Synthesis, characterization, antidepressant and antioxidant activity of novel piperamides bearing piperidine and piperazine analogues

Article abstract of DOI:10.1016/j.bmcl.2012.09.089

A series of piperamide derivatives (8a-j) was synthesized with various substituted piperidine and piperazine compounds. The prepared compounds were evaluated for antibacterial activity against gram-positive and gram-negative bacteria and antifungal activity by disc diffusion method. The antioxidant activity of the compounds was evaluated by DPPH and superoxide radical scavenging method and antidepressant activity using forced swim and tail suspension behavioral despair tests in mice. The compounds 8a, 8b and 8c were investigated for their monoamine oxidase A and B (MAO-A and MAO-B) inhibitory property. Some of the test compounds were active in forced swim test (FST) and tail suspension test (TST). Compounds 8a and 8b showed a significant effect, when compared to standard drug, clorgyline.

Full text of DOI:10.1016/j.bmcl.2012.09.089

Bioorganic & Medicinal Chemistry Letters 22 (2012) 7065–7070
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis, characterization, antidepressant and antioxidant activity of novel
piperamides bearing piperidine and piperazine analogues
M. K. Prashanth a, Hosakere D. Revanasiddappa a, , K. M. Lokanatha Rai a, B. Veeresh b
⇑
a Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India
b Department of Pharmacology, G. Pulla Reddy College of Pharmacy, Mehdipatnam, Hyderabad 580 028, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 31 July 2012
Revised 22 September 2012
Accepted 25 September 2012
Available online 2 October 2012
A series of piperamide derivatives (8a–j) was synthesized with various substituted piperidine and piper-
azine compounds. The prepared compounds were evaluated for antibacterial activity against gram-
positive and gram-negative bacteria and antifungal activity by disc diffusion method. The antioxidant
activity of the compounds was evaluated by DPPH and superoxide radical scavenging method and antide-
pressant activity using forced swim and tail suspension behavioral despair tests in mice. The compounds
8a, 8b and 8c were investigated for their monoamine oxidase A and B (MAO-A and MAO-B) inhibitory
property. Some of the test compounds were active in forced swim test (FST) and tail suspension test
(TST). Compounds 8a and 8b showed a significant effect, when compared to standard drug, clorgyline.
Ó 2012 Elsevier Ltd. All rights reserved.
Keywords:
Piperamides
Antidepressant
Antioxidant
MAO-A
MAO-B
Depression is a common psychiatric disorder, often refractive to
drug treatment, affecting quality of life and overall productivity.1 It
is characterized by anhedonia or the loss of interest or pleasure in
normal daily activities and feelings of sadness.2 Tricyclics, mono-
amine oxidase (MAO) inhibitors, selective serotonin re-uptake
inhibitors, selective noradrenaline re-uptake inhibitors, serotonin
modulators and norepinephrine serotonin modulators are the ma-
jor antidepressant drugs which are used for the treatment of
depressive disorders.3 Although several classes of antidepressants
are currently being used due to clinical limitations and adverse ef-
fects. In addition, significant proportion of these patients will not
be responding to treatment, or will show only partial response.
Thus, there is a need for development of efficient and safer drugs,
in order to limit the impact of depression on patient’s lives.4,5
In recent years, there has been an increased interest in the
application of antioxidants to medical treatment as information
is constantly gathered linking the development of human diseases
to oxidative stress. Recent evidence6 suggests that free radicals,
which are generated in many bioorganic redox processes, may oxi-
dize nucleic acids, proteins, lipids or DNA and can initiate degener-
ative disease, including cancer, arthritis, hemorrhagic shock,
autoimmune, inflammatory, cardiovascular, neurodegenerative
diseases and age-related degenerative brain diseases.7 Owing to
these facts, synthetic and natural compounds with potential
antioxidant activity are receiving increased attention in biological
research, medicine and pharmacy.8
Natural products are always special sources for the discovery of
potential drugs with novel structures and varying biological activ-
ity. The species of the Piper genus family have shown a great diver-
sity of secondary metabolites, Piperine is a major ingredient of
piper species, which have been reported to possess antipyretic,
analgesic, insecticidal, anti-inflammatory,9,10 immune-modulatory,
antitumor11 and antidepressant activities.12 Antiepilepsirine one
derivative of piperine, has been used clinically as an effective anti-
convulsant, exhibiting a more potent effect than piperine. Some
piperamides were reported as potential antidepressant and anti-
trypanosomal agents. Some researchers have reported MAO inhib-
itory activity for various piperamide derivatives.13,14
The natural product 1-[1-oxo-3(3,4-methylenedioxy-5-meth-
oxyphenyl)-2Z-propenyl] piperidine, isolated from the roots of
the Piper nigrum,15 by the reports to our knowledge, no data are
available about the synthetic and biological studies. The main
aim of this work was to synthesize the trans-isomer of this com-
pound and its analogues, and to evaluate the antimicrobial, antiox-
idant and antidepressant activity of synthesized compounds. A
recent paper reported that Z-configuration is critical for the biolog-
ical activity,16 therefore, in this study we have design the synthesis
of trans-isomer of this compound and its analogues, and to inves-
tigate various biological activities.
In view of the above findings it was considered of interest to
undertake the synthesis of piperamide derivatives, hoping that
these compounds might possess certain antimicrobial, antioxidant
⇑
Corresponding author. Tel.: +91 821 2419669; fax: +91 821 2419363.
E-mail address: hdrevanasiddappa@yahoo.com (H.D. Revanasiddappa).
0960-894X/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmcl.2012.09.089

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M. K. Prashanth et al. / Bioorg. Med. Chem. Lett. 22 (2012) 7065–7070
and antidepressant activity. The structures of the synthesized com-
pounds were deduced on the basis of 1H NMR, IR and mass spectra.
The composition of all the compounds was obtained by elemental
analysis. The proton magnetic resonance spectra of synthesized
compounds have been recorded in CDCl3. In addition, the chemical
shift and multiplicity patterns correlated well with the proposed
structures.
NMR spectra of the product 7, thus confirming the presence of
methoxy group.
The resulting compound 7 was coupling with different piperi-
dine and piperazine derivatives, in THF in presence of diehtylalu-
minium chloride,19 afforded the corresponding piperamides 8a–j.
TLC was run throughout the reaction to optimize the reaction for
purity and completion. Compounds 8a–j gave correct values in ele-
mental analysis. The IR spectrum of compound 8f shows the
absorption band at 3326 cmÀ1 is attributed to N–H stretching of
the piperazine ring and the compound 8b shows the characteristic
band at 3654 cmÀ1 due to the hydroxyl (OH) group. The IR spectra
of 8a–j shows the characteristic bands in the region of 1704–
1690 cmÀ1 and 1038–1030 cmÀ1 which indicates the presence of
carbonyl and methoxy groups, respectively.
A series of new piperamide derivatives (Scheme 1) was synthe-
sized with the readily available piperonal 1, which was treated
with malonic acid 2 in pyridine, and followed by acidification with
dilute hydrochloric acid giving carboxylic acid 3.17 This material
was subjected to esterification using sulphuric acid in ethanol to
afford the product 4. The IR spectra showed mainly absorption
bands at 1745 and 960 cmÀ1 assigned to
mC@O and dCH@CH func-
tionalities, respectively. The 1H NMR spectrum showed a triplet
signal at d 1.42 and quartet signal at d 4.10 which supported the
presence of ethyl group. In the 1H NMR spectrum, the presence
of methylenedioxy moiety was indicated by signal at d 5.96.
Subsequent nitration of 4 with nitrating mixture led to com-
pound 5 and followed by reduction of the nitro moiety of the
resulting 5 using SnCl2/EtOH18 yields the compound 6. The IR spec-
trum of compound 5 shows the characteristic band at 1526 cmÀ1
due to the nitro group. IR spectrum of compound 6 revealed the
presence of amine group at 3120 cmÀ1 and its 1H NMR spectrum
showed signal at d 6.37 singlet for amine group.
The amine group of 6 was converted to methoxy moiety in 7 by
diazotization in the presence of sodium nitrite at 0 °C, and subse-
quent addition of methanol at reflux. Compound 7 gave correct val-
ues in elemental analysis. A comparative study of spectral data on
compounds 6 and 7, revealed that the absence of a signal for amine
(at d 6.37, s, 2H) and appeared a signal at d 3.64 (s, 3H) in the 1H
The 1H NMR spectrum of each compound in the series 8a–j
showed singlet at d 3.62–3.96 which revealed the presence of
methoxy group and singlet at d 5.97–6.01 due to methylenedioxy
group. The two doublets centered at d 6.89–7.07 and 6.84–7.04,
which could be accounted for a trans double bond conjugated to
the carbonyl group. The 1H NMR spectrum of compound 8a
showed the characteristic signals for a piperidine ring at d 3.40–
3.58 (m, 4H, N–(CH2)2) and 1.66–1.89 (m, 6H, N–C–(CH2)3), to-
gether with the singlet at d 5.94 and 3.84, due to the presence of
methylenedioxy and methoxy group, respectively. The aromatic
doublets at d 7.08 and 7.03, indicating the presence of a 1,3,4,5-tet-
rasubstituted benzene ring. The signal due to OH in compound 8b
appeared as singlet at d 4.30.20 The mass spectra of compounds are
in agreement with their assigned structures. All the spectra exhibit
parent peaks due to molecular ions (M+). The mass spectrum of 8h
showed molecular ion peak M+ 397, which corresponding to the
molecular formula.
O
O
O
O
O
O
i
OH
ii
O
HO
OH
iii
O
2
3
1
O
O
O
O
O
O
OC2H5
iv
OC2H5
O
NO2
4
5
O
O
O
OC2H5
O
O
v
OC2H5
vi
NH2
OCH3
6
7
O
g, R =
N
N
N
O
H3C
CH3
H3CO
O
d, R =
N
R
a, R =
b, R =
N
N
h, R =
i, R =
H3C
O
OH
OH
OCH3
e, R =
N
CH3
N
8a-j
c, R =
N
f, R =
N
NH
j, R =
N
N
Scheme 1. The reaction sequence for the synthesis of novel piperamide derivatives (8a–j). Reagents and conditions: (i) pyridine, piperidine, 24 h; (ii) Conc H2SO4, EtOH, 4 h;
(iii) nitrating mixture, 5–10 °C; (iv) SnCl2, EtOH, NaHCO3, 2 h; (v) NaNO2, HCl, 30–60 min, MeOH, reflux, 2 h; (vi) dimethylalluminium chloride, THF, 0 °C.

M. K. Prashanth et al. / Bioorg. Med. Chem. Lett. 22 (2012) 7065–7070
7067
In this work, novel series of piperamide compounds were syn-
thesized. Synthetic Scheme 1 illustrates the way used for the syn-
thesis of target compounds. All the synthesized compounds were
screened for their anti-bacterial activity against Staphylococcus
aureus, Bacillus subtilus, Escherichia coli and Pseudomonas aerugin-
osa and anti-fungal activity against Aspergillus flavus and Candida
albicans. The antimicrobial activity of each compound was carried
out by agar disc diffusion method21 and the minimum inhibitory
concentration was determined by dilution method.22 The results
are presented in Table 1.
Most of the synthesized compounds showed good antibacterial
activity. Among them, compounds 8g and 8j exhibited the most
potent antibacterial activity against S. aureus and B. subtilis. Anti-
bacterial data of compounds 8a–j against B. subtilis reveals that
compound 8g exhibits the most potent antibacterial activity. Its
ring, in the compounds 8a–j showed the antibacterial as well as
antifungal activities. Further, the presence of electron withdrawing
group, –COCH3 in compound 8g enhances the antibacterial activity
to a greater extent.
In short, we made an attempt to enhance the biological activity
by increasing the volume of the substituents attached to the piper-
azine ring system led to different biological potency, depending on
the nature, position and number of the atoms or groups intro-
duced, whereas, high potency has been observed in the final scaf-
folds due to the presence of piperazine systems with acetyl group.
This has thrown open a new era for exploring suitably designed,
new scaffold in molecules as potential antifungal/antibacterial
drugs.
The capacity to scavenge the stable free radical 2,2-diphenyl-1-
picrylhydrazyl (DPPH) was monitored according to the Blois
method.24 DPPH radical can be used in preliminary screening of
compounds capable of scavenging reactive oxygen species, since
these nitrogen radicals are much more stable and easier to handle
than oxygen free radicals. The use of DPPH in antioxidant assays is
well documented probably because of its rapid reaction, reliability
and independent of sample polarity.25 Initially, free radical scav-
enging activities of the newly prepared piperamide compounds
were evaluated based on the DPPH decoloration range.
activity (MIC = 14.2 lg/mL) was better than that of other com-
pounds. Moreover, the activities of compounds 8h and 8j against
S. aureus and B. subtilis were comparable to 8g.
All compounds did not show any improvement of activity
against gram-negative bacteria in comparison to gram-positive
bacteria. However, the compounds 8g, 8h and 8j showed compara-
ble activity against gram-negative bacteria with respect to the
other synthetic compounds. Compound 8g has N-substitution acet-
yl group in piperazine nucleus exhibited high activity against all
tested bacterial strains. When the acetoxy group was replaced by
phenyl/2-methoxy phenyl group the activity was slightly
diminished.
If, we further take into account the substituent effect, in general
the compound with piperazine group had shown less potency than
the acetyl, 2-methoxyphenyl and pyridyl substituents. The piperi-
zine derived compounds showed excellent antibacterial activity
indicating that a wide range of alkyl and acyl substituents were
well tolerated on the piperazine N4-position for proper fit at the
potential receptor site.23
Moreover, all of the synthesized compounds exhibited a moder-
ate antifungal activity for C. albicans and A. flavus with MIC values
of 14–100 and 15.8–75 lg/mL, respectively. Among the synthe-
sized compounds, compound 8j was the most potent one and
exhibited remarkably good antifungal activity against the tested
fungi. The MIC value of compound 8j against C. albicans was
14 lg/mL, which were sevenfold more potent than that of com-
pounds 8b and 8c. It is of interest that compound 8g was found
to exhibit the significant in vitro anti-fungal activity with MICs of
All the compounds showed interesting antioxidant activity
compared to the standard (Table 2). Compound 8b was found to
be the most potent antioxidant with the least values of IC50
(8.3 0.02
among the series being compound 8i with the largest values of
IC50 (36.9 0.17 g/mL). Table 2 gives an account for this antioxi-
lg/mL, inhibition concentration) and the least active
l
dant evaluation and indicates that compounds were endowed with
substantial scavenging properties towards DPPH with potencies of
8b > 8c > 8d > 8h > 8a.
Antioxidant activity of the compounds is related with their elec-
tron or hydrogen radical releasing ability to DPPH so that they be-
come stable diamagnetic molecules. This might be the reason for
the higher antioxidant activity of the above-mentioned com-
pounds. Compounds having hydroxy and methoxy groups are
found relatively more active, for example, compounds 8b and 8c
(hydroxy derivative) are more active than 8h (dimethoxy deriva-
tive). The compounds 8b and 8c showed significance difference
in radical scavenging activity due to bearing a hydroxy group at
different position. The coupling of 2,6-dimethylpiperidine showed
much better activity than the 4-methylpiperidine. The IC50 values
15 and 22
lg/mL against C. albicans and A. flavus, respectively.
were found to vary from 8.3 to 36.9 lg/mL showed a wide range
The results of antimicrobial activity illustrate that the presence
of electron donating group, –OCH3 on the methylenedioxyphenyl
of variations in the reactivity of the samples. The wide variations
in free radical scavenging activities may be due to the variations
Table 1
Antimicrobial activity of the synthesized compounds
Compound
In vitro activity zone of inhibition in mma (MIC in
lg/mL)
Gram-positive
Gram-negative
Fungi
S. aureus
B. subtilis
E. coli
P. aeruginosa
C. albicans
A. flavus
8a
8b
8c
8d
8e
8f
8g
8h
10(24)
10(50)
08(50)
11(28)
12(24)
14(30)
11(14)
14(16.4)
12(18.3)
14(15.2)
11.6(05)
Nt
13(26)
07(50)
11(62)
12(30)
10(25)
10(50)
16(14)
16(15)
14(18.0)
12(15.5)
10.4(05)
Nt
15(30)
11(>100)
07(>100)
10(50)
10(40)
11(20)
12(18)
09(20)
10(25)
11(22)
14.5(05)
Nt
16(30)
11(>100)
12(>100)
11(30)
09(36)
13(25)
14(18.7)
11(20)
13(25)
17(20)
14(05)
Nt
12.5(28)
14(100)
18(100)
12(25)
10(30)
10(25)
11(15)
14.1(17)
13.7(25)
11.4(14)
Nt
11(30)
10.2(90)
10(>100)
15(25)
12(30)
14(15)
10.4(22)
13.6(23)
11(40)
10.9(15)
Nt
8i
8j
Streptomycin
Flucanazole
16(05)
19(05)
Nt-denotes not tested.
a
The values given are means of three experiments.

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M. K. Prashanth et al. / Bioorg. Med. Chem. Lett. 22 (2012) 7065–7070
Table 2
Table 3
Antioxidant activity of the synthesized compounds
Change in duration of immobility in forced swim test (FST) and tail suspension test
(TST) in male albino mice treated with single dose vehicle, test compounds (20 mg/kg
po.) and imipramine (20 mg/kg po.) treated groups.
Compound
IC50 (lg/mL)
Å
DPPH
O2
Compound
Mean duration of immobilitya (s)
TST
8a
8b
8c
8d
8e
8f
8g
8h
8i
14.9 0.11
8.3 0.02
13.4 0.37
13.8 0.03
15.3 0.19
20.1 0.07
23.2 0.16
14.7 0.11
36.9 0.17
19.3 0.08
12.6 0.43
Nt
18.2 0.17
12.8 0.08
16.9 0.14
15.8 0.13
19.8 0.36
38.4 0.04
21.9 0.16
19.4 0.19
55.3 0.17
18.5 0.26
Nt
FST
Control
Imipramine
75.33 3.35
32.17 2.44b
32.15 2.12b
30.8 1.30b
35.4 2.2b
185.7 5.33
79.5 1.64b
78.18 0.94b
76.18 3.02b
84.2 3.7b
8a
8b
8c
8d
8e
8f
8g
8h
8i
43.33 3.44b
51.6 1.7b
77.33 1.33b
104.9 4.8c
178 4.89
8j
71 1.91
AAa
BHAb
55.83 4.97b
59.16 4.10c
66.2 5.80c
67.6 3.64c
116.2 2.90b
124.2 1.04c
143.5 6.80c
148.5 2.50c
13.4 0.29
Nt-denotes not tested.
8j
a
Ascorbic acid.
Butylated hydroxyanisole.
b
a
b
c
All data are expressed in mean SEM (n = 10).
p <0.001 versus normal control.
p <0.01 versus normal control.
in the proton-electron transfer by the compounds due to difference
in their structures and stability. An insight to the structure–activity
relationship gives an idea that activity generally increases with
number and strength of electron donating groups.
antidepressant drugs. It discriminates antidepressants from neuro-
leptics and anxiolytics34 and also provides a useful model to study
neurobiological and genetic mechanisms underlying stress and
antidepressant responses.35 FST was designed by Porsolt as a pri-
mary screening test for antidepressant compounds, concluded that
the immobility time observed in the test reflected a state of low-
ered mood or hopelessness in animals; thus, this animal model is
the most widely used tool for preclinical screening of putative anti-
depressant agents.36,37 It is still one of the best models for this pro-
cedure. The main advantage of this method is low-cost, fast and
reliable model to test potential antidepressant treatments with a
strong predictive validity.
Tail suspension test is widely employed animal model for test-
ing antidepressant activity in mice. The same way as observed in
FST, the TST is based on the fact that animals subjected to the short
term inescapable stress of being suspended by their tail will devel-
op an immobile posture.38 The total duration of immobility in-
duced by tail suspension was measured according to the method
described by Steru et al.,30 TST is less stressful than FST and has
greater pharmacological sensitivity.39 A wide variety of antidepres-
sants, and compounds with potential antidepressant activity re-
duce the duration of immobility in the TST.40,41
Remarkably, TST has been shown to be sensitive to an array of
antidepressant treatments, including tricyclics, SSRIs, monoamine
oxidase inhibitors, atypical antidepressants, and electroconvulsive
therapy.42,43
An obvious advantage of this test is its ability to detect a broad
spectrum of antidepressants irrespective of their underlying mech-
anism; it is inexpensive, methodologically unsophisticated and
easily amenable to automation.44
Some of the hypotheses concerning the mechanism of antide-
pressant activity are based on the ability of drugs to influence
the turnover of neurotransmitters.12 Although the literature is
plenty of data on biological activities of piperamide compounds.
For several years, natural or synthetic compounds with potential
antidepressant action have been studied and the piperamides are
examples of these. The piperamides are the most important active
constituents in piper species. The natural piperamides like piper-
ine, antiepilepsirine, laetispicine, piplartine etc, showed wide
range of antidepressant activities.45,46
Superoxide radical scavenging activity was measured as de-
scribed by reported method.26 Generation of reactive oxygen spe-
cies (ROS) and free radicals in vivo is involved in a wide range of
human diseases. ROS, including super oxide anion, hydrogen per-
oxide and hydroxyl radical are byproducts of a variety of pathways
of aerobic metabolism.27 These are unstable and react readily with
a wide range of biological substrates, such as lipids, DNA and pro-
tein molecules, consequently resulting in the cell damage.28 The
enzymatic superoxide anion radical was generated by a xanthine
and xanthine oxidase reaction system.
The piperamide derivatives 8a–j were found to be moderate to
weak super oxide radical scavenger. The IC50 values of these com-
pounds were in the range 12.8 to 55.35
ide radical scavenging was found for compounds 8a, 8b, 8c, 8d and
8j ranging from 12.8 to 18.5 g/mL. Compound 8b, which bear
lg/mL. Favorable superox-
l
substituted hydroxyl group attached to piperidine ring, showed
the highest activity among the piperamide compounds 8a–j, while
as compounds 8f and 8i showed less activity. This indicates that
selective modification of the hydroxy part of 8b decreases the rad-
ical scavenging potency.
The piperamide derivatives (8a–j) were screened for their anti-
depressant activity, in two behavioral tests, modified porsolt
forced swimming test (FST) and tail suspension test (TST).29,30
Antidepressant activity was assessed as mean immobility time in
seconds and data has been presented as mean SEM. The obtained
data on the antidepressant activity of the compounds and refer-
ence drug are given in Table 3.
In the FST and TST, the treatment with doses of 20 mg/kg of 8a–
j showed significantly decreased the immobility time. Acute treat-
ment with the compounds 8a, 8b, 8c and 8d promoted a decrease
in the immobility time when compared to normal control group
and these effects were similar to standard treated group. Test com-
pounds 8a and 8b were more effective than standard treated group
in both FST and TST. The immobility time of animals treated with
the other compounds 8f, 8i and 8j did not statistically differ from
control values. However, compounds 8e, 8g and 8h shown moder-
ate decrease in duration of immobility and this effect was signifi-
cant (p <0.001) difference when compared to standard treated
group.
The behavioral despair tests, FST and TST are effective at
predicting the activity of a wide variety of antidepressants.31,32
It has good predictive value for antidepressant potency in
humans,33 as they are sensitive and selective for clinically used
The prepared compounds consists of three important compo-
nents, viz methoxy group substituted methylenedioxyphenyl
(MDP) ring, side chain with double bond and a basic piperidine/
piperazine moiety attached through a carbonyl amide linkage to

M. K. Prashanth et al. / Bioorg. Med. Chem. Lett. 22 (2012) 7065–7070
7069
Table 4
authors M. K. Prashanth thankful to the University of Mysore, My-
sore for the award of research fellowship.
In vitro inhibition activity of compounds 8a, 8b, 8c and fluoxetine on MAO activity in
mouse brain
Compound
MAO activitya (nmol/mg protein)
MAO-B
Supplementary data
MAO-A
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.bmcl.2012.09.
089.
Control
8a
8b
23.59 2.71
17.09 2.26c
14.46 1.83b
16.63 3.49c
17.05 2.52
24.06 2.52
18.01 3.27c
15.72 1.92b
17.33 2.18c
18.16 2.18
8c
Clorgyline
a
b
c
References and notes
All data are expressed in mean SEM (n = 10).
p <0.001 when compared with control group.
p <0.01 when compared with control group.
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Acknowledgments
The authors are thankful to the University of Mysore, Mysore
for providing this project. The authors are also grateful to the
MHRD and UGC, New Delhi for the funding through Institution of
Excellence Scheme. The authors are grateful to G. Pulla Reddy Col-
lege of Pharmacy, Mehdipatnam, Hyderabad, India for providing
facilities to carry out the antidepressant activity. One of the
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