Synthesis, crystal structure, anticancer and molecular docking studies of quinolinone-thiazolidinone hybrid molecules

Article abstract of DOI:10.1007/s13738-021-02342-5

A new series of quinolone-thiazolidinone hybrid molecules 8a-o were prepared. Quinoline compounds were synthesized by Meth-Cohn synthesis and were condensed with 2,3-disubstituted thiazolidinone. These molecules were screened for their anticancer activities against MDA-MB-231 and MCF-7 cell line using MTT assay. Potent compounds were tested for their cytotoxicity on normal HEK 293 cell lines and most potent compound was tested for its cell cycle analysis. Molecular docking and molecular dynamic studies were performed on human N-acetyl transferase (hNAT-1) protein using Schrodinger molecular docking toolkit. Compound 8n emerged as potent with IC₅₀ 8.16?μM against MDA-MB-231 cell line followed by 8e with IC₅₀ 17.68?μM. Compound 8n arrested cell cycle at G2/M phase and was non-toxic to human normal kidney cell line. The potent compound 8n binds well with human NAT-1 protein with remarkable hydrogen bonding and π–π interactions. Molecular dynamic studies of 8n further confirm the target for these molecules. Target quinolinone-thiazolidinones were found to be new class of compounds targeting hNAT-1 and can serve as new lead compounds in drug discovery.

Full text of DOI:10.1007/s13738-021-02342-5

Journal of the Iranian Chemical Society
https://doi.org/10.1007/s13738-021-02342-5
ORIGINAL PAPER
Synthesis, crystal structure, anticancer and molecular docking studies
of quinolinone‑thiazolidinone hybrid molecules
1
2
3
4
5
Vasantha Kumar · Vaishali M. Rai · Vishwanatha Udupi · Naveen Shivalingegowda · Vinitha R. Pai ·
6
7
Lokanath Neratur Krishnappagowda · Boja Poojary
Received: 24 March 2021 / Accepted: 11 July 2021
©
Iranian Chemical Society 2021
Abstract
A new series of quinolone-thiazolidinone hybrid molecules 8a-o were prepared. Quinoline compounds were synthesized
by Meth-Cohn synthesis and were condensed with 2,3-disubstituted thiazolidinone. These molecules were screened for
their anticancer activities against MDA-MB-231 and MCF-7 cell line using MTT assay. Potent compounds were tested for
their cytotoxicity on normal HEK 293 cell lines and most potent compound was tested for its cell cycle analysis. Molecular
docking and molecular dynamic studies were performed on human N-acetyl transferase (hNAT-1) protein using Schrodinger
molecular docking toolkit. Compound 8n emerged as potent with IC 8.16 µM against MDA-MB-231 cell line followed by
5
0
8
e with IC 17.68 µM. Compound 8n arrested cell cycle at G2/M phase and was non-toxic to human normal kidney cell line.
50
The potent compound 8n binds well with human NAT-1 protein with remarkable hydrogen bonding and π–π interactions.
Molecular dynamic studies of 8n further conꢀrm the target for these molecules. Target quinolinone-thiazolidinones were
found to be new class of compounds targeting hNAT-1 and can serve as new lead compounds in drug discovery.
Keywords Quinolinone · Thiazolidinone · Anticancer activity · hNAT-1 inhibitor · Docking studies
Introduction
Cancer is a serious health issue in both developed and
developing countries causing the death of several millions
of people [1, 2]. A recent survey reported that there will be
*
Boja Poojary
bojapoojary@gmail.com
ꢀ
ve-fold increase in the cancer cases by 2025. Since, cancer
1
PG Department of Chemistry, Sri Dharmasthala
Manjunatheshwara College (Autonomous), Ujire,
India 574240
spreads from organ to organ by a process called metastasis
rendering treatment ineꢁective. Among the various types
of cancer, breast cancer is responsible for increased death.
Since breast tissues are prone to be attacked by cancer very
rapidly. An estimated 2.3 million women were diagnosed
with breast cancer therapy in 2020 across the world. In India,
breast cancer remains as life threatening disease and mil-
lions of women are undergoing treatment every year. It is
common in the women aged above 40 years and also in the
age group of 20–30. The main problem lies in the identiꢀ-
cation of breast cancer in the early stages, thus complicat-
ing the treatment in later stages. Therefore, search of new
class of anticancer agent still remains as an important area
of research in the medicinal chemistry ꢀeld.
2
3
Department of Microbiology, St. Aloysius College
(Autonomous), Mangalore 575003, India
Department of Biotechnology and Microbiology, Sri
Dharmasthala Manjunatheshwara Centre for Research
in Ayurveda & Allied Sciences, Kuthpady 574118,
Udupi, Karnataka, India
4
Department of Physics, Faculty of Engineering &
Technology, JAIN (Deemed-to-be University), Jain Global
Campus, Ramanagara Dist., Bangalore 562112, India
5
6
7
Department of Biochemistry, Yenepoya Medical College,
Yenepoya University, Deralakatte, Mangalore 575018, India
Department of Studies in Physics, University of Mysore,
Manasagangotri, Mysuru 570006, India
Quinolinone is the important class of heterocyclic motif
found in several natural products. Quinoline derivatives are
reported to possess antimicrobial [3], antituberculosis [4],
Department of Studies and Research in Chemistry,
Mangalore University, Mangalagangothri, Karnataka 574199,
India
Vol.:(0
1
123456789)
3

Journal of the Iranian Chemical Society
anti-inꢂammatory [5], neuroprotective [6], antioxidant [7],
and antidepressant [8] activities. Moreover, Quinolinone
derivatives are well known to exhibit anticancer activity
anti-HIV-1 [26], anticonvulsant [27] and HCV NS5B poly-
merase inhibitor [28]. In the recent years, researchers are
more focussing on thiazolidinone-based small molecules in
the anticancer ꢀeld [29–31] as they are capable of bind prop-
erly into the active pockets of receptors. Notably, 4 showed
significant CAIX inhibiting activity [32] and 5 showed
excellent anticancer activity against MCF-7 breast cancer
cell lines with nanomolar level of inhibition [33] (Fig. 1).
N-acetyl transferase is an emerging target in the anticancer
ꢀeld. In the recent years, it was evidenced from the studies that
NAT1 is more expressed in cancer cells. Especially, these are
expressed in breast cancer cells. Some small molecules were
reported as NAT1 inhibitors like Rhodanine derivative (6) as a
selective inhibitor of recombinant human NAT1 and inhibited
the NAT activity of cell lysates of breast cancer cells ZR-75-1
[34]. Also, another rhodanine molecule (7) inhibited the
[
9], in particularly, compound 1–3 were emerged as potent
anti-tumour agent (Fig. 1) [10–12]. Hence, search of newer
quinolone-based entities for their diversiꢀed pharmacologi-
cal activity has gaining more focus.
Thiazolidine-4-one motifs have occupied a unique place
in the medicinal chemistry and are regarded as ‘magic moi-
ety’ which possesses most of the biological activities [13].
Due to their small size and ability to form strong binding
with receptors made the researcher to synthesize library of
thiazolidinone compounds [14–16]. Thiazolidinone deriva-
tives are associated with wide range of activities such as
antimicrobial [17, 18], anti-inꢂammatory [19, 20], antitu-
bercular [21, 22], anti-diabetic [23, 24], antiamoebic [25],
O
P
O
O
Cl
O
OH
N
H C
3
H C
3
N
H
N
N
H
O
N
O
OH
N
H
1
O
O
2
3
N
O
O
N
S
N
S
N
NH
O
O
OH
NO2
Br
4
5
R1
O
N
N
N
R
R1
R1
N
X
S
S
N
H
O
OH
X
S
R
8a-o
6
R = Alkyl, aryl
7
R = H, CH3
1
X = S, O
Fig. 1 Potential anticancer compounds (1–5), hNAT1 inhibitors (6,7) and target compounds 8a-o
1
3

Journal of the Iranian Chemical Society
NAT1 activity in intact MDA-MB-231 cells in a concentration
dependant manner. It also inhibited the proliferation by block-
(0.01 moles) and triethylamine (0.02 moles) slowly at
room temperature. Reaction mixture was stirred at room
temperature for 10 h. After the completion of reaction,
reaction mass was quenched into crushed ice. Solid precip-
itated was ꢀltered oꢁ, washed with cold water and dried.
ing the cells in G /M phase [35]. Recently, it was also shown
2
that the currently using chemotherapeutic agents such as Cis-
platin [36] and Tamoxifene [37, 38] inhibit the NAT1 activity.
The two breast cancer cells MCF-7 and MDA-MB-231 treated
with Cisplatin showed considerable NAT1 inhibition with IC
5
0
1‑(4‑ꢀuorobenzyl)‑3‑phenylthiourea (6c)
less than 100 µM. Hence, NAT1 was considered as novel target
for the development of newer drug candidates.
−1
Yield: 85%; FTIR (KBr, cm ): 3391, 3120, 3094, 3005,
Encouraged by the aforementioned activities of thiazoli-
dine-4-ones and quinolones, we planned to synthesize some
hybrid compounds comprising these two units. In our present
study, we varied thiazolidine-4-one motif by varying substitu-
1
2
982, 1597, 1543, 1184; H NMR (400 MHz, DMSO-d , δ,
6
ppm): 9.64 (s, 1H, N–H), 8.18 (s, 1H, N–H), 7.31–7.42 (m,
6
H, Ar–H), 7.12–7.18 (m, 3H, Ar–H), 4.73 (s, 2H, -CH );
2
13
C NMR (100 MHz, DMSO, δ, ppm): 181.24 (C = S),
rd
tions attached to the nitrogen atom at 3 position as well as by
1
1
60.49, 139.56, 135.75, 129.95, 128.87, 129.13, 128.90,
th
varying substituent at the 6 position of quinoline moiety. All
24.84, 124.11, 123.90, 115.53, 115.32, 46.89; LCMS
the new compounds were initially screened for anti-breast can-
cer activity on MDA-MB-231 cell line and ꢀve of the potent
compounds were then screened on MCF-7 breast cancer cell
line by MTT assay. Further to understand the mechanism of
action, cell cycle analysis was done on MDA-MB-231 cell line
by ꢂow cytometry method. Molecular docking studies were
performed to understand the possible binding interactions of
the molecules on human N-acetyl transferase (NAT-1) protein.
+
(
m/z): 261.15 (M + H) ; Anal. Calcd. For C H FN S:
1
4
13
2
C, 64.59; H, 5.03; N, 10.76. Found: C, 64.66; H, 5.09; N,
1
0.70.
General procedure for the synthesis of 2‑phenylim‑
ino‑3‑substituted‑thiazolidin‑4‑ones (7a‑c)
To the substituted phenylthiourea (0.01 moles) (6a-c)
added anhydrous sodium acetate (0.025 moles) and chlo-
roacetic acid (0.0125 moles) in absolute ethanol. Reaction
mixture was reꢂuxed for 12 h. After the completion of
reaction, it was cooled. Solid precipitated was ꢀltered oꢁ,
washed with ethanol followed by water and dried.
Experimental
General
All the starting materials were purchased from Sigma Aldrich
(
India). All the solvents and reagents were purchased from the
commercial vendors in the appropriate grade and were used
without puriꢀcation. Melting points were determined by an
open capillary method and are uncorrected. FTIR spectra were
recorded on a Shimadzu FTIR 157 Spectrometer in KBr pel-
3‑(4‑Fluorobenzyl)‑2‑(phenylimino)thiazoli‑
din‑4‑one (7c)
−
1
Yield: 90%; FTIR (KBr, cm ): 3364, 3319, 3292, 3071,
1
1
let. H NMR spectra were measured on BRUKER AVANCE
3042, 2972, 1649, 1622, 1524, 822; H NMR (400 MHz,
II-400 (300 MHz) spectrometer using TMS as an internal
standard. The chemical shifts are reported in δ units and the
coupling constants (J) are reported in hertz. Mass spectra
were recorded in Agilent Technology LC-mass spectrometer.
Elemental analyses were carried out using CHNS Elementar
Vario EL III. Purity of the compounds was checked by thin
layer chromatography (TLC) on a silica-coated aluminium
sheet (silica gel 60F254) using ethyl acetate and hexane (3:7,
v/v).
CDCl3, δ, ppm): 7.44 (t, 3H); 7.36 (t, 2H, Ar–H);
7.11–7.21 (m, 3H Ar–H), 6.91 (d, 1H, 8 Hz, Ar–H), 5.00
1
3
(s, 2H, CH2), 4.10 (s, 2H, -CH2); C NMR (100 MHz,
DMSO, δ, ppm): 172.4 (C=O), 163.2, 155.4, 148.3,
130.5, 130.4, 129.8, 128.9, 124.8, 121.3, 115.79, 115.6,
+
45.1, 33.0.; LCMS (m/z): 301.1 (M + H) ; Anal. Calcd.
For C16H13FN2OS: C, 63.98; H, 4.36; N, 9.33. Found: C,
63.94; H, 4.30; N, 9.38.
General procedure for the synthesis of (8a‑o)
Chemistry
To a solution of 7a-c (0.01 moles), substituted 2-chloro-
quinoline-3-carboxaldehyde 3a-e (0.01 moles) and anhy-
drous sodium acetate (0.025 moles) in glacial acetic acid
General procedure for the synthesis of substituted
phenylthioureas (6a‑c)
(
20 ml) was reꢂuxed for 10 h. After completion of the
reaction, it was cooled to room temperature. Resulting
To a mixture of substituted amine (0.01 moles) in N,N-
dimethyformamide (10v) added phenylisothiocyanate
1
3

Journal of the Iranian Chemical Society
solid was ꢀltered oꢁ, washed with water, dried and recrys-
6‑Methyl‑3‑(Z‑(Z‑4‑oxo‑2‑phenylimino‑3‑propylthia‑
zolidin‑5‑ylidene)methyl)‑quinolin‑2(1H)‑one (8d)
tallized from N, N-dimethyl formamide.
−
1
6
‑Fluoro‑3‑(Z‑(Z‑4‑oxo‑2‑phenylimino‑3‑propylthia‑
Yield: 71%; FTIR (KBr, cm ): 3164, 3078, 2975, 1705,
1
zolidin‑5‑ylidene)methyl)‑ quinoline‑2(1H)‑one (8a)
1658, 1524; H NMR (400 MHz, DMSO-d , δ, ppm): 12.13
6
(
s, 1H, –NH); 7.98 (s, 1H, Q-H ); 7.82 (s, 1H, HC=); 7.56
4
−
1
Yield: 90%; FTIR (KBr, cm ): 3150 (N–H), 3076 (Ar–H
(s, 1H, Q-H ); 7.41 (t, 2H, 7.4 Hz, Ar–H); 7.34 (d, 1H,
5
1
arom), 2968, 1697 (C=O), 1655 (O=C–N–H), 1128; H
8 Hz, Q-H ), 7.25–7.20 (m, 2H, Q-H & Ar–H); 7.02 (d,
7
7
NMR (400 MHz, DMSO-d , δ, ppm): 12.14 (s, 1H, NH),
2H, 8 Hz, Ar–H), 3.87 (t, 2H, 8 Hz, –CH ); 2.30 (s, 3H,
6
2
8
.00 (s, 1H, Q-H ), 7.83 (s, 1H, HC=), 7.70 (d, 1H, 8.4 Hz,
–CH3); 1.71–1.78 (m, 2H, –CH ), 0.94 (t, 3H, 8 Hz, –CH );
4
2
3
1
3
Q-H ), 7.40–7.45 (m, 3H, Q-H & Ar–H), 7.31–7.34 (m,
C NMR (100 MHz, DMSO, δ, ppm): 166.6 (C=O), 160.1,
5
8
1
H, Q-H ), 7.20 (t, 1H. 7.4 Hz, Ar–H), 7.03 (d, 2H, 7.2 Hz,
150.4, 147.4 (=CH), 140.0, 136.5, 134.1, 132.0, 130.0,
128.5, 126.0, 125.6, 125.3, 123.5, 121.2, 119.4, 115.5, 49.7,
7
Ar–H), 3.87 (t, 2H, 6.8 Hz, –CH ), 1.77–1.72 (m, 2H,
2
1
3
+
–
CH ), 0.94 (t, 3H, 7.2 Hz, –CH ); C NMR (100 MHz,
26.6, 11.7; LCMS (m/z): 404.5 (M+H) ; Anal. Calcd. For
2
3
DMSO, δ, ppm): 166.4 (C=O), 160.4(C=O), 159.8, 150.1,
C H N O S: C, 68.46; H, 5.25; N, 10.41. Found: C, 68.50;
23
21
3
2
1
1
47.8 (=CH), 140.6, 134.1, 129.9, 128.4, 126.0, 125.7,
H, 5.29; N, 10.37.
25.3, 123.4, 121.1, 119.4, 115.5, 49.7, 26.7, 11.6; LCMS
+
(
m/z): 408.1 (M+H) ; Anal. Calcd. For C H FN O S: C,
6‑Methoxy‑3‑(Z‑(Z‑4‑oxo‑2‑phenylimino‑3‑propylth‑
iazolidin‑5‑ylidene)methyl)‑ quinoli‑2(1H)‑one (8e)
2
2
18
3
2
6
4.85; H, 4.45; N, 10.31. Found: C, 64.80; H, 4.49; N, 10.38.
−
1
6
‑Chloro‑3‑(Z‑(Z‑4‑oxo‑2‑phenylimino‑3‑propylthia‑
Yield: 76%; FTIR (KBr, cm ): 3162, 3064, 2960, 1704,
1
zolidin‑5‑ylidene)methyl)‑ quinolin‑2(1H)‑one (8b)
1654, 1535; H NMR (400 MHz, DMSO-d , δ, ppm): 12.00
6
(
s, 1H, –OH); 8.01 (s, 1H, Q-H ); 7.85 (s, 1H, HC=);
4
−
1
Yield: 78%; FTIR (KBr, cm ): 3147 (N–H), 3072 (Ar–H
7.42–7.44 (t, 2H, 8 Hz, Ar–H); 7.32 (s, 1H, Q-H ); 7.28 (d,
5
1
arom), 2968, 1700 (C=O), 1656 (O=C–N–H), 828; H
1H, 7.6 Hz, Q-H ), 7.25(d,1H, 7.2 Hz, Q-H ), 7.21 (t, 1H,
7
8
NMR (400 MHz, CDCl , δ, ppm): 12.12 (s, 1H, –NH); 8.03
Ar–H); 7.01 (d, 2H, 8 Hz, Ar–H), 3.86 (t, 2H, 8 Hz, –CH );
3
2
(
(
s, 1H, QH ); 7.90 (s, 1H, Q-H ), 7.85 (s, 1H, HC=); 7.58
3.75 (s, 3H, –CH3); 1.69–1.79 (m, 2H, –CH ), 0.93 (t, 3H,
4
5
2
1
3
d, 1H, 8 Hz, Q-H ); 7.42 (t, 2H, 7.2 Hz, Ar–H); 7.32 (d,
8 Hz, –CH ); C NMR (100 MHz, DMSO, δ, ppm): 166.6
7
3
1
H, Q-H ), 7.20 (t, 1H, 7.4 Hz, Ar–H), 7.03 (d, 2H, 8.4 Hz,
(C=O), 160.0, 154.5, 150.0, 147.9 (=CH), 140.5, 134.0,
8
Ar–H), 3.87 (t, 2H, 8 Hz, -CH ), 1.70–1.79 (m, 2H,-CH ),
130.0, 126.0, 125.7, 125.4, 123.5, 122.2, 121.25 120.0,
2
2
1
3
+
0
.94 (t, 3H, 8 Hz, –CH ); C NMR (100 MHz, DMSO, δ,
116.9, 110.2, 49.7, 26.6, 11.7; LCMS (m/z): 420.2 (M+H) ;
3
ppm): 166.5 (C=O), 160.2, 150.3, 147.5 (=CH), 140.2,
Anal. Calcd. For C H N O S: C, 65.85; H, 5.05; N, 10.02.
23
21
3
3
1
1
34.0, 132.6, 129.8, 128.5, 126.0, 125.6, 125.2, 123.6,
Found: C, 65.81; H, 5.10; N, 10.06.
20.9, 119.9, 116.5, 49.8, 26.7, 11.5; LCMS (m/z): 425.0
+
(
M+H) ; Anal. Calcd. For C H ClN O S: C, 62.33; H,
3‑(Z‑(Z‑3‑Benzyl‑4‑oxo‑2‑(phenylimino)thiazoli‑
din‑5‑ylidene)methyl)‑6‑ꢀuoro‑quinolin‑2(1H)‑one
2
2
18
3
2
4
.28; N, 9.91. Found: C, 62.37; H, 4.24; N, 9.96.
(8f)
6
‑Bromo‑3‑(Z‑(Z‑4‑oxo‑2‑(phenylimino)‑3‑propylthi‑
−
1
azolidin‑5‑ylidene)methyl)‑quinolin‑2(1H)‑one (8c)
Yield: 68%; FTIR (KBr, cm ): 3147, 3039, 2980, 1709,
1
1
652, 1085; H NMR (400 MHz, DMSO-d , δ, ppm): 12.00
6
−
1
Yield: 72%; FTIR (KBr, cm ): 3152 (N–H), 3070, 2966,
(s, 1H, –OH); 8.01 (s, 1H, Q-H ); 7.85 (s, 1H, HC=); 7.71
4
1
1
1
7
7
7
1
702 (C=O), 1654; H NMR (400 MHz, DMSO-d , δ, ppm):
(d, 1H, 7.6 Hz, Q-H ), 7.47–7.40 (m, 8H, Ar–H, Q-H );
6
5
8
2.10 (s, 1H, –NH); 8.07 (s, 1H, Q-H ); 8.01 (s, 1H, Q-H );
7.35–7.30 (m, 1H, Q-H ); 7.21 (t, 1H, Ar–H); 7.01 (d, 2H,
4
5
7
1
3
.84 (s, 1H, HC=); 7.654 (d, 1H, 8 Hz, Q-H ); 7.42 (t, 2H,
8 Hz, Ar–H), 5.10 (s, 2H, –CH ); C NMR (100 MHz,
8
2
.2 Hz, Ar–H); 7.28 (d, 1H, 8 Hz, Q-H ), 7.21 (t, 1H, Ar–H,
DMSO, δ, ppm): 166.3, 160.9, 160.0, 151.0, 148.0 (=CH),
141.0, 133.9, 132.2, 129.8, 129.0, 128.7, 128.5, 128.1,
127.9, 125.9, 125.6, 125.2, 123.0, 121.1, 119.6, 115.2,
7
.6 Hz), 7.01 (d, 2H, 8 Hz, Ar–H), 3.86 (t, 2H, 8 Hz, –CH ),
2
C
1
3
.70–1.76 (m, 2H, –CH ), 0.95 (t, 3H, 8 Hz, –CH );
2
3
+
NMR (100 MHz, DMSO, δ, ppm): 166.5 (C=O), 160.0,
46.4, 31.1;LCMS (m/z): 456.3 (M+H) ; Anal. Calcd. For
1
1
2
50.1, 147.9 (=CH), 140.0, 137.2, 134.0, 132.2, 130.0,
28.4, 125.9, 125.5, 125.2, 123.4, 121.0, 119.2, 115.6, 49.8,
C H FN O S: C, 68.56; H, 3.98; N, 9.22. Found: C, 68.48;
26
18
3
2
H, 3.93; N, 9.27.
+
6.5, 11.7; LCMS (m/z): 469.6 (M+H) ; Anal. Calcd. For
C H BrN O S C: 56.42; H, 3.87; N, 8.97. Found: C, 56.47;
22
18
3
2
H, 3.83; N, 8.93.
1
3

Journal of the Iranian Chemical Society
3
‑(Z‑(Z‑3‑benzyl‑4‑oxo‑2‑(phenylimino)thiazoli‑
din‑5‑ylidene)methyl)‑6‑chloro‑quinolin‑2(1H)‑one
8 g)
3‑(Z‑(Z‑3‑benzyl‑4‑oxo‑2‑(phenylimino)thia‑
zolidin‑5‑ylidene)methyl)‑6‑methoxy‑quino‑
lin‑2(1H)‑one (8j)
(
−
1
−1
Yield: 90%; FTIR (KBr, cm ): 3151, 3045, 2972, 1704,
Yield: 74%; FTIR (KBr, cm ): 3147, 3042, 2980, 1703,
1
1
1
650, 844; H NMR (400 MHz, DMSO-d , δ, ppm): 12.00
1654, 1580; H NMR (400 MHz, DMSO-d , δ, ppm):
6
6
(
(
s, 1H, –OH); 8.00 (s, 1H, Q-H ), 7.93 (s, 1H, Q-H ), 7.84
12.01 (s, 1H, -NH); 7.98 (s, 1H, Q-H ); 7.84 (s, 1H, HC=);
4
5
4
s, 1H, HC=); 7.62 (d, 1H, 8 Hz, Q-H ); 7.37–7.45 (m, 6H,
7.37–7.44 (m, 7H, Ar–H); 7.33 (s, 1H, Q-H ); 7.28 (d, 1H,
7
5
Ar–H); 7.31 (d, 1H, Q-H ); 7.21 (t, 1H, Ar–H); 7.02 (d,
7.6 Hz, Q-H ), 7.25–7.20 (m, 2H, Q-H , Ar–H); 7.02 (d, 2H,
8
7
8
1
3
13
2
H, 8 Hz, Ar–H), 5.09 (s, 2H, –CH ); C NMR (100 MHz,
Ar–H); 5.09 (s, 2H, –CH ); 3.76 (s, 3H, -OCH ); C NMR
2
2 3
DMSO, δ, ppm): 166.4, 160.2, 150.9, 147.8 (=CH), 140.8,
(100 MHz, DMSO, δ, ppm): 166.9, 161.0, 154.8, 150.7,
147.8 (=CH), 140.7, 134.1, 132.0, 130.0, 129.1, 128.5,
128.0, 126.1, 125.8, 125.6, 123.8, 122.3, 121.0, 120.0,
1
34.0, 132.0, 130.0, 129.1, 128.9, 128.3, 128.1, 128.8, 126.0,
1
25.8, 125.4, 123.4, 121.3, 120.4, 116.8, 46.6, 31.0; LCMS
+
+
(
m/z): 473.0 (M+H) ; Anal. Calcd. For C H ClN O S: C,
116.6, 110.2, 46.4, 31.2; LCMS (m/z): (M + H) 468.5;
26
18
3
2
6
6.17; H, 3.84; N, 8.90. Found: C, 66.22; H, 3.81; N, 8.96.
Anal. Calcd. For C H N O S: C, 69.36; H, 4.53; N, 8.99.
2
7
21
3
3
Found: C, 69.32; H, 4.58; N, 8.95.
3
‑(Z‑(Z‑3‑benzyl‑4‑oxo‑2‑(phenylimino)thiazoli‑
din‑5‑ylidene)methyl)‑6‑bromo‑quinolin‑2(1H)‑one
8 h)
3‑(Z‑(Z‑3‑(4‑ꢀuorophenyl)‑4‑oxo‑2‑(phenylimino)
thiazolidin‑5‑ylidene)methyl)‑6‑ꢀuoro‑quino‑
lin‑2(1H)‑one (8 k)
(
−
1
Yield: 74%; FTIR (KBr, cm ): 3154, 3045, 2978, 1702,
1
−1
1
651, 1580; H NMR (400 MHz, DMSO-d , δ, ppm): 12.01
Yield: 68%; FTIR (KBr, cm ): 3222, 3071, 2975, 1712,
6
1
(
(
s, 1H, –OH); 8.07 (s, 1H, Q-H ); 8.00 (s,1H, Q-H ); 7.82
1653, 1582, 1184; H NMR (400 MHz, DMSO-d , δ, ppm):
4
5
6
s, 1H, HC=); 7.63 (d, 1H, 8 Hz, Q-H ); 7.37–7.47 (m, 7H,
12.00 (s, 1H, –OH); 8.01 (s, 1H, Q-H ); 7.85 (s, 1H, HC=);
8
4
Ar–H); 7.30 (d, 1H, 7.6 Hz, Q-H ), 7.20 (t, 1H, 7.4 Hz,
7.72 (d, 1H, Q-H ); 7.48–7.42 (m, 4H, Ar–H, Q-H , Q-H );
7
5
7
8
1
3
Ar–H), 7.02 (d, 2H, Ar–H); 5.07 (s, 2H, –CH ); C NMR
7.21 (t, 1H, Ar–H); 7.01 (d, 2H, 8 Hz, Ar–H), 5.02 (s,
2
1
3
(
(
100 MHz, DMSO, δ, ppm): 166.8, 161.0, 151.2, 148.0
2H, CH ); C NMR (100 MHz, DMSO, δ, ppm): 166.5,
2
=CH), 141.3, 137.5, 131.8, 134.2, 132.3, 129.9, 129.0,
163.5, 161.2, 160.8, 159.9, 150.4, 147.6 (=CH), 140.7,
134.3, 132.72, 132.66, 130.50, 130.41, 130.0, 128.7, 128.3,
125.9, 125.7, 125.1, 123.2, 121.4, 119.4, 116.1, 115.9,
1
1
28.8, 128.2, 127.9, 125.9, 125.7, 125.3, 123.5, 121.2,
+
20.0, 116.0, 46.3, 31.1; LCMS (m/z): 517.6 (M + H) ;
+
Anal. Calcd. For C H BrN O S: C, 60.47; H, 3.51; N,
115.2, 45.7; LCMS (m/z): 474.5 (M + H) ; Anal. Calcd.
2
6
18
3
2
8
.14. Found: C, 60.42; H, 3.56; N, 8.10.
For C H F N O S: C, 65.95; H, 3.62; N, 8.87. Found: C,
2
6
17
2
3
2
6
5.90; H, 3.70; N, 8.81.
3
‑(Z‑(Z‑3‑benzyl‑4‑oxo‑2‑(phenylimino)thiazoli‑
din‑5‑ylidene)methyl)‑6‑methyl‑quinolin‑2(1H)‑one
8i)
3‑(Z‑(Z‑3‑(4‑ꢀuorophenyl)‑4‑oxo‑2‑(phenylimino)
thiazolidin‑5‑ylidene)methyl)‑6‑chloro‑quino‑
lin‑2(1H)‑one (8 l)
(
−
1
Yield: 74%; FTIR (KBr, cm ): 3150, 3034, 2986, 1705,
1
−1
1
651, 1589; H NMR (400 MHz, DMSO-d , δ, ppm): 12.00
Yield: 75%; FTIR (KBr, cm ): 3218, 3068, 2971, 1714,
6
1
(
(
s, 1H, –OH); 7.97 (s, 1H, Q-H ); 7.85 (s, 1H, HC=); 7.55
1662, 1592; H NMR (400 MHz, DMSO-d , δ, ppm): 12.16
4
6
s, 1H, Q-H ), 7.36–7.43 (m, 7H, Ar–H); 7.32 (d, 1H, 8 Hz,
(s, 1H, -NH); 8.04 (s, 1H, Q-H ); 7.92 (s, 1H, H ), 7.85 (s,
5
4
5
Q-H ); 7.20 (t, 2H, Q-H , Ar–H); 7.00 (d, 2H, Ar–H); 5.10
1H, HC=); 7.61 (d, 1H, 8.4 Hz, Q-H ); 7.51 (t, 1H, 6.8 Hz,
7
8
7
1
3
(
s, 2H, –CH ); 2.31 (s, 3H, -CH ); C NMR (100 MHz,
Ar–H ), 7.39–7.45 (m, 2H, 7.6 Hz, Ar–H); 7.33 (d,1H,
2
3
o-F
DMSO, δ, ppm): 166.4, 160.8, 150.6, 148.0 (=CH), 141.0,
8 Hz, Q-H ); 7.21–7.28 (m, 3H, Ar–H); 7.00 (d, 2H, 8 Hz,
8
1
3
1
1
4
37.3, 136.3, 133.4, 132.1, 130.0, 129.0, 128.9, 128.1,
28.0, 126.0, 125.7, 125.3, 123.2, 121.4, 119.4, 115.5,
Ar–H), 5.09 (s, 2H, –CH ); C NMR (100 MHz, DMSO,
2
δ, ppm): 166.6, 163.2, 161.0, 160.0, 151.0, 148.0 (=CH),
140.2, 134.5, 133.1, 132.70, 132.64, 130.54, 130.45, 129.9,
128.5, 127.0, 126.0, 125.8, 125.4, 123.5, 121.1, 120.0,
+
6.2, 31.1; LCMS (m/z): 452.3 (M+H) ; Anal. Calcd. For
C H N O S: C, 71.82; H, 4.69; N, 9.31. Found: C, 71.78;
2
7
21
3
2
+
H, 4.75; N, 9.35.
117.0, 116.0, 115.8, 45.5; LCMS (m/z): 491.1 (M + H) ;
Anal. Calcd. For C H ClFN O S: C, 63.74; H, 3.50; N,
2
6
17
3
2
8
.58. Found: C, 63.84; H, 3.46; N, 8.62.
1
3

Journal of the Iranian Chemical Society
3
‑(Z‑(Z‑3‑(4‑ꢀuorophenyl)‑4‑oxo‑2‑(phenylimino)
Crystal structure solving procedure
thiazolidin‑5‑ylidene)methyl)‑6‑bromo‑quino‑
lin‑2(1H)‑one (8 m)
A light yellow coloured rectangle-shaped single crystal of
dimensions 0.28×0.26×0.23 mm of the title compound was
chosen for an X-ray diꢁraction study. The X-ray intensity
data were collected at a temperature of 296 K on a Bruker
Proteum2 CCD diꢁractometer equipped with an X-ray gen-
−
1
Yield: 78%; FTIR (KBr, cm ): 3225, 3068, 2970, 1718,
1
1
659, 1588; H NMR (400 MHz, DMSO-d , δ, ppm): 12.15
6
(
(
s, 1H, –NH); 8.08 (s, 1H, Q-H ); 8.00 (s, 1H, Q-H ); 7.82
4 5
s, 1H, HC=); 7.66 (d, 1H, 8.4 Hz, Q-H ); 7.39–7.47 (m,
erator operating at 45 kV and 10 mA, using CuK radiation
8
α
4
H, Ar–H); 7.30 (d, 1H, 7.6 Hz, Q-H ), 7.18–7.25 (m, 3H,
of wavelength 1.54178 Å. Data were collected for 24 frames
per set with diꢁerent settings of φ (0° and 90°), keeping the
scan width of 0.5°, exposure time of 2 s, the sample to detec-
tor distance of 45.10 mm and 2θ value at 46.6°. A complete
data set was processed using SAINT PLUS [39]. The struc-
ture was solved by direct methods and reꢀned by full-matrix
7
1
3
Ar–H); 7.02 (d, 2H, 8 Hz, Ar–H), 5.08 (s, 2H, –CH );
C
2
NMR (100 MHz, DMSO, δ, ppm): 166.5, 163.3, 160.0,
150.8, 148.3 (=CH), 140.0, 137.2, 134.1, 132.74, 132.69,
131.9, 130.58, 130.50, 130.0, 128.8, 126.0, 125.7, 125.3,
123.2, 121.3, 120.2, 116.6, 116.2, 116.0, 45.6; LCMS (m/z):
5
5
+
2
34.3 (M + H) ; Anal. Calcd. For C H BrFN O S: C,
least squares method on F using SHELXS and SHELXL
2
6
17
3
2
8.44; H, 3.21; N, 7.86. Found: C, 58.40; H, 3.25; N, 7.82.
programmes [40]. All the non-hydrogen atoms were revealed
in the ꢀrst diꢁerence Fourier map itself. All the hydrogen
atoms were positioned geometrically and reꢀned using a
riding model. After several cycles of reꢀnement, the ꢀnal
diꢁerence Fourier map showed peaks of no chemical sig-
niꢀcance and the residuals saturated to 0.0965. The geo-
metrical calculations were carried out using the programme
PLATON [41]. The molecular and packing diagrams were
generated using the software MERCURY [42].
3‑(Z‑(Z‑3‑(4‑ꢀuorophenyl)‑4‑oxo‑2‑(phenylimino)
thiazolidin‑5‑ylidene)methyl)‑6‑methyl‑quino‑
lin‑2(1H)‑one (8n)
−
1
Yield: 80%; FTIR (KBr, cm ): 3209, 3068, 2975, 1714,
1
1
660, 1595; H NMR (400 MHz, DMSO-d , δ, ppm): 12.02
6
(
(
s, 1H, –NH); 8.01 (s, 1H, Q-H ); 7.85 (s, 1H, HC=); 7.56
4
s, 1H, Q-H ); 7.51 (t, 2H, 6.4 Hz, Ar–H ), 7.45 (t, 2H,
5
o-F
Ar–H); 7.33 (d, 1H, 8 Hz, Q-H ); 7.19–7.25 (m, 4H, Ar–H);
7
7
–
1
1
1
4
.00 (d, 2H, 8 Hz, Ar–H), 5.09 (s, 2H, –CH ); 2.32 (s, 3H,
Anticancer activity (MTT assay)
2
13
CH ); C NMR (100 MHz, DMSO, δ, ppm): 166.5, 163.4,
3
61.1, 160.7, 150.2, 147.7 (=CH), 141.0, 137.7, 136.4,
34.2, 132.80, 132.74,130.55, 130.47, 129.9, 128.5, 126.0,
25.8, 125.4, 123.5, 121.6, 120.0, 116.0, 115.8, 115.2,
MDA-MB-231 cell culture was procured from National
Centre for Cell Sciences (NCCS), Pune, India. The cells
were cultured in Dulbecco’s minimum essential medium
(DMEM) supplemented with 10% Foetal bovine serum
(FBS), Penicillin (100 IU/ml), Streptomycin (100 μg/ml) and
Amphotericin-B (5 μg/ml) in a humidiꢀed atmosphere of
+
5.8, 31.0; LCMS (m/z): 470.5 (M+H) ; Anal. Calcd. For
C H FN O S: C, 69.07; H, 4.29; N, 8.95. Found: C, 69.13;
27
20
3
2
H, 4.25; N, 8.91.
5
% CO at 37°C until conꢂuent. The cells were trypsinized
2
3‑(Z‑(Z‑3‑(4‑ꢀuorophenyl)‑4‑oxo‑2‑(phenylimino)
with Trypsin-EDTA solution. The stock cultures were grown
2
thiazolidin‑5‑ylidene)methyl)‑6‑methoxyquino‑
lin‑2(1H)‑one (8o)
in 25cm ꢂasks and the studies were carried out in 96-well
microtitre plates.
The cytotoxicity activity was done by MTT assay [43,
44] Cells were plated in 96-well ꢂat-bottom microtitre plate
−
1
Yield: 76%; FTIR (KBr, cm ): 3219, 3063, 2972, 1718,
1
3
1
1
7
663, 1591; H NMR (400 MHz, DMSO-d , δ, ppm):
at a density of 5×10 cells per well and cultured for 24 h at
6
2.00 (s, 1H, –NH); 7.99 (s, 1H, Q-H ); 7.87 (s, 1H, HC=);
37°C in 5% CO atmosphere to allow cell adhesion. After
4
2
.49 (t, 2H, Ar–H ); 7.41 (t, 2H, 7.4 Hz, 7.4 Hz), 7.32
24 h, when partial monolayer was formed, medium was
removed and cells were treated with diꢁerent concentration
of standard drug (cisplatin) and sample compounds for 48 h.
After the treatment, the solutions in the wells were discarded
and 100 μl of freshly prepared MTT (1 mg/ml, prepared in
PBS) was added to each well. The plates were shaken gently
o-F
(
s, 1H, Q-H ); 7.20–7.26 (m, 5H, Ar–H); 7.01 (d, 2H,
5
8
Hz, Ar–H), 5.08 (s, 2H, –CH ); 3.77 (s, 3H, –OCH );
2 3
1
3
C NMR (100 MHz, DMSO, δ, ppm): 166.3, 163.3, 160.9,
60.5, 155.0, 150.4, 147.9 (=CH), 140.7, 134.0, 132.82,
32.79,130.57, 130.49, 130.0, 126.1, 126.0, 125.3, 123.2,
22.3, 121.5, 120.0, 117.0, 115.9, 115.7, 110.1, 56.0,
1
1
1
4
and incubated for 4 h at 37°C in 5% CO atmosphere. After
2
+
5.5; LCMS (m/z): 486.3 (M + H) ; Anal. Calcd. For
4 h, the supernatant was removed and the formazan crystals
C H FN O S: C, 66.79; H, 4.15; N, 8.65. Found: C, 66.84;
formed in the cells were solubilized by addition of 100 μl of
27
20
3
3
H, 4.21; N, 8.60.
1
3

Journal of the Iranian Chemical Society
DMSO. Finally, the absorbance was read using a Micro-plate
reader a wavelength of 540 nm.
with 1 × PBS. It was re-centrifuged and ꢀxed in 70% cold
EtOH for overnight ꢀxation at 4 °C. After centrifugation,
the cells were washed twice with ice-cold PBS and the
pellet re-suspended in 200 µl of 1 × PBS mixture contain-
ing 0.1% Triton X-100, 100 µg/ml RNase and 10 µg/ml PI
solution. The cells were incubated in the dark for 30 min
at 4 °C and then analyzed by ꢂow cytometry using MACS
Quant Analyser. The distribution of cells in G /G , S,
The percentage growth was calculated using the formula
below:
%
growth inhibition=control absorbance-test absorbance
/
control absorbance×100.
From curve IC , (Concentration of drug required to kill
5
0
5
0% of cells in exponentially growing cultures after a 48 h
0
1
exposure to the drug) values were calculated. The assay was
conducted in triplicate.
G /M phase was determined. Untreated cells harvested at
2
the same time point served as control.
Cytotoxicity on normal HEK 293 kidney cell
line
Molecular docking methods
Human embryonic kidney cell line HEK 293 was procured
from NCCS, Pune. The cytotoxicity eꢁects of 8e, 8k, 8m, 8n
and 8o were studied by MTT assay. The cells were cultured
using Eagle’s minimum essential medium (MEM) supple-
mented with 10% foetal bovine serum, penicillin (100 U
The docking studies and molecular dynamic simulation
studies of Quinolino-thiazolidinone derivatives with
hNAT-1 were performed by using Schrodinger Glide soft-
ware as described in the literature [46].
−1
−1
2
mL ) and streptomycin (100 mgmL ) and grown in 25 cm
tissue culture ꢂasks at 37 °C with 5% CO incubator (Gal-
2
axy 170S, New Brunswick). After attaining 70–80% conꢂu-
ence, cells were trypsinized and seeded to 96-well plates
in 100 mL of MEM (5000 cells/well). After 24 h, diꢁerent
concentrations of drugs were dissolved in DMSO are added
to 96-well plates and incubated for 24 h at standard condi-
tion. Untreated cells represented a control group. Four rep-
licates were set up for each test group. After completion of
Results and discussion
Synthesis
The synthetic route adapted for the preparation of 2-chlo-
roquinoline-3-aldehydes 3a-e and ꢀnal compounds 8a-o
is depicted in Scheme 1. The quinoline-3-aldehydes 3a-e
were prepared by a well-known Meth-Cohn synthetic route
[47]. Diꢁerent anilines 1a-e were reacted with acetic anhy-
dride in THF medium to obtain corresponding acetanilides
2a-e which on Vilsmeir-haack formylation reaction with
−1
the incubation time, 20 mL of MTT dye (5 mg mL in PBS)
was added to all wells; the plate was sealed with aluminium
foil and incubated for 4 h in an incubator. After 4 h, 100 mL
of DMSO was added to all the wells and mixed by uniform
shaking. Using a multi-plate reader (LisaScan®EM), the
absorbance was recorded at 570 nm.
DMF-POCl yielded 2-chloroquinoline-3-carboxaldehydes
3
3a-e. In another route, diꢁerent aliphatic/benzylamines
4a-c were made to react with phenylisothiocyanate 5 in
dimethyformamide solvent in the presence of triethyl-
amine to generate 1-(alkyl/benzyl)-3-phenylthiourea 6a-c.
These were then cyclised with chloroacetic acid in sodium
acetate to yield 3-(alkyl/benzyl)-2-(phenylamino)thiazo-
lin-4-ones7a-c. In the ꢀnal step, target compounds 8a-o
were obtained by the Knoevenegal condensation of these
thiazolidin-4-ones with diꢁerent 2-chloro-6-substituted
quinoline-3-carboxaldehyde 3a-e in acetic acid-sodium
acetate buꢁer medium. As we utilized acetic acid-sodium
acetate solvent medium, the chlorine atom at 2nd posi-
tion of quinoline ring underwent nucleophilic substitution
reaction yielding quinolin-2-one derived products 8a-o.
Characterization data of all synthesized compound is pre-
sented in Table 1.
The percentage growth inhibition was calculated using
the formula below:
%
growth inhibition=(control absorbance−test absorb-
ance /control absorbance)×100.
From curve IC (Concentration of drug required to kill
5
0
5
0% of cells in exponentially growing cultures after a 48 h
exposure to the drug) values were calculated. The assay was
conducted in triplicate.
Cell cycle analysis
The compound 8n was examined for its eꢁects on the
cell growth cycle [45]. After 24 h of serum starvation,
MDA-MB-231 cells were treated with drug concentration
8
.16 µM containing complete medium. The cells were har-
All the newly synthesized compounds were characterized
1
13
vested after 48 h and then spun at 1000 × g for 5 min. The
by IR, H NMR, C NMR, LCMS and elemental analysis.
supernatant was aspirated and the cell pellet was washed
Formation of 1-(4-ꢂuorobenzyl)-3-phenylthiourea 6c was
1
3

Journal of the Iranian Chemical Society
O
R1
R1
R1
i
O
ii
H
O
NH2
N
H
R
2
N
Cl
R1
N
1
a-e
2a-e
3a-e
S
v
N
N
H
8a-o
O
O
R
2
S
N
SCN
iv
iii
R2
N
R2 NH2
N
N
H
S
H
4
a-c
5
6a-c
7a-c
Scheme 1: (i) Ac O, THF, rt (ii) DMF-POCl , Reꢂux, 6 h (iii) TEA, DMF, rt (iv) Chloroacetic acid, sodium acetate, ethanol, reꢂux (v) NaOAc,
2
3
glac. AcOH, reꢂux
Table 1 Characterization data of compounds 3a-e, 6a-c, 7a-c and 8a-o
O
O
O
R
2
R1
R
1
S
N
H
N R
2
R2
S
N
N
H
N
H
S
N
H
a-o
O
N
Cl
N
3a-e
6a-c
7a-c
8
o
Compd
R1
R2
M.p ( C)
3
3
3
3
3
6
6
6
7
7
7
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
a
b
c
d
e
a
b
c
a
b
c
a
b
c
d
e
f
g
h
i
j
k
l
m
n
F
–
–
–
–
–
68–70 [48]
Cl
Br
Me
OMe
–
248–250 [49]
250–252 [48]
242–244 [48]
244–246 [48]
60–62 [50]
155–157 [51]
72–74 [50]
55–57 [52]
66–68
68–70
>270
>270
258–260
>270
>270
>270
>270
>270
256–258
232–234
250–252
256–258
>270
>270
246–248
–CH –CH –CH
2
2
3
–
–CH –C H
2 6 5
–
–CH –4-F-C H
2
6
4
–
–CH –CH –CH
2 2
3
–
–CH –C H
2 6 5
–
–CH –4-F-C H
2
6
4
F
–CH –CH –CH
2
2
3
3
3
3
3
Cl
Br
Me
OMe
F
Cl
Br
Me
OMe
F
Cl
Br
Me
OMe
–CH –CH –CH
2
2
–CH –CH –CH
2
2
–CH –CH –CH
2
2
–CH –CH –CH
2
2
–CH –C H
2
6
5
5
5
5
5
–CH –C H
2
6
–CH –C H
2
6
–CH –C H
2
6
–CH –C H
2 6
–CH –4-F-C H
2 6 4
–CH –4-F-C H
2 6
4
4
4
4
–CH –4-F-C H
2 6
–CH –4-F-C H
2
6
o
–CH –4-F-C H
2
6
1
3

Journal of the Iranian Chemical Society
conꢀrmed by its IR spectrum which showed two promi-
that is eliminated during the condensation process. The
−
1
−1
1
nent peak at 3391 cm and 3120 cm for N–H stretch-
H NMR spectrum of compounds 8a-o showed exocy-
−
1
ing and at 1184 cm for C=S stretching. Appearance of
two distinct broad singlets at 9.64 ppm and 8.18 ppm in
clic =C–H singlet in the region 7.70–7.90 ppm which
confirms the Knoevenagel condensation products. In
1
13
1
its H NMR spectra for two N-H protons and its C spec-
tra showed a downꢀeld signal at 181.2 ppm corresponding
to C=S carbon conꢀrms its formation. In the IR spectra of
the H NMR spectrum of compound 8o, a broad peak at
12.00 ppm for N–H confirms the nucleophilic displace-
ment reaction. The methoxy protons appeared at 3.77 ppm
(
Z)-3-(4-ꢂuorobenzyl)-2-(phenylimino)thiazolidin-4-one 7c
and CH protons at 5.08 ppm as two distinct singlets. The
2
absence of NH stretching bands and appearance new band at
exocyclic =CH proton resonated as a singlet at 7.87 ppm.
−
1
13
1
717 cm corresponding to C=O stretching clearly con-
Further, C NMR spectra of 8o, a peak correspond-
1
ꢀ
rms its cyclization from 6c. In H NMR spectra, cyclization
ing to C=O carbon appeared at 166.3 ppm and a peak
at 160.5 ppm corresponding to C=O carbon of quino-
line NH–C=O confirms the product. Also, the exocyclic
methine proton resonated at 147.9 ppm confirming its
formation. The signals corresponding to the carbons of
4-fluoro phenyl ring exhibited splitting due to the pres-
ence of fluorine atom. The carbon attached to the fluorine
atom displayed a doublet at 163.27 and 160.85 ppm with
coupling constant 242 Hz and ortho carbon appeared as
doublet with coupling constant of 21 Hz at 115.93 and
115.72 ppm. Meta and para carbons appeared as doublets
at 130.57, 130.49 ppm and 132.82, 132.79 ppm with cou-
pling constants 8 Hz and 3 Hz, respectively. The coupling
constant clearly distinguishes the different carbon atoms.
to 7c was evidenced by the emergence of a sharp singlet
at 4.10ppm corresponding to –S-CH proton with the dis-
2
1
3
appearance of two broad NH peaks. Its C NMR spectra
showed signals at 172.4 ppm and 155.4 ppm corresponding
to the ring carbonyl (C=O) carbon and C=N, respectively,
conꢀrming the formation. Its LCMS spectrum showed a
(
M+H) peak at 301.1 conꢀrming its formation.
The Knoevenagel condensation between different sub-
stituted quinoline aldehydes 3a-e and substituted thiazo-
lidinone 7a-c yielded the final compounds 8a-o. In the
−
1
IR spectra of 8a, appearance of a peak at 3150 cm for
the NH stretching confirms the nucleophilic displace-
ment of chlorine in the presence of glacial acetic acid to
form NH–C=O. Moreover, appearance two distinct car-
−
1
−1
bonyl peaks at 1697 cm and 1655 cm corresponding
to ring carbonyl and ring NH–C=O confirms its forma-
tion. The nucleophilic displacement of chlorine is due to
the presence of water molecule in the reaction medium
Crystal structure of 8a
The Z-conꢀguration of exocyclic C=C and C=N was con-
ꢀrmed by the crystal structure of 8a (Fig. 2). The details of
Fig. 2 ORTEP diagram of 8a
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Journal of the Iranian Chemical Society
Table 3 Anticancer activity of compounds 8a-o
Table 2 Crystal reꢀnement data of 8a
Parameter
Value
Comp
IC50 (µM)
CCDC deposit No
Empirical formula
Formula weight
Temperature
Wavelength
Crystal system, space group
Unit cell dimensions
1437323
MDA-MB-231
>100
>100
46.09
27.61
17.68
59.32
46.11
>100
33.77
39.99
22.20
>100
18.75
8.16
MCF-7
NT
NT
NT
NT
39.38
NT
NT
NT
NT
NT
36.98
NT
24.72
33.86
18.03
4.99
HEK-293
NT
NT
NT
NT
>1000
NT
NT
NT
NT
NT
682.12
NT
>1000
846.93
409.72
NT
C H F N O S
8a
4
4
36
2
6
4 2
814.91
293(2) K
1.54178 Å
Triclinic, P-1
a=6.5527(5) Å
b=10.4546(8) Å
c=29.118(2) Å
α=97.984(5)
β=91.684(5)
γ=106.584(5)
8b
8c
8d
8e
8f
8 g
8 h
8i
o
o
8j
8 k
8 l
8 m
8n
8o
o
3
Volume
1888.2(3)Å
3
Z, Calculated density
Absorption coeꢃcient
F(000)
2, 1.433 Mg/m
1.819 mm−
848
1
44.24
1.66
Crystal size
0.28×0.26×0.23 mm
Cisplatin
Theta range for data collection 1.54° to 58.93°
Limiting indices
Reꢂections collected/unique
Reꢀnement method
Data/restraints/parameters
Goodness-of-ꢀt on F2
Final R indices [I>2σ(I)]
R indices (all data)
−7≤h≤6, –11≤k≤11, –32≤l≤32
o
26,164/ 5370 [R(int)=0.0972]
ring bridged by the imine bond is 10.0(3) (S1A-C5A &
2
o
Full-matrix least-squares on F
5370/0/525
C11A-C20A), 10.5(3) (S1B-C5B & C11B-C20B) respec-
tively. The crystal structure is stabilized by both inter and
intramolecular hydrogen bonds of the type N—H…O and
C—H…O.
1.231
R1=0.0965, wR2=0.2482
R1=0.1127, wR2=0.2554
0.581 and−0.467 e. Å−
3
Largest diꢁ. peak and hole
Anticancer activity
All the target compounds 8a-o were tested for their anti-
cancer activity against MDA-MB-231 human breast cancer
cell line and ꢀve potent compound against MCF-7 cell lines
by MTT assay. The anticancer data are depicted in Table 3.
Compound 8n having methyl substitution at the 6th position
of quinolone and 4-ꢂuorophenyl moiety at the 3rd position
of thiazolidinone ring exhibited the excellent activity in the
series with IC 8.16 µM against MDA-MB-231 cell line
the crystal structure and data reꢀnement are given in Table 2.
The compound 8a crystallizes in the triclinic space group
P-1 with two independent molecules in the asymmetric unit.
The C5–C10 and N23-C2 bonds in both the molecules of A
and B shows a typical double-bond character correspond-
ing to ethene and imine bonds, with bond lengths 1.336(1)
Å (C5A–C10A), 1.334(1)Å (C5B–C10B) and 1.278(10) Å
5
0
(
N23A-C2A), 1.268(10) Å (N23B-C2B) respectively. The
but moderate activity against MCF-7 with IC 33.86 µM.
50
C10-C11 bond shows a partial double-bond character, with
the bond lengths 1.461(11) Å (C10A-C11A) and 1.467(10)
Å (C10B-C11B), respectively, which seems to indicate a
certain electronic delocalization between C5-C10 and C10-
C11 bonds in both the molecules. The double bonds C5-C10
and N23-C2 adopts a Z,Z conꢀguration in both the mole-
cules which is in agreement with the reported literature mol-
ecules [23, 53]. The central thiazolidinone ring is planar and
keeps the planarity across the ethene bond with the quinoline
moiety. The dihedral angle between the central thiazolidi-
none ring and the quinoline ring bridged by the ethene bond
Next best activity was exhibited by compound 8e which
has a methoxy substitution at the 6th position of quinolone
with propyl group at the 3rd position of thiazolidinone ring
showed IC 17.68 µM against MDA-MB-231 cell line and
5
0
39.38 µM on MCF-7 cell line. Compound 8 m showed good
activity with IC 18.75 µM on MDA-MB-231 cell line and
5
0
a slightly reduced activity with IC value of 24.72 µM
5
0
against MCF-7 cell line. Compounds 8 k having ꢂuorine
group at the 6th position exhibited good activity against
MDA-MB-231 cell line with IC 22.20 µM and 8o having
5
0
methoxy group showed moderate activity IC 44.24 µM
5
0
o
o
is 54.0(4) (S1A-C5A & C24A-C29A), 54.8(4) (S1B-C5B
C24B-C29B), respectively, whereas the dihedral angle
between the thiazolidinone ring and the fused heterocyclic
on MDA-MB-231, but it showed promising activity against
&
MCF-7 cell line with IC 18.03 µM. The compounds from
5
0
propyl series 8c (6-Br) and 8d (6-Me) were found to be
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Journal of the Iranian Chemical Society
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Journal of the Iranian Chemical Society
Table 4 Cell cycle analysis of 8n on MDA-MB-231 cell line
Toxicity study on normal HEK‑293 cell line
Phases
Untreated
8na
Metforminb
Toxicity proꢀle of potent compounds 8e, 8k, 8m, 8n and
8o was determined by MTT assay on normal human kidney
HEK 293 cell line and results are given in Table 3. From the
study, it was clear that all the tested compounds were found
to be non-toxic and safer to normal cell line even at higher
concentrations.
G /G
56.59
12.09
11.20
0.84
50.52
15.66
19.73
1.21
57.76
12.38
18.45
1.07
0
1
S
G /M
2
Sub G1
a
experiment carried out at 8.16 µM concentration (IC )
experiment carried out at 20 µM concentration
5
0
b
Cell cycle analysis of 8n
moderate inhibitors with IC50 46.09 and 27.61 µM respec-
tively. Benzylic series compounds exhibited moderate activ-
ity against MDA-MB-231 cell line with IC 33.77 µM and
In order to determine the mode of action of potent compound
8n, cell cycle analysis was performed at its IC concentra-
5
0
tion 8.16 µM in MDA-MB-231 cell line using Flow cytome-
5
0
3
9.99 µM for 8i (6-Me) and 8j (6-OMe) respectively. Moreo-
try method (Fig. 3 and Table 4). It was observed that 19.73%
ver, compounds 8f from the same series displayed very less
of cells were accumulated at the G /M phase as compared
2
activity with IC 59.32 µM.
to the control which has 11.20% of cells. Similarly, standard
5
0
drug Metformin has 18.45% of cells in G /M phase. At the
2
same time there is a slight increase in the cell counts in the S
phase when compared to control cells. However, there is no
considerable distribution of cells among the diꢁerent phases
Fig. 4 Docking pose of compound 8e and 8n with human NAT-1. The violet colour dotted lines represent hydrogen bonding, cyan colour lines
represents π–π interaction and blue colour dotted lines represents π-cation interactions
Table 5 Docking scores and interactions with NAT-1 protein for the compounds 8e and 8n
Compound Docking
Hydrogen bonding
π-π stacking and π-cation interactions Hydrophobic interactions
score (kcal/
mol)
8
e
− 12.592
Phe287, Arg286, Ser95, Tyr208, Thr103 Arg286, Cys100
Ile106, Ala98, Tyr101,
Val216, Phe288, Phe37,
Phe125, Phe217, Leu209 and
Val93
8
n
− 14.678
Phe287, Arg286, Ser95, Tyr208, Thr103 Phe217, Arg286, Cys100, Tyr208
Ile106, Met205, Ala98,
Tyr101, Val216, Phe288,
Phe37, Phe125, Phe217,
Leu209 and Val93
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Journal of the Iranian Chemical Society
at the IC concentration. But with the observed accumula-
Tyr101, Val216, Phe288, Phe37, Phe125, Phe127, Leu209
and Val93 residues.
5
0
tion of cells at 8.16 µM concentration, compound 8n was
found to arrest the cell cycle at G /M phase.
In the propyl series, the most potent compound 8e has
a docking score of −12.592 kcal/mol. Hydrogen bonding
interaction present between N–H of quinoline with the main
2
Molecular docking studies
o
chain oxygen of Phe287 at a distance of 1.96 A . Carbonyl
Selection of target protein
oxygen of quinoline interacted with the side chain amino
o
group of Arg286 at a distance of 1.76A and with hydroxyl
o
In order to determine the possible binding modes of potent
compounds with the protein, docking studies were carried
out on human N-acetyl transferase-1 protein (NAT-1) using
Schrodinger molecular docking toolkit. The selection of tar-
get protein for the docking studies was done on the basis of
structural similarity of reported molecules (Fig. 1). It was
reported that 5-(2-hydroxybenzylidene)-2-thioxothiazolidin-
group Ser95 with a bond length of 2.11 A . The thiazoli-
dinone carbonyl oxygen is involved in hydrogen bonding
interaction with the side chain hydroxyl group of Tyr208
o
with a bond length of 1.73 A . The exocyclic imine nitrogen
forms binding with the main chain amino group of Thr103
o
at a distance of 2.02A . This molecule forms only two salt
bridge interaction between the phenyl ring at the 2nd posi-
tion of thiazolidinone with Arg286 and Lys100. The absence
of two π–π stacking may accounts for its slightly lower activ-
ity. The residues Ile106, Ala98, Tyr101, Val216, Phe288,
Phe37, Phe125, Phe127, Leu209 and Val93 forms hydro-
phobic interaction with the molecule.
4
-oneas NAT-1 inhibitor of breast cancer cells ZR-75–1 [34]
and MDA-MB-231 [35]. Similarly, thiazolidine-2,4-diones
54] were reported as NAT inhibitors of mycobacterium
[
tuberculosis. Our target compounds 8a-o structurally mimic
the reported NAT inhibitors and modiꢀcation was done at
the 2nd, 3rd and 4th position of central thiazolidinone.
Hence, quinoline-thiazolidinones 8a-o were docked on
human N-acetyl transferase-1 protein by induced ꢀt dock-
ing method.
Molecular dynamics simulations
Molecular dynamics (MD) simulation was performed to
conꢀrm the stability of predicted binding mode of the com-
pounds to HNAT1. The molecular dynamics simulation was
run using Desmond [56]. Simulation was run for 20 ns on
equilibrated docked complex of 8n with HNAT1 structures
and at every 2 fs ensembles were saved in the trajectory.
To evaluate the stability of the protein during dynamics, all
the frames in the trajectory were aligned initial frame and
the rmsd was calculated with respect to the initial frame.
From 5 ns to till the end of simulation, the total rmsd of
protein was within a range of 0.63 A° which depicted the
protein was well stabilized during dynamics. Further, the
rmsd observed for the ligand was within the range of 0.55
A° demonstrated the protein–ligand complex was well sta-
bilized (Fig. 5).
Docking studies
The docking studies of quinazoline clubbed thiazolidinones
with hNAT-1 protein (PDB: 2PQT) were carried out by
using Schrödinger Glide [55] and the docking poses of com-
pounds 8n and 8e are depicted in Fig. 4. The corresponding
docking score and residual interaction are given in Table 5.
In the docking pose of compound 8n, which has a dock-
ing score of -14.678 kcal/mol which exhibited strong hydro-
gen bonding interaction between N–H of quinolone with
o
the backbone oxygen of Phe287 at a distance of 2.10A and
carbonyl oxygen of quinolone interacted with the side chain
o
amino group of Arg286 at a distance of 1.89 A . Also, this
carbonyl oxygen forms another hydrogen bond with hydroxyl
o
group of Ser95 with a bond length of 1.97A . The thiazoli-
dinone carbonyl oxygen also makes strong hydrogen bond
interaction with the side chain hydroxyl group of Tyr208
o
with a bond length of 1.73A . The exocyclic imine nitrogen
is involved in hydrogen bonding with the main chain amino
o
group of Thr103 at a distance of 2.01A and it also exhibits
side chain interaction with hydroxyl group of Thr103 at a
o
distance of 2.24A . The phenyl ring of quinolone moiety is
involved in a strong π–π stacking moiety with Phe-217. Also
phenyl ring at the 2nd position of thiazolidinone involved
in the salt bridge with Arg286 and Lys100. In addition, it
was stabilized by a π–π stacking interaction between phenyl
ring of 4-ꢂuro moiety and Tyr208. The molecule oriented in
hydrophobic cavity surrounded by Ile106, Met205, Ala98,
Fig. 5 The RSM deviations between the original structure and the
structure enumerated during MD simulation; the backbone ꢂuctua-
tions are shown in blue, ligand ꢂuctuations are shown in brown col-
our
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Journal of the Iranian Chemical Society
Fig. 6 Schematic diagram of 8n interaction with the amino acid resi-
dues of protein evolved during MD simulation. Interactions that occur
more than 30% of the simulation time are shown. Residues with the
ligand interactions that occurred more than 30% of the simulation
time in the trajectory is shown
Fig. 7 Interaction between
HNAT1 and 8n evolved during
MD simulation, A. depicts the
electrostatic interactions and
B. depicts the hydrophobic
interactions
For the trajectory of the stable dynamics, the interac-
tions between the protein and ligand were analysed. Fig-
ure 6 shows schematic diagram of the 8n interacting with the
amino acid residues of protein structure evolved during MD
simulation. As illustrated in the ꢀgure, the ligand–protein
interactions obtained in the docking study were conserved
throughout the MD simulation. The interactions obtained
from the trajectory shows that major interactions between
the ligand and receptor binding site amino acids are H-bond
and hydrophobic (Fig. 7). As illustrated in the Fig. 7, H-bond
amongst Phe287 and Ser95, hydrophobic interactions
amongst Phe37, Val93, Ile106, Phe125, Val216, Phe217,
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Journal of the Iranian Chemical Society
Phe222 and Phe288 with quinolinone moiety, H-bond
amongst Tyr208 and Thr103 with 2-iminothiazolidin-4-one
moiety, π-cation interaction amongst Arg286 and Lys100
with phenyl moiety and π–π stacking interaction amongst
Tyr208 with ꢂuoro-benzyl moiety were elegant in stabilizing
the ligand in protein binding pocket.
References
1. L.A. Torre, F. Bray, R.L. Siegel, J. Ferlay, J. Lortet-Tieulent, A.
Jemal, CA Cancer J. Clin. 65, 87 (2015)
2
. R. Siegel, J. Ma, Z. Zou, A. Jemal, CA Cancer J. Clin. 64, 9
(
2014)
3. K.M. El-Gamal, M.S. Hagrs, H.S. Abulkhair, Bull. Fac. Pharm.
Cairo Univ. 54, 263 (2016)
4
5
.
.
T.G. Shruthi, S. Eswaran, P. Shivarudraiah, S. Narayanan, S.
Subramanian, Bioorg. Med. Chem. Lett. 29, 97 (2019)
R.G. Kalkhambkar, G. Aridoss, G.M. Kulkarni, Monatsh.
Chem. 143, 1075 (2012)
Conclusion
In the present study, we synthesized few newer hybrid
molecules containing quinolone and thiazolidinone moie-
ties and evaluated their anticancer activities against two
breast cancer cell lines MDA-MB-231 and MCF-7. All the
compounds are characterized by spectroscopic techniques
and E/Z-conꢀgurations of ꢀnal molecules are conꢀrmed
by the crystal structure data of 8a. It indicated that both
the exocyclic C=N bond and C=C bond are in Z-conꢀg-
uration with respect to thiazolidinone ring. Few of the
compounds exhibited good to moderate anticancer activ-
ity. Compound 8n exhibited the promising activity against
MDA-MB-231 cell line with IC 8.16 µM and compound
6. M. Chioua, E. Martínez-Alonso, R. Gonzalo-Gobernado, M.I.
Ayuso, A. Escobar-Peso, L. Infantes, D. Hadjipavlou-Litina, J.J.
Montoya, J. Montaner, A. Alcázar, J. Marco-Contelles, J. Med.
Chem. 62, 2184 (2019)
7. Y. Zhang, Y. Fang, H. Liang, H. Wang, K. Hu, X. Liu, X. Yi, Y.
Peng, Bioorg. Med. Chem. Lett. 23, 107 (2013)
8
9
.
.
X.Q. Deng, M.X. Song, Y. Zheng, Z.S. Quan, Eur. J. Med.
Chem. 73, 217 (2014)
P.N. Batalha, M.C. Vieira de Souza, E. Peña-Cabrera, D.C.
Cruz, F. da Costa Santos Boechat, Curr. Pharm. Des. 22, 6009
(2016)
1
0. W.B. Kuang, R.Z. Huang, J.L. Qin, X. Lu, Q.P. Qin, B.Q. Zou,
Z.F. Chen, H. Liang, Y. Zhang, Eur. J. Med. Chem. 157, 139
(
2018)
5
0
11. Y.C. Yu, W.B. Kuang, R.Z. Huang, Y.L. Fang, Y. Zhang, Z.F.
8
o showed potent activity on MCF-7 cancer cell line with
Chen, X.L. Ma, Med. Chem. Commun. 8, 1158 (2017)
1
2. S. Raghavan, P. Manogaran, K.K. Narasimha, B.K. Kuppusami, P.
Mariyappan, A. Gopalakrishnan, G. Venkatraman, Bioorg. Med.
Chem. Lett. 25, 3601 (2015)
IC 18.03 µM. Compound 8n found to be non-toxic to
5
0
the normal human kidney cell line. It has arrested the cell
cycle at G /M phase of MDA-MB-231 cell line at its IC
13. M.S. Kaur, R. Kaur, R. Bhatia, K. Kumar, V. Singh, R. Shankar,
2
50
concentration. SAR studies demonstrated that 4-ꢂuoro
phenyl ring and electron releasing groups in the quinolone
moiety played major role in the enhancement of antican-
cer activity. Further, molecular docking studies exhibited
that these compounds have well binding interactions with
human N-acetyl transferase 1 protein having both hydrogen
and π-π interactions.
R. Kaur, R.K. Rawal, Bioorg. Chem. 75, 406 (2017)
1
1
4. M. Kalhor, S. Banibairami, RSC Adv. 10, 41410 (2020)
5. N. Azizi, M. Hasani, M. Khajeh, M. Edrisi, Tetrahedron Lett. 56,
1
189 (2015)
16. M.A. Ansari, D. Yadav, M.S. Singh, J. Org. Chem. 85, 8320
(2020)
1
1
1
7. M. Fesatidou, P. Zagaliotis, C. Camoutsis, A. Petrou, P. Elefthe-
riou, C. Tratrat, M. Haroun, A. Geronikaki, A. Ciric, M. Sokovic,
Bioorg. Med. Chem. 26, 4664 (2018)
8. M. Haroun, C. Tratrat, A. Kolokotroni, A. Petrou, A. Geronikaki,
M. Ivanov, M. Kostic, M. Sokovic, A. Carazo, P. Mladěnka, N.
Sreeharsha, Antibiotics. 10, 309 (2021)
Supporting information
9. Y. Ali, M.S. Alam, H. Hamid, A. Husain, A. Dhulap, S. Bano, C.
Kharbanda, Bioorg. Med. Chem. Lett. 27, 1017 (2017)
Spectral data associated with this article are available in
the supplementary material ꢀle.
20. S.S. Abd El-Karim, H.S. Mohamed, M.F. Abdelhameed, A.E.
Amr, A.A. Almehizia, E.S. Nossier, Bioorg. Chem. 111, 104827
(
2021)
2
1. R.N. Shelke, D.N. Pansare, A.P. Sarkate, K.S. Karnik, A.P. Sar-
Acknowledgements Authors are thankful to Yenepoya Research Cen-
tre, Yenepoya University, Deralakatte for helping in carryout anticancer
activity. Also thankful to IOE and DST-PURSE, Vijnana Bhavana,
University of Mysuru for X-ray crystallographic facility.
kate, D.B. Shinde, S.R. Thopate, J. Taibah Univ. Sci. 13, 678
(
2019)
2
2
2 N. Trotsko, Eur. J. Med. Chem. 215, 113266 (2021)
3. K.R.A. Abdellatif, W.A.A. Fadaly, G.M. Kamel, Y.A.M.M.
Elshaier, M.A. El-Magd, Bioorg. Chem. 82, 86 (2019)
Declarations
24. A.D. Patel, T.Y. Pasha, P. Lunagariya, U. Shah, T. Bhambharoliya,
R.K. Tripathi, ChemMedChem 15, 1229 (2020)
Conflict of interest The authors declare that they have no conꢂict of
25. M.F. Ansari, S.M. Siddiqui, K. Ahmad, F. Avecilla, S. Dharavath,
S. Gourinath, A. Azam, Eur. J. Med. Chem. 124, 393 (2016)
interest.
2
2
6. M.L. Barreca, A. Chimirri, L. De Luca, A.M. Monforte, P. Mon-
forte, A. Rao, M. Zappalà, J. Balzarini, E. De Clercq, C. Panne-
couque, M. Witvrouw, Bioorg. Med. Chem. Lett. 11, 1793 (2001)
7. M. Mishchenko, S. Shtrygol, D. Kaminskyy, R. Lesyk, Sci.
Pharm. 88, 16 (2020)
1
3

Journal of the Iranian Chemical Society
2
2
3
3
8. G. Çakir, İ Küçükgüzel, R. Guhamazumder, E. Tatar, D. Manvar,
A. Basu, B.A. Patel, J. Zia, T.T. Talele, N. Kaushik-Basu, Arch.
Pharm. (Weinheim). 348, 10 (2015)
40. G.M. Sheldrick, A short history of SHELX. Acta Cryst. A64, 112
(2008)
41. A.L. Spek, PLATON. Acta Cryst. A46, C34 (1990)
42. C.F. Macrae, I.J. Bruno, J.A. Chisholm, P.R. Edgington, P.
McCabe, E. Pidcock, L. Rodriguez-Monge, R. Taylor, J. Van De
Streek, P.A. Wood, J. Appl. Cryst. 41, 466 (2008)
9. D.K. Sigalapalli, V. Pooladanda, M. Kadagathur, S.D. Guggilapu,
J.L. Uppu, C. Godugu, N.B. Bathini, N.D. Tangellamudi, J. Mol.
Struct. 1225, 128847 (2021)
0. M.A. Iqbal, A. Husain, O. Alam, S.A. Khan, A. Ahmad, M.R.
Haider, M.A. Alam, Arch. Pharm. (Weinheim). 353, 2000071
43. T.J. Mosmann, Immunol. Methods. 65, 55 (1983)
44. F. Denizot, R. Lang, Immunol. Methods. 89, 271 (1986)
45. X. Yang, W. Wang, J.J. Qin, M.H. Wang, H. Sharma, J.K. Buola-
mwini, H. Wang, R. Zhang, PLoS ONE 7, e34303 (2012)
46. K.S.V. Kumar, G.S. Lingaraju, Y.K. Bommegowda, A.C. Vinay-
aka, P. Bhat, C.S.P. Kumara, K.S. Rangappa, D.C. Gowda, M.P.
Sadashiva, RSC Adv. 5, 90408 (2015)
(
2020)
1. C.M. Richardson, C.L. Nunns, D.S. Williamson, M.J. Parratt, P.
Dokurno, R. Howes, J. Borgognoni, M.J. Drysdale, H. Finch, R.E.
Hubbard, P.S. Jackson, P. Kierstan, G. Lentzen, J.D. Moore, J.B.
Murray, H. Simmonite, A.E. Surgenor, C.J. Torrance, Bioorg.
Med. Chem. Lett. 17, 3880 (2007)
47. O. Meth-Cohn, Heterocycles 35, 539 (1993)
3
3
3
2. M.F. Ansari, D. Idrees, M.I. Hassan, K. Ahmad, F. Avecilla, A.
Azam, Eur. J. Med. Chem. 144, 544 (2018)
48. G.K. Nagaraja, G.K. Prakash, M.N. Kumaraswamy, V.P. Vaidya,
K.M. Mahadevan, ARKIVOC 15, 160 (2006)
3. H.H. Abdu-Allah, S.G. Abdel-Moty, R. El-Awady, A.N. El-Shorb-
agi, Bioorg. Med. Chem. Lett. 26, 1647 (2016)
49. A. Kedjadja, F. Moussaoui, A. Debache, S. Rhouati, A. Belfaitah,
J. Soc. Alger. Chim. 14, 225 (2004)
4. A.J. Russell, I.M. Westwood, M.H. Crawford, J. Robinson, A.
Kawamura, C. Redꢀeld, N. Laurieri, E.D. Lowe, S.G. Davies, E.
Sim, Bioorg. Med. Chem. 17, 905 (2009)
50. R. Ottana, R. Maccari, M.L. Barreca, G. Bruno, A. Rotondo, A.
Rossi, G. Chiricosta, R. Di Paola, L. Sautebin, S. Cuzzocrea, M.G.
Vigorita, Bioorg. Med. Chem. 13, 4243 (2005)
3
3
5. J.M. Tiang, N.J. Butcher, R.F. Minchin, Biochem. Biophys. Res.
Commun. 393, 95 (2010)
51. P.V. Indukumari, C.P. Joshua, Indian J. Chem. Section B: Organic
Chemistry Including Medicinal Chemistry. 19B, 672 (1980)
52. T. Okawara, K. Nakayama, M. Furukawa, Heterocycles 19, 1571
(1982)
6. N. Ragunathan, J. Dairou, B. Pluvinage, M. Martins, E. Petit, N.
Janel, J.M. Dupret, F. Rodrigues-Lima, Mol. Pharmacol. 73, 1761
(
2008)
53. F. Mushtaque, Md. Avecilla, Z.B. Hafeez, M.M.A. Rizvic, J. Het-
erocycl. Chem. 56, 1794 (2019)
3
3
3
7. K.H. Lu, K.L. Lin, T.C. Hsia, C.F. Hung, M.C. Chou, Y.M. Hsiao,
J.G. Chung, Res. Commun. Mol. Pathol. Pharmacol. 109, 319
54. E.W. Brooke, S.G. Davies, A.W. Mulvaney, F. Pompeo, E. Sim,
R.J. Vickers, Bioorg. Med. Chem. 11, 1227 (2003)
(
2001)
8. J.H. Lee, H.F. Lu, D.Y. Wang, D.R. Chen, C.C. Su, Y.S. Chen,
J.H. Yang, J.G. Chung, Res. Commun. Mol. Pathol. Pharmacol.
55. Glide, version 6.7, Schrodinger, LLC, New York, NY, (2015)
56. Schrodinger release 2015–1: Desmond Molecular Dynamics Sys-
tem, version, 4.1, D.E. Shaw research, New York, NY. (2015)
1
15–116, 217 (2004)
9. Bruker, SAINT PLUS, Bruker AXS Inc., Madison, Wisconsin,
USA, (2012)
1
3