Design and synthesis of novel quinazolinone-1,2,3-triazole hybrids as new anti-diabetic agents: In vitro α-glucosidase inhibition, kinetic, and docking study

Article abstract of DOI:10.1016/j.bioorg.2018.10.023

A novel series of quinazolinone-1,2,3-triazole hybrids 10a-p were designed, synthesized, and evaluated for their in vitro α-glucosidase inhibitory activity leading to efficient anti-diabetic agents. All synthesized compounds exhibited good inhibitory acti

Full text of DOI:10.1016/j.bioorg.2018.10.023

Accepted Manuscript
Design and synthesis of novel quinazolinone-1,2,3-triazole hybrids as new anti-
diabetic agents: in vitro α -glucosidase inhibition, kinetic, and docking study
Mina Saeedi, Maryam Mohammadi-Khanaposhtani, Parvaneh Pourrabia, Nima
Razzaghi, Reza Ghadimi, Somaye Imanparast, Mohammad Ali Faramarzi,
Fatemeh Bandarian, Ensieh Nasli Esfahani, Maliheh Safavi, Hossein Rastegar,
Bagher Larijani, Mohammad Mahdavi, Tahmineh Akbarzadeh
PII:
S0045-2068(18)30869-1
DOI:
https://doi.org/10.1016/j.bioorg.2018.10.023
YBIOO 2557
Reference:
Bioorganic Chemistry
To appear in:
Received Date:
Revised Date:
Accepted Date:
12 August 2018
4 October 2018
10 October 2018
Please cite this article as: M. Saeedi, M. Mohammadi-Khanaposhtani, P. Pourrabia, N. Razzaghi, R. Ghadimi, S.
Imanparast, M. Ali Faramarzi, F. Bandarian, E. Nasli Esfahani, M. Safavi, H. Rastegar, B. Larijani, M. Mahdavi,
T. Akbarzadeh, Design and synthesis of novel quinazolinone-1,2,3-triazole hybrids as new anti-diabetic agents: in
vitro α -glucosidase inhibition, kinetic, and docking study, Bioorganic Chemistry (2018), doi: https://doi.org/
10.1016/j.bioorg.2018.10.023
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Design and synthesis of novel quinazolinone-1,2,3-triazole hybrids as new anti-diabetic agents: in
vitro α-glucosidase inhibition, kinetic, and docking study
c
b
d
Mina Saeedi a,b, Maryam Mohammadi-Khanaposhtani , Parvaneh Pourrabia , Nima Razzaghi , Reza
e
f
f
g
Ghadimi , Somaye Imanparast , Mohammad Ali Faramarzi , Fatemeh Bandarian , Ensieh Nasli
Esfahani g, Maliheh Safavi h, Hossein Rastegar i, Bagher Larijani j, Mohammad Mahdavi j,*, Tahmineh
Akbarzadeh d,b,
*
a
Medicinal Plants Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences,
Tehran, Iran
b Persian Medicine and Pharmacy Research Center, Tehran University of Medical Sciences, Tehran, Iran
c
Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of
Medical Sciences, Babol, Iran
d
Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences,
Tehran, Iran
e Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical
Sciences, Babol, Iran
f
Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research
Center, Tehran University of Medical Sciences, Tehran. Iran
g
Diabetes Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran
University of Medical Sciences, Tehran, Iran
h Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran P.O.
Box 3353-5111, Iran
i Food and Drug Research Institute, Food and Drug Administration, MOHE, Tehran, Iran
j
Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences
Institute, Tehran University of Medical Sciences, Tehran, Iran
E-mail addresses: akbarzad@tums.ac.ir (T. Akbarzadeh), momahdavi@tums.ac.ir (M. Mahdavi)
This paper is dedicated to the memory of Professor Abbas Shafiee (1937-2016)
ABSTRACT
1

A novel series of quinazolinone-1,2,3-triazole hybrids 10a-p were designed, synthesized, and evaluated
for their in vitro α-glucosidase inhibitory activity leading to efficient anti-diabetic agents. All synthesized
compounds exhibited good inhibitory activity against yeast α-glucosidase (IC50 values in the range of
181.0-474.5 µM) even much more potent than standard drug acarbose (IC50 = 750.0). Among them,
quinazolinone-1,2,3-triazoles possessing 4-bromobenzyl moiety connected to 1,2,3-triazole ring (10g and
10p) demonstrated the most potent inhibitory activity towards α-glucosidase. Compound 10g inhibited α-
glucosidase in a competitive manner with Ki value of 117 µM. Furthermore, the binding modes of the
most potent compounds 10g and 10p in the α-glucosidase active site was studied through in silico docking
studies. Also, lack of cytotoxicity of compounds 10g and 10p was confirmed via MTT assay.
Key words: Anti-diabetic activity, Competitive inhibition, α-Glucosidase, Molecular docking,
Quinazolinone, 1,2,3-Triazole
1. Introduction
α-Glucosidase is a key enzyme in the process of digestion of carbohydrates. It breaks down starch
and disaccharides to glucose leading to the release of absorbable monosaccharides and consequently
increase of blood glucose levels. In this respect, it has been considered as a therapeutic target for the
treatment of type 2 diabetes [1,2] since enzyme inhibition delays carbohydrate digestion and
monosaccharide absorption and subsequently reduces postprandial plasma glucose levels and
postprandial hyperglycemia [3]. Currently prescribed α-glucosidase inhibitors such as acarbose,
voglibose, and miglitol have depicted different side effects including bloating, diarrhea, flatulence, pain,
and abdominal discomfort [4]. Hence, discovery and development of new α-glucosidase inhibitors
possessing high efficacy and low side effects are still in high demand as an attractive target for medicinal
chemists.
2

Quinazoline and its derivatives have been found as effective and versatile pharmacophoric units in
medicinal chemistry to design and develop a wide range of bioactive compounds. Some medicinal
properties such as anticancer, antimicrobial, anti-diabetic, anti-cholinesterase, anti-inflammatory, and
dihydrofolate reductase inhibitory activities have been successfully documented in the literature [5-11].
Furthermore, recent studies confirmed α-glucosidase inhibitory activity of quinazolines [12-14]. For
example, different derivatives of A (Fig. 1) were found to be potent α-glucosidase inhibitors (IC50 = 12.5-
15.6 µM comparing with acarbose, 475.0 µM) [14].
1,2,3-triazole derivatives are undeniably important in medicinal chemistry. There are various
compounds containing 1,2,3-trizole moiety with diverse pharmacological activities such as anticancer,
anti-cholinesterase, anti-oxidant, anticonvulsant activities [15-18]. However, several 1,2,3-triazole
derivatives with high α-glucosidase inhibitory activity have been reported [19-22]. In this respect,
Chinthala et. al. reported a derivative of 1,2,3-triazole containing phenethyl side chain and
thiazolidinedione moiety B (Fig. 1) as a potent α-glucosidase inhibitor (IC50 = 0.3 µM comparing with
acarbose, 12.5 µM) [20]. Hybrid structures of 1,2,3-triazole and different heterocycles such as carbazole
(C) (IC50 = 0.8-100.8 µM comparing with acarbose, 840 µM) or triazine rings (D) (IC50 = 11.6-37.4 µM
comparing with acarbose, 817.4 µM) (Fig. 1) were also reported as highly potent α-glucosidase inhibitors
[21, 22].
Molecular hybridization (MH) is a useful tool for design and development of new biologically active
compounds which combines two or more pharmacophores to create a new hybrid molecule with improved
potency [23]. In continuation of our efforts in design and development of novel α-glucosidase inhibitors
[24-27] and focusing on compounds A, B, C, and D possessing high α-glucosidase inhibitory activity,
herein, novel quinazolinone-1,2,3-triazole hybrids 10a-p are reported based on MH. All compounds were
synthesized in good yields and evaluated for their in vitro α-glucosidase inhibitory activity. To investigate
3

the interaction of the title compounds with amino acid residues participating in the α-glucosidase, kinetic
and molecular docking studies were also performed.
2. Results and Discussion
2.1. Chemistry
Synthesis of desired compounds 10a-p was performed as outlined in Scheme 1. Required
starting materials, 2-amino-N-arylbenzamide derivatives 3 were obtained by the reaction of isatoic
anhydride 1 and amine 2 in water at room temperature. Then, reaction of compound 3 and carbon
disulfide (CS2) 4 in the presence of potassium hydroxide (KOH) in EtOH by heating at reflux gave the
corresponding thioxo-dihydroquinazolinone derivatives 5. Next, the reaction of compounds 5 and
propargyl bromide 6 in the presence of potassium carbonate (K2CO3) in DMF by heating at 80 °C
afforded propargylated derivatives 7. Finally, click reaction of compounds 7 and in situ prepared
organic azides 9 in the presence of trimethylamine in the mixture of water/tert-butyl alcohol in the
presence of catalytic amounts of CuSO4.5H2O provided the title compounds 10a-p.
2.2. In vitro a-glucosidase inhibitory activity
All synthesized compounds 10a-p were evaluated for their in vitro inhibitory activity against α-
glucosidase (Saccharomyces cerevisiae) in comparison to acarbose as the standard drug (Table 1). As can
be seen in Table 1, synthesized compounds can be divided into two groups; i) derivatives having 3-
phenethyl group (10a-g) and ii) derivatives having 3-(3,4-dimethoxyphenethyl) group (10h-p) connected
to quinazoline moiety.
IC50 values of the title compounds (ranging from 181.0 to 474.5 µM) revealed that all of them
possessed higher inhibitory activity against yeast α-glucosidase than acarbose (IC50 = 750.0 µM).
Compounds 10g and 10p containing 4-bromobenzyl moiety connected to 1,2,3-triazole ring demonstrated
4

the highest activity (181.0 and 192.3 µM, respectively). Also, compounds 10a, 10n, 10j, and 10f exhibited
good α-glucosidase inhibitory activity with IC50 values of 200.0, 202.5, 205.6, and 209.4 µM,
respectively.
The α-glucosidase inhibitory activity of the first group containing 3-phenethyl derivatives 10a-g
demonstrated that compound 10g containing 4-bromobenzyl moiety was the most potent compound.
Changing the position of bromine to the ortho position of benzyl group (compound 10f) reduced activity
(IC50 = 209.4 µM). Introduction of other halogens (F and Cl) into the benzyl moiety connected to 1,2,3-
triazole ring led to lower activity than compound 10g. Substitution of fluorine at the meta position of
benzyl moiety (compound 10b) gave inhibitory activity with IC50 = 426.4 µM. Also, the presence of
chlorine at different positions of benzyl group (compounds 10c, 10d, and 10e) afforded various inhibitory
activity, however, lower than compound 10g. Compound 10c possessing 2-chlorobenzyl group showed
IC50 = 220.5 µM and changing the position of Cl from ortho to meta (compound 10d) and para (compound
10e) led to IC50s= 369.0 and 474.5 µM, respectively. Interestingly, the α-glucosidase inhibitory activity
of compounds 10a-g was not only affected by the electronic property of halogens but also by their position
on the benzyl moiety in such a manner that 2-Cl derivative (10c)>4-Cl derivative (10e) while 4-Br
derivative (10g)>2-Br derivative (10f). Finally, introduction of methyl group into 4-position of pendant
benzyl group (compound 10a) led to good activity (IC50 = 200.0 µM). Comparing the inhibitory activity
of compounds 10a, 10e, and 10g which have different substituents at 4-position of benzyl moiety showed
the order of inhibitory activity as 4-Br>4-Me>4-Cl.
Considering the IC50 values obtained from the second category containing 3-(3,4-
dimethoxyphenethyl) group 10h-p showed some similarities comparing with their counterparts in the
first category (10a-g). In this group, 4-Br derivative (compound 10p) was the most potent compound
(IC50 = 192.3 µM), however, lower active than its counterpart 10g (IC50 = 181.0 µM). Changing the
5

position of the bromine on the pendant benzyl group from para to meta (compound 10o) and ortho
(compound 10n) slightly decreased α-glucosidase inhibitory activity with IC50s = 226.0 and 202.5 µM,
respectively. They were approximately as potent as their counterparts in the first group. Replacement of
Br by F and Cl diminished inhibitory activity and similarly the lowest inhibitory activity was obtained by
4-Cl derivative (compound 10m, IC50 = 463.0 µM). Substitution of Cl at the ortho and meta positions
(compounds 10k and 10l) gave IC50s = 222.0 and 235.8 µM, respectively. In the case of 2-Cl derivative
(compound 10k), it was approximately as potent as its counterpart compound 10c, however, compound
10k was stronger than compound 10d. Fluorinated derivatives (compounds 10i and 10j) were found to be
good α-glucosidase inhibitors with IC50s = 250.0 and 205.6 µM, respectively. Although they were a little
lower active than brominated derivatives but much more active than their counterparts in the first category
of the synthesized compounds. Finally, insertion of methyl group (compound 10h) deteriorated α-
glucosidase inhibitory activity (IC50 = 301.5 µM); also, it showed lower activity than its counterpart 10a.
2.3. Kinetic study
Kinetic study of the most potent inhibitor of α-glucosidase 10g was performed in order to gain
further insight into the mechanism of action of this compound (Fig. 2). The analysis of obtained
Lineweaver–Burk plots revealed that increasing the concentration of inhibitor did not change in Vmax
values while Km values increased. It indicated that compound 10g was a competitive inhibitor towards α-
glucosidase (Fig. 2a). The Ki value was calculated as 117 µM through the secondary re-plot of mentioned
Lineweaver–Burk plots against the different concentrations of compound 10g.
2.4. Cytotoxicity studies
As growth and proliferation of cancerous cells are very rapid, cytotoxicity of all synthesized
compounds 10a-p was evaluated against breast cancer cell line MCF-7. Also, the most active compounds
6

10g and 10p were evaluated against normal cell line HDF using MTT assay [24]. Synthesized compounds
depicted no cytotoxic activity against each of the two series of cell lines.
2.5. Docking study
Interaction modes of the most potent compounds 10g and 10p in the active site of α-glucosidase
were performed using homology model of α-glucosidase according to our previous study [26].
Superposed structure of the standard drug acarbose and the most potent compound 10g in the active site
of homology model of α-glucosidase was shown in Fig. 3. The detailed binding mode of acarbose revealed
that it interacted with residues Asn241, His279, Glu304, Arg312, Thr302, Thr307, Ser308, and Gln322
(Fig. 4).
The most active compound 10g established interactions with residues His279, Pro309, Arg312,
Val305, and Val316 (Fig. 5a). Quinazolinone moiety formed a hydrogen bond and a π–π interaction with
His279. Phenethyl group and sulfur of compound 10g interacted with Arg312. Also, a hydrophobic
interaction between Pro309 and 1,2,3-triazole ring was observed. Moreover, 4-bromobenzyl group
showed two interactions with Val305 and Val316 through 4-bromo substituent and a hydrophobic
interaction with Pro309 through phenyl ring.
Introduction of two methoxy groups at 3- and 4-position of phenethyl moiety in compound 10g
led to a slight decrease of inhibitory activity as observed in the case of compound 10p. In this case,
quinazolinone moiety established a π–π interaction with Phe300 (Fig. 5b). This compound formed a
hydrogen bond and a hydrophobic interaction with Arg312 via 3-methoxy group and phenyl ring of
phenethyl moiety. 4-Bromobenzyl group of compound 10p showed two interactions with Glu304 and
Pro309 through bromine and two interactions with His279 and Pro309 through phenyl ring (Fig. 5). Also,
sulfur of this compound interacted with Phe157. Further studies on the binding energies of compounds
10g, 10p, and acarbose showed that compounds 10g and 10p have a lower free binding energy (-8.63 and
7

-8.17 kcal/mol, respectively) than acarbose (-4.04 kcal/mol) and therefore bound more easily to α-
glucosidase than acarbose. It also can explain the difference between the α-glucosidase inhibitory activity
of compound 10g with binding energy of -8.63 kcal/mol and its counterpart 10p with binding energy of -
8.17 kcal/mol.
3. Conclusion
In summary, a novel series of quinazolinone-1,2,3-triazole hybrids 10a-p were designed and
synthesized as new potent α-glucosidase inhibitors to develop efficient anti-diabetic agents. All
synthesized compounds showed much better activity than the standard drug, acarbose. Compounds 10g
and 10p were found to be the most active among the title compounds. Also, compound 10g could inhibit
α-glucosidase in a competitive manner. Furthermore, synthesized compounds 10a-p showed no
cytotoxicity against studied cancer and normal cell lines. Docking study of the most potent compounds
10g and 10p confirmed they have been well fitted in the active site of α-glucosidase via desirable
interactions.
4. Methods and materials
1
13
Melting points were determined on a Kofler hot stage apparatus and are uncorrected. H and C NMR
spectra were recorded on a Bruker FT-500, using TMS as an internal standard. IR spectra were obtained
on a Nicolet Magna FTIR 550 spectrophotometer (KBr disks). MS were recorded on an Agilent
Technology (HP) mass spectrometer operating at an ionization potential of 70 eV. Elemental analysis was
performed on an Elementar Analysensystem GmbH VarioEL CHNS mode.
4.1. General procedure for the preparation of 2-amino-N-arylbenzamides 3
8

A mixture of isatoic anhydride 1 (20 mmol) and amines 2 (20 mmol) in water (50 mL) was stirred
for 2-3 h at room temperature. After completion of the reaction (checked by TLC, petroleum ether/ethyl
acetate: 1/2), the precipitated product was filtered off affording 2-amino-N-arylbenzamide derivatives 3
which was used for the next reaction with no purification.
4.2. General procedure for the preparation of thioxo-dihydroquinazolinones 5
A mixture of compound 3 (2 mmol), carbon disulfide 4 (5 mmol), and potassium hydroxide (2
mmol) in EtOH (10 mL) was heated at reflux for 3-5 h. After completion of the reaction (checked by
TLC, petroleum ether/ethyl acetate: 1/4), the reaction mixture was cooled down to room temperature,
poured into ice-cold water, and the precipitated product was filtered off and recystilized from EtOH to
give the corresponding thioxo-dihydroquinazolinone derivatives 5.
4.3. General procedure for the preparation of 2-(prop-2-ynylthio)quinazolin-4(3H)-one derivatives 7
A mixture of compound 5 (1 mmol), propargyl bromide (1.2 mmol) 6, and potassium carbonate
(1.5 mmol) in DMF (15 mL) was heated at 80 °C for 8 h. After that, the mixture was poured into ice-cold
water, and the precipitated product was filtered off to obtain propargylated derivatives 7.
4.4. General procedure for the synthesis of quinazolinone-1,2,3-triazole hybrids 10
A solution of benzyl chloride/bromide 8 (1.1 mmol), sodium azide (0.9 mmol), and
trimethylamine (1.3 mmol) in water (4 mL) and tert-butyl alcohol (4 mL) was stirred at room temperature
for 30 min to give azide derivatives 9. Then, compound 7 (1 mmol) and CuSO4.5H2O (7 mol%) were
added to the reaction mixture and it was continued for 24 h. Upon completion of the reaction, monitored
by TLC (petroleum ether/ethyl acetate: 1/4), the mixture was diluted with water, extracted with
chloroform, and dried over anhydrous Na2SO4. After evaporation of solvent, the residue was recrystallized
from ethyl acetate and petroleum ether to give pure product 10.
9

4.4.1.
2-(((1-(4-Methylbenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-phenethylquinazolin-4(3H)-one
(10a)
Yield: 94%; mp = 121-126 °C; IR (KBr): 3050 (C-H), 2825 (C-H), 1675 (C=O), 1661, 1528 (C=N, C=C)
1
cm-1. HNMR (CDCl3, 500 MHz): δ = 2.47 (s, 3H, CH3), 3.13-3.16 (m, 2H, CH2), 4.38-4.42 (m, 2H,
CH2), 4.76 (s, 2H, CH2), 5.57 (s, 2H, CH2), 7.23-7.28 (m, 4H, H2’, H3’, H5’, H6’), 7.39-7.44 (m, 5H,
Ph), 7.55 (t, JH6-5,6-7 = 8.0 Hz, 1H, H6), 7.60-7.62 (m, 2H, H8, triazole), 7.82 (t, JH7-6,7-8 = 8.0 Hz, 1H,
H7), 8.37 (d, JH5-6 = 8.0 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125 MHz): δ = 21.1, 26.8, 34.1, 46.2, 54.1,
119.3, 123.1, 125.7, 125.9, 126.8, 127.1, 128.1, 128.7, 128.9, 129.8, 131.5, 134.4, 137.6, 138.8, 144.0,
147.0, 155.9, 161.1 ppm. Anal. Calcd for C27H25N5OS: C, 69.35; H, 5.39; N, 14.98. Found: C, 69.48; H,
5.21; N, 15.21.
4.4.2.
2-(((1-(3-Fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-phenethylquinazolin-4(3H)-one
(10b)
Yield: 73%; mp = 148-153°C; IR (KBr): 3048 (C-H), 2829 (C-H), 1671 (C=O), 1660, 1550 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 2.97 (t , JCH2-CH2 = 7.5 Hz, 2H, CH2), 4.22 (t, JCH2-CH2 = 7.5 Hz,
2H, CH2), 4.60 (s, 2H, CH2), 5.42 (s, 2H, CH2), 6.86 (d, JH2’-3’ = 8.5 Hz, 1H, H2’), 6.93-6.97 (m, 2H,
H4’, H5’), 7.21-7.25 (m, 6H, Ph, H3’), 7.37 (t, JH6-5,6-7 = 7.0 Hz, 1H, H6), 7.46 (d, JH8-7 = 7.0 Hz, 1H,
H8), 7.51 (s, 1H, triazole), 7.65 (t, JH7-6,7-8 = 7.0 Hz, 1H, H7), 8.18 (d, JH5-6 = 7.0 Hz, 1H, H5) ppm.
13CNMR (CDCl3, 125 MHz): δ = 26.8, 34.1, 46.3, 53.6, 97.0, 115.1, 115.9, 119.4, 122.8, 123.5, 125.5,
126.0, 126.8, 127.1, 128.7, 128.9, 130.5, 134.5, 137.6, 144.5, 146.8, 155.4, 161.5, 162.2 ppm. Anal. Calcd
for C26H22FN5OS: C, 66.22; H, 4.70; N, 14.85. Found: C, 66.41; H, 4.52; N, 14.59.
4.4.3.
2-(((1-(2-Chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-phenethylquinazolin-4(3H)-one
(10c)
10

Yield: 88%; mp = 125-128°C; IR (KBr): 3050 (C-H), 2829 (C-H), 1677 (C=O), 1668, 1552 (C=N, C=C)
1
cm-1. HNMR (CDCl3, 500 MHz): δ = 3.00-3.02 (m, 2H, CH2), 4.25-4.27 (m, 2H, CH2), 4.62 (s, 2H,
CH2), 5.60 (s, 2H, CH2), 7.15-7.30 (m, 8H, Ph, H4’, H5’, H6’), 7.39-7.41 (m, 2H, H6, triazole), 7.51 (d,
13
JH8-7 = 6.0 Hz, 1H, H8), 7.65-7.69 (m, 2H, H7, H3’), 8.23 (d, JH5-6 = 6.0 Hz, 1H, H5) ppm. CNMR
(CDCl3, 125 MHz): δ = 26.9, 34.1, 46.2, 51.5, 96.1, 119.5, 123.3, 125.7, 125.9, 126.8, 127.1, 127.6, 128.7,
129.0, 129.9, 130.3, 130.4, 132.6, 134.4, 137.7, 144.2, 147.2, 155.7, 161.5 ppm. MS (m/z, %): 489
([M+2]+., 5), 487 (M+, 15), 334 (53), 281 (55), 249 (23), 230 (38), 207 (10), 178 (64), 162 (31), 125
(100), 104 (63), 89 (22), 77 (11). Anal. Calcd for C26H22ClN5OS: C, 63.99; H, 4.54; N, 14.35. Found: C,
64.28; H, 4.38; N, 14.50.
4.4.4.
2-(((1-(3-Chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-phenethylquinazolin-4(3H)-one
(10d)
Yield: 89%; mp = 126-131°C; IR (KBr): 3050 (C-H), 2829 (C-H), 1677 (C=O), 1668, 1552 (C=N, C=C)
cm-1. 1H NMR (CDCl3, 500 MHz): δ = 3.02 (t, JCH2-CH2 = 7.5 Hz, 2H, CH2), 4.27 (t, JCH2-CH2 = 7.5 Hz,
2H, CH2), 4.64 (s, 2H, CH2), 5.45 (s, 2H, CH2), 7.09 (d, JH6’-5’ = 7.5 Hz, 1H, H6’), 7.21-7.32 (m, 9H, Ph,
H2’, H4’, H5’, triazole), 7.41 (t, JH6-5,6-7 = 7.5 Hz, 1H, H6), 7.50 (d, JH8-7 = 7.5 Hz, 1H, H8), 7.70 (t, JH7-
6,7-8 = 7.5 Hz, 1H, H7), 8.23 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125 MHz): δ = 26.9, 34.1,
46.3, 53.5, 96.1, 119.6, 123.4, 125.6, 125.8, 126.0, 126.8, 127.2, 127.8, 128.1, 128.7, 129.0, 129.0, 130.4,
134.5, 137.6, 144.1, 147.2, 155.6, 168.5 ppm. MS (m/z, %): 489 ([M+2]+., 5), 487 (M+, 15), 334 (50), 281
(84), 249 (30), 230 (44), 178 (76), 162 (38), 125 (100), 104 (86), 89 (24), 77 (14). Anal. Calcd for
C26H22ClN5OS: C, 63.99; H, 4.54; N, 14.35. Found: C, 64.32; H, 4.78; N, 14.15.
4.4.5.
2-(((1-(4-Chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-phenethylquinazolin-4(3H)-one
(10e)
11

Yield: 91%; mp = 129-132 °C; IR (KBr): 3050 (C-H), 2828 (C-H), 1672 (C=O), 1665, 1552 (C=N, C=C)
1
cm-1. HNMR (CDCl3, 500 MHz): δ = 3.01-3.03 (m, 2H, CH2), 4.26-4.28 (m, 2H, CH2), 4.62 (s, 2H,
CH2), 5.45 (s, 2H, CH2), 7.15 (d, JH2’,6’-3’,5’ = 7.0 Hz, 2H, H2’, H6’), 7.26-7.31 (m, 7H, Ph, H3’, H5’),
7.42-7.50 (m, 3H, H6, H8, triazole), 7.70 (t, JH7-6,7-8 = 7.0 Hz, 1H, H7), 8.24 (d, J5-6 = 7.0 Hz, 1H, H5)
13
ppm. CNMR (CDCl3, 125 MHz): δ = 26.8, 34.1, 46.2, 53.4, 96.1, 119.2, 122.8, 123.9, 125.6, 126.0,
126.8, 127.1, 128.7, 128.9, 129.4, 133.0, 134.4, 137.6, 144.3, 147.1, 155.3, 161.4 ppm. Anal. Calcd for
C26H22ClN5OS: C, 63.99; H, 4.54; N, 14.35. Found: C, 63.78; H, 4.21; N, 14.24.
4.4.6. 2-(((1-(2-Bromobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-phenethylquinazolin-4(3H)-one (10f)
Yield: 86%; mp = 130-133 °C; IR (KBr): 3051 (C-H), 2829 (C-H), 1675 (C=O), 1665, 1550 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 3.01 (t, JCH2-CH2 = 8.0 Hz, 2H, CH2), 4.27 (t, JCH2-CH2 = 8.0 Hz, 2H,
CH2), 4.62 (s, 2H, CH2), 5.60 (s, 2H, CH2), 7.12 (d, JH6’-5’ = 7.5 Hz, 1H, H6’), 7.19-7.30 (m, 7H, Ph, H4’,
H5’), 7.41 (t, JH6-5,6-7 = 7.5 Hz, 1H, H6), 7.50 (d, JH8-7 = 7.5 Hz, 1H, H8), 7.56 (d, JH3’-4’ = 7.5 Hz, 1H,
H3’), 7.66-7.70 (m, 2H, H7, triazole), 8.23 (d, J5-6 = 7.5 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125 MHz):
δ = 26.9, 34.1, 46.2, 53.9, 96.1, 119.1 123.4, 125.8, 126.0, 126.8, 127.1, 127.3, 128.2, 128.7, 129.0, 129.1,
130.4, 133.2, 134.4, 137.6, 144.0, 147.1, 155.8, 161.2 ppm. Anal. Calcd for C26H22BrN5OS: C, 58.65; H,
4.16; N, 13.15. Found: C, 58.48; H, 4.31; N, 13.34.
4.4.7.
2-(((1-(4-Bromobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-phenethylquinazolin-4(3H)-one
(10g)
Yield: 89%; mp = 131-133 °C; IR (KBr): 3050 (C-H), 2829 (C-H), 1672 (C=O), 1669, 1578 (C=N, C=C)
1
cm-1. H NMR (CDCl3, 500M Hz): δ = 3.02-3.04 (m, 2H, CH2), 4.27-4.29 (m, 2H, CH2), 4.61 (s, 2H,
CH2), 5.43 (s, 2H, CH2), 7.08 (d, JH2’,6’-3’,5’ = 8.0 Hz, 2H, H2’, H6’), 7.24-7.32 (m, 5H, Ph), 7.41-7.46 (m,
5H, H6, H8, H3’, H5’, triazole), 7.70 (t, JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.24 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm.
13CNMR (CDCl3, 125 MHz): δ = 26.8, 34.1, 46.2, 53.5, 96.0, 119.5, 123.0, 125.7, 126.0, 126.8, 127.1,
12

128.7, 128.9, 129.7, 132.3, 133.4, 134.4, 137.7, 140.2, 147.1, 155.5, 161.4 ppm. Anal. Calcd for
C26H22BrN5OS: C, 58.65; H, 4.16; N, 13.15. Found: C, 58.47; H, 4.40; N, 13.28.
4.4.8.
3-(3,4-Dimethoxyphenethyl)-2-(((1-(4-methylbenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)
quinazolin-4(3H)-one (10h)
Yield: 90%; mp = 135-138 °C; IR (KBr): 3055 (C-H), 2829 (C-H), 1678 (C=O), 1663, 1558 (C=N, C=C)
1
cm-1. HNMR (CDCl3, 500 MHz): δ = 2.34 (s, 3H, CH3), 2.96-2.98 (m, 2H, CH2), 3.83 (s, 3H, OMe),
3.86 (s, 3H, OMe), 4.26-4.28 (m, 2H, CH2), 4.60 (s, 2H, CH2), 5.42 (s, 2H, CH2), 6.79-6.83 (m, 2H, H2”,
H5”), 6.86 (d, JH6’’-5’’ = 8.0 Hz, 1H, H6”), 7.09-7.13 (m, 5H, H2’, H3’, H5’, H6’, triazole), 7.41 (t, JH6-
5,6-7 = 7.5 Hz, 1H, H6), 7.45 (d, JH8-7 = 7.5 Hz, 1H, H8), 7.68 (t, JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.23 (d, JH5-6
= 7.5 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125 MHz): δ = 21.2, 26.9, 33.6, 46.4, 54.0, 55.8, 55.9, 96.0,
111.4, 112.1, 119.4, 121.0, 125.7, 125.9, 127.0, 128.1, 129.7, 130.2, 131.4, 134.4, 138.7, 144.5, 147.1,
147.9, 149.0, 155.6, 161.5 ppm. Anal. Calcd for C29H29N5O3S: C, 66.01; H, 5.54; N, 13.27. Found: C,
66.31; H, 5.38; N, 13.51.
4.4.9.
3-(3,4-Dimethoxyphenethyl)-2-(((1-(3-fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)
quinazolin-4(3H)-one (10i)
Yield: 70%; mp = 150-151°C; IR (KBr): 3050 (C-H), 2829 (C-H), 1677 (C=O), 1660, 1556 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 2.98-3.00 (m, 2H, CH2), 3.82 (s, 3H, OMe), 3.85 (s, 3H, OMe),
4.28-4.29 (m, 2H, CH2), 4.60 (s, 2H, CH2), 5.48 (s, 2H, CH2), 6.77-6.80 (m, 3H, H2’’, H5’’, H6”), 6.88
(d, JH6’-5’ = 7.0 Hz, H6’), 6.89 (d, JH2’-F = 7.0 Hz, H2’), 6.96-7.03 (m, 2H, H5’, triazole), 7.28 (t, JH4’-5’,4’-F
= 7.0 Hz, 1H, H4’), 7.41 (t, JH6-5,6-7 = 7.5 Hz, 1H, H6),7.45 (d, JH8-7 = 7.5 Hz, 1H, H8), 7.69 (t, JH7-6,7-8
=
7.5 Hz, 1H, H7), 8.23 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125 MHz): δ = 26.1, 33.6, 46.4,
52.5, 55.9, 56.0, 96.1, 111.5, 112.2, 115.0 (d, J = 21.2 Hz), 115.8 (d, J = 20.0 Hz), 119.5, 121.1, 123.5,
125.7, 125.9, 127.1, 130.2, 130.7 (d, J = 8.7 Hz), 134.4, 136.9, 145.5, 147.2, 147.9, 149.0, 155.5, 161.4,
13

162.9 (d, J = 246.2 Hz) ppm. MS (m/z, %): 531 (M+, 15), 341 (28), 164 (100), 149 (17), 109 (62). Anal.
Calcd for C28H26FN5O3S: C, 63.26; H, 4.93; N, 13.17. Found: C, 63.51; H, 4.71; N, 13.29.
4.4.10.
3-(3,4-Dimethoxyphenethyl)-2-(((1-(4-fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)
quinazolin-4(3H)-one (10j)
Yield: 73%; mp = 151-153°C; IR (KBr): 3054 (C-H), 2828 (C-H), 1675 (C=O), 1662, 1558 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 2.97-2.99 (m, 2H, CH2), 3.82 (s, 3H, OMe), 3.85 (s, 3H, OMe),
4.27-4.29 (m, 2H, CH2), 4.59 (s, 2H, CH2), 5.44 (s, 2H, CH2), 6.78-6.81 (m, 2H, H2”, H5”), 6.85 (d, JH6’’-
5’’ = 7.5 Hz, 1H, H6”), 7.00 (t, JH3’,5’-2’,6’-F = 7.5 Hz, 2H, H3’, H5’), 7.17-7.22 (m, 3H, H2’, H6’, triazole),
7.40-7.44 (m, 2H, H6, H8), 7.68 (t, JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.23 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm.
13CNMR (CDCl3, 125 MHz): δ = 27.5, 33.6, 46.4, 53.5, 55.9, 56.0, 96.1, 111.5, 112.2, 116.0 (d, J = 22.5
Hz), 119.4, 121.0, 125.7, 126.0, 127.1, 130.0, 130.1 (d, J = 8.0 Hz), 134.4, 135.2, 144.5, 147.1, 147.9,
149.0, 155.7, 161.4, 162.5 (d, J = 245. Hz) ppm. Anal. Calcd for C28H26FN5O3S: C, 63.26; H, 4.93; N,
13.17. Found: C, 63.41; H, 5.24; N, 12.88.
4.4.11.
2-(((1-(2-Chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-(3,4-dimethoxyphenethyl)
quinazolin-4(3H)-one (10k)
Yield: 80%; mp = 135-139 °C; IR (KBr): 3050 (C-H), 2828 (C-H), 1672 (C=O), 1665, 1558 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 2.96 (t, JCH2-CH2 = 7.0 Hz, 2H, CH2), 3.83 (s, 3H, OMe), 3.85 (s,
3H, OMe), 4.24-4.26 (m, 2H, CH2), 4.62 (s, 2H, CH2), 5.61 (s, 2H, CH2), 6.77-6.80 (m, 3H, H6’, H2’’,
H5’’), 6.84 (d, JH6’’-5’’ = 7.5 Hz, 1H, H6’’), 7.15 (d, JH3’-4’ = 7.0 Hz, 1H, H3’), 7.20 (t, JH4’-3’,4’-5’ = 7.0 Hz,
1H, H4’), 7.27 (t, JH5’-4’,5’-6’ = 7.0 Hz, 1H, H5’), 7.37-7.43 (m, 2H, H6, triazole), 7.50 (d, JH8-7 = 7.5 Hz,
1H, H8), 7.69 (t, JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.23 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125
MHz): δ = 26.8, 33.6, 46.4, 51.5, 55.9, 56.0, 96.1, 111.5, 112.1, 119.6, 121.0, 125.7, 125.9, 127.1, 127.6,
14

129.9, 130.3, 130.4, 132.4, 134.4, 144.2, 147.1, 147.8, 149.1, 151.9, 154.1, 155.7, 161.4 ppm. Anal. Calcd
for C28H26ClN5O3S: C, 61.36; H, 4.78; N, 12.78. Found: C, 61.58; H, 4.59; N, 12.51.
4.4.12.
2-(((1-(3-Chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-(3,4-dimethoxyphenethyl)
quinazolin-4(3H)-one (10l)
Yield: 76%; mp = 138-140 °C; IR (KBr): 3050 (C-H), 2828 (C-H), 1675 (C=O), 1663, 1559 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 3.03-3.05 (m, 2H, CH2), 3.88 (s, 3H, OMe), 3.91 (s, 3H, OMe),
4.33-4.35 (m, 2H, CH2), 4.68 (s, 2H, CH2), 5.52 (s, 2H, CH2), 6.84-6.87 (m, 2H, H2”, H5”), 6.92 (d, JH6’’-
5’’ = 7.5 Hz, 1H, H6”), 7.14 (d, JH6’-5’ = 7.0 Hz, 1H, H6’), 7.26-7.36 (m, 4H, H2’, H4’, H5’, triazole), 7.47
(t, JH6-5,6-7 = 7.5 Hz, 1H, H6), 7.53 (d, JH8-7 = 7.5 Hz, 1H, H8), 7.76 (t, JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.29 (d,
JH5-6 = 7.5 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125 MHz): δ = 26.9, 33.6, 46.4, 50.9, 54.0, 55.9, 96.0,
111.5, 112.1, 119.4, 121.1, 125.7, 125.9, 126.1, 127.0, 128.1, 129.0, 130.2, 130.3, 134.5, 135.0, 136.4,
147.1, 147.9, 149.0, 151.8, 155.5, 161.4 ppm. Anal. Calcd for C28H26ClN5O3S: C, 61.36; H, 4.78; N,
12.78. Found: C, 61.60; H, 4.87; N, 12.84.
4.4.13.
2-(((1-(4-Chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-(3,4-dimethoxyphenethyl)
quinazolin-4(3H)-one (10m)
Yield: 84%; mp = 137-140 °C; IR (KBr): 3058 (C-H), 2828 (C-H), 1675 (C=O), 1667, 1561 (C=N, C=C)
cm-1. 1H NMR (CDCl3, 500 MHz): δ = 2.96-2.98 (m, 2H, CH2), 3.83 (s, 3H, OMe), 3.86 (s, 3H, OMe),
4.26-4.28 (m, 2H, CH2), 4.60 (s, 2H, CH2), 5.45 (s, 2H, CH2), 6.78-6.81 (m, 2H, H2”, H5”), 6.85 (d, JH6’’-
5’’ = 8.0 Hz, 1H, H6”), 7.14 (d, JH2’,6’-3’,5’ = 7.5 Hz, 2H, H2’, H6’), 7.29 (d, JH3’,5’-2’,6’ = 7.5 Hz, 2H, H3’,
H5’), 7.40-7.44 (m, 3H, H6, H8, triazole), 7.70 (t, JH7-8 = 7.5 Hz, 1H, H7), 8.24 (d, JH8-7 = 7.5 Hz, 1H,
H8) ppm. 13CNMR (CDCl3, 125 MHz): δ = 26.9, 33.6, 46.4, 53.5, 55.8, 55.9, 96.0, 111.5, 112.1, 119.4,
121.0, 125.7, 126.0, 127.1, 129.3, 129.4, 130.2, 132.9, 134.4, 135.8, 145.8, 147.1, 147.9, 149.0, 155.5,
15

161.5 ppm. Anal. Calcd for C28H26ClN5O3S: C, 61.36; H, 4.78; N, 12.78. Found: C, 61.46; H, 4.49; N,
12.51.
4.4.14.
2-(((1-(2-Bromobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-(3,4-dimethoxylphenethyl)
quinazolin-4(3H)-one (10n)
Yield: 84%; mp = 142-145 °C; IR (KBr): 3050 (C-H), 2829 (C-H), 1675 (C=O), 1663, 1585 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 2.96 (t, JCH2-CH2 = 8.0 Hz, 2H, CH2), 3.83 (s, 3H, OMe), 3.85 (s,
3H, OMe), 4.25 (t, JCH2-CH2 = 8.0 Hz, 2H, CH2), 4.62 (s, 2H, CH2), 5.60 (s, 2H, CH2), 6.79 (d, J5’’-6’’ = 8.5
Hz, 1H, H5”), 6.81 (s, 1H, H2’’), 6.85 (d, JH6’’-5’’ = 8.5 Hz, 1H, H6”), 7.13 (d, JH6’-5’ = 7.0 Hz, 1H, H6’),
7.19 (t, JH4’-3’,4’-5’ = 7.0 Hz, 1H, H4’), 7.24 (t, JH5’-4’,5’-6’ = 7.0 Hz, 1H, H5’),7.41 (t, JH6-5,6-7 = 7.5 Hz, 1H,
H6), 7.51 (d, JH8-7 = 7.5 Hz, 1H, H8), 7.55 (d, JH3’-4’ = 7.5 Hz, 1H, H3’), 7.66 (s, 1H, triazole), 7.69 (t,
JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.23 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm. 13CNMR (CDCl3, 125 MHz): δ = 26.8,
33.6, 46.4, 53.9, 55.9, 56.0, 97.5, 111.5, 112.1, 119.5, 121.0, 123.4, 123.5, 125.7, 125.9, 127.1, 128.2,
130.2, 130.4, 133.2, 134.0, 134.4,144.1, 147.1, 147.9, 149.0, 155.6, 161.4 ppm. Anal. Calcd for
C28H26BrN5O3S: C, 56.76; H, 4.42; N, 11.82. Found: C, 56.58; H, 4.21; N, 12.10.
4.4.15.
2-(((1-(3-Bromobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-(3,4-dimethoxyphenethyl)
quinazolin-4(3H)-one (10o)
Yield: 86%; mp = 144-148 °C; IR (KBr): 3050 (C-H), 2828 (C-H), 1671 (C=O), 1666, 1566 (C=N, C=C)
cm-1. 1HNMR (CDCl3, 500 MHz): δ = 2.97-2.99 (m, 2H, CH2), 3.82 (s, 3H, OMe), 3.85 (s, 3H, OMe),
4.26-4.28 (m, 2H, CH2), 4.61 (s, 2H, CH2), 5.46 (s, 2H, CH2), 6.77-6.80 (m, 2H, H2”, H5”), 6.85 (d, JH6’’-
5’’= 7.0, 1H, H6”), 7.13 (d, JH6’-5’ = 7.0 Hz, 1H, H6’), 7.19 (t, JH5’-4’,5’-6’ = 7.0 Hz, 1H, H5’), 7.37-7.48 (m,
5H, H6, H8, H2’, H4’, triazole), 7.70 (t, JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.23 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm.
13CNMR (CDCl3, 125 MHz): δ = 26.9, 33.6, 46.4, 52.5,55.8, 55.9, 96.1, 115.5, 112.2, 119.5, 121.1,
123.1,125.7, 126.0, 126.5, 127.1, 130.2, 130.6,131.0, 131.9, 134.5, 136.7, 146.0, 147.1, 147.9, 149.0,
16

155.6, 161.4 ppm. Anal. Calcd for C28H26BrN5O3S: C, 56.76; H, 4.42; N, 11.82. Found: C, 56.81; H, 4.27;
N, 11.67.
4.4.16.
2-(((1-(4-Bromobenzyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-3-(3,4-dimethoxyphenethyl)
quinazolin-4(3H)-one (10p)
Yield: 84%; mp = 144-146 °C; IR (KBr): 3052 (C-H), 2828 (C-H), 1672 (C=O), 1680, 1556 (C=N, C=C)
cm-1. 1H NMR (CDCl3, 500 MHz): δ = 2.96-2.98 (m, 2H, CH2), 3.82 (s, 3H, OMe), 3.85 (s, 3H, OMe),
4.25-4.27 (m, 2H, CH2), 4.59 (s, 2H, CH2), 5.43 (s, 2H, CH2), 6.77 (s, 1H, H2’’), 6.80 (d, JH5’’-6’’ = 7.5
Hz, 1H, H5’’), 6.84 (d, JH6’’-5’’ = 7.5 Hz, 1H, H6’’), 7.08 (d, JH2’,6-3’,5’ = 8.0, 2H, H2’, H6’), 7.41-7.45 (m,
5H, H6, H8, H3’, H5’, triazole), 7.70 (t, JH7-6,7-8 = 7.5 Hz, 1H, H7), 8.24 (d, JH5-6 = 7.5 Hz, 1H, H5) ppm.
13CNMR (CDCl3, 125 MHz): δ = 26.7, 33.6, 46.4, 55.7, 55.9, 96.1, 111.5, 112.2, 119.5, 121.1, 123.0,
125.7, 126.0, 127.1, 129.7, 130.2, 132.3, 133.5, 134.4, 144.2, 147.1, 147.9, 149.0, 155.6, 161.4 ppm.
Anal. Calcd for C28H26BrN5O3S: C, 56.76; H, 4.42; N, 11.82. Found: C, 56.91; H, 4.65; N, 11.67.
4.5. In vitro α-Glucosidase inhibition assay
α-Glucosidase (Saccharomyces cerevisiae, EC3.2.1.20, 20 U/mg) and substrate (p-nitrophenyl
glucopyranoside) were purchased from Sigma-Aldrich. Desired concentrations of enzyme was prepared
by potassium phosphate buffer (pH 6.8, 50 mM), and the target compounds 10a-p were dissolved in
DMSO (10 % final concentration). The enzyme solution (20 μL), different concentrations of compounds
10a-p (20 μL), and potassium phosphate buffer (135 μL) were added to the 96-well plate and incubated
at 37 °C for 10 min. Then, p-nitrophenyl glucopyranoside as substrate (25 μL, 4 mM) was added to each
well and allowed to be incubated at 37 °C for 20 min. Finally, the change in the absorbance was measured
at 405 nm by using spectrophotometer (Gen5, Power wave xs2, BioTek, America). DMSO and acarbose
were used as the control and standard inhibitor, respectively. The percentage of inhibition for target
compounds, control, and the standard inhibitor was calculated by using the following formula:
17

% Inhibition = [(Abs control - Abs sample)/Abs control] ×100
IC50 values of tested compounds were obtained from the nonlinear regression curve using the Logit
method.
4.6. Kinetic study
The enzyme solution (1 U/mL, 20 µL) was incubated with different concentrations of 0, 140, 160,
and 180 µM of the most potent compound 10g (20 µL) for 15 min at 30 ºC. The reaction was then initiated
by adding various concentrations of substrate (p-nitrophenyl glucopyranoside, 1-4 mM). Then, change in
the absorbance was determined for 20 min at 405 nm by using spectrophotometer (Gen5, Power wave
xs2, BioTek, America) [25].
4.7. In vitro cytotoxicity assay
Evaluation of cytotoxic effects of the quinazolinone-1,2,3-triazole hybrids 10a-p was performed
exactly based on the literature [15].
4.8. Docking study
Building the homology model of α-glucosidase and docking of the most potent compounds 10g
and 10p in this enzyme were performed by Auto dock Tools, using previously described method [26].
Conflict of interest
The authors have declared no conflict of interest.
Acknowledgment
This work was supported by Research Council of Tehran University of Medical Sciences with grant No.
97-02- 96-39641.
18

References
[1] M. Saeedi, A. Hadjiakhondi, S.M. Nabavi, A. Manayi, Heterocyclic compounds: effective α-amylase
and α-glucosidase inhibitors, Curr. Top. Med. Chem. 17 (2016), 428-440.
[2] A.J. Hirsh, S.Y. Yao, J.D. Young, C.I. Cheeseman, Inhibition of glucose absorption in the rat jejunum:
a novel action of alpha-D-glucosidase inhibitors, Gastroenterology 113(1997) 205-211.
[3] S.R. Joshi, E. Standl, N. Tong, P. Shah, S. Kalra, R. Rathod, Therapeutic potential of α-glucosidase
inhibitors in type 2 diabetes mellitus: an evidence-based review, Expert Opin. Pharmacother. 16 (2015)
1959-1981.
[4] P. Hollander, Safety profile of acarbose, an α-glucosidase inhibitor, Drugs 44 Suppl 3 (1992), 47-53.
[5] M. Ghasemian, M. Mahdavi, P. Zare, M.A.H. Feizi, Spiroquinazolinone-induced cytotoxicity and
apoptosis in K562 human leukemia cells: alteration in expression levels of Bcl-2 and Bax, J. Toxicol. Sci.
40 (2015) 115-126.
[6] F. Khajoee Nejad, M. Khosravan, S.Y. Ebrahimipour, F. Bisceglie, A mixed-ligand quinazoline-based
Ni (II) Schiff base complex: Synthesis, characterization, crystal structure, antimicrobial investigation and
catalytic activity for the synthesis of 2H–indazolo[2,1-b] phthalazine-triones, Appl. Organometal. Chem.
32 (2018) e3907.
[7] M.S. Malamas, J. Millen, Quinazolineacetic acids and related analogs as aldose reductase inhibitors,
J. Med. Chem. 34 (1991) 1492-1503.
[8] T. Mohamed, P.P.N. Rao, 2,4-Disubstituted quinazolines as amyloid-β aggregation inhibitors with
dual cholinesterase inhibition and antioxidant properties: Development and structure-activity relationship
(SAR) studies, Eur. J. Med. Chem. 126 (2017) 823-843.
19

[9] C. Balakumar, P. Lamba, D.P. Kishore, B.L. Narayana, K.V. Rao, K. Rajwinder, A.R. Rao, B.
Shireesha, B. Narsaiah, Synthesis, anti-inflammatory evaluation and docking studies of some new
fluorinated fused quinazolines, Eur. J. Med. Chem. 45 (2012) 4904-4913.
[10] S.T. Al-Rashood, I.A. Aboldahab, M.N. Nagi, L.A. Abouzeid, A.A. Abdel-Aziz, S.G. Abdel-hamide,
K.M. Youssef, A.M. Al-Obaid, H.I. El-Subbagh, Synthesis, dihydrofolate reductase inhibition, antitumor
testing, and molecular modeling study of some new 4 (3H)-quinazolinone analogs, Bioorg. Med. Chem.
14 (2006) 8608-8621.
[11] A. Gangjee, O.O. Adair, M. Pagley, S.F. Queener, N9-substituted 2, 4-diaminoquinazolines:
synthesis and biological evaluation of lipophilic inhibitors of Pneumocystis carinii and Toxoplasma
gondii dihydrofolate reductase, J. Med. Chem. 51 (2008) 6195-6200.
[12] V. Gurram, R. Garlapati, C. Thulluri, N. Madala, K.S. Kasani, P.K. Machiraju, R. Doddapalla, U.
Addepally, R. Gundla, B. Patro, N. Pottabathini, Design, synthesis, and biological evaluation of
quinazoline derivatives as α-glucosidase inhibitors, Med. Chem. Res. 24 (2015) 2227-2237.
[13] K. Javaid, S.M. Saad, S. Rasheed, S.T. Moin, N. Syed, I. Fatima, U. Salar, K.M. Khan, S. Perveen,
M.I. Choudhary, 2-Arylquinazolin-4(3H)-ones: A new class of α-glucosidase inhibitors, Bioorg. Med.
Chem. 23 (2015) 7417-7421.
[14] M. Wei, W.M. Chai, R. Wang, Q. Yang, Z. Deng, Y. Peng, Quinazolinone derivatives: synthesis and
comparison of inhibitory mechanisms on α-glucosidase, Bioorg. Med. Chem. 25 (2017) 1303-1308.
[15] M. Mohammadi-Khanaposhtani, M. Safavi, R. Sabourian, M. Mahdavi, M. Pordeli, M. Saeedi, S.K.
Ardestani, A. Foroumadi, A. Shafiee, T. Akbarzadeh, Design, synthesis, in vitro cytotoxic activity
evaluation, and apoptosis-induction study of new 9(10H)-acridinone-1,2,3-triazoles, Mol. Diversity 19
(2015) 787-795.
20

[16] M. Saeedi, S. Ansari, M. Mahdavi, R. Sabourian, T. Akbarzadeh, A. Foroumadi, A. Shafiee,
Synthesis of novel 1,2,3-triazole-dihydro[3,2-c]chromenones as acetylcholinesterase inhibitors, Synth.
Commun. 45 (2015) 2311-2318.
[17] W. Tan, Q. Li, W. Li, F. Dong, Z. Guo, Synthesis and antioxidant property of novel 1,2,3-triazole-
linked starch derivatives via ‘click chemistry’. Int. J. Biol. Macromol. 82 (2016) 404-410.
[18] A. Ayati, S. Emami, A. Foroumadi, The importance of triazole scaffold in the development of
anticonvulsant agents, Eur. J. Med. Chem. 109 (2016) 380-392.
[19] F. Jabeen, S.A. Shehzadi, M.Q. Fatmi, S. Shaheen, L. Iqbal, N. Afza, S.S. Panda, F.L. Ansari,
Synthesis, in vitro and computational studies of 1,4-disubstituted 1,2,3-triazoles as potential α-
glucosidase inhibitors. Bioorg. Med. Chem. Lett. 26 (2016), 1029-1038.
[20] Y. Chinthala, A.K. Domatti, A. Sarfaraz, S.P. Singh, N.K. Arigari, N. Gupta, S.K. Satya, J.K. Kumar,
F. Khan, A.K. Tiwari, G. Paramjit, Synthesis, biological evaluation and molecular modeling studies of
some novel thiazolidinediones with triazole ring, Eur. J. Med. Chem. 70 (2013) 308-314.
[21] S. Iqbal, M.A. Khan, K. Javaid, R. Sadiq, S. Fazal-Ur-Rehman, M.I. Choudhary, F.Z. Basha, New
carbazole linked 1,2,3-triazoles as highly potent non-sugar α-glucosidase inhibitors, Bioorg. Chem. 74
(2017) 72-81.
[22] G. Wang, Z. Peng, J. Wang, X. Li, J. Li, Synthesis, in vitro evaluation and molecular docking studies
of novel triazine-triazole derivatives as potential α-glucosidase inhibitors, Eur. J. Med. Chem. 125 (2017)
423-429.
[23] C. Viegas-Junior, A. Danuello, V. da Silva Bolzani, E.J. Barreiro, C.A.M. Fraga, Molecular
hybridization: a useful tool in the design of new drug prototypes, Curr. Med. Chem. 14 (2007) 1829-1852.
21

[24] H. Nikookar, M. Mohammadi-Khanaposhtani, S. Imanparast, M.A. Faramarzi, P.R. Ranjbar, M.
Mahdavi, B. Larijani, Design, synthesis and in vitro α-glucosidase inhibition of novel dihydropyrano [3,2-
c]quinoline derivatives as potential anti-diabetic agents. Bioorg. Chem. 77 (2018) 280-286.
[25] M. Mohammadi-Khanaposhtani, S. Rezaei, R. Khalifeh, S. Imanparast, M.A. Faramarzi, S.
Bahadorikhalili, M. Safavi, F. Bandarian, E.N. Esfahani, M. Mahdavi, B. Larijani, Design, synthesis,
docking study, α-glucosidase inhibition, and cytotoxic activities of acridine linked to thioacetamides as
novel agents in treatment of type 2 diabetes, Bioorg. Chem. 80 (2018) 288-295.
[26] M. Adib, F. Peytam, M. Rahmanian-Jazi, S. Mahernia, H.R. Bijanzadeh, M. Jahani, M. Mohammadi-
Khanaposhtani, S. Imanparast, M.A. Faramarzi, M. Mahdavi, B. Larijani, New 6-amino-pyrido [2,3-
d]pyrimidine-2,4-diones as novel agents to treat type 2 diabetes: A simple and efficient synthesis, α-
glucosidase inhibition, molecular modeling and kinetic study, Eur. J. Med. Chem. 155 (2018) 353-363.
[27] Z. Heydari, M. Mohammadi-Khanaposhtani, S. Imanparast, M.A. Faramarzi, M. Mahdavi, P.R.
Ranjbar, B. Larijani, Pyrano[3,2-c]quinoline derivatives as new class of α-glucosidase inhibitors to treat
type 2 diabetes: synthesis, in vitro biological evaluation and kinetic study, Med. Chem. In press, DOI:
10.2174/1573406414666180528110104.
[28] M. Taha, N.H. Ismail, S. Imran, A. Wadood, F. Rahim, S.M. Saad, K.M. Khan, A. Nasir, Synthesis,
molecular docking and α-glucosidase inhibition of 5-aryl-2-(6′-nitrobenzofuran-2′-yl)-1,3,4-oxadiazoles,
Bioorg. Chem.66 (2016) 117-123.
[29] F. Rahim, F. Malik, H. Ullah, A. Wadood, F. Khan, M.T. Javid, M. Taha, W. Rehman, A.U. Rehman,
K.M. Khan, Isatin based Schiff bases as inhibitors of α-glucosidase: Synthesis, characterization, in vitro
evaluation and molecular docking studies, Bioorg. Chem.60 (2015) 42-48.
22

O
N
N
N
N
S
O
O
B
O
R1
R1
O
N
N
S
O
N
N
O
N N
NH
N
N
Ar
N
N
R
C
A
R2
Designed compounds 7a-p
N
S
N
N
N
O
N N
R
N
H
D
Fig. 1. Design strategy of novel quinazolinoe derivatives as novel α-glucosidase inhibitors based on
molecular hybridization of pharmacophoric units of potent reported α-glucosidase inhibitors.
23

a)
b)
60
50
40
30
20
10
0
Concentration of compound 10g
10
8
0 µM
140 µM
160 µM
180 µM
6
4
2
0
-200
-150
-100
-50
0
50
100
150
200
-1.5
-1.0
-0.5
0.0
0.5
1.0
-1
1.5
Compound10g (µM)
1/[S](PNPG, mM)
Fig. 2. Kinetic studies of α-gluosidase inhibition by 10g: (a) The Lineweaver–Burk plot in the absence
and presence of different concentrations of 10g, (b) The secondary plot between Km and various
concentrations of 10g.
24

Fig. 3. Acarbose (cyan) and the most potent compound 10g (pink) superimposed in the active site of α-glucosidase.
25

Fig. 4. Binding mode of acarbose in the active site of α-glucosidase.
26

(a)
(b)
Fig. 5. Binding mode of the most potent compounds 10g and 10p in the α-glucosidase active site.
27

R1
R1
R1
R1
O
O
O
NH2
6
Br
O
4
H2O, rt
2-3 h
CS2 , KOH
N
N
+
H
R1
EtOH, reflux
3-5 h
N
H
1
O
N
H
5
S
DMF, K2CO3
80 oC, 8 h
NH2
R1
3
2
X
NaN
+
3
R2
X = Cl, Br
8
NEt3
rt/1 h
R1
R1
3''
R1
R1
O
N3
2''
1''
O
5
4''
N
6
5''
9
N
R2
CuSO
6''
2'
N
S
7
4.5H O/24 h
sodium as2corbate
1'
6'
N
S
3'
4'
N
N
8
7
N
10
5'
R2
1
2
1
2
1
2
1
10a
10b
: R = H, R2 = 4-Cl,
10i
10c
10d
: R = H,
: R = H, R = 4-CH3,
: R = H, R = 3-f,
: R = H, R = 2-Cl,
R2 = 3-Cl,
: R = H, R2 = 2-Br,
: R1 = OCH3, R2 = 3-F,
: R = H, R2 = 4-Br
1
1
1
10e
10f
10g
: R1 = OCH3, R2 = 4-CH3,
: R1 = OCH3, R2 = 4-F,
10h
10j
1
2
1
2
1
2
10k
10n
10l
10m
: R = OCH3, R = 2-Cl,
: R = OCH3, R = 3-Cl,
: R = OCH3, R = 4-Cl,
1
2
1
2
1
2
10o
10p
: R = OCH3, R = 2-Br,
: R = OCH3, R = 3-Br,
: R = OCH3, R = 4-Br,
Scheme 1. Synthesis of quinazolinone-1,2,3-triazole hybrids 10a-p.
28

Table 1
The IC50 values of compounds 10a-p against α-glucosidase
R1
R1
O
N
N
S
N
N
N
R2
Compound
10a
R1
H
R2
IC50 (µM)a
200.0 ± 0.8
426.4 ± 1.5
220.5 ± 1.2
369.0 ± 1.5
474.5 ± 1.0
209.4 ± 1.5
181.0 ± 1.4
301.5 ± 2.2
250.0 ± 1.2
205.6 ± 1.0
222.0 ± 1.0
235.8 ± 1.3
463.0 ± 0.6
202.5 ± 1.2
226.0 ± 0.8
192.3 ± 1.8
750.0 ± 1.5b
4-CH3
3-F
10b
H
10c
H
2-Cl
3-Cl
4-Cl
2-Br
4-Br
4-CH3
3-F
10d
H
10e
H
10f
H
10g
H
10h
OCH3
OCH3
OCH3
OCH3
OCH3
OCH3
OCH3
OCH3
OCH3
-
10i
10j
4-F
10k
2-Cl
3-Cl
4-Cl
2-Br
3-Br
4-Br
-
10l
10m
10n
10o
10p
Acarbose
a Data are expressed as Mean ± SE (three independent experiments).
b IC50 values of 856±5.60 and 840±1.73 were also reported for acarbose [28, 29].
29