Synthesis and biological activity of 4-aryl-3-benzoyl-5- phenylspiro[pyrrolidine-2.3′-indolin]-2′-one derivatives as novel potent inhibitors of advanced glycation end product

Article abstract of DOI:10.1016/j.ejmech.2014.04.022

Diabetic complications and their detrimental effects caused by sugar derived substances, have been the serious issue for the last few years and have yet not been fully combated. The key point of the present study is to synthesize some newer chemical entities which can eradicate such ailments to the maximum possible extent. So with this aim synthesis of some biologically interesting spiro-indolone-pyrrolidine derivatives was accomplished by 1,3-dipolar cycloaddition reaction of azomethine ylide 6 generated in situ from isatin and benzyl amine with the substituted α,β-unsaturated carbonyl compounds 3 as dipolarophile, leading to the formation of new 4-aryl-3-benzoyl-5- phenylspiro[pyrrolidine-2.3′-indolin]-2′-one derivatives 7 stereoselectively in excellent yields. The synthesized compounds have been screened for their advanced glycation end (AGE) product formation inhibitory activity on the basis of their ability to inhibit the formation of AGEs in the bovine serum albumin (BSA)-glucose assay and have been found to exhibit significant activity against AGE formation.

Full text of DOI:10.1016/j.ejmech.2014.04.022

European Journal of Medicinal Chemistry 79 (2014) 282e289
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and biological activity of 4-aryl-3-benzoyl-5-phenylspiro
[pyrrolidine-2.30-indolin]-20-one derivatives as novel potent inhibitors
of advanced glycation end product
,
a
b
Anjandeep Kaur a, Baldev Singh a , Bhawna Vyas , Om Silakari
*
a Department of Chemistry, Punjabi University, Patiala 147002, India
b Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Diabetic complications and their detrimental effects caused by sugar derived substances, have been the
serious issue for the last few years and have yet not been fully combated. The key point of the present
study is to synthesize some newer chemical entities which can eradicate such ailments to the maximum
possible extent. So with this aim synthesis of some biologically interesting spiro-indolone-pyrrolidine
derivatives was accomplished by 1,3-dipolar cycloaddition reaction of azomethine ylide 6 generated in
Received 18 November 2013
Received in revised form
11 March 2014
Accepted 5 April 2014
Available online 8 April 2014
situ from isatin and benzyl amine with the substituted
a,b-unsaturated carbonyl compounds 3 as
dipolarophile, leading to the formation of new 4-aryl-3-benzoyl-5-phenylspiro[pyrrolidine-2.30-indolin]-
20-one derivatives 7 stereoselectively in excellent yields. The synthesized compounds have been
screened for their advanced glycation end (AGE) product formation inhibitory activity on the basis of
their ability to inhibit the formation of AGEs in the bovine serum albumin (BSA)-glucose assay and have
been found to exhibit significant activity against AGE formation.
Keywords:
Azomethine ylide
Pyrrolidine
Cycloaddition
Stereoselective
Antiglycation
Ó 2014 Elsevier Masson SAS. All rights reserved.
1. Introduction
undergo Amadori rearrangement along with subsequent oxidation,
dehydration and cyclization to form stable AGEs. The consequence
Diabetes mellitus (DM) is a long-term issue, characterized by a
state of fasting hyperglycemia [1]. DM and its complications, arising
subsequently wizard macrovascular (coronary artery disease,
stroke) and microvascular (retinopathy, neuropathy, nephropathy,
and other microangiopathies) are the fourth most important causes
of mortality. Hyperglycemia is one of the causative factors of dia-
betic complications, like atheroma, hypertension and micro-
angiopathy. Its detrimental effects are mostly attributed to the
formation of sugar-derived substances called advanced glycation
end products (AGEs) [2]. The presence of advanced glycation end
products (AGEs) is closely related to hyperglycemia and their
patho-biochemistry could explain many of the changes observed in
diabetes related complications. AGEs are a heterogeneous group of
molecules formed by the non-enzymatic reaction of reducing
sugars and the free amino groups of proteins, lipids, and nucleic
acids [3]. Sugars react reversibly with the amino groups in those
macromolecules to form Schiff’s base adducts which further
of AGE formation is the reticulation of proteins. This phenomenon
has been observed in long-lived proteins such as tissue collagen,
lens crystallin, fibronectin, tubulin, laminin, actin, hemoglobin, al-
bumin and lipids associated with low-density lipoproteins. The
formation and accumulation of increased AGEs have been impli-
cated in the development of cataracts, uremia, atherosclerosis,
Alzheimer’s disease, Parkinson’s disease and above all, clinical
complications of type 2 diabetes, such as micro- and macro-
angiopathy, retinopathy, nephropathy, neuropathy and ulcer [4e
12].
The valuable and diverse biological activity of molecules con-
taining pyrrole, spiropyrrolidine, spiro-indolone-pyrrolidine, pyr-
rolidinone and indole moieties confers on them
a high
pharmacological value. Spiropyrrolidine and oxindole or indolone
ring system forms the core structure of many pharmacological
agents and alkaloids which find use as indigenous medicine [13e
19]. Spiro-indole-pyrrolidine derivatives exhibit a wide array of
biological activities like anti-bacterial [20,21] anti-fungal [22],
acetylcholinesterase inhibitors [23], anti-cancer [24] anti-
inflammatory [25], anti-tubercular [26,27], anti-leukemic [28]
anti-convulsant [29] and anti-viral [30].
* Corresponding author.
E-mail
addresses:
singhbldv52@gmail.com,
drbaldev.chem@yahoo.com
(B. Singh).
http://dx.doi.org/10.1016/j.ejmech.2014.04.022
0223-5234/Ó 2014 Elsevier Masson SAS. All rights reserved.

A. Kaur et al. / European Journal of Medicinal Chemistry 79 (2014) 282e289
283
Differently substituted spiropyrrolidine-tetrones derivatives
were reported to be active for the inhibition of aldose reductase
activity, the enzyme responsible for diabetic complications [31,32].
Ko et al. and Kim et al. reported the aldose reductase inhibitory
activity of spirosuccinimides which are pyrrolidine-dione de-
rivatives [33,34]. Substituted piperidinyl glycinyl 2-cyano-4,5-
methano pyrrolidines and cyano-pyrrolidine derivatives were
evaluated as potent and stable dipeptidyl peptidase IV inhibitors,
thus useful for the treatment of diabetes [35,36]. Many pyrrolo[1,2-
c]imidazole-1,3-dione moieties and their analogs rosiglitazone and
pioglitazone have been developed as potent inhibitors of aldose
reductase and were proposed as anti-diabetic agents [37,38]. Pol-
yhydroxylated pyrrolizidine alkaloids, Uniflorine and Alexine, and
many dispiropyrrolidine derivatives synthesized through 1,3-
dipoar cycloaddition of azomethine ylides have also been found
to be anti-diabetic in nature [39e41].
Many hexahydro-pyridoindole derivatives serve as a potential
remedy for diabetes induced abnormalities due to their aldose
reductase inhibitory activity [42,43]. Li et al. evaluated the insulin
sensitizing and glucose lowering abilities of indole derivatives [44].
Indolyl-carboxylate moieties act as dual action anti-diabetic agents
that inhibit glycogen phosphorylase and activate glucokinase [45].
Dong et al. have also reported that indole derivatives possess potent
PPARc protein binding activity comparable to rosiglitazone [46].
The anti-diabetic activity of fluorinated spiro-indole-thiazinones/
thiazolidinones was also comparable to the standard drug Met-
formin [47]. Pyrimido[1,2-a]indole moieties have also been used as
oral hypoglycemic agents [48].
carbonyl compounds i.e. chalcones 3 (Scheme 1) were synthesized
by following the procedure as reported in literature [53]. This
cycloaddition proceeded in a highly regio- and stereocontrolled
fashion to afford single product i.e. 4-aryl-3-benzoyl-5-phenylspiro
[pyrrolidine-2.30-indolin]-20-one derivatives (7a-i), as indicated by
TLC in excellent yields (Scheme 2). This cycloaddition is regiose-
lective with the electron-rich carbon of the dipole adding to the
b-
carbon of the -unsaturated moiety of 3a-i, and is stereoselective,
a,b
affording only one diastereomer exclusively, despite the presence
of three stereocenters in the product as found in many similar
cycloaddition studies [54,55].
Structural elucidation of the 4-aryl-3-benzoyl-5-phenylspiro
[pyrrolidine-2.30-indolin]-20-ones was unambiguously accom-
plished by using one and two dimensional spectroscopic tech-
niques (IR, 1H NMR, 13C NMR, 1H-1H COSY, NOESY, D2O-exchange,
ESI-MS) and elemental analyses data as described for 7a. In the IR
spectrum of 3-benzoyl-4,5-diphenylspiro[pyrrolidine-2.30-indo-
lin]-20-one (7a) the -NH group of indolone moiety exhibited a sharp
absorption peak at higher frequency i.e. 3338 cmꢀ1 due to the
presence of adjacent carbonyl group while the peak at lower fre-
quency 3210 cmꢀ1 was assigned to -NH group of pyrrolidine ring. A
strong absorption band at 1701 cmꢀ1 was due to indolone carbonyl
moiety and a shoulder band at 1686 cmꢀ1 due to benzoyl carbonyl.
However, in the 1H-NMR spectrum it displayed a singlet at
(1H for -NH group of indolone moiety), multiplet signal at
d
10.41
7.45-
d
6.42 (equivalent to 19H, Ar-H), a broad doublet at
d 4.99 (1H, H-5)
due to its coupling with H-4 (J ¼ 10.24 Hz) and broad nature due to
further slight interaction with 1N-H proton, another doublet at
Jang et al. reported the advanced glycation end product for-
mation inhibitory activity of pyrrolidinone epicathechins [49].
Pyrrolidine-carboxamide and pyrrolidine-carbothioamide de-
rivatives were also reported as advanced glycation end product
inhibitors by Shantharam et al. [50]. Khan et al. reported the
indolone based bis-Schiff bases of isatin to exhibit advanced gly-
cation end product inhibitory activity [51].
d
4.61 (1H, H-3) due to coupling with proton H-4 (J ¼ 10.56 Hz) and
a broad triplet at
d
4.04 (2H, H-4 and 1N-H) due to coupling of H-4
with both the protons H-3 and H-5 (J ¼ 10.44 Hz) and the distorted
nature of triplet due to mergence of 1N-H peak in this triplet. The
presence of -NH protons was further supported by measuring the
1H-NMR spectra in the presence of D2O as discussed in Supporting
information (Fig. 1 in Supporting information).
Thus the spiro-indolone-pyrrolidine moieties serve as versatile
synthetic intermediates with immense biological activities
including a potential to inhibit advanced glycation end product
formation. So in continuation with our previous research activity
directed towards construction of pyrrolo-isoxazolidines as bio-
active heterocycles especially those associated with advance gly-
cation end product formation inhibitory activity [52], the present
study has been designed to synthesize variously substituted spiro-
indolone-pyrrolidines from azomethine ylide substrates and to
evaluate these compounds for their advanced glycation end-
product formation inhibitory activity. The finding that spiro-indo-
lone-pyrrolidine moieties display high efficacy in AGE-inhibitory
activity may open up new avenues for the development of thera-
peutics targeted against protein glycation in hyperglycemic
conditions.
Further confirmation of the structure comes from the 2-
dimensional 1H,1H-COSY spectrum (Fig.
2
in Supporting
information). As evident from the 1H-NMR spectrum, the most
downfield doublet in the aliphatic region at 4.99 was assigned to
d
proton H-5 of the pyrrolidine ring due to the presence of an adja-
cent nitrogen atom and its identification triggers the assignment of
all the connected protons in the ring by its 1H,1H-COSY spectral
analysis. From the 1H,1H-COSY correlation of H-5 (off diagonal cross
peaks at
assigned to the adjacent proton i.e. H-4. Further from the COSY
correlation of proton H-4, as evident from the cross peaks at 4.04/
4.61 (J ¼ 10.56 Hz) was assigned to the
d
4.99/4.04), the triplet at
d
4.04 (J ¼ 10.44 Hz) was
d
4.61, the doublet at
adjacent H-3 proton.
d
In the NOESY (Fig. 3 in Supporting information and Fig. 1)
spectrum, there existed correlation cross peaks from protons H-3/
The theoretical calculations of frontier molecular orbital (FMO)
energies have proven to be an important tool in these reactions for
predicting the stability of the synthesized products and evaluating
the mechanism and reactivity of azomethine ylide cycloadditions,
on the basis of both thermodynamic and kinetic aspects.
H-5 at
Further the cross peaks from protons H-3/(H-2000, H-6000) at
7.30 and H-5/(H-2000, H-6000) at
4.99/7.30 indicated the spatial
d
4.62/4.99 showing the syn-geometry of these protons.
d
4.62/
d
proximity of H-3 and H-5 with the C4-phenyl ring protons which
signified the cis-relationship between H-3, H-5 and C4-phenyl ring.
The syn-geometry of H-4 and C5-phenyl ring was evident from the
2. Results and discussion
off diagonal cross peaks at d ,
4.04/7.34 due to protons H-4/(H-20000
H-60000). Besides this -NH proton of indolone ring also revealed the
cross peak with proton H-70 proving these protons to lie in the same
plane.
2.1. Chemistry
Our synthetic approach was based on a three-component
strategy involving the 1,3-dipolar cycloaddition between a,b-un-
The 13C-NMR spectrum of 7a exhibited the presence of two
carbonyl carbons, one due to benzoyl and another due to indolone
saturated carbonyl compounds 3aei and non stabilized azome-
thine ylide, generated in situ via condensation of isatin and benzyl
moiety at
omatic carbons in the region of
the pyrrolidine ring appeared as the most downfield signal at
d
196.76 and
d
181.72 respectively and the signals of ar-
d
141.36-108.90. The spiro carbon of
amine in refluxing methanol. The starting,
a,b-unsaturated

284
A. Kaur et al. / European Journal of Medicinal Chemistry 79 (2014) 282e289
Scheme 1. Schematic diagram describing the synthesis of differently substituted chalcones.
Scheme 2. Schematic diagram describing the synthesis of cycloadducts from differently substituted chalcones and azomethine ylide.
activity by following the similar procedure as reported in the
literature [56]. The potential of the compounds 7a-i to inhibit AGEs-
formation is summarized in Table 1. All the synthesized compounds
have shown considerable advanced glycation end product forma-
tion inhibitory activity as the fluorescence of AGEs was shown to be
remarkably inhibited by all the synthesized compounds. Among
the variously synthesized 4-aryl-3-benzoyl-5-phenylspiro[pyrroli-
dine-2.30-indolin]-20-one derivatives the compounds 7a, 7c, 7d, 7e
and 7h were more potent than the standard drug aminoguanidine.
The most active compound 7a (IC50 ¼ 11.37 ꢁ 0.52
times while the compounds 7c (IC50 ¼ 20.67 ꢁ 3.63
(IC50 ¼ 19.57 ꢁ 1.31 M) and 7h (IC50 ¼ 21.23 ꢁ 0.91 M) were twice
more active than the standard drug aminoguanidine
m
M) was four
mM), 7e
m
m
(IC50 ¼ 40.54 ꢁ 2.0
m
m
M). Further, the potency of compound 7d
M) was comparable to the standard drug.
(IC50 ¼ 39.67 ꢁ 1.42
However, the compounds 7b, 7f, 7h and 7i exhibited lower anti-
glycation activity as compared to the standard drug having IC50
values 111.45
104.49 ꢁ 1.78
ꢁ
3.02, 57.31
ꢁ
2.56, 97.77
ꢁ
3.64 and
Fig. 1. Structure of compound 7a and NOE correlation.
m
M respectively. The graphical representation of this
data has also been shown in the form of bar graphs in Fig. 2.
As evident from the results, among all the synthesized com-
pounds, the compound with no substitution (7a) was found out to
be the most active, which may be due to its small size and simple
nature which may enhance the binding abilities. The compounds
7c, 7d, 7e and 7h having substituents capable of forming hydrogen
bonds i.e. eOCH3, eNO2, eOH, exhibited better activity than the
compounds having substituents incapable of showing such
bonding interactions. This suggests the better bonding of such
compounds with the protein (albumin) molecule via hydrogen
bonds and inhibition of AGEs-formation. Further among these
compounds, the compound having 4-OH substitution was the most
active followed by the compounds with 4-OCH3, 3,4-(OCH3)2 and 4-
NO2 substitution, which suggests that the compounds with
d
67.52 among all the carbons of this ring while the peak at
was regarded due to C-3 because of an adjacent carbonyl group of
benzoyl moiety. While signal at 61.90 was assigned to C-5 due to
presence of an adjacent nitrogen atom of pyrrolidine ring and
d 67.06
d
another most upfield signal at
d 55.13 was due to C-4. The mass
spectrum of 7a revealed the molecular ion peak [Mþ þ 1] at m/z 445
and similar peak pattern was obtained with other derivatives of 4-
aryl-3-benzoyl-5-phenylspiro[pyrrolidine-2.30-indolin]-20-one.
2.2. Advanced glycation end product formation inhibitory activity
All the synthesized compounds 7a-i were subjected to in vitro
bioassay to Advanced Glycation End Product formation inhibitory

A. Kaur et al. / European Journal of Medicinal Chemistry 79 (2014) 282e289
285
Table 1
the LUMO is directly related to the electron affinity and charac-
terizes the susceptibility of the molecule toward attack by nucle-
ophiles. The energy minimized diagrams of all the reactants and the
synthesized products are given in Figs. 6 and 7 in Supporting
information.
Advanced glycation end-product formation inhibitory activity of 4-aryl-3-benzoyl-
5-phenylspiro[pyrrolidine-2.30-indolin]-20-one derivatives (7a-i).
Table 2 (Supporting information) lists the HOMO and LUMO
energies for 1,3-dipole 6 and variously substituted dipolarophiles
3a-i together with the FMO energy gaps (eV), calculated by using
Schrödinger (9.3) software. We conclude that the different 1,3-
dipoles react with dipolarophiles under a HOMOdipole-LUMOdipo-
control, or in a normal electron-demand fashion, because
larophile
the values of HOMOdipole-LUMOdipolarophile were lower than the
corresponding HOMOdipolarophile-LUMOdipole
Table 3 given in supporting information shows the values of the
electronic chemical potentials ( ), chemical hardness and the
electrophilicity indices of the reactants ( ). The electronic chemical
potentials (opposite of electronegativity of a species) of all the
Entry
1
Compounds
R
IC50 (mM)
.
m
h
7a
11.37 ꢁ 0.52
111.45 ꢁ 3.02
20.67 ꢁ 3.63
39.67 ꢁ 1.42
19.57 ꢁ 1.31
57.31 ꢁ 2.56
u
m
dipolarophiles 3a-i are smaller than that of dipole 6 indicating that
charge transfer will take place from the dipole to the dipolar-
2
3
4
5
6
7b
7c
7d
7e
7f
ophiles. Moreover, the electrophilicity index
u (a measure of sta-
bilization of a species that arises from accepting charge), of all the
dipolarophiles (3a-i) is higher than that of dipole 6, consequently
dipolarophiles will act as electrophile where as dipole will act as
nucleophile, and hence the reaction between 3a-i and 6 belongs to
normal electron demand (NED) type. Thus the analysis of HOMO/
LUMO energy gaps, electronic chemical potentials and electrophi-
licity indices all indicate a normal electron demand character for
the reaction. The electronic chemical potential
m, chemical hard-
ness and electrophilicity index were evaluated in terms of the
h
u
energies of FMOs i.e. HOMO and LUMO, using Eqs. (1)e(3)
respectively:
m
h
¼ εHOMO þ εLUMO=2
(1)
(2)
7
8
7g
7h
97.77 ꢁ 3.64
21.23 ꢁ 0.91
¼ εHOMO ꢀ εLUMO
.
u
¼
m2
2
h
(3)
Furthermore the relative reactivities of different dipolarophiles
in 1,3-dipolar cycloaddition reactions correlate with the HOMOdi-
pole-LUMOdipolarophile energy gap which is helpful in determining
the kinetic aspects of the reaction and thus help in the selection of
the best candidate for the reaction. Time taken by variously
substituted reactants to undergo cycloaddition can be explained by
the correlation with their HOMOdipole-LUMOdipolarophile energy gaps
(Table 4 in Supporting information). The results indicate that
electron donating substituents on C4-phenyl ring decrease the
reactivity of the dipolarophiles by raising the LUMO energy thus
increasing the HOMOdipole-LUMOdipolarophile energy gap while
electron withdrawing substituents increase the reactivity by
decreasing the energy of LUMO thus decreasing the energy gap. The
N,N-dimethyl substituted dipolarophile (3f), possessing electron
donating group, displays the largest energy gap due to high energy
of its LUMO and this therefore appears as the dominant factor that
suppresses its cycloaddition and thus this reaction takes the longest
time for its completion. On the other hand electron withdrawing
groups like eNO2, eCl, eC]C-Ph, eOCH3, etc. lower the energies of
9
7i
104.49 ꢁ 1.78
40.54 ꢁ 2.01
10
Aminoguanidine
e
stronger electron donating group (EDG) i.e. -OH at C4-phenyl ring
are more active than the compounds with weaker EDG (-OCH3) and
electron withdrawing group (EWG) i.e. -NO2. Also the same trend
was observed in less active compounds i.e. the compounds having
EWGs like -Cl (7b and 7i) and eC]C-Ph (7g) exhibited weaker
activity than the compound with EDG (7f).
2.3. Computational details
The 1,3-dipolar cycloaddition reactions are explicable by the
frontier molecular orbital approach, which is based on the
assumption that bonds are formed by a flow of electrons from the
highest occupied molecular orbital (HOMO) of one reactant to the
lowest unoccupied molecular orbital (LUMO) of another reactant.
But the tricky part here is deciding which molecule supplies the
HOMO and which the LUMO. The energy of the HOMO is directly
related to the ionization potential and characterizes the suscepti-
bility of the molecule toward attack by electrophiles. The energy of
their LUMO orbitals respectively, which leads to small HOMOdipole
-
LUMOdipolarophile energy gaps and thus favor the cycloaddition and
thus these reactions get completed in a smaller time.
Further, the correlation between the energies of the final
products (7a-i) and their percentage yield is helpful in determining
the thermodynamic control of the reaction (Table 5 in Supporting
information). As evident from the results, lesser the energy of the

286
A. Kaur et al. / European Journal of Medicinal Chemistry 79 (2014) 282e289
infrared spectrophotometer (manufactured at Buckinghamshire,
England) using KBr pellets. 1H-NMR, 1H,1H-COSY and NOESY were
recorded at 400 MHz on BRUKER spectrometer (manufactured at
Fallanden, Switzerland) using tetramethylsilane (TMS) as internal
standard. The 13C NMR spectra were recorded at 100-MHz on
BRUKER spectrometer using TMS as internal standard. Mass spectra
were recorded on Waters Micromass Q-T of Micro (ESI) spectrom-
eter (manufactured at Vernon Hills, USA). Fluorescence spectra
were recorded on a Shimadzu RF-5301PC fluorescence spectro-
photometer manufactured in Tokyo, Japan. Elemental analysis was
carried out using Elementar Vario MICRO cube CHN analyzer
(Frankfurt, Germany). Thin-layer chromatography (TLC) analysis
was carried out on glass plates coated with silica gel-G (Loba
Chemie) suspended in methanol-chloroform. Column chromatog-
raphy was performed using silica gel (100e200 mesh, Loba
Chemie). All chemicals were purchased from Sigma Aldrich and
used without further purification. All the solvents were dried
before use.
Fig. 2. Graphical representation of IC50 (mM) values of 4-aryl-3-benzoyl-5-phenylspiro
[pyrrolidine-2.30-indolin]-20-one derivatives with the standard drug Aminoguanidine.
4.1.2. General procedure for the synthesis of chalcones (3a-i)
A solution of 0.01 mol of the aryl aldehydes and 0.01 mol of the
acetophenone in 10 mL of 95% ethanol was taken in a 25-mL
Erlenmeyer flask equipped with a magnetic stirring bar. To this
solution 3.5 mL of 6 M NaOH solution was then added with the help
of a Pasteur pipette. The reaction temperature was maintained
between 20-25 ꢂC by keeping the flask in cold water bath. The
reaction mixture was stirred for 4-5 h and was subsequently
neutralized by 0.1-0.2 N HCl providing the crude product which
was recrystallized from rectified spirit. The residue was purified
further by column chromatography using hexane-ethyl acetate in
ratio the 9:1 as eluent to afford the pure chalcones (Scheme 1).
product, more is its stability and hence better would be its yield.
The compound 7e is having the least energy (403.562 kJ/mol)
among all the synthesized compounds, thus is having the
maximum yield (87%), followed by the compounds 7b, 7g, 7a, 7i,
7d, 7c and 7h respectively, as evident from their % age yields. The
compound 7f shows least thermodynamic stability as it possesses
maximum energy 481.173 kJ/mol among the variously synthesized
products, thus is having lowest % age yield.
3. Conclusion
We have examined the thermodynamic and kinetic aspects of
five membered nitrogen-containing heterocycles synthesized by
1,3-dipolar cycloaddition reactions, using computational chemistry
techniques. It is concluded that HOMO/LUMO energy gaps, elec-
4.1.3. General procedure for the synthesis of 4-aryl-3-benzoyl-5-
phenylspiro[pyrrolidine-2.30-indolin]-20-one derivatives (7a-i)
An oven-dried flask was cooled under a stream of nitrogen and
charged with a mixture of chalcones (3a-i) (1.0 mmol), isatin 4
(1.0 mmol), benzyl amine 5 (1.0 mmol) in methanol (25 ml). The
mixture was refluxed until the disappearance of the starting ma-
terials as evidenced by the TLC (Scheme 2). After the reaction was
over, the solvent was removed in vacuo and the residue was
chromatographed on silica gel using hexane-ethyl acetate (8:2) as
eluent to give the cycloadducts (7a-i).
tronic chemical potentials (m) and electrophilicity indices (u) all
indicated a normal electron demand character for the reaction.
Further in accordance with the experimentally obtained results, the
relative kinetics of addition have been rationalized by utilizing
HOMOdipole-LUMOdipolarophile energy gaps from which we
concluded that with increasing electron withdrawing power of the
dipolarophile substituents, the energy gap decreases and thus re-
actions with the same dipole become faster, while the thermody-
namic stability of the products influenced the yield of the reaction
i.e. lesser the energy of the product better would be its yield.
Also from the antiglycation activity results, we concluded that
novel 4-aryl-3-benzoyl-5-phenylspiro[pyrrolidine-2.30-indolin]-20-
one derivatives exhibited significant advanced glycation end
product formation inhibitory activity. The activity was mainly
influenced by the presence of electron withdrawing/releasing
substitutions on the C4-phenyl ring and their hydrogen bond
forming abilities. Thus it is concluded that 4-aryl-3-benzoyl-5-
4.1.3.1. 3-Benzoyl-4,5-diphenylspiro[pyrrolidine-2.30-indolin]-20-one
(7a). Compound obtained as a creamish solid (0.37 g, 83%), m.p.
230-232 ꢂC; IR (KBr pellets, nmax/cmꢀ1): 1686, 1701 (C]O), 3210,
3338 (N-H); 1H-NMR (400 MHz, DMSO-d6): dH 4.04 (t, 2H,
J ¼ 10.44 Hz, H-4, 1N-H), 4.61 (d, 1H, J ¼ 10.56 Hz, H-3), 4.99 (d, 1H,
J ¼ 10.24 Hz, H-5), 6.42-7.45 (m, 19H, ArH), 10.41 (s, 1H, 1N-H); 13C-
NMR (100 MHz, DMSO-d6):
d 55.13 (C-4), 61.90 (C-5), 67.06 (C-3),
60700.52 (C-2), 108.90 00(0C-3a0), 121.37 (C-70), 125.76 (C-50), 126.54 (C-
4000),126.98 (C-2000, 6 ),127.07 (C-40000),127.11 (C-20000, 60000),127.80 (C-
3 , 5000), 127.98 (C-30000, 50000), 128.07 (C-60), 128.17 (C-40), 128.37 (C-
300, 500), 129.94 (C-200, 600), 132.61 (C-1000), 136.68 (C-400), 139.29 (C-
10000), 141.14 (C-100), 141.36 (C-7a0), 181.72 (C-20, C]O), 196.76 (3-C]
O); MS: m/z: 445 [Mþ þ 1], Anal. Calcd. for C30H24N2O2: C, 81.08; H,
5.40; N, 6.30, Found: C, 80.86; H, 5.39; N, 6.28.
phenylspiro[pyrrolidine-2.30-indolin]-20-one
derivatives
may
serve as a template for the synthesis of potent aldose reductase
inhibitors. The future studies shall be directed for more complete
biological activity of these synthesized compounds in in vivo model
of diabetic complication in rodents.
4. Experimental
4.1.3.2. 3-Benzoyl-4-(4-Chlorophenyl)-5-phenylspiro[pyrrolidine-
2.30-indolin]-20-one (7b). Compound obtained as a white solid
(0.41 g, 85%), m.p. 242-246 ꢂC; IR (KBr pellets, nmax/cmꢀ1): 1682,
1710 (C]O), 3185, 3337 (N-H); 1H-NMR (400 MHz, DMSO-d6): dH
3.62 (brs, 1H, 1N-H), 4.06 (t, 1H, J ¼ 10.44 Hz, H-4), 4.59 (d, 1H,
J ¼ 10.56 Hz, H-3), 4.99 (dd, 1H, J ¼ 5.16, 10.48 Hz, H-5), 6.41-7.39
(m, 18H, ArH), 10.30 (s, 1H, 1N-H); 13C-NMR (100 MHz, DMSO-d6):
4.1. Chemistry
4.1.1. General
Melting points were recorded on GalleneKamp apparatus and
are uncorrected. IR spectra were recorded on a Perkin Elmer RXIFT

A. Kaur et al. / European Journal of Medicinal Chemistry 79 (2014) 282e289
287
d
54.53 (C-4), 61.79 (C-5), 67.03 (C-3),060007.49 (C-2), 108.95 (C-3a0),
1H, 1’N-H); 13C-NMR (100 MHz, DMSO-d6):
d
52.47 (-NCH3), 53.30
121.42 (C-70), 125.61 (C-50), 126.86 (0C00-2 , 40000, 60000), 127.06 (C-30000
,
(-NCH3), 54.37 (C-4), 62.00 (C-5), 67.47 (C-3), 71.84 (C-2), 111.55 (C-
3a0), 112.21 (C-4000), 121.35 (C-70), 121.44 (C-1000), 122.76 (C-50), 125.81
(C-40000), 126.58 (C-20000, 60000), 127.05 (C-30000, 50000), 127.74 (C-2000, 6000),
127.96 (C-60), 128.17 (C-40), 128.22 (C-300, 500), 128.50 (C-200, 600),
132.58 (C-400), 137.40 (C-10000), 141.29 (C-100), 142.28 (C-7a0), 149.07
(C-4000), 172.61 (C-20, C]O), 197.59 (3-C]O); MS: m/z: 488 [Mþ þ 1],
Anal. Calcd. for C32H29N3O2: C, 78.85; H, 5.95; N, 8.62, Found: C,
78.97; H, 5.93; N, 8.65.
50000), 127.20 (C-3000, 5000), 127.85 (C-2 , 6000), 127.87 (C-60), 128.16 (C-
40), 128.39 (C-300, 500), 129.68 (C-200, 600), 131.61 (C-1000), 132.55 (C-400),
136.57 (C-10000), 138.04 (C-4000), 140.72 (C-100), 141.28 (C-7a0), 181.64
(C-20, C]O), 196.63 (3-C]O); MS: m/z: 479 [Mþ þ 1], 480 [Mþ þ 2],
Anal. Calcd. for C30H23N2O2Cl: C, 75.23; H, 4.80; N, 5.85, Found: C,
75.10; H, 4.81; N, 5.83.
4.1.3.3. 3-Benzoyl-4-(4-methoxyphenyl)-5-phenylspiro[pyrrolidine-
2.30-indolin]-20-one (7c). Compound obtained as a creamish solid
(0.36 g, 77%), m.p. 234-236 ꢂC; IR (KBr pellets, nmax/cmꢀ1): 1678,
1702 (C]O), 3160, 3334 (N-H); 1H NMR (400 MHz, DMSO-d6): dH
3.65 (d, 1H, J ¼ 5.44 Hz, 1N-H), 3.67 (s, 3H, 4000-OCH3), 4.01 (t, 1H,
J ¼ 10.48 Hz, H-4), 4.58 (d, 1H, J ¼ 10.64 Hz, H-3), 4.96 (dd, 1H,
J ¼ 5.24, 10.32 Hz, H-5), 6.41-7.40 (m, 18H, ArH), 10.30 (s, 1H, 1’N-H);
4.1.3.7. 3-Benzoyl-5-phenyl-4-styrylspiro[pyrrolidine-2.30-indolin]-
20-one (7g). Compound obtained as a creamish solid (0.38 g, 81%),
m.p. 214-216 ꢂC; IR (KBr pellets, nmax/cmꢀ1): 1681, 1705 (C]O),
3155, 3337 (N-H); 1H-NMR (400 MHz, DMSO-d6): dH 3.85 (brs, 1H,
1N-H), 3.98 (t, IH, J ¼ 9.24 Hz, H-4), 5.14 (t, IH, J ¼ 10.48, H-3), 5.51 (t,
1H, J ¼ 5.12 Hz, H-5), 5.93 (dd, 1H, J ¼ 7.68, 14.00 Hz, 4-CH]CH),
6.16 (d, 1H, J ¼ 15.84 Hz, 1000-CH]CH), 6.75-7.67 (m, 19H, ArH),10.22
13C-NMR (100 MHz, DMSO-d6):
d
54.48 (C-4), 54.66 (4000-OCH3),
61.96 (C-5), 66.99 (C-3), 67.46 (C-2), 108.89 (C-3a0), 113.58 (C-3000,
(s, 1H, 1’N-H); 13C-NMR (100 MHz, DMSO-d6):
d 52.85 (C-5), 53.90
5000), 121.38 (C-70), 125.77 (C-1000), 126.98 (C-50), 127.06 (C-20000, 40000
,
(C-3), 61.66 (C-2), 71.16 (C-4), 109.22000(0C-3a0), 121.67 (4-C]C-),
123.54 (C-70), 125.23 (C-50), 125.79 (C-2 , 40000, 60000), 126.61 (C-2000,
4000, 6000), 126.99 (C-3000, 5000), 127.22 (C-30000, 50000), 127.78 (C-300, 500),
128.19 (C-40), 128.49 (C-60), 132.52 (C-10000), 132.74 (C-200, 400, 600),
136.17 (C-100), 137.32 (1000-C]C-), 141.74 (C-7a0), 142.27 (C-1000),
180.77 (C-20, C]O), 197.63 (3-C]O); MS: m/z: 471 [Mþ þ 1], Anal.
Calcd. for C32H26N2O2: C, 81.70; H, 5.53; N, 5.95, Found: C, 81.92; H,
5.51; N, 5.93.
60000), 127.79 (C-30000, 50000), 127.96 (C-2000, 6000), 128.32 (C-60), 128.97 (C-
40),130.03 (C-300, 500),130.99 (C-200, 600),132.58 (C-400),136.74 (C-10000),
141.29 (C-100), 141.32 (C-7a0), 157.90 (C-4000), 181.75 (C-20, C]O),
196.84 (3-C]O); MS: m/z: 475 [Mþ
þ
1], Anal. Calcd. for
31H26N2O3: C, 78.48; H, 5.48; N, 5.91, Found: C, 78.18; H, 5.46; N,
5.89.
C
4.1.3.4. 3-Benzoyl-4-(4-nitrophenyl)-5-phenylspiro[pyrrolidine-2.30-
indolin]-20-one (7d). Compound obtained as a light yellow solid
(0.38 g, 78%), m.p. 236-238 ꢂC; IR (KBr pellets, nmax/cmꢀ1): 1688,
1707 (C]O), 3190, 3333 (N-H); 1H NMR (400 MHz, DMSO-d6): dH
3.80 (d, 1H, J ¼ 5.48 Hz, 1N-H), 4.21 (t, 1H, J ¼ 10.36 Hz, H-4), 4.65 (d,
1H, J ¼ 10.48 Hz, H-3), 5.08 (dd, 1H, J ¼ 5.44, 10.24 Hz, H-5), 6.41-
8.11 (m, 18H, ArH), 10.35 (s, 1H, 1’N-H); 13C-NMR (100 MHz, DMSO-
4.1.3.8. 3-Benzoyl-4-(3,4-dimethoxyphenyl)-5-phenylspiro[pyrroli-
dine-2.30-indolin]-20-one (7h). Compound obtained as a creamish
solid (0.36 g, 72%), m.p. 208-210 ꢂC; IR (KBr pellets, nmax/cmꢀ1):
1680, 1702 (C]O), 3157, 3323 (N-H); 1H-NMR (400 MHz, DMSO-
d6): dH 3.42 (s, 3H, 3000-OCH3), 3.67 (brs, 4H, 4000-OCH3, 1N-H), 4.37 (d,
1H, J ¼ 11.60 Hz, H-3), 5.59 (dd, 1H, J ¼ 5.04, 10.48 Hz, H-5), 5.69 (t,
1H, J ¼ 10.92 Hz, H-4), 6.32-7.75 (m, 17H, ArH), 9.83 (s, 1H, 1’N-H);
d6):
d 55.04 (C-4), 61.77 (C-5), 67.07 (C-3), 67.59 (C-2), 109.00 (C-
3a0), 121.45 (C-70), 123.30 (C-50), 125.60 (C-3000, 5000), 126.81 (C-40000),
127.11 (C-20000, 60000),127.39 (C-2000, 6000),127.88 (C-30000, 50000),127.95 (C-
60), 128.51 (C-40), 129.32 (C-300, 500), 129.50 (C-200, 600), 132.64 (C-400),
136.41 (C-10000), 140.36 (C-1000), 141.36 (C-100), 146.38 (C-7a0),147.39
(C-4000), 181.52 (C-20, C]O), 196.41 (3-C]O); MS: m/z: 490 [Mþ þ 1],
Anal. Calcd. for C30H23N3O4: C, 73.62; H, 4.70; N, 8.59, Found: C,
73.46; H, 4.69; N, 8.56.
13C-NMR (100 MHz, DMSO-d6): 51.72 (C-4), 53.44 (4000-OCH3),
d
54.72 (3000-OCH3), 55.11 (C-5), 60.94 (C-3), 71.94 (C-2), 109.19 (C-
3a0), 110.44 (C-2000), 111.23 (C-5000), 118.50 (C-6000), 121.56 (C-70),
123.51 (C-50), 126.64 (C-20000, 40000, 60000), 127.03 (C-30000, 50000), 127.64
(C-1000), 127.70 (C-60), 127.99 (C-40), 128.13 (C-300, 500), 128.43 (C-200,
600), 130.51 (C-400), 132.58 (C-10000), 137.29 (C-100), 142.05 (C-7a0),
142.27 (C-4000), 147.42 (C-3000), 180.61 (C-20, C]O), 197.51 (3-C]O);
MS: m/z: 505 [Mþ þ 1], Anal. Calcd. for C32H28N2O4: C, 76.19; H,
5.55; N, 5.55, Found: C, 75.97; H, 5.53; N, 5.56.
4.1.3.5. 3-Benzoyl-4-(4-hydroxyphenyl)-5-phenylspiro[pyrrolidine-
2.30-indolin]-20-one (7e). Compound obtained as a white solid
(0.40 g, 87%), m.p. 152-154 ꢂC; IR (KBr pellets, nmax/cmꢀ1): 1684,
1713 (C]O), 3165, 3336 (N-H); 1H-NMR (400 MHz, DMSO-d6): dH
3.99 (m, 2H, H-4, 1N-H), 4.58 (d, 1H, J ¼ 10.64 Hz, H-3), 4.94 (dd, 1H,
J ¼ 5.56,10.32 Hz, H-5), 6.40-7.38 (m,18H, ArH), 9.01 (s, 1H, 4000-OH),
4.1.3.9. 3-Benzoyl-4-(2-chlorophenyl)-5-phenylspiro[pyrrolidine-
2.30-indolin]-20-one (7i). Compound obtained as white solid (0.38 g,
80%), m.p. 214-216 ꢂC; IR (KBr pellets, nmax/cmꢀ1): 1685, 1712 (C]
O), 3195, 3340 (N-H); 1H-NMR (400 MHz, DMSO-d6): dH 3.89 (d, 1H,
J ¼ 5.24 Hz, 1N-H), 4.73 (m, 2H, H-3, H-4), 4.96 (m, 1H, H-5), 6.43-
7.89 (m, 18H, ArH), 10.40 (s, 1H, 1’N-H); 13C-NMR (100 MHz, DMSO-
10.26 (s, 1H, 1’NH); 13C-NMR (100 MHz, DMSO-d6):
d 54.48 (C-4),
61.96 (C-5), 67.06 (C-3), 67.49 (C-2), 108.89 (C-3a0), 115.06 (C-3000,
5000), 121.40 (C-70), 125.71 (C-50), 126.95 (C-1000), 127.04 (C-20000, 40000
,
d6):
d
50.45 (C-4), 61.47 (C-5), 67.67 (C-3), 060070 .94 (C-2), 108.96 (C-
60000), 127.73 (C-30000, 50000), 127.90 (C-2000, 6000), 128.29 (C-60), 128.84 (C-
40), 129.16 (C-300, 500),130.01 (C-200, 600), 132.48 (C-400), 136.80 (C-10000),
141.24 (C-100), 141.28 (C-7a0), 155.94 (C-4000), 181.79 (C-20, C]O),
3a0), 121.41 (C-70), 125.83 (C-50), 126.81 (C-2 , 40000, 60000), 127.11 (C-
5000), 127.23 (C-4000),127.76 (C-6000), 127.87 (C-30000, 50000), 128.05 (C-3000),
128.48 (C-60), 129.00 (C-40), 129.16 (C-300, 500), 129.70 (C-200, 600),
132.67 (C-400), 134.19 (C-10000), 136.63 (C-1000), 140.57 (C-100), 141.45
(C-7a0),181.66 (C-20, C]O),196.63 (3-C]O); MS: m/z: 479 [Mþ þ 1],
480 [Mþ þ 2], Anal. Calcd. for C30H23N2O2Cl: C, 75.23; H, 4.80; N,
5.85, Found: C, 75.04; H, 4.81; N, 5.87.
196.91 (3-C]O); MS: m/z: 461 [Mþ
C
þ
1], Anal. Calcd. for
30H24N2O3: C, 78.26; H, 5.21; N, 6.08, Found: C, 78.01; H, 5.20; N,
6.10.
4.1.3.6. 3-Benzoyl-4-[4-(dimethylamino)phenyl]-5-phenylspiro[pyr-
rolidine-2.30-indolin]-20-one (7f). Compound obtained as a cream-
ish solid (0.31 g, 65%), m.p. 226-228 ꢂC; IR (KBr pellets, nmax/cmꢀ1):
1680, 1699 (C]O), 3205, 3347 (N-H); 1H-NMR (400 MHz, DMSO-
d6): dH 2.74 (s, 3H, -NCH3), 2.80 (s, 3H, -NCH3), 3.81 (brs, 1H, 1N-H),
3.95 (t, 1H, J ¼ 10.52 Hz, H-4), 4.55 (d, 1H, J ¼ 10.64 Hz, H-3), 4.92
(dd, 1H, J ¼ 3.84, 10.28 Hz, H-5), 6.36-7.67 (m, 18H, ArH), 10.25 (s,
4.2. Advanced glycation end-product formation inhibitory activity
The assay for the ability of the pyrrolo-isoxazolidines to inhibit
the glucose-mediated protein glycation and the development of
fluorescent AGEs was performed [56]. Different concentrations of
various compounds were prepared by dissolving in DMSO. Bovine

288
A. Kaur et al. / European Journal of Medicinal Chemistry 79 (2014) 282e289
serum albumin (400
mg) was incubated with glucose (200 mM),
References
10
m
l of test sample solution in phosphate buffered-saline (pH 7.4)
[1] N.C. Turner, Drug Discovery Today 1 (1996) 109e116.
[2] M. Brownlee, Diabetes 43 (1994) 836e841.
[3] N. Ahmed, Diabetes Research and Clinical Practice 67 (2005) 3e21.
[4] N. Ahmed, P.J. Thornalley, J. Dawczynski, S. Franke, J. Strobel, G. Stein,
G.M. Haik, Investigative Ophthalmology & Visual Science 44 (2003) 5287e
5292.
(PBS) (500
m
l total volume) 37 ꢂC, were incubated at 60 ꢂC for 30 h.
A blank, which contained the protein and glucose but no test
sample, was kept at 4 ꢂC until measurement. After cooling, aliquots
of 250 ml were transferred to 1.5 ml plastic tubes, then, 25 ml of 100%
(w/v) trichloroacetic acid were added to each tube and stirred and
centrifuged (15,000 rpm) for 4 min at 4 ꢂC. The supernatant con-
taining glucose, inhibitor and interfering substance, was removed
and pellet containing advanced glycation end products (AGEs)-BSA
was dissolved in 1 ml ammonia- ammonium chloride buffer (pH
10). Fluorescence of these solutions was measured on a spectro-
photometer at the excitation and emission maxima of 360 and
460 nm, respectively, against the unincubated blank. Amino-
guanidine was used as a positive control. The formation of AGE was
firstly assessed by the characteristic fluorescence (excitation
wavelength of 370 nm and emission wavelength of 440 nm).
Percent inhibition was calculated as follows:
[5] T.P. Degenhardt, L. Grass, S. Reddy, S.R. Thorpe, E.P. Diamandis, J.W. Baynes,
Kidney International 52 (1997) 1064e1067.
[6] J.M. Forbes, L.T.L. Yee, V. Thallas, M. Lassila, R. Candido, K.A. Jandeleit-Dahm,
M.C. Thomas, W.C. Burns, E.K. Deemer, S.M. Thorpe, M.E. Cooper, T.J. Allen,
Diabetes 53 (2004) 1813e1823.
[7] G. Mnch, A.M. Cunningham, P. Riederer, E. Braak, Brain Research 796 (1998)
307e310.
[8] M.J. Picklo Sr., T.J. Montine, V. Amarnath, M.D. Neely, Toxicology and Applied
Pharmacology 184 (2002) 187e197.
[9] S. Dukic-Stefanovic, R. Schinzel, P. Riederer, G. Munch, Biogerontology 2
(2001) 19e34.
[10] G. Munch, H.J. Lüth, A. Wong, T. Arendt, E. Hirsch, R. Ravid, P.J. Riederer,
Journal of Chemical Neuroanatomy 20 (2000) 253e257.
[11] J.M. Bohlender, S. Franke, G. Stein, G. Wolf, American Journal of Physiology e
Renal Physiology 289 (2005) 645e659.
[12] N. Ahmed, P.J. Thornalley, Diabetes, Obesity and Metabolism 9 (2007) 233e
245.
[13] M.N.G. James, G.J.B. Williams, Canadian Journal of Chemistry 50 (1972) 2407e
2412.
Inhibition % ¼ ½1 ꢀ ðAo ꢀ AbÞ=ðAc ꢀ AbÞꢃ ꢄ 100
Where Ao is the fluorescence of the incubated mixture with sample,
and Ac and Ab are the fluorescence of the incubated mixture
without sample as a positive control and the fluorescence of
incubated mixture without sample as a blank control. All experi-
ments were performed in triplicate, and all compounds were tested
at least at a minimum of ten different concentrations from 0.39 to
[14] A. Jossang, P. Jossang, H.A. Hadi, T. Sevenet, B. Bodo, Journal of Organic
Chemistry 56 (1991) 6527e6530.
[15] P.K. Banerjee, S. Ghosal, Australian Journal of Chemistry 22 (1969) 275e
277.
[16] K. Jones, J. Wilkinson, Journal of the Chemical Society Chemical Communi-
cations (1992) 1767e1769.
[17] S.I. Bascop, J. Sapi, J.Y. Laronze, J. Levy, Heterocycles 38 (1994) 725e732.
[18] C. Pellegrini, C. Strassler, M. Weber, H.J. Borschberg, Tetrahedron Asymmetry
5 (1994) 1979e1992.
200 mg/ml for various compounds.
[19] G. Palmisano, R. Annunziata, G. Papeo, M. Sisti, Tetrahedron Asymmetry 7
(1996) 1e4.
[20] K. Karthikeyan, P.M. Sivakumar, M. Doble, P.T. Perumal, European Journal of
Medicinal Chemistry 45 (2010) 3446e3452.
4.3. Computational method
[21] A. Thangamani, European Journal of Medicinal Chemistry 45 (2010) 6120e
6126.
[22] A.A. Raj, R. Raghunathan, M.R. SrideviKumari, N. Raman, Bioorganic & Me-
dicinal Chemistry 11 (2003) 407e419.
In cycloaddition reactions two chemical components, i.e. dipole
and dipolarphile, are involved, and the spontaneity of the reaction
process is determined by the feasibility of the overlap between
HOMO (highest occupied molecular orbital) of one component, and
the LUMO (lowest unoccupied molecular orbital) of the other one.
Thus the reactivity of cycloaddition reactions correlates with the
HOMO-LUMO energy gap.
All the calculations (regarding energy, chemical potentials and
electrophilicity indices) were performed using Schrödinger (9.3)
software running on CentOS linux operating system installed in hp
Z200 workstation. The chemical structures of all the synthesized
molecules were sketched using ‘builder tool’ option of the Maestro
program. Thereafter, all molecules were energy minimized in ‘lig-
prep’ program, using OPLS_2005 force field, and subsequently the
least energy conformer of each molecule was generated in the
‘ConfGen’ program of the Schrödinger software. The Quantum
calculations of the all molecular electronic structures were per-
formed using AM1 semi-empirical method, which is based on the
neglect of differential diatomic overlap (NDDO) integral approxi-
mation [57].
[23] Z. Ul-Haq, B. Wellenzohn, S. Tonmunphean, A. Khalid, M.I. Choudhary,
B.M. Rode, Bioorganic & Medicinal Chemistry Letters 13 (2003) 4375e4380.
[24] A.S. Girgis, European Journal of Medicinal Chemistry 44 (2009) 91e100.
[25] E.M. Hussein, M.I. Abdel-Monem, ARKIVOC x (2011) 85e98.
[26] P. Prasanna, K. Balamurugan, S. Perumal, P. Yogeeswari, D. Sriram, European
Journal of Medicinal Chemistry 45 (2010) 5653e5661.
[27] R.R. Kumar, S. Perumal, P. Senthilkumar, P. Yogeeswari, D. Sriram, Journal of
Medicinal Chemistry 51 (2008) 5731e5735.
[28] J.B. Jones, J.M. Young, Journal of Medicinal Chemistry 11 (1968) 1176e1182.
[29] M.A. Abou-Gharbia, P.H. Doukas, Heterocycles 12 (1979) 637e640.
[30] K. Lundahl, J. Schut, J.L.M.A. Schlatmann, G.B. Paerels, A. Peters, Journal of
Medicinal Chemistry 15 (1972) 129e132.
[31] K. Ko, Y. Won, Bioorganic & Medicinal Chemistry 13 (2005) 1445e1452.
[32] T. Negoro, M. Murata, S. Ueda, B. Fujitani, Y. Ono, A. Kuromiya, M. Komiya,
K. Suzuki, J.I. Matsumoto, Journal of Medicinal Chemistry 41 (1998) 4118e
4129.
[33] K. Ko, H. Won, Y. Won, Bioorganic & Medicinal Chemistry 14 (2006) 3090e
3097.
[34] J.R. Kim, Y. Won, Bulletin of the Korean Chemical Society 25 (2004) 1874e
1876.
[35] G. Zhao, C. Kwon, A. Wang, J.G. Robertson, J. Marcinkeviciene, R.A. Parker,
M.S. Kirby, L.G. Hamann, Bioorganic & Medicinal Chemistry Letters 23 (2013)
1622e1625.
[36] D.J. Madar, H. Kopecka, D. Pireh, H. Yong, Z. Pei, X. Li, P.E. Wiedeman,
S.W. Djuric, T.W.V. Geldern, M.G. Fickes, L. Bhagavatula, T. McDermott,
S. Wittenberger, S.J. Richards, K.L. Longenecker, K.D. Stewart, T.H. Lubben,
S.J. Ballaron, M.A. Stashko, M.A. Long, H. Wells, B.A. Zinker, A.K. Mika,
D.W.A. Beno, A.J. Kempf-Grote, J. Polakowski, J. Segreti, G.A. Reinhart,
R.M. Fryer, H.L. Sham, J.M. Trevillyan, Journal of Medicinal Chemistry 49
(2006) 6416e6420.
[37] I. Yamawaki, Y. Matsushita, N. Asaka, K. Ohmori, N. Nomura, K. Ogawa, Eu-
ropean Journal of Medicinal Chemistry 28 (1993) 481e498.
[38] B.R.P. Kumar, N.R. Baig, S. Sudhir, K. Kar, M. Kiranmai, M. Pankaj, N.M. Joghee,
Bioorganic Chemistry 45 (2012) 12e28.
Acknowledgment
The authors acknowledge the financial support from University
Grant Commission (UGC) New Delhi and are grateful to Department
of Chemistry, Punjabi University, Patiala and Sophisticated
Analytical Instrumentation Facility (SAIF) Panjab University, Chan-
digarh for spectral analysis.
[39] C. Parmeggiani, D. Martella, F. Cardona, A. Goti, Journal of Natural Products 72
(2009) 2058e2060.
[40] T.J. Donohoe, R.E. Thomas, M.D. Cheeseman, C.L. Rigby, G. Bhalay, I.D. Linney,
Organic Letters 10 (2008) 3615e3618.
Appendix A. Supplementary data
[41] R. Murugan, S. Anbazhagan, S.S. Narayanan, European Journal of Medicinal
Chemistry 44 (2009) 3272e3279.
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.ejmech.2014.04.022.

A. Kaur et al. / European Journal of Medicinal Chemistry 79 (2014) 282e289
289
[42] M. Stefek, V. Snirc, P.O. Djoubissie, M. Majekova, V. Demopoulos, L. Rackova,
Z. Bezakova, C. Karasu, V. Carbone, O. El-Kabbani, Bioorganic & Medicinal
Chemistry 16 (2008) 4908e4920.
[43] C. Karasu, Open Cardiovascular Medicine Journal 4 (2010) 240e256.
[44] Y.Y. Li, H.S. Wu, L. Tang, C.R. Feng, J.H. Yu, Y. Li, Y.S. Yang, B. Yang, Q.J. He,
Pharmacological Research 56 (2007) 335e343.
[50] C.S. Shantharam, D.M.S. Vardhan, R. Suhas, M.B. Sridhara, D.C. Gowda, Euro-
pean Journal of Medicinal Chemistry 60 (2013) 325e332.
[51] K.M. Khan, M. Khan, M. Ali, M. Taha, S. Rasheed, S. Perveen, M.I. Choudhary,
Bioorganic & Medicinal Chemistry 17 (2009) 7795e7801.
[52] A. Kaur, B. Singh, A.S. Jaggi, Bioorganic & Medicinal Chemistry Letters 23
(2013) 797e801.
[45] L. Zhang, X. Chen, J. Liu, Q. Zhu, Y. Leng, X. Luo, H. Jiang, H. Liu, European
Journal of Medicinal Chemistry 58 (2012) 624e639.
[53] A.N. Chaudhary, V. Juyal, International Journal of Pharmacy and Pharmaceu-
tical Sciences 3 (2011) 125e128.
[46] X. Dong, Z. Zhang, R. Wen, J. Shen, X. Shen, H. Jiang, Bioorganic & Medicinal
Chemistry Letters 16 (2006) 5913e5916.
[54] R. Badru, S. Shah, B. Singh, Journal of Heterocyclic Chemistry 49 (2012) 336e
341.
[47] K. Arya, D.S. Rawat, A. Dandia, H. Sasai, Journal of Fluorine Chemistry 137
(2012) 117e122.
[55] K.K. Singhal, B. Singh, B. Singh, Indian Journal of Chemistry 38B (1999) 292e
296.
[48] I.A. Cliffe, E.L. Lien, H.L. Mansell, K.E. Steiner, R.S. Todd, A.C. White, R.M. Black,
Journal of Medicinal Chemistry 35 (1992) 1169e1175.
[49] D.S. Jang, G.Y. Lee, Y.M. Lee, Y.S. Kim, H. Sun, D.H. Kim, J.S. Kim, Chemical and
Pharmaceutical Bulletin 57 (2009) 397e400.
[56] N. Matsuura, T. Aradate, C. Sasaki, H. Kojima, M. Ohara, J. Hasegawa,
M. Ubukata, Journal of Health Science 48 (2002) 520e526.
[57] M.J.S. Dewar, E.G. Zoebisch, E.F. Healy, J.J.P. Stewart, Journal of the American
Chemical Society 107 (1985) 3902e3909.