Synthesis, characterization and biological evaluation of some novel 2,4-thiazolidinediones as potential cytotoxic, antimicrobial and antihyperglycemic agents

Article abstract of DOI:10.1016/j.bmcl.2012.08.052

A series of some novel 2,4-thiazolidinediones (TZDs) (2a-x) have been synthesized and characterized by FTIR, ¹H NMR, ¹³C NMR and LC mass spectral analysis. All the synthesized compounds were evaluated for their cytotoxicity, antimicr

Full text of DOI:10.1016/j.bmcl.2012.08.052

Bioorganic & Medicinal Chemistry Letters 22 (2012) 6442–6450
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis, characterization and biological evaluation of some novel
2,4-thiazolidinediones as potential cytotoxic, antimicrobial and antihypergly-
cemic agents
Vasudeva Rao Avupati a, , Rajendra Prasad Yejella a, Annapurna Akula b, Girija Sankar Guntuku c,
⇑
Bhagya Raju Doddi a, Venkata Rao Vutla a, Suvarna Ratna Anagani a, Lakshmana Santhi Adimulam a,
Aruna Kumar Vyricharla a
a Pharmaceutical Chemistry Division, AU College of Pharmaceutical Sciences, Andhra University, Visakhapatnam 530003, Andhra Pradesh, India
b Pharmacology Division, AU College of Pharmaceutical Sciences, Andhra University, Visakhapatnam 530003, Andhra Pradesh, India
c Pharmaceutical Biotechnology Division, AU College of Pharmaceutical Sciences, Andhra University, Visakhapatnam 530003, Andhra Pradesh, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 25 June 2012
Revised 13 July 2012
Accepted 14 August 2012
Available online 21 August 2012
A series of some novel 2,4-thiazolidinediones (TZDs) (2a–x) have been synthesized and characterized by
FTIR, 1H NMR, 13C NMR and LC mass spectral analysis. All the synthesized compounds were evaluated for
their cytotoxicity, antimicrobial and in vivo antihyperglycemic activities. Among the tested compounds
for cytotoxicity using Brine Shrimp Lethality assay, compound 2t ((Z)-5-(4-((E)-3-oxo-3-(thiophen-2-
yl)prop-1-enyl)benzylidene)-1,3-thiazolidine-2,4-dione) exhibited significant inhibitory activity at ED50
value 4.00 0.25
lotoxin with ED50 value 3.61 0.17
assay method against selected Gram-positive, Gram-negative and fungal strains and the activity
expressed as the minimum inhibitory concentration (MIC) in g/mL. From the results of antimicrobial
activity compound 2s ((Z)-5-(4-((E)-3-(3,5-bis(benzyloxy)phenyl)-3-oxoprop-1-enyl)benzylidene)-1,3-
thiazolidine-2,4-dione) was found to be the most active against all the tested strains of microorganisms
l
g/mL and this level of activity was comparable to that of the reference drug podophyl-
Keywords:
l
g/mL. Antimicrobial activity was screened using agar well diffusion
2,4-Thiazolidinediones
Brine Shrimp Lethality assay
Agar well diffusion assay
Antihyperglycemic activity
Molecular docking
l
with MIC value 16 lg/mL. In vivo antihyperglycemic effect of twenty four TZDs (2a–x) at different doses
10, 30 and 50 mg/kg b.w (oral) were assessed using percentage reduction of plasma glucose (PG) levels in
streptozotocin-induced type II diabetic rat models. From the results, the novel compound 2x ((Z)-5-(4-
((E)-3-(9H-fluoren-2-yl)-3-oxoprop-1-enyl)benzylidene)-1,3-thiazolidine-2,4-dione) exhibited consider-
ably potent blood glucose lowering activity than that of the standard drug rosiglitazone and it could
be a remarkable starting point to evaluate structure–activity relationships and to develop new lead mol-
ecules with potential cytotoxicity, antimicrobial and antihyperglycemic activities. In addition molecular
docking studies were carried out against PPAR
accomplish preliminary confirmation of the observed in vivo antihyperglycemic activity.
Ó 2012 Elsevier Ltd. All rights reserved.
c molecular target using Molegro Virtual Docker v 4.0 to
In recent years, the chemistry of 2,4-thiazolidinediones (TZDs)
captivated importance as these compounds have been found to ex-
hibit several biological activities, such as antihyperglycemic,1
euglycemic,2 anti-inflammatory,3 antimalarial,4 antioxidant,5
thyroid hormone receptor antagonist,22 PTP1B inhibitor,23 human
PTP1B and LMW-PTP inhibitor,24 Raf/MEK/Extracellular signal reg-
ulated kinase (ERK1/2) inhibitor,25 dual inhibitor of the Raf/MEK/
ERK and the PI3K/Akt signaling pathways,26 serine/threonine
protein kinases Pim-1 and Pim-2 inhibitor,27 G-protein coupled
receptor 40 (GPR40) agonist,28 MurD ligase inhibitor,29 monoamine
oxidase B (MAO-B) inhibitor30 and neuroprotective.31 Having such
diverse range of pharmacological activities, these molecules have
attracted medicinal chemists and consequently a number of strate-
gies have been originated to synthesize them.
antitumor,6 cytotoxic,7 antimicrobial,8 antiproliferative,9 PPAR
c
agonist,10 dual PPAR activator,11 free radical scavenger,12 LDL
a/c
oxidation inhibitor,13 glycogen synthase kinase (GSK) 3 inhibitor,14
aldose reductase inhibitor,15 cholesterol esterase inhibitor,16
15-hydroxyprostaglandin dehydrogenase (15-PGDH) inhibitor,17
human b3 agonist,18 chymase inhibitor,19 bacterial arylamine
N-Acetyltransferases (NATs) inhibitor,20 P2X7 receptor antagonist,21
A series of TZDs (2a–x) synthesized in the present study were
studied for their cytotoxicity, antimicrobial and antihyperglycemic
activities. In fact, compounds having
1,3-thiazolidine-2,4-dione moieties were earlier reported to
a,b-unsaturated ketone or
⇑
Corresponding author. Tel.: +91 9030805658.
E-mail address: vasudevaraoavupati@gmail.com (V.R. Avupati).
0960-894X/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmcl.2012.08.052

V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
6443
possess cytotoxicity32–39, antimicrobial40–47 and antihyperglyce-
mic48–55 activities and thus the synthesized compounds now are
expected to possess synergistic effect, as both the features form
part of these molecules. In the present investigation, the aim of
and ÀC@CÀ (aromatic) stretching bands at frequencies 1685 cm
À1
and 1598 cmÀ1, respectively. The 1H NMR spectrum of 1 re-
vealed characteristic peaks of 5-benzylidene (HC@C) and NH pro-
tons as two singlets, one at d 7.86 ppm and the other one at d
12.74 ppm (broad) providing evidence for formation of 1 and
reconfirmed by the 13C NMR peaks at d 126.78 ppm and d
115.14 ppm due to 5-methylidene carbon and carbon (C5) of 1,3-
thiazolidine-2,4-dione. The ESI mass spectrum (positive ion mode)
of 1 revealed a (M+H)+ ion at m/z 234. The geometry of all TZDs
(2a–x) were assumed to be (Z) configuration because of its high de-
gree of thermal stability of this isomer.60
molecular docking study of a series of TZDs (2a–x) against PPAR
c
(PDB ID: 3CS8) is to predict and compare the ligand conformation
and orientation within a targeted binding site. To the best of our
knowledge there is, to date, no report was published regarding
the binding properties of TZDs (2a–x) against PPARc 3CS8 Ligand
Binding Domain (LBD).
The reaction sequence employed for the synthesis of title com-
pounds (2a–x) is shown in Scheme 1, and their physical properties
are depicted in Table 1. As described by Momose et al.56 and Bruno
et al.57 2,4-thiazolidinedione can undergo a Knoevenagel conden-
sation with a variety of substituted aldehydes to produce 5-arylid-
ene-2,4-thiazolidinediones. The key intermediate in the present
study (Z)-4-((2,4-dioxo-1,3-thiazolidin-5-ylidene)methyl)benzal-
dehyde 1 was prepared by Knoevenagel condensation reaction be-
tween terephthaldehyde and 1,3-thiazolidine-2,4-dione. Further,
subsequent base catalyzed condensation of the 1 with appropriate
substituted aromatic/heteroaromatic ketones in the presence of
pulverized sodium hydroxide in boiling dimethylformamide
(DMF) afforded a series of 2,4-thiazolidinediones (2a–x) in good
yield.58,59
The IR spectrum of all the compounds (2a–x) exhibited the
characteristic absorptions at various frequencies correspondingly
at 3300–3100 cmÀ1 and 1650–1735 cmÀ1 suggesting the presence
of a secondary amine group and
a,b-unsaturated carbonyl group,
respectively. In the 1H NMR spectra of TZDs (2a–x), a singlet inte-
grating for one proton characteristic of the HC@C group was ob-
served in between d 7.72–8.10 ppm and a singlet integrating for
one proton of the NH group was observed in between d 12.5–
13.5 ppm as a broad signal. The 1H NMR spectrum of the com-
pound 2a exhibited characteristic peaks of H-
of ,b-unsaturated carbonyl group as two doublets, one at d
8.01 ppm (H-b, J = 15.2 Hz) and the other one at d 7.78 ppm (H-
a and H-b protons
a
a,
J = 15.2 Hz). The large J value clearly reveals the trans geometry
All the synthesized compounds as mentioned in Table 1 were
characterized by CHN elemental analysis and spectroscopic meth-
ods such as FTIR, 1H NMR, 13C NMR and LC mass spectral analysis.
The IR spectrum of 1 exhibited characteristic ÀC@CÀ (aliphatic)
at the double bond. In the 13C NMR spectra, the presence of char-
acteristic signals correspondingly at
142.76 ppm indicating the presence of C-
d
a
123.36 ppm and
and C-b carbon atoms
d
of
a,b-unsaturated carbonyl group confirmed the formation of
Scheme 1. Reagents and conditions: (i) Piperidine, ethanol, reflux, 8 h; (ii) dry dimethylformamide (DMF), pulverized NaOH, substituted aromatic/heteroaromatic ketones.
Table 1
Physical characterization and cytotoxicity data of TZDs (2a–x) produced via Scheme 1
Compound
R
Yielda (%)
Molecular weight
Molecular formula
Mp (°C)
ED50 (lg/mL) (mean SEM)
2a
2b
2c
2d
2e
2f
2g
2h
2i
2j
2k
2l
2m
2n
2o
2p
2q
2r
2s
2t
2u
2v
C6H5
4-MeC6H4
3-OMeC6H4
4-OMeC6H4
2-OHC6H4
88
84
83
91
91
87
83
83
90
81
81
80
86
84
92
90
93
89
94
88
87
84
81
79
—
335.58
349.40
365.40
365.40
351.38
351.38
367.38
367.38
365.07
365.07
350.07
350.07
380.05
380.05
369.82
369.82
353.05
353.05
547.62
341.40
336.06
336.06
385.08
423.48
—
C19H13NO3S
C20H15NO3S
C20H15NO4S
C20H15NO4S
C19H13NO4S
C19H13NO4S
C19H13NO5S
C19H13NO5S
C20H15NO4S
C20H15NO4S
C19H14N2O3S
C19H14N2O3S
C19H12N2O5S
C19H12N2O5S
C19H12ClNO3S
C19H12ClNO3S
C19H12FNO3S
C19H12FNO3S
C33H25NO5S
212–215
179–182
181–184
218–221
189–192
206–209
215–218
213–216
125–128
221–224
211–214
231–234
255–258
217–220
219–222
206–209
212–215
199–203
229–233
207–210
194–197
205–208
216–219
218–221
—
44.73 0.12
19.66 0.25
18.72 0.15
16.24 0.52
41.35 0.33
36.20 0.23
49.21 0.25
46.71 0.15
39.42 0.52
33.12 0.21
33.18 0.15
28.82 0.12
56.06 0.25
49.28 0.15
24.82 0.12
12.06 0.25
9.28 0.15
4.32 0.52
26.82 0.12
4.00 0.25
4-OHC6H4
2,4-diOHC6H3
2,5-diOHC6H3
2-OH,5-MeC6H3
6-OH,5-MeC6H3
3-NH2C6H4
4-NH2C6H4
3-NO2C6H4
4-NO2C6H4
3-ClC6H4
4-ClC6H4
3-FC6H4
4-FC6H4
3,5-diC7H7OC6H3
Thiophen-2-yl
Pyridin-2-yl
Pyridin-3-yl
Naphthalen-2-yl
Fluoren-2-yl
—
C
C
C
C
C
17H11NO3S2
18H12N2O3S
18H12N2O3S
23H15NO3S
26H17NO3S
30.28 0.15
31.42 0.52
48.11 0.33
39.66 0.31
3.61 0.17
2w
2x
Standardb
—
a
Crystallization solvent is ethanol.
Podophyllotoxin.
b

6444
V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
compound 2a. Further, the ESI mass spectrum (positive ion mode)
of compound 2a revealed a (M+H)+ ion at m/z 336. Eventually all
the spectra of the new products are in keeping with the expected
structures.
2b–2d and 2i–2l, substituted with electron releasing groups was
found to be biologically relevant and the activity order was (2d
(4-OCH3,
18.72 0.15) > 2b (4-CH3, ED50: 19.66 0.25
ED50: 28.82 0.12 g/mL) > 2k (3-NH2, ED50: 33.18 0.15
ED50
:
16.24 0.52
l
g/mL) > 2c
(3-OCH3,
g/mL) > 2l (4-NH2,
g/mL),
ED50:
l
The cytotoxicity potential of the synthesized compounds (2a–x)
was determined by Brine Shrimp Lethality assay as described by
Meyer et al.61 Brine Shrimp (Artemia salina) nauplii were hatched
in sterile brine solution (prepared using sea water salt 38 g/L and
adjusted the pH to 8.5 using 1 N NaOH) under constant aeration
for 38 h. After hatching, 10 nauplii were placed in each vial and
added various concentrations of drug solutions in a final volume
of 5 mL, maintained at 37 °C for 24 h under light of incandescent
lamps and surviving larvae were counted. Each experiment was
conducted along with control (vehicle treated) at various concen-
trations of the test substances. The percentage lethality was deter-
mined by comparing mean surviving larvae of test and control
tubes. The ED50 values were obtained using fenny probed analysis
software.62 The result for the test compound was compared with
the positive control podophyllotoxin. The results of cytotoxicity
study are given in Table 1.
l
l
respectively. It is important that less activity was observed when
the hydroxyl groups are substituted at different positions on the
phenyl ring as seen in the case of compounds 2e–2h and the order
of activity was 2f (4-OH, ED50: 36.20 0.23
ED50: 41.35 0.33) > 2h (2,5-diOH, ED50: 46.71 0.15
(2,4-diOH, ED50: 49.21 0.25 g/mL), respectively. It is notable
that loss of activity observed when the nitro groups are introduced
on the phenyl ring of ,b-unsaturated carbonyl system as seen in
the case of compounds 2m and 2n with ED50 values 56.06 0.25
and 49.28 0.15 g/mL. The compounds 2j (ED50 33.12
0.21 g/mL) and 2i (ED50: 33.12 0.21 g/mL) having the methyl
lg/mL) > 2e (2-OH,
l
g/mL) > 2g
l
a
l
:
l
l
group substitution on the phenyl ring at position 5 along with
the hydroxyl group substitution at 6 (2j) and 2 (2i) positions,
respectively, showed enhanced level of cytotoxicity when com-
pared with that of the compounds (2e–2h) possessing only hydro-
xyl group substitution. The compound 2s (ED50: 26.82 0.12 lg/
mL) having dibenzyloxy substitution on the phenyl ring at 3 and
The investigation of cytotoxicity screening data of all the syn-
thesized TZDs (2a–x) revealed that the compounds 2t, 2r and 2q
demonstrated comparatively the most potent cytotoxicity, with
5 positions is also relevant for enhancing the cytotoxicity.
ED50 values of 4.00 0.25, 4.32 0.52 and 9.28 0.15 lg/mL,
With respect to the antimicrobial activity, the standard strains
were procured from the National Collection of Industrial Microor-
ganisms (NCIM), National Chemical Laboratory, Pune, India. The
antimicrobial activity of the synthesized compounds (2a–x) was
determined by agar well diffusion method as recommended by
the National Committee for Clinical Laboratory Standards,
(NCCLS).63–65 The compounds were evaluated for antimicrobial
activity against bacteria viz. Bacillus subtilis (NCIM 2063), Bacillus
pumilus (NCIM 2327), Staphylococcus aureus (NCIM 2079),
Micrococcus luteus (NCIM 2155), Pseudomonas aeruginosa (NCIM
2036), Klebsiella pneumonia (NCIM 5082), Escherichia coli
(NCIM 2065), Proteus vulgaris (NCIM 2813), Candida albicans (NCIM
3102), Aspergillus niger (NCIM 548), Aspergillus oryzae (NCIM 643)
and Penicillium chrysogenum (NCIM 738). Serial solutions of com-
pounds (2a–x) were diluted in dimethyl sulfoxide (1% DMSO) to
respectively (Table 1). It is interesting to note that the compounds
2p, 2d, 2c and 2b also showed appreciable cytotoxicity with ED50
values
19.66 0.25
2o, 2s, 2l and 2u showed moderate level of activity at concentra-
tions ranging from 24.82 0.12 – 30.28 0.15 g/mL. The com-
of
12.06 0.25,
16.24 0.52,
18.72 0.15
and
lg/mL, respectively. The other compounds such as
l
pounds 2v, 2j, 2k, 2f, 2i, 2x, 2e, 2a, 2h, 2w, 2g, 2n and 2m
exhibited comparatively less activity with ED50 values ranging
from 31.42 0.52 – 56.06 0.25
lg/mL in comparison with the
standard drug (podophyllotoxin, ED50: 3.61 0.17
l
g/mL).
A close look at the SAR (Structure–Activity Relationship) of
these compounds clearly revealed the inherent cytotoxicity associ-
ated with the basic nucleus consisting of 2,4-thiazolidinedione and
a,b-unsaturated ketone moieties as seen in case of the unsubstitut-
ed compound 2a with ED50 value of 44.73 0.12 g/mL, which in
l
give a final concentration ranging from 16 to 512 lg/mL used for
some cases was enhanced by the influence of some substituents
determining MIC value. The Minimum inhibitory concentration
(MIC) was defined as the lowest concentration of compound re-
quired for a complete inhibition of the bacterial and fungal growth
after incubation time. For antibacterial activity nutrient agar was
used seeded with 0.1 mL of the respective bacterial culture strains
suspension prepared in a sterile saline (0.85%) of 105 CFU/mL dilu-
tion. For antifungal activity, different fungal spore suspensions in
sterile distilled water were adjusted to give a final concentration
of 106 CFU/mL. An inoculum of 0.1 mL spore suspension of each
fungus was spread on Potato-Dextrose-Agar (PDA) plates. The
wells of 6 mm diameter were filled with 0.1 mL of each compound
having different concentrations separately for each test of bacterial
and fungi strain. The DMSO (1%) alone was used as a control. The
and decreased by some other substituents. For example, the com-
pounds
2r(p-F,
ED50
:
4.32 0.52
lg/mL) > 2q(m-F,
ED50:
9.28 0.15
l
g/mL) > 2p(p-Cl, ED50
:
12.06 0.25 l
g/mL) having
halogen substituents either at meta or para positions significantly
enhanced the activity. A reduction in the activity was observed
when the substituted phenyl ring was replaced by a naphthalene
moiety, as seen in the case of compound 2w with ED50 value
48.11 0.33
2x (ED50: 39.66 0.31
ring of ,b-unsaturated carbonyl system enhanced the activity
lg/mL. The presence of a fluorene ring in compound
l
g/mL) in the place of substituted phenyl
a
compared to the one possessing naphthalene moiety, but less than
that of the one having substituted phenyl ring. It is also interesting
to see the presence of pyridine ring in the place of substituted phe-
nyl ring contributing to an increase in activity compared to the one
possessing fluorene moiety, as seen in the case of compounds 2u
and 2v with ED50 values 30.28 0.15 and 31.42 0.52 lg/mL,
respectively. It is interesting to note that an enhanced level of
activity was observed when the thiophene ring is introduced in
antibiotic chloramphenicol (16 lg/mL) and ketoconazole (16 lg/
mL) are used as reference antibacterial and antifungal agents,
respectively, for comparison. Inoculated plates in triplicate were
then incubated at 37 0.5 °C for antibacterial activity for 24 h
and 48 h at 28 0.2 °C for antifungal activity. After incubation,
the minimum inhibitory concentrations (MICs) were noted. The re-
sults of antimicrobial activity studies are given in Table 2.
The results of antimicrobial activity of the synthesized
compounds (2a–x) against selected Gram-positive, Gram-negative
bacteria and fungi are illustrated in Table 2. The compounds 2r and
2s were found to be more active than other compounds with MIC
the place of substituted phenyl ring of
system, as seen in case of compound 2t, with ED50 value
4.00 0.25 g/mL.
However, it was revealed that various aromatic/heteroaromatic
rings substituted at position 3 of ,b-unsaturated carbonyl system
a,b-unsaturated carbonyl
l
a
followed its activity order as thiophen-2-yl > pyridine-2-yl >
pyridine-3-yl > fluoren-2-yl > phenyl > naphthalene-2-yl moieties,
respectively. It is also reported that the cytotoxicity of compounds
16–32
lg/mL against all tested microorganisms. Compounds 2a,
2e–2h, 2k, 2m, 2n, 2w and 2x showed comparatively less antimi-

V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
6445
Table 2
Antimicrobial activity of TZDs (2a–x)
Compound
R
Minimum inhibitory concentration (MIC) (lg/mL)
Gram positive bacteria
Gram negative bacteria
Fungi
Bs
Bp
Sa
Ml
Pa
Kp
Ec
Pv
Ca
An
Ao
Pc
2a
2b
2c
2d
2e
2f
2g
2h
2i
2j
2k
2l
2m
2n
2o
2p
C6H5
256
32
128
64
256
32
128
64
512
32
128
32
512
64
256
64
256
32
128
64
256
512
256
512
256
64
128
64
128
256
32
512
64
128
64
256
32
128
32
256
128
256
256
128
64
512
64
256
64
512
256
128
128
512
512
256
128
128
64
256
128
512
256
128
64
512
256
64
512
64
512
64
4-MeC6H4
3-OMeC6H4
4-OMeC6H4
2-OHC6H4
4-OHC6H4
2,4-diOHC6H3
2,5-diOHC6H3
2-OH,5-MeC6H3
6-OH,5-MeC6H3
3-NH2C6H4
4-NH2C6H4
3-NO2C6H4
4-NO2C6H4
3-ClC6H4
256
128
512
256
256
256
64
128
128
128
128
512
64
256
128
512
512
256
128
64
256
256
256
256
256
64
128
512
256
256
256
128
128
64
128
256
512
64
512
256
256
512
128
64
256
128
256
256
64
512
128
256
256
256
128
256
128
256
512
64
256
128
256
256
256
128
256
128
128
512
64
512
256
512
512
512
512
256
256
256
512
64
512
128
256
256
128
64
256
128
256
512
64
512
512
256
512
512
32
256
256
512
512
32
64
128
128
512
64
4-ClC6H4
32
16
32
64
32
16
32
32
64
64
64
2q
3-FC6H4
32
32
32
64
32
32
32
64
64
64
64
64
2r
4-FC6H4
16
16
32
32
16
16
16
32
32
32
32
16
2s
2t
2u
2v
2w
2x
3,5-diC7H7OC6H3
Thiophen-2-yl
Pyridin-2-yl
Pyridin-3-yl
Naphthalen-2-yl
Fluoren-2-yl
—
16
32
16
16
64
128
512
256
16
—
—
16
32
64
128
512
256
16
—
—
16
32
32
128
512
512
16
—
—
16
32
16
16
64
128
512
256
16
—
—
32
32
64
128
512
128
16
—
—
32
64
64
256
512
512
16
—
—
16
32
64
128
512
256
—
16
—
16
32
64
256
512
256
—
16
—
16
32
64
128
512
256
—
16
—
16
32
128
128
512
256
16
128
128
512
128
16
128
256
512
512
—
Standarda
Standardb
DMSO (1%)
—
—
—
—
—
—
16
—
Bs: Bacillus subtilis (NCIM 2063), Bp: Bacillus pumilus (NCIM 2327), Sa: Staphylococcus aureus (NCIM 2079), Ml: Micrococcus luteus (NCIM 2155), Pa: Pseudomonas aeruginosa
(NCIM 2036), Kp: Klebsiella pneumonia (NCIM 5082), Ec: Escherichia coli (NCIM 2065), Pv: Proteus vulgaris (NCIM 2813), Ca: Candida albicans (NCIM 3102), An: Aspergillus niger
(NCIM 548), Ao: Aspergillus oryzae (NCIM 643) and Pc: Penicillium chrysogenum (NCIM 738).
a
Chloramphenicol.
Ketoconazole.
b
crobial activity with MIC 256–512
organisms. From the results of antibacterial activity, compound 2s
was found to be more active against all Gram-positive bacteria
l
g/mL against all tested micro-
compounds 2m and 2n having nitro group either at meta or para
position of the phenyl ring is not relevant for enhancing the anti-
microbial activity. An increase in the antifungal activity was also
observed for the compounds having halogen substitution but the
level of activity in many cases is found to be less than that of the
antibacterial activity. Similarly, the presence of dibenzyloxy group
at position 3 and 5 of the phenyl ring as seen in case of compound
2s also improved the antibacterial activity but the level of activity
is much enhanced in case of antifungal activity.
As a general rule, the acute toxicological studies of TZDs (2a–x)
were performed as per OECD 425 guidelines in mice. All the tested
compounds were found to be safe upto dose (median lethal dose)
2000 mg/kg b.w. No changes in any of vital functions were ob-
served throughout the study period.
With respect to the antihyperglycemic activity, Wistar albino
rats of either sex weighing 150–200 g were used for this study.
All animals were maintained under 12 h light and 12 h dark cycle
at 25 1 °C. All animals were fed with standard pellet diet and
water ad libitum. Animals were fasted for 16 h prior to drug
administration, allowing access only to water and were deprived
of both food and water during the experiment. The animal housing
and handling were in accordance with Committee for the Purpose
of Control and Supervision of Experiments on Animals (CPCSEA)
guidelines and the experimental protocol has been approved by
the Institutional Animal Ethics Committee (IAEC) (Proceedings
No. 516/01/A/CPCSEA). To induce type II diabetes, the acclimatized
animals were fasted over night before injecting with streptozoto-
cin (STZ). STZ was dissolved in citrate buffer pH 4.5 and a dose of
65 mg/kg was given after the administration of 150 mg/kg dose
of Nicotinamide which is helpful to produce partial destruction
of pancreas. The blood glucose levels were estimated after 48 h
with MIC value 16
pound 2r showed significant inhibition against all Gram-negative
bacteria with MIC 16 g/mL except a moderate potency (32 g/
lg/mL. Among all the tested compounds, com-
l
l
mL) against Proteus vulgaris. A broad spectrum of antifungal activ-
ity of the compound 2s was obtained against all the fungi with MIC
16
activity.
From the obtained data, the following conclusions on antimi-
lg/mL, while other compounds displayed less antifungal
crobial activity can be made: the compounds substituted with
halogens on the phenyl ring at meta and para positions enhanced
the antibacterial activity (F > Cl) as seen in the case of compounds
2o–2r. It is noteworthy that compounds 2b–2d, 2k and 2l having
electron donating substituents (4-CH3 > 4-OCH3 > 3-OCH3 > 4-
NH2 > 3-NH2) on the phenyl ring at meta and para positions was
found to enhance the antibacterial activity. It is also interesting
to observe that various aromatic/heteroaromatic ring substituted
at position 3 of a,b-unsaturated carbonyl system was found to be
biologically relevant and followed its activity order as thiophen-
2-yl (2t) > pyridine-2-yl (2u), pyridine-3-yl (2v) > phenyl (2a),
fluoren-2-yl (2x) > naphthalen-2-yl (2w) moieties, respectively. A
decrease in the antimicrobial activity is attributed to the presence
of hydroxyl group on the phenyl ring at ortho, meta and para posi-
tions as seen in the case of compounds 2e–2h. The compounds 2j
and 2k having the methyl group substitution on the phenyl ring
at position 5 along with the hydroxyl group substitution on at 6
(2j) and 2 (2i) positions, respectively, showed enhanced level of
antimicrobial activity when compared with that of the compounds
(2e–2h) possessing only hydroxyl group substitution. The

6446
V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
for the confirmation of diabetes induction. The diabetic rats were
divided into four groups of six rats each. Control animals received
distilled water only (Group I), diabetic animals received STZ injec-
tion (Group II), diabetic animals orally fed with rosiglitazone (as
0.25% sodium CMC suspension) at doses 10, 30 and 50 mg/kg
(Group III) and the diabetic rats orally fed with synthesized TZDs
(2a–x) (as 0.25% sodium CMC suspension) at doses 10, 30 and
50 mg/kg (Group IV). For single dose study (acute study) the fast-
ing blood glucose samples were taken before the administration
of the test compounds at doses 10, 30 and 50 mg/kg for one day,
the blood samples were collected from the retro orbital plexus
periodically at 1, 2, 4, 6, 8, 12 and 24 h and were analyzed for plas-
ma glucose (PG) content. Levels of plasmatic glucose were ana-
lyzed using commercially available glucometer kits (ACCU-CHEK
ACTIVE), based on enzymatic methods. All the data were statisti-
cally analyzed for variance and significance, by one way ANOVA
followed by Student’s t-test and Dunett’s test. All results are ex-
pressed as Mean SEM and observed P value is <0.05. The results
of antihyperglycemic activity studies are given in Table 3.66
The results of in vivo antihyperglycemic activity of the synthe-
sized TZDs (2a–x) showed that all the compounds were found to
possess moderate to potential ability to reduce blood glucose levels
in streptozotocin- induced type II diabetic rats. We consequently
found that the% PG reduction ability of the titled compounds
(2a–x) was followed a dose-dependent manner. Among all the
tested compounds, compound 2x showed significant antihypergly-
cemic activity at various doses such as 10, 30 and 50 mg/kg b.w
with% PG reduction values 39.83 0.29, 44.62 0.32 and
52.81 0.32 mg/dL, respectively. Correspondingly, compounds 2j,
2d and 2h also showed promising antihyperglycemic activity. In
the same way, compounds such as 2u, 2i, 2g, 2f, 2w, 2p, 2c, 2e,
2r, 2v and 2s exhibited moderate range of antihyperglycemic activ-
ity at all the doses. The other compounds such as 2l, 2b, 2n, 2o, 2k,
2q, 2m, 2a and 2t showed lower level of antihyperglycemic activity
when compared to that of the reference drug rosiglitazone (% PG
reduction values at doses: 10 mg/kg b.w (38.57 0.25 mg/dL),
30 mg/kg b.w (14.83 0.18 mg/dL) and 50 mg/kg b.w.
(12.74 0.16 mg/dL), respectively). The results of antihyperglyce-
mic activity are summarized in Table 3.
From the results described in Table 3, we could establish the
structure-activity relationships for antihyperglycemic activity of
TZDs (2a–x) synthesized in the present study. It is clear from the
results of antihyperglycemic activity that the structural require-
ments for retaining (or enhancing) antihyperglycemic property in
TZDs (2a–x) are not rigid. As such, the observations supported
the following general conclusions: The
a,b-unsaturated ketone
Table 3
Dose-response effect of the TZDs (2a–x) on blood glucose levels in streptozotocin-induced type II diabetic rats
Compound
R
Dose (mg/kg b.w)
(oral)
% Reduction, PG
(mg/dL) (mean SEM)
Compound
R
Dose (mg/kg b.w)
(oral)
% Reduction, PG
(mg/dL) (mean SEM)
2a
C6H5
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
NS
2o
3-ClC6H4
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
10
30
50
-
11.71 0.23
15.42 0.78
21.83 0.43
26.74 0.22
32.38 0.41
36.17 0.21
12.08 0.56
16.87 0.27
20.66 0.66
22.74 0.34
25.67 0.21
33.12 0.28
21.76 0.34
26.87 0.32
30.12 0.48
NS
11.66 0.78
13.71 0.74
22.78 0.12
34.68 0.16
43.72 0.10
19.04 0.19
27.86 0.31
31.81 0.17
23.75 0.18
31.84 0.22
36.93 0.18
39.83 0.29
44.62 0.32
52.81 0.32
2.78 2.41
11.51 0.61
15.61 0.22
17.66 0.34
21.81 0.22
28.72 0.32
16.41 0.65
28.73 0.75
34.61 0.22
33.88 0.21
37.04 0.55
48.71 0.13
NS
2b
2c
2d
2e
2f
4-MeC6H4
2p
4-ClC6H4
3-FC6H4
3-OMeC6H4
4-OMeC6H4
2-OHC6H4
2q
2r
4-FC6H4
2s
3,5-diC7H7OC6H3
Thiophen-2-yl
Pyridin-2-yl
Pyridin-3-yl
Naphthalen-2-yl
Fluoren-2-yl
-
NS
14.44 0.25
21.83 0.22
30.21 0.61
37.12 0.75
26.86 0.12
33.72 0.22
41.67 0.43
30.74 0.22
38.86 0.34
47.73 0.57
31.76 0.34
37.03 0.25
42.13 0.32
36.76 0.66
43.14 0.35
49.99 0.62
12.14 0.32
15.36 0.57
21.66 0.21
21.34 0.35
24.72 0.28
29.87 0.26
11.18 0.32
14.72 0.45
16.56 0.27
13.63 0.32
16.74 0.22
22.73 0.54
4-OHC6H4
2t
2g
2h
2i
2,4-diOHC6H3
2,5-diOHC6H3
2-OH,5-MeC6H3
6-OH,5-MeC6H3
3-NH2C6H4
4-NH2C6H4
3-NO2C6H4
4-NO2C6H4
2u
2v
2w
2j
2x
2k
2l
Group-I
Group-II
Group-III
-
-
1.78 6.32
2m
2n
-
10
30
50
38.57 0.25
14.83 0.18
12.74 0.16
NS: Not significant; n = 6; P < 0.05

V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
6447
and 2,4-thiazolidinedione moieties are critical for enhancing the
antihyperglycemic activity. The substitution of phenyl ring of
encompasses all protein within 15.0 Ao of bound crystallographic
ligand atom with a size of X: 18.89 Ao, Y: 2.16 Ao and Z: 30.05 Ao
axes, respectively. Default settings were used for all the calcula-
tions. Docking was performed using a grid resolution of 0.30 Ao
and for each of the 10 independent runs; a maximum number of
1500 iterations were executed on a single population of 50 individ-
uals. The active binding site was considered as a rigid molecule,
whereas the ligands were treated as being flexible, that is, all
non-ring torsions were allowed. This approach seems to be consis-
tent with the structural similarity observed between rosiglitazone
and compounds under investigation. The results of molecular
docking studies are given in Table 4.
a,b-unsaturated carbonyl system with a fluorene ring as in com-
pound 2x exhibited significant increase in activity compared to
the compounds possessing other aromatic or heteroaromatic ring
systems, the order of activity was 2u (pyridin-2-yl) > 2w (naphtha-
len-2-yl) > 2v (pyridin-3- yl) > 2a (phenyl) > 2t (thiophen-2-yl),
respectively. It is noteworthy that enhanced level of activity was
observed when the phenyl ring of a,b-unsaturated carbonyl system
is substituted with different functional groups and decreased by
some other substituents. The order of activity was 2j (6-OH,5-
CH3) > 2d
(4-OCH3) > 2h
(2,5-diOH) > 2i
(2-OH,5-CH3) > 2g
(2,4-diOH) > 2f (4-OH) > 2p (4-Cl) > 2c (3-OCH3) > 2e (2-OH) > 2r
(4-F) > 2s (3,5-dibenzyloxy) > 2l (4-NH2) > 2b (4-CH3) > 2n (4-
NO2) > 2o (3-Cl) > 2k (3-NH2) > 2q (3-F) > 2m (3-NO2), respec-
tively. An ortho, meta and para substitution on the phenyl ring of
In order to gain insight into the putative binding mode of TZDs
(2a–x) with PPAR
lographic structure of human PPAR
c
, these compounds were docked with a crystal-
. The crystallographic struc-
c
ture was obtained from the Protein Data Bank (PDB), accession
a
,b-unsaturated carbonyl system with hydroxyl group may
increase the activity. A para-substitution on the phenyl ring of
,b-unsaturated carbonyl system with electron-donating groups
possibly will increase the activity. A para-substitution on the
phenyl ring of ,b-unsaturated carbonyl system with less electro-
code 3CS8.69 This is the unique study describing the molecular
docking of these TZDs (2a–x) with PPARc. Before docking TZDs,
the docking protocol of Molegro Virtual Docker (MVD) was
validated by predicting the binding mode of the crystallographic li-
gand (rosiglitazone), a full agonist of PPARc. The Figure 1 shows a
a
a
negative halogens compared to fluorine, such as chloro- may in-
crease the activity. On the other hand, molecular docking studies
were performed on a series of TZDs (2a–x) against PPARc target
comparison between binding mode of the crystallographic
ligand and the binding mode predicted by MVD. Figure 1 clearly
shows that MVD successfully predicted the binding mode of
crystallographic mode with a root-mean square (RMS) deviation
of 1.78 Ao.
protein 3CS8 to predict and compare the ligand conformation
and orientation of binding properties of TZDs (2a–x) with that of
the compound proven by experimental studies within the targeted
binding site region. The binding mode analyses of the compounds
TZDs (2a–x) with the active site residues provided important infor-
mation of the catalytic site.
With respect to the molecular modeling study, software Mole-
gro Virtual Docker (MVD) v 4.0.0 (www.molegro.com) along with
Graphical User Interface (GUI), MVD tools was utilized to generate
grid, calculate dock score and evaluate conformers. The structures
of title compounds (2a–x) were drawn using Chemdraw ultra v
10.0 (Chemical Structure Drawing Standard; Cambridge Soft corpo-
ration, USA), copied to Chem3D ultra v 10.0 to create a 3D model
and, finally subjected to energy minimization using molecular
mechanics (MM2). The minimization was executed until the root
Table 4
Synthesized TZDs (2a-x) with their Moldock scores and corresponding H-bond
interacting residues with 3CS8 (PPARc).
Compound
R
Moldock score
(kcal/mol)
No of H-bonds/interacting
residues
2a
2b
C6H5
4-MeC6H4
À133.14
3/Glu 259, Arg 280, Cys 285
5/Glu 259, Arg 280, Gly
284, Cys 285
À140.547
2c
2d
2e
2f
3-OMeC6H4
4-OMeC6H4
2-OHC6H4
4-OHC6H4
À152.395
À135.297
À139.881
À149.367
2/Cys 285, Gly 344
4/Glu 259, Glu 272, Arg 280
1/Phe 282
4/Pro 227, Leu 228, Leu
340, Gly 344
mean square gradient value reached
a value smaller than
0.001 kcal/mol. Such energy minimized structures are considered
for molecular docking studies. However, corresponding pdb files
were prepared using Chem3D ultra v 10.0 integral option (save
as /Protein Data Bank (pdb)). The selection of protein for molecular
docking studies is based upon several factors, that is, structure
should be determined by X-ray diffraction, and resolution should
be between 2.5–3.0 Ao, it should contain a co-crystallized ligand;
the selected protein should not have any protein breaks in their
3D structure. On the other hand, we considered Ramachandran
plot statistics as the important filter for protein selection with
none of the residues present in disallowed region. Finally the resul-
tant protein target was prepared for molecular docking simulation
in such a way that all heteroatoms (i.e., nonreceptor atoms such as
water, ions, etc) were removed. Kollmann charges were assigned.
2g
2h
2i
2,4-
diOHC6H3
2,5-
diOHC6H3
2-OH,5-
MeC6H3
6-OH,5-
MeC6H3
3-NH2C6H4
À142.347
À145.75
6/Glu 259, Cys 285, Arg 288
5/Glu 259, Cys 285, Arg 288
4/Glu 259, Cys 285
À144.919
À135.386
À145.035
À144.691
2j
2/Ile 281, Gln 345
2k
2l
5/Glu 259, Glu 272, Arg
280, Glu 291
5/Glu 259, Glu 272, Arg
280, Glu 291
4/Lys 261, Arg 288, Ser 342
1/Ile 281
1/Tyr 473
4/Arg 280, Cys 285
2/Glu 259
5/Glu 259, Glu 272, Arg
280, Glu 291
6/Leu 228, Lys 261, Gly
284, Arg 288, Glu 291
2/Ile 281, Arg 288
4-NH2C6H4
2m
2n
2o
2p
2q
2r
3-NO2C6H4
4-NO2C6H4
3-ClC6H4
4-ClC6H4
3-FC6H4
À120.87
À119.159
À143.839
À140.932
À140.733
À142.35
Among all the entries of PPARc proteins deposited in RCSB Protein
4-FC6H4
Data Bank (http://www.rcsb.org/pdb/home/home.do), 3CS8 was
selected for molecular docking analysis, where the residues were
bonded more closely to the rosiglitazone agonist, co-crystallized
2s
2t
3,5-
À204.925
À137.203
diC7H7OC6H3
Thiophen-2-
yl
Pyridin-2-yl
Pyridin-3-yl
Naphthalen-
2-yl
with PPAR
(LBD) forms a homodimer in which both monomers have nearly
identical C conformations. The structure of the ‘A’ monomer of
c. In this crystal structure, the Ligand Binding Domain
2u
2v
2w
À130.577
À130.181
À157.389
2/Ile 281, Arg 288
2/Ile 281, Arg 288
5/Glu 259, Glu 272, Arg
280, Glu 291
5/ Glu 259, Glu 272, Arg
280, Cys 285
a
the LBD homodimer was selected for docking studies. Molecular
docking was performed using MolDock67 docking engine of
software. The scoring function used by MolDock is derived from
the Piecewise Linear Potential (PLP) scoring functions.68 The active
binding site region was defined as a spherical region which
2x
Fluoren-2-yl
À170.113
À131.877
Rosiglitazone
—
4/His 449, Tyr 473, Cys 285

6448
V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
Figure 1. Superimposed binding orientation of the crystallographic ligand (pink) and docked conformer (green) predicted by MVD in the 3CS8 active binding site. The amino
acid residues are shown in stick model. The binding site residues involved are labeled (dark green).
The predicted binding energies and the corresponding hydrogen
bond forming residues for the TZDs (2a–x) are summarized in Ta-
ble 4. According to the crystallographic structure of rosiglitazone in
same observation is valid in the TZDs (2a–x) synthesized in the
present investigation, as they also consist of similar ,b-unsatu-
a
rated ketone moiety in the general structure. Finally, we evaluated
all the synthesized compounds for their in vivo antihyperglycemic
activity. The synthesized compounds were showed moderate anti-
hyperglycemic activity when compared to standard molecule,
though they have significant binding scores in silico. Therefore, this
correlation is less consistent, because the docking results are re-
lated exclusively to the ligand-receptor interaction, while the
experimental results take into account the pharmacokinetic param-
eters also.75 However, we did not analyze whether the antihyper-
glycemic effects of our compounds were derived from a PPAR
agonist effect, since we did not evaluate their direct effects or bind-
the Ligand Binding Domain (LBD) of PPARc, the thiazolidinedione
ring revealed some specific interactions with neighboring amino
acid residues of the LBD. These interactions include hydrogen
bonding with amino acids Cys 285, His 449 and Tyr 473 as reported
in the literature.70–72 The binding profile of TZDs (2a–x) was com-
pared with the profile of the rosiglitazone molecule. The Figure 2
(a–h) summarizes the binding modes and hydrogen bond interac-
tions of the pharmacologically active TZDs (2x, 2j, 2d and 2h) pre-
dicted by MVD. According to the docking models, all TZDs (2a–x)
were predicted to bind into the LBD, thus sharing a very similar
binding mode. Interestingly, we found the docking scores of TZDs
(2a–x) except 2m, 2n, 2u and 2v are favorable for the most stable
conformations (most negative docking energies ranging from
À204.925 to À133.14 kcal/mol) than that of the crystallographic
ligand (rosiglitazone) and it could be the remarkable in silico con-
firmation to evaluate these compounds for their in vivo antihyper-
glycemic activity.
ing affinities to the PPARc.
In summary, we could synthesis and characterize a series of
some novel 2,4-thiazolidinediones (2a–x). These compounds were
screened for cytotoxicity, antimicrobial and antihyperglycemic
activities and the results revealed the positive contribution of
a,b-unsaturated ketone and 2,4-thiazolidinedione moieties to-
wards the observed cytotoxicity, antimicrobial and antihypergly-
cemic properties. The structure-activity relationship studies
indicated that the introduction of an aromatic or heteroaromatic
However, the docking analysis of the TZDs (2a–x) in the present
study revealed the PPAR
lock’’ as seen in case of compounds 2a, 2b, 2c, 2g, 2h, 2i, 2p and
2x in silico binding covalently to Cys 285 within the PPAR
LBD.73
c activating process, termed ‘‘dock and
ring system at position 3 of the
a,b-unsaturated ketone bridge
c
plays a key role in determining the potency of observed pharmaco-
logical activities. Computational molecular docking study rational-
izes the selectivity and provides a binding model for the further
refinement of this chemo type. Therefore, this series of TZDs (2a–
x) have considerable promise for development as potential cyto-
toxic, antimicrobial and antihyperglycemic agents.
Thus these compounds suggested that the formation of a covalent
bond with Cys 285 causes a conformational transmission to the
receptor surface. We consequently found
group is the fundamental moiety of naturally occurring ligands to
exhibit PPAR
agonistic activity as reported earlier74 and also the
a,b-unsaturated ketone
c

V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
6449
Figure 2. (a) Compound 2x with PPAR
c
(3CS8). (b) Hydrogen bond interactions (green dashes) of predicted binding mode of 2x (orange). (c) Compound 2j with PPAR
c
(3CS8).
(d) Hydrogen bond interactions (green dashes) of predicted binding mode of 2j (white). (e) Compound 2d with PPAR
predicted binding mode of 2d (blue). (g) Compound 2h with PPAR (3CS8). (h) Hydrogen bond interactions (green dashes) of predicted binding mode of 2h (pink). It shows
the binding mode and hydrogen bond interactions of active ligands in the ligand binding site. The side chains of the residues are shown in stick model. Blue ribbon represents
the secondary structure of the protein PPAR (3CS8).
c (3CS8). (f) Hydrogen bond interactions (green dashes) of
c
c

6450
V. R. Avupati et al. / Bioorg. Med. Chem. Lett. 22 (2012) 6442–6450
27. Xia, Z.; Knaak, C.; Ma, J.; Beharry, Z. M.; McInnes, C.; Wang, W.; Kraft, A. S.;
Acknowledgments
Smith, C. D. J. Med. Chem. 2009, 52, 74.
28. Zhou, C.; Tang, C.; Chang, E.; Ge, M.; Lin, S.; Cline, E.; Tan, C. P.; Feng, Y.; Zhou, Y.
P.; Eiermann, G. J.; Petrov, A.; Salituro, G.; Meinke, P.; Mosley, R.; Akiyama, T.
E.; Einstein, M.; Kumar, S.; Berger, J.; Howard, A. D.; Thornberry, N.; Mills, S. G.;
Yang, L. Bioorg. Med. Chem. Lett. 2010, 20, 1298.
29. Zidar, N.; Toma, T.; Sink, R.; Rupnik, V.; Kova, A.; Turk, S.; Patin, D.; Blanot, D.;
Contreras, C.; Martel, M.; Dessen, A.; Premru, M. M.; Zega, A.; Gobec, S.; Ma, L.
P.; Kikelj, D. J. Med. Chem. 2010, 53, 6584.
30. Carroll, R. T.; Dluzen, D. E.; Stinnett, H.; Awale, P. S.; Funk, M. O.; Geldenhuys,
W. J. Bioorg. Med. Chem. Lett. 2011, 21, 4798.
31. Youssef, A. M.; White, M. S.; Villanueva, E. B.; ElAshmawy, I. M.; Klegeris, A.
Bioorg. Med. Chem. 2010, 18, 2019.
One of the authors (Vasudeva Rao Avupati) is thankful to the
Council of Scientific and Industrial Research (CSIR), Government
of India, New Delhi for providing Senior Research Fellowship
(SRF). We also thank Dr. Rene Thomsen, Molegro ApS (www.mole-
gro.com), Denmark for providing software Molegro Virtual Docker
to carry out computational studies and to the Principal, Andhra
University College of Pharmaceutical Sciences, Visakhapatnam for
providing required help in carrying out the pharmacological
activities.
32. Kumar, S. K.; Hager, E.; Catherine, P.; Gurulingappa, H.; Davidson, N. E.; Khan, S.
R. J. Med. Chem. 2003, 46, 2813.
33. Rao, Y. K.; Fang, S.; Tzeng, Y. Bioorg. Med. Chem. 2004, 12, 2679.
34. Peyrot, V.; Leynadier, D.; Sarrazin, M.; Briand, C.; Rodriquez, A.; Nieto, J. M.;
Andreu, J. M. J. Biol. Chem. 1989, 264, 21296.
Supplementary data
35. Peyrot, V.; Leynadier, D.; Sarrazin, M.; Briand, C.; Menendez, M.; Laynez, J.;
Andreu, J. M. Biochemistry 1992, 31, 11125.
36. Kitamura, S.; Miyazaki, Y.; Shinomura, Y.; Kondo, S.; Kanayama, S.; Matsuzawa,
Y. Jpn. J. Cancer Res. 1999, 90, 75.
37. Takashima, T.; Fujiwara, Y.; Higuchi, K.; Arakawa, T.; Yano, Y.; Hasuma, T.;
Otani, S. Int. J. Oncol. 2001, 19, 465.
38. Yoshizumi, T.; Ohta, T.; Ninomiya, I.; Terada, I.; Fushida, S.; Fujimura, T.;
Nishimura, G.; Shimizu, K.; Yi, S.; Miwa, K. Int. J. Oncol. 2004, 25, 631.
39. Li, M.; Lee, T. W.; Mok, T. S.; Warner, T. D.; Yim, A. P.; Chen, G. G. J. Cell. Biochem.
2005, 96, 76.
Supplementary data (Supplementary material that may be
helpful in the review process should be prepared and provided as
a separate electronic file. That file can then be transformed into
PDF format and submitted along with the manuscript and graphic
files to the appropriate editorial office.) associated with this article
can be found, in the online version, at http://dx.doi.org/10.1016/
j.bmcl.2012.08.052.
40. Lopez, S. N.; Castelli, M. V.; Zacchino, S. A.; Dominguez, J. M.; Lobo, G.; Jaime, C.
C.; Cortes, J. C. G.; Ribas, J. C.; Devia, C.; Ana, M. R.; Ricardo, D. E. Bioorg. Med.
Chem. 2001, 9, 1999.
References and notes
41. Bandgar, B. P.; Gawande, S. S. Bioorg. Med. Chem. 2010, 18, 2060.
42. Bandgar, B. P.; Patil, S. A.; Korbad, B. L.; Nile, S. H.; Khobragade, C. N. Eur. J. Med.
Chem. 2010, 45, 2629.
43. Chen, Z. H.; Zheng, C. J.; Sun, L. P.; Piao, H. R. Eur. J. Med. Chem. 2010, 45, 5739.
44. Nasr, M. N.; Gineinah, M. M.; El-Bendary, E. R. Arch. Pharm. 2003, 336, 560.
45. DeLima, M. C. A.; Costa, D. L. B.; Goes, A. J. S.; Galdino, S. L.; Pitta, I. R.; Luu-Duc,
C. Pharmazie 1992, 47, 182.
1. Cantello, B. C. C.; Cawthorne, M. A.; Cottam, G. P.; Duff, P. T.; Haigh, D.; Hindley,
R. M.; Lister, C. A.; Smith, S. A.; Thurlby, P. L. J. Med. Chem. 1994, 37, 3977.
2. Lohray, B. B.; Bhushan, V.; Rao, B. P.; Madhavan, G. R.; Murali, N.; Rao, K. N.;
Reddy, A. K.; Rajesh, B. M.; Reddy, P. G.; Chakrabarti, R.; Vikramadithyan, R. K.;
Rajagopalan, R.; Mamidi, R. N. V. S.; Jajoo, H. K.; Subramaniam, S. J. Med. Chem.
1998, 41, 1619.
3. Prabhakar, C.; Madhusudhan, G.; Sahadev, K.; Maheedhara Reddy, C.; Sarma, M.
R.; Om Reddy, G.; Chakrabarti, R.; Seshagiri Rao, C.; Dileep Kumar, T.;
Rajagopalan, R. Bioorg. Med. Chem. Lett. 1998, 8, 2725.
4. Sunduru, N.; Srivastava, K.; Rajakumar, S.; Puri, S. K.; Saxena, J. K.; Chauhan, P.
M. S. Bioorg. Med. Chem. Lett. 2009, 19, 2570.
46. Labouta, I. M.; Salama, H. M.; Eshba, N. H.; Kader, O.; El-Chrbini, E. Eur. J. Med.
Chem. 1987, 22, 485.
47. Chandrakant, G. B.; Naresh, J. G. Bioorg. Med. Chem. 2004, 12, 2151.
48. Rong Min, C.; Li Hong, H.; Tian Ying, A.; Jia, L.; Qiang, S. Bioorg. Med. Chem. Lett.
2002, 12, 3387.
5. Reddy, K. A.; Lohray, B. B.; Bhushan, V.; Reddy, A. S.; Kishore, P. H.; Rao, V. V.;
Saibaba, V.; Bajji, A. C.; Rajesh, B. M.; Reddy, K. V.; Chakrabarti, R.; Rajagopalan,
R. Bioorg. Med. Chem. Lett. 1998, 8, 999.
6. Hafez, H. N.; ElGazzar, A. R. B. A. Bioorg. Med. Chem. Lett. 2009, 19, 4143.
7. Patil, V.; Tilekar, K.; Munj, S. M.; Mohan, R.; Ramaa, C. S. Eur. J. Med. Chem. 2010,
45, 4539.
49. Severi, F.; Benvenuti, S.; Constantino, L. C.; Vampa, G.; Antolini, L. Eur. J. Med.
Chem. 1998, 3, 859.
50. Seo, W. D.; Kim, J. H.; Kang, J. E.; Ryu, H. W.; Long, M. J. C.; Lee, H. S.; Yang, M. S.;
Park, K. H. Bioorg. Med. Chem. Lett. 2005, 15, 5514.
51. Bharatham, K.; Bharatham, N.; Park, K. H.; Lee, K. L. J. Mol. Graphics Modell.
2008, 26, 1202.
8. Bonde, C. G.; Gaikwad, N. J. Bioorg. Med. Chem. 2004, 12, 2151.
9. Fan, Y. H.; Chen, H.; Natarajan, A.; Guo, Y.; Harbinski, F.; Iyasere, J.; Christ, W.;
Aktasa, H.; Halperina, J. A. Bioorg. Med. Chem. Lett. 2004, 14, 2547.
10. Jeon, R.; Park, S. Y. Arch. Pharm. Res. 2004, 27, 1099.
11. Madhavan, G. R.; Chakrabarti, R.; Reddy, K. A.; Rajesh, B. M.; Balraju, V.; Rao, P.
B.; Rajagopalan, R.; Iqbal, J. Bioorg. Med. Chem. 2006, 14, 584.
12. Hossain, S. U.; Bhattacharya, S. Bioorg. Med. Chem. Lett. 2007, 17, 1149.
13. Jeong, T.; Kim, J.; Kim, K. S.; Cho, K.; Bae, K.; Lee, W. S. Bioorg. Med. Chem. 2004,
12, 4017.
52. Spiegelman, B. M. Diabetes 1998, 47, 507.
53. Iwata, Y.; Miyamoto, S.; Takamura, M.; Yanagisawa, H.; Kasuya, A. J. Mol.
Graphics Modell. 2001, 19, 536.
54. Boyle, P. J.; King, A. B.; Olansky, L.; Marchetti, A.; Lau, H.; Magar, R.; Martin, J.
Clin. Ther. 2002, 24, 378.
55. Nolte, R. T.; Wisely, G. B.; Westin, S.; Cobb, J. E.; Lambert, M. H.; Kurokawa, R.;
Rosenfeld, M. G.; Willson, T. M.; Glass, C. Nature 1998, 395, 137.
56. Momose, Y.; Meguro, K.; Ikeda, H.; Hatanaka, C.; Oi, S.; Sohda, T. Chem. Pharm.
Bull. 1991, 39, 1440.
14. Martinez, M.; Alonso, A.; Castro, I.; Dorronsoro, J. L.; Gelp, F. J.; Luque, C.; Perez,
F. J.; Moreno, M. J. Med. Chem. 2005, 48, 7103.
15. Sambasivarao, S. V.; Soni, L. K.; Gupta, A. K.; Hanumantharao, P.; Kaskhedikar,
S. G. Bioorg. Med. Chem. Lett. 2006, 16, 512.
16. Heng, S.; Tieu, W.; Hautmann, S.; Kuan, K.; Pedersen, D. S.; Pietsch, M.;
Gutschow, M.; Abell, A. D. Bioorg. Med. Chem. 2011, 19, 7453.
17. Wu, Y.; Tai, H. H.; Cho, H. Bioorg. Med. Chem. 2010, 18, 1428.
18. Hu, B.; Ellingboe, J.; Gunawan, I.; Han, S.; Largis, E.; Li, Z.; Malamas, M.; Mulvey,
R.; Oliphant, A.; Sum, F.; Tillett, J.; Wong, V. Bioorg. Med. Chem. Lett. 2001, 11,
757.
57. Bruno, G.; Costantino, L.; Curinga, C.; Maccari, R.; Monforte, F.; Nicolo, F.;
Ottana, R.; Vigorita, M. G. Bioorg. Med. Chem. 2002, 10, 1077.
58. Jung, S. H.; Park, S. Y.; Kim-Pak, Y.; Lee, H. K.; Park, S. Y.; Shin, K. H.; Ohuchi, K.;
Shin, H. K.; Keum, S. R.; Lim, S. S. Chem. Pharm. Bull. 2006, 54, 368.
59. Liu, X. F.; Zheng, C. J.; Sun, L. P.; Liu, X. K.; Piao, H. R. Eur. J. Med. Chem. 2011, 46,
3469.
60. Zuping, X.; Christian, K.; Jian, M.; Zanna, M.; Beharry, C. M.; Wenxue, W.;
Andrew, S. K.; Charles, D. S. J. Med. Chem. 2009, 52, 74.
61. Meyer, B. N.; Ferrigni, N. R.; Putnam, J. E.; Jacobsen, L. B.; Nichols, D. E.;
McLaughlin, J. L. Planta Med. 1982, 45, 31.
19. Koide, Y.; Tatsui, A.; Hasegawa, T.; Murakami, A.; Satoh, S.; Yamada, H.;
Kazayamaa, S.; Takahashia, A. Bioorg. Med. Chem. Lett. 2003, 13, 25.
20. Brooke, E. W.; Davies, S. G.; Mulvaney, A. W.; Okada, M.; Pompeo, F.; Sim, E.;
Vickersa, R. J.; Westwooda, I. M. Bioorg. Med. Chem. Lett. 2003, 13, 2527.
21. Alcaraz, L.; Baxter, A.; Bent, J.; Bowers, K.; Braddock, M.; Cladingboel, D.;
Donald, D.; Fagura, M.; Furber, M.; Laurent, C.; Lawson, M.; Mortimore, M.;
McCormick, M.; Robertsa, N.; Robertson, M. Bioorg. Med. Chem. Lett. 2003, 13,
4043.
62. Finney, D. J. Probit Analysis, 3rd ed.; Cambridge University Press: London, 1971.
63. NCCLS Approved Standard M-27-A, 17(9) Villanova, PA, 19997.
64. NCCLS Approved Standard M7-A, Villanova, PA, 1997.
65. National Committee for Clinical Laboratory Studies (1998), Performance
Standards For Antimicrobial Susceptibility.
66. Tim, K. I. Lab. Anim. Sci. 1979, 29, 636.
67. Thomsen, R.; Christensen, M. H. J. Med. Chem. 2006, 49, 3315.
68. Yang, J. M.; Chen, C. C. Proteins 2004, 55, 288.
22. Komatsu, T.; Hirano, T.; Songkram, C.; Kawachi, E.; Kagechika, H. Bioorg. Med.
Chem. 2007, 15, 3115.
69. Li, Y.; Kovach, A.; Suino Powell, K.; Martynowski, D.; Xu, H. E. J. Biol. Chem.
2006, 28, 19132.
23. Bhattarai, B. R.; Kafle, B.; Hwang, J. S.; Ham, S. W.; Lee, K. H.; Park, H.; Han, I. O.;
Cho, H. Bioorg. Med. Chem. Lett. 2010, 20, 6758.
70. Gampe, R. T.; Montana, V. G.; Lambert, M. H. Mol. Cell 2000, 5, 545.
71. Nolte, R. T.; Wisely, G. B.; Westin, S. Nature 1998, 395, 137.
72. Pochetti, G.; Godio, C.; Mitro, N. J. Biol. Chem. 2007, 282, 17314.
73. Shiraki, T.; Kamiya, N.; Shiki, S.; Nakagawa, T.; Jingami, H. J. Biol. Chem. 2006,
393, 749.
74. Shiraki, T.; Kamiya, N.; Shiki, S.; Kodama, T. S.; Jingami, H. J. Biol. Chem. 2005,
280, 14145.
75. Lipinski, C. A. Adv. Drug Delivery Rev. 1997, 23, 3.
24. Ottana, R.; Maccari, R.; Ciurleo, R.; Paoli, P.; Jacomelli, M.; Manao, G.; Camici,
G.; Laggner, C.; Langer, T. Bioorg. Med. Chem. 2009, 17, 1928.
25. Li, Q.; AlAyoubi, A.; Guo, T.; Zheng, H.; Sarkar, A.; Nguyen, T.; Eblen, S. T.; Grant,
S.; Kellogg, G. E.; Zhang, S. Bioorg. Med. Chem. Lett. 2009, 19, 6042.
26. Li, Q.; Wu, J.; Zheng, H.; Liu, K.; Guo, T. L.; Liu, Y.; Eblen, S. T.; Grant, S.; Zhang, S.
Bioorg. Med. Chem. Lett. 2010, 20, 4526.