Synthesis, α-glucosidase and α-amylase inhibitory activities, acute toxicity and molecular docking studies of thiazolidine-2,4-diones derivatives

Article abstract of DOI:10.1080/07391102.2021.1911854

In the present study, a series of thiazolidine-2,4-diones derivatives (3a–3e) and (4a–4e) were synthesized and characterized by ¹H NMR, ¹³C NMR and ESI-MS spectrometry. All compounds were screened for their α-glucosidase and α-amylase inhibitory activities. In vitro biological investigations revealed that most of compounds were active against α-glucosidase with IC₅₀ values in the range of 43.85 ± 1.06 to 380.10 ± 1.02 μM, and α-amylase with IC₅₀ in the range of 18.19 ± 0.11 to 208.10 ± 1.80 μM. Some of the tested compounds were found to be more potent inhibitors than the clinical drug Acarbose (IC_{50glucosidase} = 97.12 ± 0.35 μM and IC_50amylase = 2.97 ± 0.004 μM). The lead compounds were evaluated for their acute toxicity on Swiss mice and found to be completely non-toxic with LD > 2000 mg/kg BW. Furthermore, the Structure–activity relationship (SAR) and the binding interactions of all compounds with the active site of α-glucosidase and α-amylase were confirmed through molecular docking and stabilizing energy calculations. This study has identified the inhibitory potential a new class of synthesized thiazolidine-2,4-diones in controlling both hyperglycemia and type 2 diabetes mellitus. Furthermore, the theoretical binding mode of the target molecules was evaluated by molecular docking studies against the 3D Crystal Structure of human pancreatic α-amylase (PDB ID: 1B2Y) and α-glucosidase (PDB ID: 3W37) Communicated by Ramaswamy H. Sarma.

Full text of DOI:10.1080/07391102.2021.1911854

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Synthesis, α-glucosidase and α-amylase inhibitory
activities, acute toxicity and molecular docking
studies of thiazolidine-2,4-diones derivatives
Saad Fettach, Fatima Zahra Thari, Zakaria Hafidi, Hamza Tachallait, Khalid
Karrouchi, Mohammed El achouri, Yahia Cherrah, Hassan Sefrioui, Khalid
Bougrin & My El Abbes Faouzi
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Faouzi (2021): Synthesis, α-glucosidase and α-amylase inhibitory activities, acute toxicity and
molecular docking studies of thiazolidine-2,4-diones derivatives, Journal of Biomolecular Structure
and Dynamics, DOI: 10.1080/07391102.2021.1911854
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JOURNAL OF BIOMOLECULAR STRUCTURE AND DYNAMICS
https://doi.org/10.1080/07391102.2021.1911854
Synthesis, a-glucosidase and a-amylase inhibitory activities, acute toxicity
and molecular docking studies of thiazolidine-2,4-diones derivatives
Saad Fettacha, Fatima Zahra Tharib, Zakaria Hafidic , Hamza Tachallaitb, Khalid Karrouchid, Mohammed El
achouric, Yahia Cherraha , Hassan Sefriouie, Khalid Bougrinb,f
and My El Abbes Faouzia
aLaboratory of Pharmacology and Toxicology, Biopharmaceutical and Toxicological Analysis Research Team, Faculty of Medicine and
b
ꢀ
Pharmacy, Mohammed V University in Rabat, Rabat, Morocco; Equipe de Chimie des Plantes et de Synthese Organique et Bioorganique,
URAC23, Faculty of Science, Geophysics, Natural Patrimony and Green Chemistry (GEOPAC) Research Center, Mohammed V University in
c
ꢁ
ꢁ
Rabat, Rabat, Morocco; Laboratoire de Physico-Chimie des Materiaux Inorganiques et Organiques, Centre des Sciences des Materiaux, Ecole
d
ꢁ
Normale Superieure-Rabat, Mohammed V University in Rabat, Rabat, Morocco; Laboratory of Analytical Chemistry and Bromatology,
Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, Rabat, Morocco; Moroccan Foundation for Science, Innovation &
Research (MAScIR), Centre de Biotechnologie Medicale, Rabat, Morocco; Mohammed VI Polytechnic University, Benguerir, Morocco
e
f
ꢁ
Communicated by Ramaswamy H. Sarma
ABSTRACT
ARTICLE HISTORY
Received 19 December 2020
Accepted 26 March 2021
In the present study, a series of thiazolidine-2,4-diones derivatives (3a–3e) and (4a–4e) were synthe-
1
sized and characterized by H NMR, 13C NMR and ESI-MS spectrometry. All compounds were screened
for their a-glucosidase and a-amylase inhibitory activities. In vitro biological investigations revealed
that most of compounds were active against a-glucosidase with IC50 values in the range of
43.85 1.06 to 380.10 1.02 mM, and a-amylase with IC50 in the range of 18.19 0.11 to
208.10 1.80 mM. Some of the tested compounds were found to be more potent inhibitors than the
clinical drug Acarbose (IC50glucosidase ¼ 97.12 0.35 mM and IC50amylase ¼ 2.97 0.004 lM). The lead
compounds were evaluated for their acute toxicity on Swiss mice and found to be completely non-
toxic with LD > 2000 mg/kg BW. Furthermore, the Structure–activity relationship (SAR) and the bind-
ing interactions of all compounds with the active site of a-glucosidase and a-amylase were confirmed
through molecular docking and stabilizing energy calculations. This study has identified the inhibitory
potential a new class of synthesized thiazolidine-2,4-diones in controlling both hyperglycemia and
type 2 diabetes mellitus. Furthermore, the theoretical binding mode of the target molecules was eval-
uated by molecular docking studies against the 3D Crystal Structure of human pancreatic a-amylase
(PDB ID: 1B2Y) and a-glucosidase (PDB ID: 3W37)
KEYWORDS
Thiazolidine-2,4-diones;
a-amylase; a-glucosidase;
SAR; docking; acute toxicity
1. Introduction
of starch and oligosaccharides respectively into monosac-
charides such as glucose and fructose (Joshi et al., 2015). In
this regard, inhibition of a-amylase and a-glucosidase play a
critical role in modulating the absorption of carbohydrates
and preventing postprandial hyperglycemia, making inhibi-
tors a useful solution in the management of type 2 diabetes
(Leroux-Stewart et al., 2014). Thiazolidine-2,4-diones
(Glitazones) are an important class of oral antidiabetic agents
that have attracted the community attention for their excel-
lent control of glucose increasing effect without causing
hypoglycemia (Bloomgarden et al., 2018). Due to their flex-
ible and diverse nature, thiazolidinediones (TZDs) show also
a wide range of pharmacological activities which include
anti-hyperglycemic (Naim et al., 2017), anti-proliferative (Patil
et al., 2010), anti-obesity (Bhattarai et al., 2010), anti-micro-
bial (Avupati et al., 2012; Sun et al., 2019) and anti-inflamma-
tory effects (Prabhakar et al., 1998). Furthermore, TZDs
Over 90% of diabetic patients suffer from type 2 diabetes
mellitus (T2DM), which is a multifactorial metabolic disorder,
characterized by an uncontrolled chronic hyperglycemia,
related to failure of insulin function (insulin resistance) over
extended periods in peripheral tissues (Hameed et al., 2015).
This chronic high blood glucose level leads to severe compli-
cations such as cardiovascular diseases, neuropathy, kidney
failure and obesity (Abbas et al., 2019; Hanefeld et al., 1996).
This makes it necessary to maintain a normal blood glucose
level, especially postprandial hyperglycemia, as a solution for
the control of this pathology and prevent their complica-
tions. One of the approaches to manage diabetes is to
enhance the functionality of pancreatic a-amylase and intes-
tinal a-glucosidase (Joshi et al., 2015; Rafique et al., 2020),
which are two enzymes positioned in the digestive system.
These enzymes are responsible for the degradation process derivatives also reported as a-glucosidase inhibition
ꢀ
Equipe de Chimie des Plantes et de Synthese Organique et Bioorganique, URAC23, Faculty of Science, B.P.
CONTACT Khalid Bougrin
1014, Geophysics, Natural Patrimony and Green Chemistry (GEOPAC) Research Center, Mohammed V University in Rabat, Rabat, Morocco; My El Abbes Faouzi
myafaouzi@yahoo.fr Laboratory of Pharmacology and Toxicology, Biopharmaceutical and Toxicological Analysis Research Team, Faculty of Medicine and
kbougrin@yahoo.fr
Pharmacy, University Mohammed V in Rabat, Rabat, Morocco.
Supplemental data for this article can be accessed online at https://doi.org/10.1080/07391102.2021.1911854.
ß 2021 Informa UK Limited, trading as Taylor & Francis Group

2
S. FETTACH ET AL.
Figure 1. Some representative marketed drugs with thiazolidine-2,4-dione moiety.
(Chinthala et al., 2013). Despite their diverse therapeutic pro- digestive enzymes (a-glucosidase and a-amylase), the
file and excellent antidiabetic properties, thiazolidinediones molecular docking studies were performed on the two
possess some severe side effects, such as weight gain
(Fonseca, 2003), plasma-volume expansion, bone related dis-
orders and edema (Berlie et al., 2007; Forman et al., 2000;
Okazaki et al., 1999; Willson et al., 2000). One of the mar-
keted glitazone drugs (Figure 1), Troglitazone, has been
removed due to its hepatotoxicity (Smith, 2003). In this con-
text, extensive research on TZD has been going around the
globe to develop novel or improved derivatives better and
safer without compromising the diabetic potential. In a
recent publication, our research team has reported work on
the design and synthesis of new thiazolidine-2,4-dione deriv-
atives, in search of potential lead compounds, which can
demonstrate promising results. The aim of this study consists
of the evaluation of the in vitro antidiabetic profile of a
library of newly synthesized thiazolidine-2,4-dione derivatives
enzymes to predict the mechanism of inhibition and the
orientation within a targeted binding site.
2. Results and discussion
2.1. Chemistry
First, we examined the survey of the Knoevenagel condensa-
tion reaction by using TZD 1 and benzaldehyde 2a as models
adsorbed on mineral support under solvent-free MW condi-
tions. All minerals solid supports used are commercially avail-
able. These conditions, which are collected in Table 1, included
nature of solid support, reaction time and temperature.
Therefore, we found that the reaction carried out in basic alu-
mina irradiated in a microwave digestion system in open ves-
(3a–3e) and (4a–4e) by showing their potential to reduce sel afforded the desired product 3a as
a single (Z)-
postprandial blood hyperglycemia by the inhibition of diastereoisomer in high yield 95% yield at 108 ꢀC for short
Table 1. Optimization of different supports for the synthesis of 3a model product.
Entrya
Mineral support
Al2O3 (basic)
No
Al2O3 (acidic)
aAl2O3 (calcined)
Al2O3 (basic)
SiO2
Al2O3 (neutral)
K10 bentonite clay
NaOH
T (ꢀC)
Time (min)
Yield (%)b
1
2
3
4
5
6
7
8
9d
110
110
109
110
108
105
108
112
75
10
20
10
20
5
5
5
30c
Nr
75
Nr
95
89
79
Nr
70
20
300
aExperimental conditions: TZD (1 mmol) and benzaldehyde (1 equiv) were adsorbed on solid support (1 g/mmol of TZD) and irradiated under solvent-free MW
(105 ꢀC < T < 112 ꢀC, reaction temperature was digitally measured by infrared thermometer.
bYield of the isolated product 3a using open vessel.
cYield of the isolated product 3a using closed vessel.
dUnder classical conditions (see Ref. Thari et al. 2020).

JOURNAL OF BIOMOLECULAR STRUCTURE AND DYNAMICS
3
Table 2. Synthesis of 5-arylidenethiazolidine-2,4-dione derivatives (3a–3e).
Table 4. a-glucosidase and a-amylase inhibitory activities for the synthe-
Entrya
Product
R1
R2
Yield (%)b
M.p. (ꢀC)
sized compounds.
IC50 SD (mM)a
1
2
3
4
5
3a
3 b
3c
3d
3e
H
CH3
F
Br
Cl
H
H
H
H
Cl
95
92
97
93
89
246–248
229–231
218–220
243–245
215–217
Compound
R1
R2
a-glucosidase
a-amylase
3a
3 b
3c
3d
3e
4a
4b
4c
H
CH3
F
H
H
H
H
Cl
H
H
H
H
Cl
–
98 .88 1.11
380.10 0.01
339.7 1.02
156.3 7.93
84.95 1.01
98.45 0.54
120.8 1.10
211.6 3.25
101.9 0.43
43.85 1.06
97.12 0.35
126.67 2.10
286.25 4.30
263.73 1.54
173.30 4.70
47.09 0.04
108.14 2.05
167.02 0.97
195.77 2.14
156.48 3.17
18.19 0.11
2.975 0.01
aExperimental conditions: TZD 1 (1 mmol) and aromatic aldehyde 2 (1 mmol)
were adsorbed on basic alumina (1 g/mmol of TZD) and irradiated under MW
for 5 min at 108 ꢀC, temperature measurement in microwave-assisted open
teflon reactors.
Br
Cl
H
CH3
F
Br
Cl
–
bYield of isolated product.
4d
4e
Acarbose
aSD means Standard Deviation of the Mean.
Table 3. Synthesis of N-allyl 5-arylidenethiazolidine-2,4-dione deriva-
tives (4a–4e).
Entrya
Product
R1
R2
Yield (%)b
M.p. (ꢀC)
compounds 3a–3e were submitted to N-allylation with NaOH
as base in EtOH/H2O (v/v, 2:1), the desired products 4a–4e
were obtained in 49–68% yields at 75 ꢀC for 5 to 6 h
(Table 3).
1
2
3
4
5
4a
4 b
4c
4d
4e
H
CH3
F
Br
Cl
H
H
H
H
Cl
62
65
58
55
60
102
116
121
146
113
aExperimental conditions: Product 3 (1 mmol) and Allyl bromide (1.2 mmol) in
EtOH/H2O (2:1, 10 mL) at 25 ꢀC were added NaOH (1 mmol), and the reaction
mixture was stirred and heated at 75 ꢀC for 5–6 h.
2.2. Biology
bYield of isolated product.
2.2.1. a-Glucosidase inhibition
In an ongoing project which is aimed to develop new
enzyme inhibitors, all newly synthesized thiazolidine-2,4-
dione derivatives (3a–3e) and (4a–4e) were screened for
their in vitro a-glucosidase inhibitory potential. The inhibitory
effects were plotted against the log of concentrations using
non-linear regression curve approach from which IC50 values
were calculated. The all tested compounds exhibited a good
to moderate inhibitory activity with IC50 values between
43.85 1.06 and 380.10 1.02 mM, when compared to stand-
ard inhibitor acarbose (IC50 ¼ 97.12 0.35 mM) (Table 4). Five
compounds 3a, 3e, 4a, 4d and 4e were found to be the
most potent inhibitors than the rest of tested compounds,
with IC50 values of 98.88 1.11, 84.95 1.01, 98.45 0.54,
101.9 0.43 and 40.67 1.81, respectively, in comparison
with the standard drug acarbose. Furthermore, Compounds
3b, 3c, 3d, 4b and 4c showed moderate inhibitory activity
with IC50 values of 380.10 1.11, 339.70 1.02, 156.3 7.93,
120.8 1.10, 207.9 4.76 and 211.6 3.25. Based on these
results, and to develop the structure-activity relationship
(SAR) study, we have divided the synthesized molecules in
two groups; Compounds (3a–3e), with different substitutions
at variable positions of benzene and (4a–4e) obtained by
the N-allylation of compounds (3a–3e). The general struc-
tural features of the synthetic molecule comprise of thiazoli-
dine-2,4-dione (TZD) ring, aryl ring and allyl group. All these
parts are playing important role in the activity, however, a
slight variation in the structure of the synthesized molecules
such as the position and the nature of the substituents on
the aryl or the N-allylation of TZD could make a great vari-
ation in the a-glucosidase inhibitory activity. In fact, within
the inhibitory activity of 5-arylidenethiazolidine-2,4-dione
derivatives (3a–3e), compound 3a (IC50 ¼ 98.88 1.11 mM)
bearing benzene ring without any substitution displayed
good activity among the serie studied. Compound 3d (IC50
time (5 min) as compared with reaction carried out under clas-
sical synthetic conditions (70%, 5 h) (Table 1, entries 4 and 9).
However, the use of the use of closed vessel microwave
assisted Knoevenagel reaction has not favored the reaction for
10 min at 110 ꢀC. Reversible dehydration condensation under
pressure is in principle a difficult transformation because the
amount of water removed from the product in a closed system
pushes the equilibrium in favor of the hydrated compounds
(Brahmachari, 2016; Murase et al., 2012). Moreover, the con-
densation reaction realized without support or by using of cal-
cined alumina or K10 bentonite clay, did not work under
microwave irradiation even at same temperature and longer
reaction time (entries 2, 4 and 8). The condensation reaction
has been improved also on acidic alumina and silica (entries 3
and 6), and the reaction requires a few minutes with improved
yields using MW. It is interesting to note that the reactivity
increases remarkably in the presence of hydroxylated supports,
we observed a significant effect leading to an increase of yield
of 3a in a short reaction time (5–10 min) (Table 2, entries 5–7)
The involvement of surface hydroxyl groups on no calcined
alumina, and silica supports plays a determinant role in the
chemical activation of methylene group condensation with aro-
matic aldehydes (Khalafinezhad et al., 2001; Kwon et al., 1997;
Syassi et al., 1997).
After optimization of the reaction conditions, this method-
ology was extended for the synthesis of 5-arylidenethiazoli-
dine-2,4-dione via Knoevenagel condensation reaction
between TZD 1 and various aromatic aldehydes. It was found
that basic Al2O3 catalyzes the synthesis of 5-arylidenethiazoli-
dine-2,4-diones (3a-3e) in an efficient manner and excellent
yields (90–95%) of the desired products were obtained
(Table 2, entries 1–5).The synthesized products (3a–3e) were
1
characterized by H NMR, 13C NMR and ESI-MS, and melting
point, which were in accordance with the literature data ¼ 156.3 7.93 mM) bearing bromo substituent in para pos-
(Giles et al., 2000; Zhang Zhou, 2012). Then, the ition of phenyl ring showed moderate activity. Additionally,
&

4
S. FETTACH ET AL.
the insertion of a methyl or fluoro groups in para position group in the para position of the phenyl ring proved to be
afforted compounds 3 b (IC50 ¼ 380.10 1.11 mM) and 3c indifferent or negligible for the affinity with a-amylase in
(IC50 ¼ 339.70 1.02 mM), resulted in a sharp decrease in
comparison with the corresponding unsubstituted derivative
inhibitory activity against a-glucosidase enzyme. However,
3a (IC50 ¼ 126.67 2.10 mM). These results confirm clearly
compound 3d (IC50 ¼ 380.10 1.11 mM) substituted with
that the presence of electron releasing substituents (Me) or
chloro group in ortho and para positions showed the best
inhibitory activity compared to compound 3a and acarbose.
In general, the presence of electron-releasing (Me) or either
electron-withdrawing (Br or F) substituents on the phenyl of
5-arylidenethiazolidine-2,4-dione moiety reduced the inhibi-
tory activity as compared with the unsubstituted phenyl
(compound 3a), and there was no clear difference between
them. In fact, several compounds characterized by the pres-
ence of substituents with opposite electronic effects showed
the same potency. For example, compound 3 b contains the
electron-releasing methyl group showed similar activity
against a-glucosidase enzyme as product 3c containing the
electron-withdrawing fluoro group.
In the serie of N-allyl-5-arylidene-thiazolidine-2,4-dione deriv-
atives (4a–4e), compound 4e (IC50 ¼ 43.85 1.81 mM) with two
electron withdrawing atom Chlorine on benzyl have in ortho
and para positions exhibited more inhibition potential, in com-
parison with their analog non-allylated 3a and acarbose. In
fact, the compound 4e obtained by N-allylation of 3e proved
to be 2-fold more active than the corresponding analog 3e.
electron attracting substituents (Br or F) on phenyl ring
reduced the inhibitory activity compared to unsubstituted
phenyl, in good agreement with the results found in the
a-glucosidase test. On the other hand, the presence of two
chloro groups in the ortho and para position (compound 3e)
has been found to induce a clear advantageous effect reduc-
ing the IC50 value to 47.09 0.04 mM.
Moreover, N-allyl-5-arylidenethiazolidine-2,4-dione deriva-
tives (4a–4e) were even more active than their analogs
N-unallylated by inhibiting the enzyme with IC50 values rang-
ing from 18.19 0.11 to 208.10 1.80 mM (Table 4).
The allyl group on N-3 of thiazolidine-2,4-dione once
again proved to play a critical role in the inhibitory activity
of compounds (4a–4e) against a-amylase by resulting in the
reduction of IC50 values up to two times in comparison with
N-unallylated compounds (3a–3e). Among N-allylated inhibi-
tors, compounds 4a (IC50 ¼ 108.14 2.05 mM), 4b (IC50
¼
167.02 0.97 mM), 4c (IC50 ¼ 195.77 2.14 mM) and 4d (IC50
¼ 156.48 3.17 mM) the differences of IC50 values were
important, in comparison with their analogs N-unallylated 3a
(IC50 ¼ 126.67 2.10 mM), 3b (IC50 ¼ 286.25 4.30 mM), 3c
(IC50 ¼ 263.73 1.54 mM) and 3d (IC50 ¼ 173.30 4.70 mM),
Compounds 4b (IC50
¼
120.8 1.10 mM), 4c (IC50
¼
211.6 3.25 mM) and 4d (IC50 ¼ 101.9 0.43 mM) obtained by
N-allylation of 3b, 3c and 3d, showed a considerable increase
in inhibitory activity, compared to their non-allylated analogs.
For example, compound 4b obtained by N-allylation of 3b
proved to be 3-fold more active than the N-unallylated analog
3b. Therefore, it can be concluded that the ally group on N-3
of thiazolidine-2,4-dione system once again proved to play a
critical role in the binding of compounds (4a–4e) to the active
site of a-glucosidase enzyme by resulting in the reduction of
IC50 values up to one three times, in comparison with N-unally-
lated compounds (3a–3e).
respectively. In fact, the N-allyl derivative 4e (IC50
¼
18.19 0.11 mM) with two chloro groups in ortho and para
positions was found to be the most active in the series and
was found to be 2 times more active than its corresponding
N-unallylated analog 3e.
Our results demonstrate that the substitution of the phe-
nyl ring by two chloro groups in the ortho and para position
and N-allylation of thaizolidine-2,4-dione ring are very closely
related to the ability of these compounds to inhibit a-gluco-
sidase and a-amylase enzymes.
2.2.2. a-Amylase inhibition
2.3. Molecular docking studies
In the pursuit of exploration new anti-diabetic compounds
with enzymatic inhibition, we have screened our thiazoli-
dine-2,4-dione compounds (3a–3e) and (4a–4e) for human
pancreatic a-amylase inhibitory activity. The inhibitory con-
centrations of the synthesized inhibitors were determined
using acarbose as a standard inhibitor with an IC50 value of
2.975 0.004 lM. The bioactivity results are presented in
Table 4. Among the evaluated molecules, compounds 4e
and 3e revealed to be the most active analog in the series
with a strength inhibitory effect, providing an IC50 value of
18.19 0.103 lM and 47.09 0.037 mM, respectively.
The selected substituents inserted on the phenyl ring in
different positions were found to produce opposite effects
on the a-amylase inhibitory activity of the two series of com-
pounds (3a–3e) and (4a–4e). In fact, within the inhibitory
activity of 5-arylidenethiazolidine-2,4-dione derivatives
To understand the observed activities concerning the differ-
ent molecular structures of inhibitor tested, the molecular
docking studies were carried out to shed light on the bind-
ing modes between docked ligands and enzyme targets
(Hafidi et al., 2021). According to the molecular structures of
the ligands (Figure 2), they can be divided into two series
with a common carbon skeleton (mentioned in blue color),
the change of the organic group (R ¼ CH3, F, Br and Cl) it
will be the challenges of the discussion below.
The likeliest docked poses of ligands with the best bind-
ing affinity for ligands complexes in the active site of the tar-
geted enzyme a-amylase and a-glucosidase are shown in
Figures 3 and 4.
The docking results of the synthesized compounds with
the enzyme’s targets have given good information about the
(3a–3e), the effects triggered by the introduction of a methyl nature of the binding mode.
(3b, IC50 286.25 4.30 mM), fluoro (3c, IC50
The analysis of the binding site revealed that the synthe-
263.73 1.54 mM) or bromo (3d, IC50 ¼ 173.30 4.70 mM) sized ligands are stabilized by several favorable interactions
¼
¼

JOURNAL OF BIOMOLECULAR STRUCTURE AND DYNAMICS
5
Figure 2. Chemical structure designed for the TZD ligand of two series tested against the receptors a-amylase (PDB ¼ 1B2Y) and a-glucosidase (PDB ¼ 3W37),
the common carbon skeleton is mentioned by the blue color.
Figure 3. Ligand-receptor interaction for the best ligand (a ¼ 3 b, b ¼ 4a) which has more hydrogen interactions for the a-amylase target enzyme (PDB ¼ 1B2Y).

6
S. FETTACH ET AL.
Figure 4. Ligand-receptor interaction for the best ligand (a ¼ 3 b, b ¼ 3d) which has more hydrogen interactions for the a-glucosidase target enzyme (PDB
¼ 3W37).
Table 5. Docking binding energies, number of hydrogen bonds and hydrophobic interaction for the docked ligand TZD and the reference drug within the active
binding site of the targeted a-amylase (PDB ¼ 1B2Y) and a-glucosidase (PDB ¼ 3W37).
Free binding energy
H-Bonds
Numbers
Name of synthesized compounds
(kcal molꢁ1
)
Hydrophobic interaction number
IC50 SEM
a-amylase (PDB 5 1b2y)
3a
3 b
3c
3d
3e
4a
4 b
4c
4d
4e
Acarbose
ꢁ7.1
ꢁ7.5
ꢁ7.3
ꢁ7.2
ꢁ8
3
3
3
0
2
4
2
2
0
0
7
2
4
2
5
5
4
3
3
5
4
0
126.67 2.10
286.25 4.3
263.73 1.54
173.30 4.70
47.09 0.04
108.14 2.05
167.02 0.97
195.77 2.14
156.48 3.17
18.19 0.11
2.975 0.01
ꢁ8
ꢁ7.5
ꢁ8
ꢁ7.3
ꢁ6.8
ꢁ10.4
a-glucosidase (PDB 5 3W37)
3a
3 b
3c
3d
3e
4a
4 b
4c
4d
4e
ꢁ6.3
ꢁ6.3
ꢁ6.3
ꢁ6.2
ꢁ6.1
ꢁ7.5
ꢁ6.8
ꢁ7.7
ꢁ6.6
ꢁ6.8
ꢁ11.4
3
3
2
1
1
0
0
3
0
0
5
0
3
3
3
4
2
8
6
2
98 .88 1.11
380.10 0.01
339.7 1.02
156.3 7.93
84.95 1.01
98.45 0.54
120.8 1.10
211.6 3.25
101.9 0.43
43.85 1.06
97.12 0.35
0
15
Acarbose

JOURNAL OF BIOMOLECULAR STRUCTURE AND DYNAMICS
7
including polar, hydrogen bond, hydrophobic and electro- hydrophobic, electrostatic and halogen bonding with differ-
static interactions (Tables S1–S4). It was observed that all the ent residues.
compounds exhibited high free energy binding between ꢁ6
The presence of -CH3 in 3b structures hinder the contribu-
and ꢁ8 kcal/mol. For the reference drug Acarbose, we can tion of the two common active site S (sulfur) and the hydro-
see from Table 5 that is obvious from the docking results in gen of NH, on the other hand, these two sites represent
that the high activity of the reference drug acarbose com- their activity for the ligands 3a and 3c. The absence of the
pared to the others studied compounds is due mainly to the contribution of the NH site has noted in the 3d and 3e
stability of the complex acarbose with target enzyme and
the high number of hydrogen bonds formed between the
acarbose and the active residues.
mode of interaction. 3d and 3e exhibit only one hydrogen
interaction in which the carbonyl group is in contribution
against the residue ARG552. Similar to the 1B2Y enzyme,
against a-glucosidase, the contribution of Br and Cl for 3d
and 3e is limited only in the hydrophobic interaction.
Among series 1, the 3 b is the most one that makes more of
the hydrogen interaction with different residue ASP232,
ASN496 and SER497. Compared to the 3a, the presence of
the methyl group in 3 b molecular structure increases the
number of hydrophobic interactions with different residues
PHE476, ALA231 and ILE233. The specificity of the existence
of Halogen interactions has only been observed for 3c inter-
action mode against residues ASP357 and ASP469.
Different types of interaction have been observed in the
interaction modes of the ligands of series 2. According to
Table S4, among the ligands of this series, the 4c with a
Fluorine group is the only one that contributed to three
hydrogen bonding against the residues ARG552 and ASP469.
The contribution of the C ¼ C group in hydrophobic interac-
tions was observed in the interaction modes of all ligands.
For 4d and 4e, their interaction mode exhibits no hydrogen
interaction, the presence of Br and Cl in the two structures
of 4d and 4e precisely increases their hydrophobic inter-
action character. The only halogen interaction was observed
of 4c ligand against the residues ASP357 and ASP469.
According to the behavior of the ligands tested against the
two enzymes, we can build a general idea concerning
the contribution by which each fragment participated in the
interaction modes.
From the results presented in Tables S1–S4 of docking
results, we note that at the level of the common carbon skel-
eton between all the ligands (mentioned in blue color
Scheme 1), the two reactive rings sites with 6 and 5 carbons
atoms participate in the majority of cases in the hydrophobic
interactions types, sometimes we can see their contribution
in the interaction of Pi-anion types.
Between the two series 1 and 2, the substitution of the
hydrogen atom of nitrogen by a propene group leads to a
decrease of participation of the common carbon skeleton in
the hydrogen interactions type, but this replacing group has
a very important role to increase the number of hydrophobic
interactions against the numerous residues in the two
enzyme target.
2.3.1. Against a-amylase enzyme target (PDB ¼ 1B2Y)
We can see from Table S1 that the 3a, 3 b, 3c, 3d and 3e
compounds of the series 1 present the same categories of
interaction (hydrogen and hydrophobic interactions) with the
same residues: ARG195, HIS299, ASP300, LEU165 and, TYR62.
The number of interactions brought into contact between
the inhibitors and the residues shows a dependence on the
molecular structure. The two additional hydrophobic interac-
tions Pi-Alkyl type have been observed against TRP95 in the
3b interaction mode which essentially due to the existence
in its molecular structure of a methyl group (ꢁCH3).
The halogen grouping (Fluorine) does not present any
modification concerning the number and the type of inter-
action, in the structure of 3c, the fluorine group affects just
the interaction distance against the same residue presented
in the 3a interaction mode.
The contribution of the sulfur atom was observed just in
the interaction modes of 3d and 3e against residues TRP58,
TYR62, HIS299 and ASP197. The only electrostatic interaction
has been observed for 3d against ASP300 residue, further,
the halogen Br and Cl groups appear in the chemical struc-
ture of 3e and 3d participates just in hydrophobic inter-
action against the following residues TRP59, TYR62, LEU165
and LEU162. The 3d does not present any hydrogen inter-
action, on the other hand, two Hydrogen interactions have
been observed in the mode of interaction of 3d against the
residue ASP300 and HIS299.
From Table S2, by comparison with 4a molecular struc-
ture, the addition of a methyl group (-CH3) in the structure
of 4 b affecting a decrease of the participation of the two
groups Ethylene (C ¼ C) and Phenyl (Ring(C6)) in the hydro-
phobic interaction. Moreover, the molecular structure of 4 b
promotes the contribution of the sulfur atom in three Pi-sul-
fur interactions with the residues TRP58, TYR62 and HIS299.
Two hydrogen bonds have been observed in the mode of
action of 4c, in which the carbonyl (C ¼ O) and H (CH2) are
in contribution against ARG195 and GLU233. With compari-
son to 4 b, the same Pi-sulfur interaction with the same resi-
due was observed in the interaction of 4c. Moreover, just
hydrophobic interactions have been observed in the 4d and
4e interaction modes against residues TRP59, ALA198,
LEU162 and LEU165.
Among the halogen groups (Br, Cl and F) only the fluorine
which exhibits the halogen interaction types precisely
against the 3W37 enzyme target for the ligands 3c and 4c,
the other halogens such as bromide and chloride their main
contribution are hydrophobic interactions in the two pro-
teinic pockets 3W37 and 1B2Y.
2.3.2. Against a-glucosidase target enzyme (PDB¼ 3W37)
From Table S3, all the ligands of series 1 exhibit, in their
It is important to mention here that the residues Asp197,
interaction
mode
different
interactions,
hydrogen, Glu233 and Asp300 have been observed in the interaction

8
S. FETTACH ET AL.
Scheme 1. Synthetic route for preparation of compounds (3a–3e) and (4a–4e).
modes for certain ligands against the target of the enzyme
1B2Y, each residue among those motioned having a very
important role, according to the work of Rydberg and Zhang
(Rydberg et al., 2002; Zhang et al., 2009), For the residue
Asp197, it was previously reported as a nucleophilic catalytic
in the hydrolysis reactions of polymeric substrates as food
starch, besides (Rydberg et al., 2002; Zhang et al., 2009), the
Asp300 residue has been identified as the player for optimiz-
ing the orientation of the substrate molecule using the
hydrogen bonding interaction and as a steric conflict regula-
tor for better binding conformation of the substrate
(Williams et al., 2012). The last residue Glu233 is known to
act as an acid-base catalyst during substrate hydrolysis reac-
tions (Li et al., 2005; Williams et al., 2012).
3. Conclusion
A variety of synthesized thiazolidine-2,4-dione derivatives
were screened for their in vitro a-glucosidase and a-amylase
inhibitory activities and acute oral toxicity on Swiss mice in
order to get more potent and non-toxic molecules for treat-
ment of type 2 diabetes mellitus. In the present investiga-
tion, we identified lead compounds that have shown to be
dual inhibitors ofa-glucosidase and a-amylase. The enzymatic
screening revealed compounds 3e, 4a and 4e were signifi-
cantly highly potent against two enzymes a-glucosidase
(IC50: 84.95 1.01; 98.45 0.54; 43.85 1.06 mM, respectively)
and
18.19 0.11 mM, respectively) as well as standard acarbose
(IC50glucosidase 97.12 0.35 mM; IC50amylase
a-amylase
(IC50:
47.09 0.04;
108.14 2.05;
¼
¼
2.975 0.01 mM). The most potent compounds were also
found to be non-toxic at concentration of 2000 mg/kg.
Additionally, the molecular docking studies were also carried
out on all the molecules, in order to obtain an insight into
the binding interactions with the active sites. Some mole-
2.4. Acute oral toxicity
The maximal dose (2000 mg/kg B.W) of each thiazolidinde-
2,4-diones derivatives do not shows any related signs of mor-
tality or toxicity tested animals of each group, during the cules showed high binding affinity with enzymes due to their
high interaction with some sensible amino acid residues,
thus indicating their high stability along with activity poten-
tials similar to control Acarbose.
14 days of test. No weight loss or abnormal changes in the
behavioral pattern or any undesired pathologic changes of
the animals have been observed during the treatment.
Therefore, the oral lethal doses of these products are greater
than 2000 mg/kg (Table 6).
4. Experimental
4.1. General methods
Table 6. Effects of 3e and 4e products on body weight variation of swiss
mice with a dose of 2000 mg/kg.
Different reagents and solvents were of analytical reagent
(AR) grade and Sigma Aldrich. q-Nitrophenyl-a-D-glucopyra-
noside (pNPG), a-glucosidase from Saccharomyces cerevisiae,
soluble starch, a-amylase from Human Pancreas, acarbose
were also purchased from Sigma-Aldrich (France). TLC has
been performed on pre-coated silica gel plates (Kieselgel
60 F254, Merck, Germany). NMR spectroscopies were recorded
Body Weight (g)
Dose
(mg/kg)
Initial weight
(1st day)a
Final weight
(14th day)a
Groups
Difference
3e
4e
Control
2000
2000
D.W
29.99 1.88
28.82 1.82
27.68 3.53
32.67 0.95
31.23 0.86
29.63 3.08
þ 2.48
þ 2.41
þ 1.95
aData are expressed as mean SD (n ¼ 6).

JOURNAL OF BIOMOLECULAR STRUCTURE AND DYNAMICS
9
in dry deuterated DMSO on a Bruker AC spectrometer at
4.2.1.5.
(Z)-5-(2,4-dichlorobenzylidene)thiazolidine-2,4-
1
200 MHz for H NMR and 50 MHz for 13C NMR. Mass spectra
dione (3e). White solid, Yield: 89%, mp ¼ 216 ꢀC (EtOH), Lit
(Zhang & Zhou, 2012). 213–215 ꢀC. FTIR (ATR, cmꢁ1): 3310
(NH), 3040 (ArC-H), 1700 (C ¼ O), 1602 (C ¼ O). 1H-NMR
(200 MHz, DMSO-d6, d (ppm)): 7.99 (1H, s, ArCH¼C); 7.23 (1H,
d, J ¼ 2.0 Hz, H Ar); 7.18 (1H, d, J ¼ 8.5 Hz, H Ar); 7.12 (1H, dd,
J ¼ 8.5, 2.0 Hz, H Ar). 13C-NMR (50 MHz, DMSO-d6, d (ppm)):
166.5, 164.0, 139.4, 135.3, 129.6, 128.9, 128.4, 128.0, 126.5,
118.0. MS (ESIþ): m/z ¼ 275.1 [M þ H]þ.
(ESI-MS) were recorded on a Bruker Daltonics Esquire 3000þ,
and the samples were diluted in methanol.
4.2. Chemistry
4.2.1. General procedure for the synthesis of (Z)-5-arylide-
nethiazolidine-2,4-dione 3a-3e
A mixture of TZD (1 mmol) and aromatic aldehyde (1 mmol)
was dissolved in CH2Cl2 (5 mL) then mineral support (1 g)
was added and stirred. After 5 min the solvent was removed
under vacuum and the dry-powder was irradiated in a micro-
wave for appropriate time. After the completion of reaction,
CH2Cl2 is added the chilled reaction mixture, then stirred for
5 min. The reaction mixture is filtered under vacuum and
washed with of CH2Cl2 (3 ꢂ 5 mL). The combined organics
were dried over MgSO4 and the solvent was evaporated
under reduced pressure, the product was crystallized in etha-
nol to give pure product.
4.2.2. General procedure for the synthesis of 3-allyl-5-ary-
lidenethiazolidine-2,4-dione 4a-4e
The thiazolidine-2,4-dione derivatives (4a–4e) were synthe-
sized according to the previously described procedures
(Thari et al., 2020). A mixture of 5-arylidenethiazolidine-2,4-
dione (3a–3e) (1 mmol), allyl bromide (1.2 mmol) in EtOH/
H2O (v/v; 2:1) (10 mL) was treated with sodium hydroxide
(1 mmol), were added. The resulting mixture was stirred and
heated at 75 ꢀC for 5–6 h. The completion of the reaction
was monitored by TLC. The reaction mixture was cooled and
acidified with diluted HCl (4 N). The precipitated solid was fil-
tered and purified by recrystallization from ethanol to give
pure compounds 4a–4e.
4.2.1.1. (Z)-5-benzylidenethiazolidine-2,4-dione (3a). White
solid, Yield: 95% (144 mg), mp ¼ 247 ꢀC (EtOH), Lit (Giles
et al., 2000). 247–249 ꢀC. FTIR (ATR, cmꢁ1): 3220 (NH),
2900–3009 (C-H), 1736 (C ¼ O), 1681 (C ¼ O). 1H-NMR
(200 MHz, DMSO-d6) d, ppm (J, Hz): 12.60 (1H, s, NH); 7.76
(1H, s, PhCH ¼ C); 7.59–7.43 (5H, m, H Ar). 13C-NMR (50 MHz,
DMSO-d6): d, ppm: 167.7 (C ¼ O); 167.2 (C ¼ O); 132.9
(CH ¼ C); 131.6 (C-5 TZD); 130.3 (C-1 Ar); 129.9 (C-3 Ar); 129.2
(C-2 Ar); 123.4 (C-4 Ar). MS (ESIþ): m/z ¼ 206.1 [M þ H]þ.
4.2.2.1. 3-Allyl-5-(benzylidene) thiazolidine-2,4-dione (4a).
White solid, Yield: 62%, mp ¼ 102 ꢀC (EtOH). FTIR (ATR,
cmꢁ1): 3210 (NH), 3048 (ArC-H), 1731 (C ¼ O), 1674 (C ¼ O).
1H-NMR (200 MHz, DMSO-d6, d (ppm)): 8.01–7.88 (m, 2H, H
Ar), 7.63–7.38 (m, 3H, H Ar), 7.51 (s, 1H, ArCH¼C), 6.08–5.67
(m, 1H, CH¼CH2), 5.30 (dd, J ¼ 13.7, 10.2 Hz, 1H, CH¼CH2),
5.05 (dd, J ¼ 16.5, 13.8 Hz, 1H, -CH¼CH2), 4.15 (d, J ¼ 6.2 Hz,
2H, N-CH2).13C-NMR (50 MHz, DMSO-d6,d (ppm)): 172.1, 169.1,
136.1, 133.1, 132.9, 130.2, 129.7, 129.1, 118.1, 117.6, 44.2. MS
(ESIþ): m/z ¼ 246.1 [M þ H]þ.
4.2.1.2. (Z)-5-(4-methylbenzylidene) thiazolidine-2,4-dione
(3 b). White solid, Yield: 92%, mp ¼ 230 ꢀC (EtOH), Lit (Zhang
& Zhou, 2012). 230–232 ꢀC. FTIR (ATR, cmꢁ1): 3188 (NH), 3044
1
(ArC-H), 1733 (C ¼ O), 1681 (C ¼ O). H-NMR (200 MHz, DMSO-
d6, d (ppm)): 12.56 (1H, s, NH); 7.73 (1H, s, ArCH ¼ C); 7.46
(2H, d, J ¼ 4.4 Hz,H Ar); 7.32 (2H, d, J ¼ 4.4 Hz, H Ar); 2.33 (3H,
s, CH3). 13C-NMR (50 MHz, DMSO-d6, d (ppm)): 167.8, 167.3,
140.6, 131.8, 130.2, 130.0, 129.8, 122.2, 21.0. MS (ESIþ):
m/z ¼ 220.2 [M þ H]þ.
4.2.2.2. 3-Allyl-5-(4-methylbenzylidene) thiazolidine-2,4-
dione (4 b). White solid, Yield: 65%, mp ¼ 117 ꢀC (EtOH).
FTIR (ATR, cmꢁ1): 3320 (NH), 3048 (ArC-H), 1728 (C ¼ O), 1668
(C ¼ O). 1H-NMR (200 MHz, DMSO-d6, d (ppm)): 7.81 (1H, s,
ArCH¼C); 7.34 (2H, d, J ¼ 8.2 Hz, H Ar); 7.21 (2H, d, J ¼ 7.2 Hz,
H Ar); 5.88–5.69 (1H, m, CH¼CH2); 5.23 (1H, dd, J ¼ 12 Hz,
1.4 Hz, CH ¼ CH2); 5.16 (1H, dd, J ¼ 5.7 Hz, 1.4 Hz, CH ¼ CH2);
4.27 (2H, d, J ¼ 6.0 Hz, NCH2); 2.33 (3H, s, CH3). 13C-NMR
(50 MHz, DMSO-d6, d (ppm)): 167.6, 166.0, 141.3, 134.0, 130.4,
130.3, 130.2, 129.9, 120.1, 118.8, 43.7, 21.5. MS (ESIþ):
m/z ¼ 260.0 [M þ H]þ, 282.0 [M þ Na]þ.
4.2.1.3. 5-(4-Fluorobenzylidene) thiazolidine-2,4-dione (3c).
Yellow solid, Yield: 97%, mp ¼ 219 ꢀC (EtOH), Lit (Giles et al.,
2000). 219–220 ꢀC. FTIR (ATR, cmꢁ1): 3132 (NH), 3042 (ArC-H),
1750 (C ¼ O), 1689 (C ¼ O). 1H-NMR (200 MHz, DMSO-d6, d
(ppm)): 12.60 (1H, s, NH); 7.77 (1H, s, ArCH ¼ C); 7.64 (2H, m,
H Ar); 7.35 (2H, m, H Ar). 13C-NMR (50 MHz, DMSO-d6, d
(ppm)): 167.7, 167.3, 162.7, 132.3, 130.5, 129.7, 123.3, 116.14.
MS (ESIþ): m/z ¼ 224.1 [M þ H]þ.
4.2.2.3. 3-Allyl-5-(4-fluorobenzylidene) thiazolidine-2,4-
dione (4c). White solid, Yield: 58%, mp ¼ 121 ꢀC (EtOH). FTIR
(ATR, cmꢁ1): 3225 (NH), 3042 (ArC-H), 1735 (C ¼ O), 1684
(C ¼ O). 1H-NMR (200 MHz, DMSO-d6, d (ppm)): 7.80 (1H, s,
ArCH¼C); 7.52 ꢁ 7.35 (2H, m, H Ar); 7.24 ꢁ 7.01 (2H, m, H Ar);
5.93 ꢁ 5.64 (m, CH¼CH2); 5.24 (1H, dd, J ¼ 12.0, 2.0 Hz,
CH ¼ CH2); 5.17 (1H, dd, J ¼ 6.0, 2.0 Hz, CH ¼ CH2); 4.28 (2H, d,
J ¼ 6.0 Hz, NCH2). 13C-NMR (50 MHz, DMSO-d6, d (ppm)):
4.2.1.4. 5-(4-Bromobenzylidene) thiazolidine-2,4-dione
(3d). White solid, Yield: 93%, mp ¼ 246 ꢀC (EtOH), Lit (Giles
et al., 2000). 242–244 ꢀC. FTIR (ATR, cmꢁ1): 3200 (NH), 3042
1
(ArC-H), 1713 (C ¼ O), 1608 (C ¼ O). H-NMR (200 MHz, DMSO-
d6, d (ppm)): 12.31 (1H, s, NH); 7.77 (2H, d, J ¼ 7.5 Hz, H Ar);
7.61 (2H, d, J ¼ 6.8 Hz, H Ar); 7.55 (1H, s, ArCH¼C). 13C-NMR
(50 MHz, DMSO-d6, d (ppm)): 173.0, 172.4, 138.1, 136.9, 135.5, 167.1, 166.1, 163.4, 132.6, 132.2, 130.0, 129.5, 121.0, 119.0,
135.1, 134.4, 128.7. MS (ESIþ): m/z ¼ 284.4 [M þ H]þ.
116.3, 43.8. MS (ESIþ): m/z ¼ 264.2 [M þ H]þ.

10
S. FETTACH ET AL.
4.2.2.4.
3-Allyl-5-(4-bromobenzylidene)thiazolidine-2,4-
dione (4d). White crystals, Yield: 50%, mp ¼ 146 ꢀC (EtOH).
FTIR (ATR, cmꢁ1): 3315 (NH), 3051 (ArC-H), 1729 (C ¼ O), 1684
(C ¼ O). 1H-NMR (200 MHz, DMSO-d6, d (ppm)): 7.76 (1H, s,
ArCH¼C); 7.54 (2H, d, J ¼ 8.5 Hz, H Ar); 7.29 (2H, d, J ¼ 8.6 Hz,
H Ar); 5.92–5.66 (1H, m, CH¼CH2); 5.24 (1H, dd, J ¼ 12.0,
2.0 Hz, CH ¼ CH2); 5.17 (1H, dd, J ¼ 5.0, 2.0 Hz, CH ¼ CH2). 4.28
(2H, d, J ¼ 6.0 Hz, NCH2). 13C-NMR (50 MHz, DMSO-d6,
d
Figure 5. Re-docking pose for the original ligand Acarbose and RMSD value of
0.40 Å (yellow ¼ docked, gray ¼ original) in the PDB ¼ 3W37 target enzyme.
(ppm)): 166.9, 165.7, 132.5, 132.4, 132.0, 131.4, 130.0, 125.0,
122.1, 119.1, 43.9. MS (ESIþ): m/z ¼ 348.4 [M þ Na]þ.
crystallized ligand Acarbose was redocked into the active site
of 1B2Y and 3W37 targets. The precision evaluation for
protocol docking was based on the Root-Mean-Square
Deviation (RMSD) parameter, the prediction is acceptable if
4.2.2.5. 3-Allyl-5-(2,4-dichlorobenzylidene)thiazolidine-2,4-
dione (4e). Yellow solid, Yield 58%, mp 113 ꢀC (EtOH). FTIR
(ATR, cmꢁ1): 3290 (NH), 3033 (ArC-H), 1735 (C ¼ O), 1678
1
(C ¼ O). H-NMR spectrum (200 MHz, DMSO-d6, d (ppm)): 8.09
its value does not exceed
2 angstroms (Kadukova &
(1H, s, ArCH¼C); 7.44 (1H, d, J ¼ 2.0 Hz, H Ar); 7.39 (1H, d,
J ¼ 8.5 Hz, H Ar); 7.29 (1H, dd, J ¼ 8.5, 2.0 Hz, H Ar); 5.88–5.69
(1H, m, -CH¼CH2); 5.24 (1H, dd, J ¼ 13.0, 1.2 Hz, CH¼CH2);
5.18 (1H, dd, J ¼ 5.8, 1.1 Hz, CH¼CH2); 4.30 (2H, d, J ¼ 6.0 Hz,
NCH2). 13C-NMR (50 MHz, DMSO-d6, d (ppm)): 166.8, 165.2,
136.7, 136.6, 130.4, 130.3, 129.9, 129.5, 128.8, 127.7, 124.9,
119.3, 44.1. MS (ESIþ): m/z ¼ 313.1 [M þ H]þ.
Grudinin, 2018). The superimposition (Figure 5) of the
redocked and the cocrystallized acarbose show the low
RMSD value of 0.50 Ð and 0.40Ð for 1B2Y and 3W37,
respectively.
4.5. Acute oral toxicity
The thiazolidine-2,4-diones derivatives that showed the best
inhibitory effect of the two enzymes have been assessed for
their acute oral toxicity, according to the guideline of the
Organization for Economic Testing of Chemicals no 423, the
assay was tested on swiss females mice (Fettach et al., 2019).
Six mice for each group were received a maximal single oral
dose of 2000 mg/kg B.W, after fasting overnight. A follow-up
of the mortality rate, macroscopic parameters (neurological,
autonomic behaviors) and toxic sings for 5 h after product
administration and daily for 2 weeks was carried out. Body
weight was recorded daily for 14 days. The control group
(n ¼ 6) received distilled water as a vehicle.
4.3. Biological activity
4.3.1. In vitro a-glucosidase and a-amylase inhib-
ition assay
The a-glucosidase and a-amylase inhibitory activities of syn-
thesized compounds were determined according to the
method described in our previous work (Fettach et al., 2019;
Pillai et al., 2019).
4.4. Molecular docking studies
In order to reveal the binding modes of synthesized 5-aryli-
dene-2,4-thiazolidindione (3a–3e) and (4a–4e), molecular
docking simulation was carried out as a significant tool for
computer-aided drug design and molecular structural biol-
ogy using AutodockVina (Trott & Olson, 2010). It comprised a
4.6. Statistical analysis
series of steps that includes a selection of protein and its All the experiments were carried out in triplicate (n ¼ 3). The
preparation, receptor grid generation, preparation of ligands,
and there docking to the receptors. The 3 D Crystal Structure
of human pancreatic a-amylase (PDB ID: 1B2Y) (Nahoum
et al., 2000) and a-glucosidase (PDB ID: 3W37) (Tagami et al.,
2013) complexed with the carbohydrate inhibitor (acarbose)
was used as target enzyme. The pretreatment of the target
crystal structure (1B2Y and 3W37) was done using PYMOL
(http://www.pymol.org) (Chen et al., 2017), for the removal
of water molecules, heteroatom, ions, and ligands of origin
in the crystalline structure (Ladbury, 1996; Lu et al., 2007). All
the ligands are drawn using Chemdraw12.0 software (Li
et al., 2004). To select the most stable conformation, the
geometry of these ligands was subsequently optimized using
Molecular Force Field (MMFF94) as implemented in the same
Software. The Discovery Studio Client (version 17.2.0) was
used for graphical visualization for the best interactions of
complex protein-ligand conformations. To evaluate and valid-
data were described as the mean standard deviation (SD)
of mean and expressed by one-way analysis of variance
(ANOVA), followed by Duncan’s new analysis to identify sig-
nificant differences between means using the Multiple Range
Test (p < 0.05). All statistical analysis was determined using
GraphPad Prism 8.0.2.
Acknowledgements
The authors would like to acknowledge the UATRS-CNRST and Analysis
and Characterization Platform ACP-FSR for 13C NMR, 1H NMR, mass spec-
tra and IR respectively.
Disclosure statement
The authors declare that they have no competing financial interests that
ate the binding prediction of docking protocol, the co- could have appeared to influence the work reported in this paper.

JOURNAL OF BIOMOLECULAR STRUCTURE AND DYNAMICS
11
Hafidi, Z., Yakkou, L., Guouguaou, F. E., Amghar, S., & Achouri, M. E.
(2021). Aminoalcohol-based surfactants (N-(hydroxyalkyl)- N, N-
dimethyl N-alkylammonium bromide): evaluation of antibacterial
activity and molecular docking studies against dehydrosqualene syn-
thase enzyme (CrtM). Journal of Dispersion Science and Technology,
42(4), 514–525.
Funding
This work is supported by CNRST-Morocco, UM5R, and UM6P.
Hameed, I., Masoodi, S. R., Mir, S. A., Nabi, M., Ghazanfar, K., & Ganai,
B. A. (2015). Type 2 diabetes mellitus: From a metabolic disorder to
an inflammatory condition. World Journal of Diabetes, 6(4), 598–612.
https://doi.org/10.4239/wjd.v6.i4.598
Hanefeld, M., Fischer, S., Julius, U., Schulze, J., Schwanebeck, U.,
Schmechel, H., Ziegelasch, H. J., Lindner, J., & Group, D. I. S. (1996).
Risk factors for myocardial infarction and death in newly detected
NIDDM: The Diabetes Intervention Study, 11-year follow-up.
ORCID
Zakaria Hafidi
http://orcid.org/0000-0001-8554-5189
http://orcid.org/0000-0001-7890-9028
http://orcid.org/0000-0001-9553-8310
http://orcid.org/0000-0003-3863-4677
Yahia Cherrah
Khalid Bougrin
My El Abbes Faouzi
References
Diabetologia,
39(12),
1577–1583.
https://doi.org/10.1007/
s001250050617
Abbas, G., Al Harrasi, A., Hussain, H., Hamaed, A., & Supuran, C. T. (2019).
The management of diabetes mellitus-imperative role of natural prod-
ucts against dipeptidyl peptidase-4, a-glucosidase and sodium-
dependent glucose co-transporter 2 (SGLT2). Bioorganic Chemistry, 86,
305–315. https://doi.org/10.1016/j.bioorg.2019.02.009
Avupati, V. R., Yejella, R. P., Akula, A., Guntuku, G. S., Doddi, B. R., Vutla,
V. R., Anagani, S. R., Adimulam, L. S., & Vyricharla, A. K. (2012).
Synthesis, characterization and biological evaluation of some novel
2,4-thiazolidinediones as potential cytotoxic, antimicrobial and antihy-
perglycemic agents. Bioorganic & Medicinal Chemistry Letters, 22(20),
6442–6450. https://doi.org/10.1016/j.bmcl.2012.08.052
Berlie, H. D., Kalus, J. S., & Jaber, L. A. (2007). Thiazolidinediones and the
risk of edema: A meta-analysis. Diabetes Research and Clinical Practice,
76(2), 279–289. https://doi.org/10.1016/j.diabres.2006.09.010
Bhattarai, B. R., Kafle, B., Hwang, J.-S., Ham, S. W., Lee, K.-H., Park, H.,
Han, I.-O., & Cho, H. (2010). Novel thiazolidinedione derivatives with
anti-obesity effects: Dual action as PTP1B inhibitors and PPAR-c acti-
vators. Bioorganic & Medicinal Chemistry Letters, 20(22), 6758–6763.
https://doi.org/10.1016/j.bmcl.2010.08.130
Bloomgarden, Z., Einhorn, D., Handelsman, Y., Misra, A., Zonszein, J.,
Grunberger, G., Jellinger, P. S., & Garber, A. J. (2018). ACP diabetes
guidelines attempt to turn back the clock, conflating good HbA1c
with hypoglycemia. Journal of Diabetes,10(8), 618–620.
Brahmachari, G. (2016). Design for carbon–carbon bond forming reac-
tions under ambient conditions. RSC Advances, 6(69), 64676–64725.
https://doi.org/10.1039/C6RA14399G
Chen, F., Wang, Z., Wang, C., Xu, Q., Liang, J., Xu, X., Yang, J., Wang, C.,
Jiang, T., & Yu, R. (2017). Application of reverse docking for target
prediction of marine compounds with anti-tumor activity. Journal of
Molecular Graphics & Modelling, 77, 372–377. https://doi.org/10.1016/j.
jmgm.2017.09.015
Chinthala, Y., Kumar Domatti, A., Sarfaraz, A., Singh, S. P., Kumar Arigari,
N., Gupta, N., Satya, S. K. V. N., Kotesh Kumar, J., Khan, F., Tiwari, A. K.,
& Paramjit, G. (2013). Synthesis, biological evaluation and molecular
modeling studies of some novel thiazolidinediones with triazole ring.
European Journal of Medicinal Chemistry, 70, 308–314. https://doi.org/
10.1016/j.ejmech.2013.10.005
Fettach, S., Mrabti, H. N., Sayah, K., Bouyahya, A., Salhi, N., Cherrah, Y., &
El Abbes, F. M. (2019). Phenolic content, acute toxicity of Ajuga iva
extracts and assessment of their antioxidant and carbohydrate digest-
ive enzyme inhibitory effects. South African Journal of Botany, 125,
381–385. https://doi.org/10.1016/j.sajb.2019.08.010
Fonseca, V. (2003). Effect of thiazolidinediones on body weight in
patients with diabetes mellitus. The American Journal of Medicine,
115(8), 42–48. https://doi.org/10.1016/j.amjmed.2003.09.005
Forman, L. M., Simmons, D. A., & Diamond, R. H. (2000). Hepatic failure
in a patient taking rosiglitazone. Annals of Internal Medicine, 132(2),
118–121. https://doi.org/10.7326/0003-4819-132-2-200001180-00005
Giles, R. G., Lewis, N. J., Quick, J. K., Sasse, M. J., Urquhart, M. W., &
Youssef, L. (2000). Regiospecific reduction of 5-benzylidene-2,4-thiazo-
lidinediones and 4-oxo-2-thiazolidinethiones using lithium borohy-
dride in pyridine and tetrahydrofuran. Tetrahedron, 56(26), 4531–4537.
https://doi.org/10.1016/S0040-4020(00)00361-6
Joshi, S. R., Standl, E., Tong, N., Shah, P., Kalra, S., & Rathod, R. (2015).
Therapeutic potential of a-glucosidase inhibitors in type 2 diabetes
mellitus: An
Pharmacotherapy,
14656566.2015.1070827
evidence-based
review.
Expert
https://doi.org/10.1517/
Opinion
on
16(13), 1959–1981.
Kadukova, M., & Grudinin, S. (2018). Docking of small molecules to farne-
soid X receptors using AutoDock Vina with the Convex-PL potential:
Lessons learned from D3R Grand Challenge 2. Journal of Computer-
Aided Molecular Design, 32(1), 151–162. https://doi.org/10.1007/
s10822-017-0062-1
Khalafinezhad, A., Hashemi, A., & Chem, I. J. (2001). Microwave enhanced
knoevenagel condensation of barbituric acid with aromatic aldehydes
on basic aIumina. Iranian Journal of Chemistry and Chemical
Engineering, 20, 9–11.
Kwon, P. S., Kim, Y. M., Kang, C. J., Kwon, T. W., Chung, S. K., & Chang,
Y. T. (1997). Microwave enhanced Knoevenagel condensation of mal-
onic acid on basic alumina. Synthetic Communications, 27(23),
4091–4100. https://doi.org/10.1080/00397919708005456
Ladbury, J. E. (1996). Just add water! The effect of water on the specifi-
city of protein-ligand binding sites and its potential application to
drug design. Chemistry & Biology, 3(12), 973–980. [Database] https://
doi.org/10.1016/s1074-5521(96)90164-7
Leroux-Stewart, J., Rabasa-Lhoret, R., & Chiasson, J.-L. (2014). Diabetic
mastopathy: case report and summary of literature. Canadian Journal
of Diabetes, 38(5), 305–306.
Li, C., Begum, A., Numao, S., Kwan, H. P., Withers, S. G., & Brayer, G. D.
(2005). Acarbose rearrangement mechanism implied by the kinetic
and structural analysis of human pancreatic alpha-amylase in complex
with analogues and their elongated counterparts. Biochemistry, 44(9),
3347–3357. https://doi.org/10.1021/bi048334e
Li, Z., Wan, H., Shi, Y., & Ouyang, P. (2004). Personal experience with four
kinds of chemical structure drawing software: Review on ChemDraw,
ChemWindow, ISIS/Draw, and ChemSketch. Journal of Chemical
Information and Computer Sciences, 44(5), 1886–1890. https://doi.org/
10.1021/ci049794h
Lu, Y., Wang, R., Yang, C. Y., & Wang, S. (2007). Analysis of ligand-bound
water molecules in high-resolution crystal structures of protein-ligand
complexes. Journal of Chemical Information and Modeling, 47(2),
668–675. https://doi.org/10.1021/ci6003527
Murase, T., Nishijima, Y.,
& Fujita, M. J. (2012). Cage-catalyzed
Knoevenagel condensation under neutral conditions in water. Journal
of the American Chemical Society, 134(1), 162–164. https://doi.org/10.
1021/ja210068f
ꢁ
Nahoum, V., Roux, G., Anton, V., Rouge, P., Puigserver, A., Bischoff, H.,
Henrissat, B., & Payan, F. (2000). Crystal structures of human pancre-
atic a-amylase in complex with carbohydrate and proteinaceous
inhibitors. Biochemical Journal, 346(1), 201–208. https://doi.org/10.
1042/bj3460201
Naim, M. J., Alam, M. J., Ahmad, S., Nawaz, F., Shrivastava, N., Sahu, M., &
Alam, O. (2017). Therapeutic journey of 2,4-thiazolidinediones as a
versatile scaffold: An insight into structure activity relationship.
European Journal of Medicinal Chemistry, 129, 218–250. https://doi.org/
10.1016/j.ejmech.2017.02.031

12
S. FETTACH ET AL.
Okazaki, R. Y. O., Miura, M., Toriumi, M., Taguchi, M., Hirota, Y.,
Fukumoto, S., Fujita, T., Tanaka, K., & Takeuchi, Y. (1999). Short-term
derivatives as FabH inhibitors. Bioorganic Chemistry, 88, 102958.
https://doi.org/10.1016/j.bioorg.2019.102958
treatment with troglitazone decreases bone turnover in patients with Syassi, B., Bougrin, K., & Soufiaoui, M. (1997). Addition dipolaire-1,3 des
ꢀ
type 2 diabetes mellitus. Endocrine Journal, 46(6), 795–801. https://doi.
org/10.1507/endocrj.46.795
Patil, V., Tilekar, K., Mehendale-Munj, S., Mohan, R., & Ramaa, C. S. (2010).
arylnitriloxydes avec quelques dipolarophiles olefiniques sur alumine
en milieu sec et sous micro-ondes. Tetrahedron Letters, 38(51),
8855–8858. https://doi.org/10.1016/S0040-4039(97)10392-6
Synthesis and primary cytotoxicity evaluation of new 5-benzylidene- Tagami, T., Yamashita, K., Okuyama, M., Mori, H., Yao, M., & Kimura, A.
2,4-thiazolidinedione derivatives. European Journal of Medicinal
(2013). Molecular basis for the recognition of long-chain substrates by
Chemistry, 45(10), 4539–4544. https://doi.org/10.1016/j.ejmech.2010.07.
plant a-glucosidases. The Journal of Biological Chemistry, 288(26),
014
19296–19303. https://doi.org/10.1074/jbc.M113.465211
ꢁ
ꢁ
ꢁ
Pillai, R. R., Karrouchi, K., Fettach, S., Armakovic, S., Armakovic, S. J., Brik, Thari, F. Z., Tachallait, H., Alaoui, N. E., Talha, A., Arshad, S., Alvarez, E.,
Y., Taoufik, J., Radi, S., Faouzi, M. E. A., & Ansar, M. (2019). Synthesis,
spectroscopic characterization, reactive properties by DFT calculations,
molecular dynamics simulations and biological evaluation of Schiff
bases tethered 1,2,4-triazole and pyrazole rings. Journal of Molecular
Structure, 1177, 47–54. https://doi.org/10.1016/j.molstruc.2018.09.037
Karrouchi, K., & Bougrin, K. (2020). Ultrasound-assisted one-pot green
synthesis of new N-substituted-5-arylidene-thiazolidine-2,4-dione-iso-
xazoline derivatives using NaCl/Oxone/Na3PO4 in aqueous media.
Ultrasonics Sonochemistry, 68, 105222. https://doi.org/10.1016/j.ult-
sonch.2020.105222
Prabhakar, C., Madhusudhan, G., Sahadev, K., Reddy, C. M., Sarma, M. R., Trott, O., & Olson, A. J. (2010). AutoDock Vina: Improving the speed and
Reddy, G. O., Chakrabarti, R., Rao, C. S., Kumar, T. D., & Rajagopalan, R.
(1998). Synthesis and biological activity of novel thiazolidinediones.
Bioorganic & Medicinal Chemistry Letters, 8(19), 2725–2730. https://doi.
org/10.1016/s0960-894x(98)00485-5
Rafique, R., Khan, K. M., Arshia, Kanwal, Chigurupati, S., Wadood, A.,
Rehman, A. U., Karunanidhi, A., Hameed, S., Taha, M., & Al-Rashida, M.
(2020). Synthesis of new indazole based dual inhibitors of a-glucosi-
accuracy of docking with a new scoring function, efficient optimiza-
tion, and multithreading. Journal of Computational Chemistry, 31(2),
455–461. https://doi.org/10.1002/jcc.21334
Williams, L. K., Li, C., Withers, S. G., & Brayer, G. D. (2012). Order and dis-
order: Differential structural impacts of myricetin and ethyl caffeate
on human amylase, an antidiabetic target. Journal of Medicinal
Chemistry, 55(22), 10177–10186. https://doi.org/10.1021/jm301273u
dase and a-amylase enzymes, their in vitro, in silico and kinetics stud- Willson, T. M., Brown, P. J., Sternbach, D. D., & Henke, B. R. (2000). The
ies. Bioorganic Chemistry, 94, 103195.
Rydberg, E. H., Li, C., Maurus, R., Overall, C. M., Brayer, G. D., & Withers,
PPARs: From orphan receptors to drug discovery. Journal of Medicinal
Chemistry, 43(4), 527–550. https://doi.org/10.1021/jm990554g
S. G. (2002). Mechanistic analyses of catalysis in human pancreatic Zhang, R., Li, C., Williams, L. K., Rempel, B. P., Brayer, G. D., & Withers,
alpha-amylase: Detailed kinetic and structural studies of mutants of
three conserved carboxylic acids. Biochemistry, 41(13), 4492–4502.
https://doi.org/10.1021/bi011821z
S. G. (2009). Directed "in situ" inhibitor elongation as a strategy to
structurally characterize the covalent glycosyl-enzyme intermediate of
human pancreatic alpha-amylase. Biochemistry, 48(45), 10752–10764.
https://doi.org/10.1021/bi901400p
Smith, M. T. (2003). Mechanisms of troglitazone hepatotoxicity. Chemical
Research in Toxicology, 16(6), 679–687. https://doi.org/10.1021/ Zhang, Y., & Zhou, Z. (2012). A solvent-free protocol for the green syn-
tx034033e
thesis of 5-arylidene-2,4-thiazolidinediones using ethylenediamine
diacetate as catalyst. Organic Chemistry International, 2012, 1–5.
https://doi.org/10.1155/2012/194784
Sun, J., He, W., Liu, H. Y., Qin, J., & Ye, C. L. (2019). Design, synthesis and
molecular docking of 1,4-benzodioxane thiazolidinedione piperazine