.14, 120.48, 116.63, 111.98; ESI-HRMS calcd
for C14H9BrN2O+([M + H]+): 230.9898; found: 230.9890.
344
Chem Biol Drug Des 2016; 87: 342–351

3-Phenyliminoindolin-2-one Derivatives
3-(4-bromophenylimino)indolin-2-one (3n)
taining 10 cm of water at 22 Æ 3 °C. Mice were assigned
into different groups (n = 8 for each group). Then, the
mice were dropped individually into the pelxiglass cylinder
and left in the water for 6 min. After the first 2 min of the
initial vigorous struggling, the animals were immobile. The
duration of immobility was recorded during the last 4 min
of the 6-min test. All test swim sessions were recorded by
a video camera positioned directly above the cylinder. Two
competent observers, who were unaware of the treatment
each mouse had received, scored the videotapes. Immo-
bility period was regarded as the time spent by the mouse
floating in the water without struggling and making only
those movements necessary to keep its head above the
water (17).
Yield 63.8%; m.p. 220.9–223.0 °C; IR (KBr) cmÀ1: 3342,
1745, 1648, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.81
(1H, s, -NH), 7.37–7.87 (4H, m, -C6H4), 6.93–7.13 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 164.11, 152.09,
147.63, 138.56, 134.89, 131.35, 127.83, 126.13, 124.80,
112.89, 122.13, 120.47, 116.62, 111.97; ESI-HRMS calcd
for C14H9BrN2O+([M + H]+): 230.9898; found: 230.9889.
3-(4-trifluoromethylphenylimino)indolin-2-one (3o)
Yield 45.8%; m.p. 245.5–248.9 °C; IR (KBr) cmÀ1: 3340,
1740, 1647, 1250; 1H-NMR (CDCl3, 300 MHz): d 10.87
(1H, s, -NH), 7.31–7.82 (4H, m, -C6H4), 6.91–7.15 (4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 165.47, 159.64,
156.71, 150.88, 145.21, 143.00, 137.99, 133.98, 129.86,
127.86, 122.65, 119.01, 117.59, 110.23; ESI-HRMS calcd
for C15H9F3N2O+ ([M + H]+): 291.0667; found: 291.0658.
The tail suspension test (TST)
Mice were individually suspended by tail with clamp (2 cm
from the tip of the end) in a box (25 9 25 9 30 cm) with
the head 5 cm to the bottom. Testing was carried out in a
darkened room with minimal background noise. All animals
were suspended for total 6 min, and the duration of immo-
bility was observed and measured during the final 4-min
interval of the test. All test sessions were recorded by a
video camera positioned directly above the box. Two com-
petent observers blind to treatment scored the videotapes.
Mice were considered to be immobile only when they
hung passively and completely motionless (18,19).
3-(2,4-dichlorophenylimino)indolin-2-one (3p)
Yield 47.6%; m.p. 239.8–246.3 °C; IR (KBr) cmÀ1: 3344,
1746, 1648, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.70
(1H, s, -NH), 7.48–7.64 (4H, m, -C6H4), 6.91–7.07 (3H, m,
-C6H3); 13C-NMR (CDCl3, 75 MHz): d 163.45, 159.52,
156.66, 150.67, 145.27, 143.04, 137.39, 131.21, 129.80,
127.86, 122.75, 121.98, 117.41, 110.12; ESI-HRMS calcd
for C14H8Cl2N2O+([M + H]+): 291.0014; found: 291.0001.
3-(2,4-dibromophenylimino)indolin-2-one (3q)
The open-field test
Yield 50.6%; m.p. 238.4–240.0 °C; IR (KBr) cmÀ1: 3341,
1740, 1648, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.81
(1H, s, -NH), 7.48–7.59 (4H, m, -C6H4), 6.89–7.15(3H, m,
-C6H3); 13C-NMR (CDCl3, 75 MHz): d 165.41, 159.64,
156.84, 150.49, 145.32, 143.27, 137.37, 131.31, 129.94,
127.86, 122.64, 121.65, 117.41, 110.10; ESI-HRMS calcd
for C14H8Br2N2O+([M + H]+): 378.9003; found: 378.9984.
The open-field test was carried out in mice according to
the method of Archer with slight modifications (20,21).
Each mouse was placed individually in the center of the
open-field apparatus, and the locomotor activity was
assessed. The open-field apparatus was a non-transpar-
ent plastic container (80 9 60 9 30 cm), with the under-
side divided into 48 units of size 10 9 10 cm, without
walls. The animals were gently placed in the center of the
platform and were allowed to explore their surroundings.
Hand-operated counters were used to score locomotion
(ambulation, numbers of crossing lines with all four paws)
and rearing frequencies (number of times an animal stood
on its hind legs) for 3 min. The researchers, who did not
know which groups had been treated, scored the behav-
iors in the open field. The experiments were performed in
a dark room, and the apparatus was illuminated by a 60-
W bulb giving a yellowish light, positioned 1 m above the
center of the apparatus.
3-(4-nitrophenylimino)indolin-2-one (3r)
Yield 45.5%; m.p. 231.1–236.4 °C; IR (KBr) cmÀ1: 3342,
1731, 1648, 1251; 1H-NMR (CDCl3, 300 MHz): d 10.82
(1H, s, -NH), 7.50–8.11 (4H, m, -C6H4), 6.91–7.07(4H, m,
-C6H4); 13C-NMR (CDCl3, 75 MHz): d 165.39, 159.50,
156.84, 150.44, 145.21, 143.28, 137.37, 131.11, 129.79,
127.86, 122.63, 121.97, 117.42, 110.14; ESI-HRMS calcd
for C14H9N3O +([M + H]+): 268.0644; found: 268.0632.
3
Pharmacology
The sample preparation
The forced swimming test
The dose of 50 mg/kg compound 3r and fluoxetine was
employed for testing the effect on monoamine neurotrans-
mitter concentrations in the rats’ brain. A normal vehicle
group without any stress was added as a control group for
normal condition comparison. The vehicle group in animal
test was marked as stress + vehicle group. When the
Male Balb/e mice (20 Æ 2 g) were used in the The forced
swimming test (FST) under standard conditions with free
access to food and water. They were housed in groups of
six. On the test day, mice were dropped one at a time into
a plexiglass cylinder (height 25 cm, diameter 10 cm) con-
Chem Biol Drug Des 2016; 87: 342–351
345

Ma et al.
activity tests were completed, mice were killed by decapita-
tion, and the brains were rapidly removed and dissected on
an ice-cold plate and stored at À80 °C until assay. The
brain tissues were weighted and homogenized by ultrasoni-
cation in ice-cold 0.02 M perchloric acid. An internal stan-
dard (DHBA) at a concentration of 1.0 lm was also
included. The homogenates were centrifuged at 13000 9 g
for 15 min at 4 °C, and the supernatant was separated and
filtered through a membrane filter pore size 0.45 lm.
an accelerating rotarod of diameter 3.2 cm that rotates at
10 rpm. Trained animals were given an intraperitoneal
injection of the test compounds. Neurotoxicity was indi-
cated by the inability of the animal to maintain equilibrium
on the rod for at least 1 min in each of the trials (24).
Statistical analysis
Results are expressed as mean Æ SEM. n represents the
number of animals. Data obtained from pharmacological
experiments were analyzed with the Turkey’s multiple
comparison tests, using GRAPHPAD PRISM program (Graph-
Pad Software, Inc., San Diego, CA, USA). A p-value of
< 0.05 was considered statistically significant.
HPLC condition and test
The brain tissues were sonicated in 0.1 M NaH2PO4 aque-
ous solution including 0.85 mM OSA, 0.5 mM EDTAÁNa2
and centrifuged (14 000 rpm, 30 min). Then, 5-HT, NE,
DA, 5-HIAA, and DHBA were assayed by HPLC-ECD. The
HPLC system consisted of a microbore reverse-phase col-
umn (Shimadzu LC-10ATVP HPLC system, Tokyo, Japan,
Shimadzu L-ECD-6A electrochemical detector, N2000
HPLC workstation software, Hypersil ODS C18 Column
4.6 9 150 mm 5 lm). The mobile phase consisted of
0.1 M NaH2PO4 aqueous solution including 0.85 mM OSA,
0.5 mM EDTAÁNa2, and 11% methanol adjusted to pH 3.4
with phosphate acid and filtered through 0.45-lm pore
size filter. External standard curves were used to quantify
the amounts of 5-HT, 5-HIAA, NE, and DA in each sample
calculated by area under curve (AUC). The volume of
injection was 20 lL. The detection limit of the assay was
20 pg/g sample. The filtrate sample was used for quantifi-
cation of 5-HT, NE, DA, and 5-HIAA by HPLC coupled
with electrochemical detection in brain region.
Results and Discussion
Chemistry
The target compounds were synthesized according to the
route depicted in Scheme 1. Briefly, the starting material
amine reacted with chloral hydrate and sodium sulfate to
yield the intermediate 1. Then, compound 1 was stirred
with concentrated sulfuric acid to give compound
2
according to methods previously described in the literature
(15,16). 3-phenyliminoindolin-2-one derivatives (3a–3r)
were obtained by a nucleophilic addition–elimination reac-
tion of substituted aniline with compound 2. The chemical
structures of these compounds were characterized by IR,
1H NMR, and 13C NMR, and mass spectroscopy. The IR
spectra of the compounds afforded NH stretching (3340–
3346 cmÀ1
)
bands and C=O stretching (1731–
1746 cmÀ1). In the 1H-NMR spectra of the compounds,
N-H protons of indoline ring were observed at 10.65–
10.89 ppm generally as broad bands, and 13C-NMR
spectra of the compounds C=O were seen at 161.72–
169.27 ppm.
sc-PTZ-induced seizures
At 30 min after the administration of the test compound,
85 mg/kg PTZ dissolved in saline was administered sc.
The animals (five mice in one group) placed in individual
cages and observed for 1 h. The number of clonic and
tonic seizures as well as the number of deaths was noted
(22,23).
Biological evaluation
Both the FST and TST are the accepted stress models of
depression, which induce a state of despair in animals
and have good reliability and predictive validity in mice
(25,26). In the two models, mice are restricted and cannot
escape, inducing a characteristic behavior of immobility.
Neurotoxicity screening
The neurotoxicity of the compounds was measured in
mice by the rotarod test. The mice were trained to stay on
Scheme 1: The synthesis route of compounds 3a–3r.
346
Chem Biol Drug Des 2016; 87: 342–351

3-Phenyliminoindolin-2-one Derivatives
Immobility displayed in both of these behavioral despair
models has been hypothesized to reflect behavioral des-
pair which in turn may reflect depressive disorders in
human. There was a significant correlation between clinical
potency and the potency of antidepressants in both mod-
els. Thus, two models are usually used to screen or evalu-
ate antidepressant activity (27). In the FST or TST model,
total immobility time is reduced by the majority of antide-
pressants when administered acutely or subchronically to
animals.
% DID values of 90.91% than that of FLU (% DID = 73.15)
and appeared to be provide higher levels of antidepressant
activity compared with FLU (as duration of immobility(s):
3r = 12.8 Æ 6.4, FLU = 37.8 Æ 13.1).
Compounds 3o, 3p, and 3r were found to the most
potent antidepressant activity in the FST and were further
evaluated to effectively confirm its antidepressant activity in
Table 1: Evaluation of the antidepressant-like activity of
compounds 3a–3r in the FST
The FST is the most widely used model to screen new
antidepressant drugs, and a wide variety of antidepres-
sants and compounds with potential antidepressant-like
activity reduce the duration of immobility in the FST (28). In
the FST, the antidepressant activity of the tested com-
pounds 3a–3r and the reference drug FLU through
injected intraperitoneally (i.p.) is shown in Figure 3. The
results showed that 13 compounds (3a, 3b, 3d, 3f, 3g,
3j–3l, and 3n–3r) produced a marked reduction in immo-
bility times at a dose of 50 mg/kg, indicating a significant
antidepressant-like activities. Among them, compounds
3o, 3p, and 3r in particular led to significant reductions in
the duration of the immobility time compared with the con-
trol group with p < 0.001, and exhibited good antidepres-
sant activity, similar to or better than the positive control
FLU (p < 0.001). Compound 3r led to the strongest reduc-
tion in the duration of the immobility time compared with
the control group (p < 0.001). For a more detailed under-
standing of the antidepressant activities of 3a–3r and FLU,
the percentage decrease in the immobility duration (%
DID) was calculated using the formula %DID = [(Y-X)/
Y] 9 100, where Y is the duration of immobility (s) in the
control group and X is the duration of immobility (s) in the
test group. As shown in Table 1, compounds 3a, 3b, 3d,
3f, 3g, 3j–3l, and 3n–3r examined reduced the duration
of immobility and gave high % DID values. Among these,
the % DID for compounds 3o (% DID = 71.02) and 3p (%
DID = 75.99) was similar to that for FLU at 50 mg/kg dose
levels in the FST. However, compound 3r exhibited higher
Antidepressant activitya
Compounds
R
Duration of immobility(s)
DID (%)b
3a
-H
98.2 Æ 10.4*
96.5 Æ 14.7*
112.5 Æ 14.1
61.8 Æ 5.5**
134.3 Æ 16.6
72.0 Æ 12.7**
80.7 Æ 12.8**
105.0 Æ 15.7
128.8 Æ 14.3
43.7 Æ 12.5***
94.3 Æ 23.3*
75.8 Æ 13.5**
138.5 Æ 18.4
91.8 Æ 18.6*
40.8 Æ 13.6***
33.8 Æ 9.6***
90.3 Æ 13.9*
12.8 Æ 6.4***
37.8 Æ 13.1***
140.8 Æ 28.5
30.26
31.46
20.09
56.12
4.62
48.86
28.34
25.43
8.52
68.96
33.03
46.16
1.63
34.80
71.02
75.99
35.87
90.91
73.15
–
3b
3c
2-CH3
4-CH3
2-OCH3
4-OCH3
2-F
3-F
4-F
2-Cl
3-Cl
3d
3e
3f
3g
3h
3i
3j
3k
4-Cl
3l
2-Br
3-Br
4-Br
4-CF3
2,4-Cl2
2,4-Br2
4-NO2
–
3m
3n
3o
3p
3q
3r
FLU
Control
–
Values are the mean Æ SEM (n = 8).
*Significantly different compared with control (*p < 0.05,
**p < 0.01, ***p < 0.001).
aCompounds and FLU were administered intraperitoneally at
50 mg/kg.
b%DID: percentage decrease in immobility duration.
Figure 3: Effects of 3a–3r and the positive
control fluoxetine (FLU) on immobility time in
the forced swim test in mice. Data are
expressed as the mean Æ SEM (n = 8).
*p < 0.05, **p < 0.01, and ***p < 0.001
compared with vehicle control.
Chem Biol Drug Des 2016; 87: 342–351
347

Ma et al.
the TST. The results are shown in Figure 4. The decrease
in immobility time in the TST showed similarity to that seen
in the FST, and compounds 3o, 3p, and 3r exhibited a
significant decrease in immobility duration at a dose of
50 mg/kg, similar to or than good the positive control FLU
changes in the immobility were associated with changes in
the motor activity, compound 3r on spontaneous locomo-
tor activity was evaluated in the open-field test. This study
demonstrated that compound 3r did not significantly
change the motor activity (crossing, rearing, or grooming)
in mice (Figure 5). This result indicates that the antidepres-
sant-like effects induced by compound 3r in the FST and
TST were not caused by CNS-stimulating effects.
(as
duration
of
immobility(s):
3o = 45.7 Æ 10.2,
3p = 37.5 Æ 9.8, 3r = 17.6 Æ 7.8, FLU = 38.4 Æ 8.1),
indicating a significant antidepressant-like effect.
In the present study, consideration of the biological activi-
ties of the synthesized compounds revealed the following
structure activity relationships. For four electron-donor
groups with the introduction of -CH3 and -OCH3 on the
phenyl ring (3b–3e), two compounds (3b, 3e) showed the
potent antidepressant effects in the FST. For compounds
3f–3q, a halogen atom was substituted on the phenyl ring,
which the variations in activity were observed. The intro-
duction of F atoms (3f, 3g, 3o), Cl atoms (3j, 3k, and 3p),
or Br atoms (3l, 3n, and 3q) significantly reduced immobil-
ity time in the FST and displayed the antidepressant-like
activity. In addition, the position of the halogen atom sub-
stituted greatly influenced the antidepressant activity.
Compared with compounds with different F-substituted
positions on the phenyl ring, the order of activity was 4-
CF3>2-F > 3-F > 4-F, and the order of activity observed
for Cl-substituted positions was 2,4-Cl2>3-Cl>4-Cl>2-Cl.
The order of activity for with different Br-substituted posi-
tions was 2-Br>2,4-Br2>4-Br>3-Br.
The monoamine hypothesis supposed that depression
was a result of the depletion of 5-HT, NE, and DA in addi-
tion to activation of monoamine oxidase in the CNS. A
metabolic disorder of monoamine neurotransmitters is
believed to be the main biochemical cause of depression
in the CNS. Depression can be alleviated by increasing the
levels of monoamine neurotransmitters in the CNS (29–
32). Compound 3r significantly increased 5-HT and NE
levels in mouse brain in the FST, similar to the positive
control drug FLU. However, no significant change in brain
DA level was observed. Compared with the stress vehicle
group, compound 3r administration significantly increased
5-HT and NE levels as well as 5-HIAA levels, which likely
indicates that the rate of 5-HT metabolism was reduced.
Interestingly, we also found that the stress of the FST pro-
cedure alone reduced brain 5-HT, NA, and 5-HIAA levels
without altering DA levels. These findings suggest that the
action of compound 3r is likely mediated through an
increase in CNS 5-HT and NE (Table 2).
Some compounds that change the motor activity may be
give the false-positive/negative effects in the FST and TST,
in particular psychomotor stimulants and drugs enhancing
motor activity, which decrease immobility time by stimulat-
ing locomotor activity. To determine whether the observed
The anticonvulsant activities of compounds 3a–3r were
evaluated using the chemical-induced seizure PTZ test
and administrated intraperitoneally (i.p.) at a dose of
100 mg/kg, and the observations were taken at time inter-
vals of 1.0 h. The results are shown in Table 3. All of com-
pounds did not inhibit the clonic seizures induced by sc-
PTZ, but 15 compounds (3a, 3c, 3e–3h, and 3j–3r) inhib-
ited the tonic seizures and reduced lethality in significant
degrees. Among them, compounds 3m and 3n inhibited
Figure 4: Effect of 3o, 3p, and 3r on immobility time in the TST
in mice. Data are expressed as the mean Æ SEM (n = 8). Symbol
(***) indicates statistically in comparison with vehicle at
p < 0.001.
Figure 5: Exploratory activity (counts) compound 3r in the open-
field test. Locomotion: number of line crossings; rearing: number
of times seen standing on hind legs; grooming: number of
modifications. The values represent the mean Æ SEM (n = 8).
348
Chem Biol Drug Des 2016; 87: 342–351

3-Phenyliminoindolin-2-one Derivatives
Table 2: Effects of 3r and FLU on brain
monoamine neurotransmitter levels in
stressed and normal mice
Group
5-HT
5-HIAA
NE
DA
Normal vehicle 629.3 Æ 28.6
Stress vehicle 422.3 Æ 50.6
397.4 Æ 27.6
183.9 Æ 20.4+
707.3 Æ 62.3
266.4 Æ 50.4
690.7 Æ 58.3
423.1 Æ 52.3
++
3r
658.4 Æ 47.8**
339.5 Æ 22.2**,+ 697.5 Æ 45.6***,+ 432.3 Æ 55.2
309.1 Æ 21.6**,+ 705.1 Æ 49.5***,+ 451.2 Æ 57.1
FLU
601.6 Æ 45.1**
Normal vehicle 726.3 Æ 44.8
347.4 Æ 29.1
353.3 Æ 27.3
343.5 Æ 27.7
636.5 Æ 48.9
640.4 Æ 41.6
634.4 Æ 56.7
609.3 Æ 40.7
618.6 Æ 49.9
626.3 Æ 53.1
3r
678.6 Æ 54.7
687.2 Æ 49.7
FLU
The dose of 3r was 50 mg/kg and FLU was 10 mg/kg. Neurotransmitter concentrations
were expressed as ng/g per brain region wet weight. Data expressed as mean Æ SEM
(n = 10). Statistical analysis of data was carried out by one-way analysis of variance
followed by the Turkey’s test.
**p < 0.01, ***p < 0.001 when compared to the stressed animals, +p < 0.05,
++p < 0.01 when compared to the normal animals.
Table 3: Primary evaluation of compounds
3a–3r in anticonvulsant activity
PTZa
Neurotoxicityb
Clonic
Tonic
Compounds
R
Seizures
Seizures
Lethality
0.5 h
4 h
3a
3b
-H
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
5/5
3/5
5/5
1/5
5/5
4/5
3/5
3/5
4/5
5/5
4/5
3/5
4/5
0/5
0/5
3/5
3/5
4/5
4/5
0/5
5/5
4/5
5/5
1/5
5/5
3/5
4/5
3/5
4/5
5/5
3/5
1/5
4/5
0/5
0/5
4/5
2/5
3/5
2/5
0/5
5/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
–
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/5
–
2-CH3
4-CH3
2-OCH3
4-OCH3
2-F
3-F
4-F
2-Cl
3-Cl
3c
3d
3e
3f
3g
3h
3i
3j
3k
4-Cl
3l
3m
2-Br
3-Br
4-Br
4-CF3
2,4-Cl2
2,4-Br2
4-NO2
–
3n
3o
3p
3q
3r
Carbamazepine
Control
–
a100 mg/kg of doses was administered (i.p.).
bA dash indicates an absence of activity or toxicity at maximum dose administered
(300 mg/kg).
the tonic seizures and death induced at the rate of 100%
and 100%, respectively. PTZ has been reported to pro-
duce seizures by inhibiting gamma-aminobutyric acid
(GABA) neurotransmission (33,34). GABA is the main inhi-
bitory neurotransmitter substance in the brain and is widely
implicated in epilepsy. Inhibition of GABAergic neurotrans-
mission or activity has been shown to promote and facili-
tate seizures, while enhancement of GABAergic
neurotransmission is known to inhibit or attenuate sei-
zures. The findings of the present study tend to suggest
that the test compounds might have inhibited or attenu-
ated PTZ-induced seizures in mice by enhancing GABAer-
gic neurotransmission. The rotarod toxicity test results
indicated that all compounds did not show neurotoxic
effects for doses up to and including 300 mg/kg.
Conclusion
In the present study, a series of 3-phenyliminoindolin-2-
one derivatives (3a–3r) were synthesized and evaluated for
their antidepressant and anticonvulsant activities. Com-
pounds 3o, 3p, and 3r induced significant antidepressant-
like effects in the FST and TST. This action of compound
3r is likely mediated by an increase in CNS 5-HT and NE,
although other neurochemical systems may also be
Chem Biol Drug Des 2016; 87: 342–351
349

Ma et al.
involved. A total of 15 compounds showed some degree
of against PTZ-induced seizure. These compounds could
potentially be used as adjuncts of the antidepressants to
treat depression in patients with epilepsy.
12. Pakravan P., Kashanian S., Khodaei M.M., Harding
F.J. (2013) Biochemical and pharmacological charac-
terization of isatin and its derivatives: from structure to
activity. Pharmacolo Rep;65:313–335.
13. Strydom B., Bergh J.J., Petzer J.P. (2013) Inhibition of
monoamine oxidase by phthalide analogues. Bioorg
Med Chem Lett;235:1269–1273.
Acknowledgments
14. Phogat P., Singh P. (2015) A mini review on central
nervous system potential of isatin derivatives. Cent
Nerv Syst Agents Med Chem;15:28–31.
15. Xie C., Tang L.M., Pan C., Guan L.P. (2013) Synthesis
and anticonvulsant and antidepressant activity of some
2-(6-bromo-2,3-dioxoindolin)-N-substituted phenylac-
etamide derivatives. Drug Res;63:607–613.
This work was supported by the National Spark Plan Pro-
ject of China (No. 2013GA700255) and the Natural
Science Foundation of Zhejiang Province of China (No.
LY14C190001).
References
16. Xie C., Tang L.M., Li F.N., Guan L.P., Pan C.Y., Wang
S.H. (2014) Structure-based design, synthesis, and
anticonvulsant activity of isatin-1-N-phenylacetamide
derivatives. Med Chem Res;23:2161–2168.
17. Porsolt R.D., Bertin A., Jalfre M. (1997) Behavioural
despair in mice: a primary screening test for antide-
pressants. Arch Int Pharmacodyn;229:327–336.
18. Steru L., Chermat R., Thierry B., Simon P. (1985) The
tail suspension test: a new method for screening
1. McNamara J.O. (2011) Pharmacotherapy of the epilep-
sies. In: Brunton L.L., Chabner B.A., Knollmann B.C.,
editors. Goodman & Gilman’s the Pharmacological
Basis of Therapeutics, 12th edn. New York: McGraw-
Hill; p. 583–608.
€
€
2. Schroder J., Bruckner K., Fischer A., Lindenau M.,
€
Kother U., Vettorazzi E., Moritz S. (2014) Efficacy of a
psychological online intervention for depression in peo-
ple with epilepsy: a randomized controlled trial. Epilep-
sia;55:2069–2076.
3. Kanner A.M. (2014) Is depression associated with an
increased risk of treatment-resistant epilepsy?
Research strategies to investigate this question.
Epilepsy Behav;38:3–7.
antidepressants
ogy;85:367–370.
in
mice.
Psychopharmacol-
19. Rane R.A., Napahde S., Bangalore P.K., Sahu N.U.,
Shah N., Kulkarni Y.A., Barve K., Lokare L., Karpoor-
math R. (2014) Synthesis and evaluation of novel mar-
ine bromopyrrole alkaloid-based derivatives as
potential antidepressant agents. Chem Biol Drug
Des;84:593–602.
4. Fiest K.M., Patten S.B., Altura K.C., Bulloch A.G., Max-
ꢀ
well C.J., Wiebe S., Macrodimitris S., Jette N. (2014)
20. Archer J. (1973) Tests for emotionality in rats and
mice: a review. Anim Behav;21:205–235.
21. Elliott P.J., Chan J., Parker Y.M. (1986) Behavioral
effects of neurotensin in the open field: structure-activ-
ity studies. Brain Res;381:259–265.
Patterns and frequency of the treatment of depression
in persons with epilepsy. Epilepsy Behav;39:59–64.
5. Fiest K.M., Patten S.B., Wiebe S., Bulloch A.G., Max-
ꢀ
well C.J., Jette N. (2014) Validating screening tools for
depression in epilepsy. Epilepsia;55:1642–1650.
6. Kanner A.M. (2005) Depression in epilepsy: a neurobio-
logic perspective. Epilepsy Curr;5:21–27.
7. Deng X.Q., Song M.X., Zheng Y., Quan Z.S. (2014) De-
sign, synthesis and evaluation of the antidepressant
and anticonvulsant activities of triazole-containing
quinolinones. Eur J Med Chem;73:217–224.
8. Siddiqui N., Alam M.S., Stables J.P. (2011) Synthesis
and anticonvulsant properties of 1-(amino-N- aryl-
methanethio)-3-(1-substitutedbenzyl-2,3-dioxoindolin-5-
yl)urea derivatives. Eur J Med Chem;46:2236–2242.
9. Praveen C., Ayyanar A., Perumal P.T. (2011) Practical
synthesis, anticonvulsant, and antimicrobial activity of
N-allyl and N-propargyl di(indolyl)indolin-2-ones. Bioorg
Med Chem Lett;21:4072–4077.
10. Sridhar S.K., Pandeya S.N., Stables J.P., Ramesh A.
(2002) Anticonvulsant activity of hydrazones, Schiff and
Mannich bases of isatin derivatives. Eur J Pharm
Sci;16:129–132.
22. Porter R.J., Cereghino J.J., Gladding G.D., Hessie
B.J., Kupferberg H.J., Scoville B., White B.G. (1984)
Antiepileptic drug development program. Cleve Clin
Q;51:293–305.
23. Zhang L., Guan L.P., Sun X.Y., Wei C.X., Chai K.Y.,
Quan Z.S. (2009) Synthesis and anticonvulsant activity
of 6-alkoxy-[1,2,4]triazolo[3,4-a]phthalazines. Chem
Biol Drug Des;73:313–319.
24. Chen J., Sun X.Y., Chai K.Y., Lee J.S., Song M.S.,
Quan Z.S. (2007) Synthesis and anticonvulsant evalua-
tion of 4-(4-alkoxylphenyl)-3-ethyl-4H-1,2,4-triazoles as
open-chain analogues of 7-alkoxyl- 4,5-dihydro[1,2,4]-
triazolo[4,3-a]quinolines. Bioorg Med Chem;15:6775–
6781.
25. Borsini F., Voltera G., Meli A. (1986) A dose the behav-
ioral ‘despair’ test measure ‘despair’. Physiol
Behav;38:385–389.
26. de Oliveira K.N., Costa P., Santin J.R., Mazzambani
€
L., Burger C., Mora C., Nunes R.J., de Souza M.M.
11. Pal M., Sharma N.K., Priyanka P., Jha K.K. (2011)
Synthetic and biological multiplicity of isatin: a review.
J Adv Sci Res;2:35–44.
(2011) Synthesis and antidepressant-like activity evalu-
ation of sulphonamides and sulphonyl- hydrazones.
Bioorg Med Chem;19:4295–4306.
350
Chem Biol Drug Des 2016; 87: 342–351

3-Phenyliminoindolin-2-one Derivatives
ꢀ
27. Rogoz Z. (2009) Potentiation of the antidepressant-like
31. Mahesh R., Dhar A.K., Jindal A., Bhatt S. (2014) De-
sign, synthesis and evaluation of antidepressant activity
of novel 2-methoxy 1, 8 naphthyridine 3-carboxamides
as 5-HT3 receptor antagonists. Chem Biol Drug
Des;83:583–591.
32. Tao G., Irie Y., Li D.J., Keung W.M. (2005) Eugenol
and its structural analogs inhibit monoamine oxidase A
and exhibit antidepressant-like activity. Bioorg Med
Chem;13:4777–4788.
effect of desipramine or reboxetine by metyrapone in
the forced swimming test in rats. Pharmacol
Rep;61:1173–1178.
28. Yu H.L., Deng X.Q., Li Y.J., Li Y.C., Quan Z.S., Sun
X.Y. (2011) N-palmitoylethanolamide, an endocannabi-
noid, exhibits antidepressant effects in the forced swim
test and the tail suspension test in mice. Pharmacolo
Rep;63:834–839.
29. Dhanda S., Sandhir R. (2015) Role of dopaminergic
and serotonergic neurotransmitters in behavioral alter-
ations observed in rodent model of hepatic
encephalopathy. Behav Brain Res;286:222–235.
30. Waszkielewicz A.M., Pytka K., Rapacz A., Wełna E.,
33. Abbasi E., Nassiri-Asl M., Shafeei M., Sheikhi M.
(2012) Neuroprotective effects of vitexin, a flavonoid,
on pentylenetetrazole-induced seizure in rats. Chem
Biol Drug Des;80:274–278.
34. Zhong M., Zhang Y., He X. (2014) Synthesis and anti-
convulsant activity of ethyl 2,2-dimethyl-1-(2- substitut-
_
Jarzyna M., Satała G., Bojarski A., Sapa J., Zmudzki
P., Filipek B., Marona H. (2015) Synthesis and evalua-
tion of antidepressant-like activity of some 4-substi-
tuted 1-(2-methoxyphenyl)piperazine derivatives. Chem
Biol Drug Des;85:326–335.
edhydrazinecarboxamido)
derivatives. Chem Biol Drug Des;84:234–241.
cyclopropanecarboxylate
Chem Biol Drug Des 2016; 87: 342–351
351