Synthesis and biological evaluation of certain hydrazonoindolin-2-one derivatives as new potent anti-proliferative agents

Article abstract of DOI:10.1080/14756366.2018.1462802

In connection with our research program on the development of novel indolin-2-one-based anticancer candidates, herein we report the design and synthesis of different series of hydrazonoindolin-2-ones 3a-e, 5a-e, 7a-c, and 10a-l. The synthesised derivatives were in vitro evaluated for their anti-proliferative activity towards lung A-549, colon HT-29, and breast ZR-75 human cancer cell lines. Compounds 5b, 5c, 7b, and 10e emerged as the most potent derivatives with average IC₅₀ values of 4.37, 2.53, 2.14, and 4.66 μM, respectively, which are superior to Sunitinib (average IC₅₀ = 8.11 μM). Furthermore, compounds 7b and 10e were evaluated for their effects on cell cycle progression and levels of phosphorylated retinoblastoma (Rb) protein in the A-549 cancer cell line. Moreover, 7b and 10e inhibited the cell growth of the multidrug-resistant lung cancer NCI-H69AR cell line with IC₅₀ = 16 μM. In addition, the cytotoxic activities of 7b and 10e were assessed towards three non-tumorigenic cell lines (Intestine IEC-6, Breast MCF-10A, and Fibroblast Swiss-3t3) where both compounds displayed mean tumor selectivity index (1.6 and 1.8) higher than that of Sunitinib (1.4).

Full text of DOI:10.1080/14756366.2018.1462802

Journal of Enzyme Inhibition and Medicinal Chemistry
ISSN: 1475-6366 (Print) 1475-6374 (Online) Journal homepage: http://www.tandfonline.com/loi/ienz20
Synthesis and biological evaluation of certain
hydrazonoindolin-2-one derivatives as new potent
anti-proliferative agents
Wagdy M. Eldehna, Reem I. Al-Wabli, Maha S. Almutairi, Adam B. Keeton,
Gary A. Piazza, Hatem A. Abdel-Aziz & Mohamed I. Attia
To cite this article: Wagdy M. Eldehna, Reem I. Al-Wabli, Maha S. Almutairi, Adam B.
Keeton, Gary A. Piazza, Hatem A. Abdel-Aziz & Mohamed I. Attia (2018) Synthesis and
biological evaluation of certain hydrazonoindolin-2-one derivatives as new potent anti-
proliferative agents, Journal of Enzyme Inhibition and Medicinal Chemistry, 33:1, 867-878, DOI:
10.1080/14756366.2018.1462802
To link to this article: https://doi.org/10.1080/14756366.2018.1462802
© 2018 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
Group.
Published online: 30 Apr 2018.
Submit your article to this journal
Article views: 17
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at
http://www.tandfonline.com/action/journalInformation?journalCode=ienz20

JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
2018, VOL. 33, NO. 1, 867–878
https://doi.org/10.1080/14756366.2018.1462802
RESEARCH PAPER
Synthesis and biological evaluation of certain hydrazonoindolin-2-one derivatives
as new potent anti-proliferative agents
Wagdy M. Eldehnaa, Reem I. Al-Wablib, Maha S. Almutairib, Adam B. Keetonc, Gary A. Piazzac,
Hatem A. Abdel-Azizd and Mohamed I. Attiab,e
b
aDepartment of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt; Department of Pharmaceutical
c
Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia; Department of Oncologic Sciences and Pharmacology, Drug
d
Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA; Department of Applied Organic Chemistry,
e
National Research Centre, Giza, Egypt; Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research
Division, National Research Centre (ID: 60014618), Giza, Egypt
ABSTRACT
ARTICLE HISTORY
Received 25 February 2018
Revised 22 March 2018
Accepted 3 April 2018
In connection with our research program on the development of novel indolin-2-one-based anticancer
candidates, herein we report the design and synthesis of different series of hydrazonoindolin-2-ones 3a-e,
5a-e, 7a-c, and 10a-l. The synthesised derivatives were in vitro evaluated for their anti-proliferative activity
towards lung A-549, colon HT-29, and breast ZR-75 human cancer cell lines. Compounds 5b, 5c, 7b, and
10e emerged as the most potent derivatives with average IC50 values of 4.37, 2.53, 2.14, and 4.66 mM,
respectively, which are superior to Sunitinib (average IC50 ¼ 8.11 mM). Furthermore, compounds 7b and
10e were evaluated for their effects on cell cycle progression and levels of phosphorylated retinoblastoma
(Rb) protein in the A-549 cancer cell line. Moreover, 7b and 10e inhibited the cell growth of the multi-
drug-resistant lung cancer NCI-H69AR cell line with IC50 ¼ 16 mM. In addition, the cytotoxic activities of 7b
and 10e were assessed towards three non-tumorigenic cell lines (Intestine IEC-6, Breast MCF-10A, and
Fibroblast Swiss-3t3) where both compounds displayed mean tumor selectivity index (1.6 and 1.8) higher
than that of Sunitinib (1.4).
KEYWORDS
Synthesis; indolin-2-one;
retinoblastoma (Rb) protein;
multidrug resistant cancer
cell lines; cell cycle
progression
Introduction
clinically available cancer chemotherapeutic agents aroused the
necessity to search for newer more potent and safer cancer che-
motherapeutic candidates2,3. Subsequently, there is an urgent
need to pay much attention to modify and update drug leads
from the point of view of medicinal chemistry and drug design to
fulfill more effective and potent anticancer agents.
Cancer is a major health burden worldwide and it is deemed to
be the second leading cause of mankind mortality after cardiovas-
cular diseases. Most of the clinically available anticancer chemo-
therapeutic agents are not able to discriminate between cancer
cells and the rapidly dividing healthy cells1. Moreover, the growing
Isatin (1H-indole-2,3-dione) is a privileged scaffold that is pre-
increase in drug resistance and undesired side effects of the sent endogenously in both human and other mammalian fluids
CONTACT Wagdy M. Eldehna
Egypt; Mohamed I. Attia mattia@ksu.edu.sa
wagdy2000@gmail.com
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh,
Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
ß 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.

868
W. M. ELDEHNA ET AL.
and tissues, in addition to its presence in diverse naturally occur- multikinase inhibitor that targets VEGFR-1, VEGFR-2, PDGFRb, and
ring components such as marine natural products and alkaloids4. c-Kit.
Recently, our research group has paid much attention to
develop many novel small molecules based on the indolin-2-one
Isatin constitutes a leading class of heterocycles that is endowed
with interesting biological activities4–8, chiefly anticancer activity.
R
Nintedanib (OfevV) I (Figure 1), an orally available triple angioki- core as potent anticancer agents14–22. In 2017, we reported two
nase inhibitor, is approved in Europe in combination with doce- studies14,15 regarding development of hydrazonoindolin-2-one-
taxel for patients with advanced non-small cell lung cancer of based derivatives and evaluation of their anti-proliferative activity
adenocarcinoma who have progressed to first-line chemotherapy9. against A549 (lung), HT-29 (colon), and ZR-75 (breast) human can-
Currently, Nintedanib is being investigated in patients with various cer cell lines, beside evaluation of their pro-apoptotic activity. In
solid tumors including phase III studies in colorectal cancer10,11 the first study14, a series of hydrazonoindolin-2-ones were synthe-
R
and phase I studies in breast cancer12. Sunitinib (SutentV) II sized with general structure of III [3-((-benzylidene)hydrazono)in-
(Figure 1), a 5-fluoro-3-substituted isatin derivative, has been dolin-2-one] (Figure 2). The SAR study concerning compounds III
approved by the FDA for the treatment of gastrointestinal stromal suggested that incorporation of lipophilic groups, as methoxy
tumors (GIST) and advanced renal cell carcinoma (RCC)13. It is a groups, enhances the anti-proliferative activity. Regarding the
O
N
N
N
O
N
F
N
H
NH
O
HN
O
O
N
H
O
N
H
Nintedanib I
Sunitinib II
Figure 1. Structures of the isatin-based approved anticancer drugs; Nintedanib I and Sunitinib II.
O
Large lipophilic
groups
R1
N
O
N
R
N
H
3a-e; R
1 = Me, OMe
R1
Lipophilic groups
improved
R
the activity
Bioisosteres of
Y
aryl group
Z
N
N
X
N
R
N
R
O
O
N
H
N
H
III
5a-e; X = S, Y = N, Z = CH, R1 = H or Me
7a-c
; X = NH, Y = CH, Z = N, R1 = H
Hybridization with
different heterocycles
is an efficient
approach to improve
the activity
Ar
Ar
Hybridization
with
arylthiazoles
N
N
N
S
NH
O
N
NH
O
N
R
R
N
N
H
H
IV
10a-l
Figure 2. Structures of some reported hydrazonoindoline-2-ones III & IV, and the target derivatives 3a-e, 5a-e, 7a-c, and 10a-l.

JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
869
second study15, we adopted the molecular hybridisation approach methyl alcohol (30 ml) containing catalytic amount of glacial acetic
to design and synthesise four different sets of isatin-quinazoline, acid was refluxed for 4 h, and then cooled to room temperature.
isatin-phthalazine, and isatin-quinoxaline hybrids, where phthala- The precipitates formed were collected by filtration, dried and
zine hybrids IV (Figure 2) emerged as the most active anti-prolif- crystallised from EtOH/DMF to afford compounds 3a-e, 5a-e, and
erative series in this study.
7a-c, respectively.
Based on the aforementioned findings and in connection with
our research program on the development of indolin-2-one-based
anticancer candidates14–22, it was thought worthwhile to extend
our investigations to probe certain hydrazonoindolin-2-ones dis-
playing promising anti-proliferative activity. In this study, we
reported the design and synthesis of different series of hydrazo-
noindolin-2-ones 3a-e, 5a-e, 7a-c, and 10a-l, adopting three dis-
tinctive strategies to develop such derivatives (Figure 2). The first
one focused on grafting of large lipophilic ester or acetyl groups
on the pendant phenyl ring of lead structure III to furnish target
compounds 3a-e (Figure 2). In the second strategy, a bioisosteric
tactic was utilised to replace the pendant substituted phenyl ring
in compounds 3a-e with 2-thiazolyl ring, as in compounds 5a-e,
or 5-pyrazolyl ring, as in compounds 7a-c (Figure 2), to carry out
further elaboration of the hydrazonoindolin-2-ones scaffold and to
investigate a valuable SAR. Finally, the hybridisation approach was
adopted to conjugate 4-arylthiazoles with indolin-2-one moiety,
compounds 10a-l (Figure 2).
3-((4-Acetylbenzylidene)hydrazono)indolin-2-one (3a). Yield 73%,
m.p. 228–230 ꢀC; IR (KBr, ꢀ cmꢁ1): 3184 (NH), 1722 and 1660
(2 ꢂ C¼O), 1616 (C¼N); 1H NMR (DMSO-d6) d: 2.64 (s, 3H, CH3),
6.91 (d, J ¼ 7.5 Hz, 1H, H-7 isatin), 7.03 (t, J ¼ 7.5 Hz, 1H, H-5 isatin),
7.42 (t, J ¼ 7.5 Hz, 1H, H-6 isatin), 7.80 (d, J ¼ 7.5 Hz, 1H, H-4 isatin),
8.04–8.14 (m, 4H, of 4-COCH3-C6H4), 8.64 (s, 1H, –CH¼N), 10.91 (s,
1H, NH); 13C NMR (DMSO-d6) d: 27.4 (CH3), 111.5, 116.7, 122.9,
129.1, 129.2, 129.3, 129.4, 134.5, 137.7, 139.4, 145.7, 150.4, 158.3,
164.8 (C¼O), 198.1 (C¼O); MS m/z: 291 [Mþ]; Anal. Calcd for
C17H13N3O2 (291.30): C, 70.09; H, 4.50; N, 14.42; Found C, 69.88; H,
4.56; N, 14.51.
Methyl
4-(((2-oxoindolin-3-ylidene)hydrazono)methyl)benzoate
(3b). Yield 70%, m.p. 225–227 ꢀC; IR (KBr, ꢀ cmꢁ1): 3275 (NH), 1724
and 1675 (2 ꢂ C¼O), 1612 (C¼N); 1H NMR (DMSO-d6) d: 3.91 (s,
3H, CH3), 6.92 (d, J ¼ 8.0 Hz, 1H, H-7 isatin), 7.01 (t, 1H, H-5 isatin,
J ¼ 8.0 Hz), 7.41 (t, J ¼ 8.0 Hz, 1H, H-6 isatin), 7.51 (d, J ¼ 7.5 Hz, 1H,
H-4 isatin), 8.09–8.13 (m, 4H, of 4-COOCH3-C6H4), 8.65 (s, 1H,
–CH¼N), 11.00 (s, 1H, NH); 13C NMR (DMSO-d6) d: 53.1 (COOCH3),
116.2, 123.1, 128.8, 129.5, 130.4, 134.9, 137.4, 138.1 (2C), 145.2,
145.5, 150.4, 158.5, 164.10, 164.9, 166.1 (C¼O); MS m/z: 307 [Mþ];
Anal. Calcd for C17H13N3O3 (307.30): C, 66.44; H, 4.26; N, 13.67;
Found C, 66.69; H, 4.21; N, 13.52.
The synthesised hydrazonoindolin-2-ones (3a-e, 5a-e, 7a-c, and
10a-l) were in vitro evaluated for their anti-proliferative activity
towards three human cancer cell lines, namely lung cancer A-549,
human colon cancer HT-29, and breast cancer ZR-75 cell lines.
Furthermore, the most active anti-proliferative congeners were fur-
ther evaluated for their effects on cell cycle progression and levels
of phosphorylated retinoblastoma (Rb) protein in the A-549 cancer
cells. In addition, their effect on multidrug-resistant lung cancer
NCI-H69AR cell line was assessed. Finally, the cytotoxic activities of
Methyl 4-(((5-chloro-2-oxoindolin-3-ylidene)hydrazono)methyl)ben-
the active members were assessed towards three non-tumorigenic zoate (3c). Yield 65%, m.p. 266–268ꢀC; IR (KBr, ꢀ cmꢁ1): 3215 (NH),
1
cell lines (Intestine IEC-6, Breast MCF-10A, and Fibroblast Swiss 1734 and 1680 (2 ꢂ C¼O), 1616 (C¼N); H NMR (DMSO-d6) d: 3.91
3t3) to estimate their selectivity for tumor cells.
(s, 3H, CH3), 6.94 (d, J ¼ 8.0 Hz, 1H, H-7 isatin), 7.49 (d, J ¼ 8.0 Hz,
1H, H-6 isatin), 7.74 (s, 1H, H-4 isatin), 8.08–8.15 (m, 4H, of 4-
COOCH3-C6H4), 8.68 (s, 1H, –CH¼N), 11.06 (s, 1H, NH); 13C NMR
Materials and methods
(DMSO-d6) d: 52.9 (COOCH3), 113.1, 117.6, 126.4, 128.4, 129.4, 130.5,
132.8, 133.9, 134.4, 137.7, 144.4, 149.8, 159.3, 163.8, 164.5, 166.1
(C¼O); MS m/z: 341 [Mþ]; Anal. Calcd for C17H12ClN3O3 (341.75): C,
59.75; H, 3.54; N, 12.30; Found C, 60.02; H, 3.49; N, 12.18.
Chemistry
Melting points were measured with a Stuart melting point appar-
atus (Bibby Scientific Limited, Staffordshire, UK) and were uncor-
rected. Mass spectra were recorded using Agilent Quadrupole
6120 LC/MS with ESI (Electrospray ionisation) source (Agilent
Technologies, Palo Alto, CA). NMR spectra were recorded on a
3-((4-Acetylbenzylidene)hydrazono)-5-bromoindolin-2-one
(3d).
Yield 80%, m.p. 270–272 ꢀC; IR (KBr, ꢀ cmꢁ1): 3178 (NH), 1751 and
1718 (2 ꢂ C¼O), 1612 (C¼N); 1H NMR (DMSO-d6) d: 2.65 (s, 3H,
CH3), 6.88 (d, J ¼ 8.0 Hz, 1H, H-7 isatin), 7.59 (d, J ¼ 7.5 Hz, 1H, H-6
isatin), 7.89 (s, 1H, H-4 isatin), 8.07 (d, J ¼ 8.0 Hz, 2H, H-2 and H-6
of 4-COCH3-C6H4), 8.14 (d, J ¼ 8.5 Hz, 2H, H-3 and H-5 of 4-COCH3-
C6H4), 8.67 (s, 1H, –CH¼N), 11.06 (s, 1H, NH); 13C NMR (DMSO-d6)
d: 27.5 (CH3), 113.5, 113.9, 118.3, 129.3, 129.5, 131.2, 136.6, 137.5,
139.5, 144.8, 145.9, 149.1, 159.4, 164.3 (C¼O), 198.1 (C¼O); MS m/
z: 370 [Mþ]; Anal. Calcd for C17H12BrN3O2 (370.20): C, 55.15; H,
3.27; N, 11.35; Found C, 54.89; H, 3.33; N, 11.49.
1
Bruker NMR spectrometer (Bruker, Karlsruhe, Germany). H spectra
were run at 500 MHz and 13C spectra were run at 125 MHz in deu-
terated dimethyl sulfoxide (DMSO-d6). Chemical shifts are
expressed in values d (ppm) using the solvent peak as internal
standard. All coupling constant (J) values are given in Hertz. The
abbreviations used are: “s” for singlet, “d” for doublet, and “m” for
multiplet. Elemental analyses were carried out at the Regional
Center for Microbiology and Biotechnology, Al-Azhar University,
Cairo, Egypt. Analytical thin layer chromatography (TLC) on silica
gel plates containing UV indicator was employed routinely to fol-
low the course of reactions and to check the purity of products.
All reagents and solvents were purified and dried by stand-
ard techniques.
Methyl 4-(((5-bromo-2-oxoindolin-3-ylidene)hydrazono)methyl)ben-
zoate (3e). Yield 85%, m.p. 283–285 ꢀC; IR (KBr, ꢀ cmꢁ1): 3157
1
(NH), 1705 and 1685 (2 ꢂ C¼O), 1618 (C¼N); H NMR (DMSO-d6) d:
3.91 (s, 3H, CH3), 6.89 (d, J ¼ 8.5 Hz, 1H, H-7 isatin), 7.60 (dd,
J ¼ 8.5, 2.0 Hz, 1H, H-6 isatin), 7.86 (d, J ¼ 2.0 Hz, 1H, H-4 isatin),
8.08 (d, J ¼ 8.5 Hz, 2H, H-2 and H-6 of 4-COOCH3-C6H4), 8.15 (d,
J ¼ 8.0 Hz, 2H, H-3 and H-5 of 4-COOCH3-C6H4), 8.67 (s, 1H,
General procedure for the synthesis of hydrazones 3a-e, 5a-e,
and 7a-c
A mixture of equimolar quantities of previously reported hydra- –CH¼N), 11.07 (s, 1H, NH); 13C NMR (DMSO-d6) d: 52.9 (COOCH3),
zones 1a-c19 (2 mmol) and aldehydes 2a,b, 4a,b, or 6 (2 mmol) in 113.5, 113.9, 118.3, 129.3 (2 ꢂ C), 130.4 (2 ꢂ C), 131.2, 132.7, 136.6,

870
W. M. ELDEHNA ET AL.
137.7, 144.8, 149.6, 159.0, 164.3, 166.1 (C¼O); MS m/z: 386 [Mþ]; J ¼ 7.5 Hz, 1H, H-6 isatin), 7.51 (d, J ¼ 7.5 Hz, 1H, H-4 isatin),
Anal. Calcd for C17H12BrN3O3 (386.20): C, 52.87; H, 3.13; N, 10.88;
Found, 53.10; H, 3.08; N, 10.72.
7.96–8.00 (m, 1H, Ar-H), 8.55 (s, 1H, –CH¼N), 11.01 (s, 1H, NH),
13.54 (s, 1H, NH); 13C NMR (DMSO-d6) d: 102.9, 111.2, 118.6, 122.8,
123.0, 131.7, 134.9, 142.0, 145.4, 145.9, 156.3, 165.0 (C¼O); MS m/z:
239 [Mþ]; Anal. Calcd for C12H9N5O (239.23): C, 60.25; H, 3.79; N,
3-(((4-Methylthiazol-2-yl)methylene)hydrazono)indolin-2-one (5a).
Yield 70%, m.p. 238–240 ꢀC; IR (KBr, ꢀ cmꢁ1): 3199 (NH), 1732
29.27; Found C, 60.07; H, 3.82; N, 29.39.
(C¼O), 1614 (C¼N); 1H NMR (DMSO-d6) d: 2.45 (s, 3H, CH3), 6.91
(dd, J ¼ 7.5, 3.5 Hz, 1H, H-7 isatin), 7.03 (t, J ¼ 7.5 Hz, 1H, H-5 isatin),
3-(((1H-pyrazol-5-yl)methylene)hydrazono)-5-chloroindolin-2-one
(7b). Yield 77%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3221 (NH), 1735
(C¼O), 1620 (C¼N); 1H NMR (DMSO-d6) d: 6.90 (d, J ¼ 9.0 Hz, 1H,
Ar-H), 6.94 (d, J ¼ 8.0 Hz, 1H, Ar-H), 7.46 (dd, J ¼ 8.0, 2.5 Hz, 1H, Ar-
H), 7.74 (d, J ¼ 2.5 Hz, 1H, Ar-H), 7.96 (d, J ¼ 8.0 Hz, 1H, Ar-H), 8.59
(s, 1H, –CH¼N), 11.00 (s, 1H, NH), 13.17 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 103.0, 112.5, 118.9, 125.7, 127.5, 135.9, 137.1, 140.5,
144.7, 147.1, 157.1, 164.2 (C¼O); MS m/z: 273 [Mþ]; Anal. Calcd for
C12H8ClN5O (273.68): C, 52.66; H, 2.95; N, 25.59; Found C, 52.43; H,
3.00; N, 25.75.
7.42 (d ꢂ t, J ¼ 8.0, 3.5 Hz, 1H, H-6 isatin), 7.68 (s, 1H, H-5 thiazole),
7.75 (d, J ¼ 7.5 Hz, 1H, H-4 isatin), 8.69 (s, 1H, –CH¼N), 10.93 (s, 1H,
NH); 13C NMR (DMSO-d6) d: 17.2 (CH3), 111.6, 116.6, 120.0, 122.9,
129.3, 134.8, 145.9, 151.0, 153.3, 155.4, 162.5, 164.6 (C¼O); MS m/z:
270 [Mþ]; Anal. Calcd for C13H10N4OS (270.31): C, 57.76; H, 3.73; N,
20.73; Found C, 57.65; H, 3.75; N, 20.68.
5-Chloro-3-((thiazol-2-ylmethylene)hydrazono)indolin-2-one
(5b).
Yield 75%, m.p. 293–295 ꢀC; IR (KBr, ꢀ cmꢁ1): 3217 (NH), 1722
(C¼O), 1614 (C¼N); 1H NMR (DMSO-d6) d: 6.93 (d, J ¼ 8.5 Hz, 1H,
H-7 isatin), 7.49–755 (m, 2H, Ar-H), 7.79 (s, 1H, H-4 isatin), 8.19 (d,
J ¼ 3.0 Hz, 1H, Ar-H), 8.82 (s, 1H, –CH¼N), 11.08 (s, 1H, NH); 13C
NMR (DMSO-d6) d: 113.2, 117.6, 125.9, 126.5, 128.4, 134.1, 144.7,
146.0, 150.9, 154.9, 163.2, 164.4 (C¼O); MS m/z: 290 [Mþ]; Anal.
Calcd for C12H7ClN4OS (290.73): C, 49.57; H, 2.43; N, 19.27; Found
C, 49.70; H, 2.48; N, 19.16.
3-(((1H-pyrazol-5-yl)methylene)hydrazono)-5-bromoindolin-2-one
(7c). Yield 85%, m.p. 264–266 ꢀC; IR (KBr, ꢀ cmꢁ1): 3209 (NH), 1734
(C¼O), 1612 (C¼N); 1H NMR (DMSO-d6) d: 6.82 (d, J ¼ 8.5 Hz, 1H,
Ar-H), 6.87 (d, J ¼ 8.0 Hz, 1H, Ar-H), 7.58 (d, J ¼ 8.5 Hz, 1H, Ar-H),
7.94 (s, 1H, Ar-H), 8.10 (d, J ¼ 8.0 Hz, 1H, Ar-H), 8.60 (s, 1H, –CH¼N),
11.04 (s, 1H, NH), 13.62 (s, 1H, NH); 13C NMR (DMSO-d6) d: 104.76,
113.28, 118.65, 122.19, 127.95, 131.43, 136.39, 144.51, 147.30,
150.39, 156.64, 164.61 (C¼O); MS m/z: 318 [Mþ]; Anal. Calcd for
C12H7brN5O (318.13): C, 45.31; H, 2.53; N, 22.01; Found C, 45.49; H,
2.55; N, 21.86.
5-Chloro-3-(((4-methylthiazol-2-yl)methylene)hydrazono)indolin-2-
one (5c). Yield 77%, m.p. 290–292 ꢀC; IR (KBr, ꢀ cmꢁ1): 3230 (NH),
1718 (C¼O), 1614 (C¼N); 1H NMR (DMSO-d6) d: 2.45 (s, 3H, CH3),
6.90 (d, J ¼ 8.0Hz, 1H, H-7 isatin), 7.61 (d, J ¼ 8.0, 2.0Hz, 1H, H-6 isa-
tin), 7.75 (s, 1H, H-5 thiazole), 7.81 (s, 1H, H-4 isatin), 8.73 (s, 1H,
–CH¼N), 11.10 (s, 1H, NH); 13C NMR (DMSO-d6) d: 17.2 (CH3), 113.1,
117.6, 120.6, 126.4, 128.4, 128.9, 134.1, 144.7, 146.3, 155.1, 162.2,
164.4 (C¼O); MS m/z: 304 [Mþ]; Anal. Calcd for C13H9ClN4OS
(304.75): C, 51.23; H, 2.98; N, 18.38; Found C, 51.39; H, 3.03; N, 18.23.
General procedure for the synthesis of thiazoles 10a-l
A
mixture of previously reported thiosemicarbazones 8a-c23
(2 mmol) and bromoethanones (9a-d) (2 mmol) in absolute ethanol
(20 ml) was heated under reflux for 3 h, then left to cool. The pre-
cipitated solid was collected by filtration, washed with ethanol,
dried and recrystallised from EtOH/DMF to yield the corresponding
thiazole derivatives 10a-l, respectively. Compounds 10a-e and
5-Bromo-3-((thiazol-2-ylmethylene)hydrazono)indolin-2-one
(5d).
Yield 83%, m.p. 260–262 ꢀC; IR (KBr, ꢀ cmꢁ1): 3236 (NH), 1718
(C¼O), 1612 (C¼N); 1H NMR (DMSO-d6) d: 6.89 (d, J ¼ 8.0 Hz, 1H,
H-7 isatin), 7.61 (d, J ¼ 8.5 Hz, 1H, H-6 isatin), 7.93 (s, 1H, H-4 isa-
tin), 8.16 (d, J ¼ 3.0 Hz, 1H, H-5 thiazole), 8.20 (d, J ¼ 3.0 Hz, 1H, H-4
thiazole), 8.81 (s, 1H, –CH¼N), 11.08 (s, 1H, NH); 13C NMR (DMSO-
d6) d: 118.3, 125.9, 130.4, 131.7, 136.9, 145.1, 145.3, 146.1, 150.9,
154.9, 163.2, 164.2 (C¼O); MS m/z: 335 [Mþ]; Anal. Calcd for
C12H7BrN4OS (335.18): C, 43.00; H, 2.11; N, 16.72; Found C, 42.79;
H, 2.14; N, 16.85.
10g-l24–29
.
3–(2-(4-Phenylthiazol-2-yl)hydrazono)indolin-2-one (10a). Yield
70%, m.p. 275–277 ꢀC; IR (KBr, ꢀ cmꢁ1): 3136 (NH), 1707 (C¼O),
1616 (C¼N); 1H NMR (DMSO-d6) d:6.96 (dd, J ¼ 8.0, 3.5 Hz, 1H, H-7
isatin), 7.09 (t, J ¼ 7.5 Hz, 1H, H-5 isatin), 7.30–7.54 (m, 6H, Ar-H),
7.64 (s, 1H, H-5 thiazole), 7.89 (d, J ¼ 7.5 Hz, 1H, H-4 isatin), 11.26
(s, 1H, NH), 13.32 (s, 1H, NH); 13C NMR (DMSO-d6) d: 107.3, 111.6,
119.9, 120.4, 121.8, 122.9, 126.0, 128.5, 129.2, 130.9, 132.6, 134.4,
141.8, 148.8, 151.5, 163.7, 166.5 (C¼O); MS m/z: 320 [Mþ]; Anal.
Calcd for C17H12N4OS (320.37) C, 63.73; H, 3.78; N, 17.49; Found, C,
63.91; H, 3.81; N, 17.49.
5-Bromo-3-(((4-methylthiazol-2-yl)methylene)hydrazono)indolin-2-
one (5e). Yield 80%, m.p. 248–250 ꢀC; IR (KBr, ꢀ cmꢁ1): 3138 (NH),
1735 (C¼O), 1612 (C¼N); 1H NMR (DMSO-d6) d: 2.46, 2.48 (2s, 3H,
CH3), 6.88 (d, J ¼ 8.0 Hz, 1H, H-7 isatin), 7.60 (dd, J ¼ 8.0, 2.0 Hz, 1H,
H-6 isatin), 7.72, 7.83 (2s, 1H, H-5 thiazole), 7.90, 7.94 (2d,
J ¼ 2.0 Hz, 1H, H-4 isatin), 8.53, 8.75 (2 ꢂ s, 1H, –CH¼N), 11.07,
11.11 (2 ꢂ s, 1H, NH); 13C NMR (DMSO-d6) d: 16.9, 17.2 (2 ꢂ CH3),
113.6, 114.1, 115.7, 118.0, 118.4, 120.6, 121.4, 130.9, 131.7, 132.4,
3–(2-(4–(4-Tolyl)thiazol-2-yl)hydrazono)indolin-2-one (10b). Yield
67%, m.p. 284–286 ꢀC; IR (KBr, ꢀ cmꢁ1): 3315 (NH), 1707 (C¼O),
1612 (C¼N); 1H NMR (DMSO-d6) d: 2.38 (s, 3H, CH3), 6.96 (dd,
135.4, 136.8, 136.9, 144.8, 145.0, 150.9, 152.3, 154.9 155.1, 155.6, J ¼ 8.0, 3.5 Hz, 1H, H-7 isatin), 7.08 (t, J ¼ 7.5 Hz, 1H, H-5 isatin),
162.2, 164.1, 164.2 (C¼O); MS m/z: 349 [Mþ]; Anal. Calcd for
C13H9BrN4OS (349.21): C, 44.71; H, 2.60; N, 16.04; Found C, 44.90;
H, 2.54; N, 16.15.
7.20–7.38 (m, 3H, Ar-H), 7.53 (d, J ¼ 8.0 Hz, 1H, H-4 isatin), 7.68 (s,
1H, H-5 thiazole), 7.79 (d, J ¼ 8.5 Hz, 2H, H-2 and H-6 of 4-CH3-
C6H4), 11.26 (s, 1H, NH), 13.33 (s, 1H, NH); 13C NMR (DMSO-d6) d:
21.3 (CH3), 119.9, 120.3, 121.8, 122.9, 126.1, 128.3, 129.5, 129.8,
130.6, 130.9, 131.8, 132.5, 137.8, 141.75, 151.5, 163.5, 166.4 (C¼O);
MS m/z: 334 [Mþ]; Anal. Calcd for C18H14N4OS (334.39): C, 64.65; H,
3-(((1H-pyrazol-5-yl)methylene)hydrazono)indolin-2-one (7a). Yield
74%, m.p. 283–285 ꢀC; IR (KBr, ꢀ cmꢁ1): 3215 (NH), 1708 (C¼O),
1
1618 (C¼N); H NMR (DMSO-d6) d: 6.93–7.05 (m, 3H, Ar-H), 7.39 (t, 4.22; N, 16.75; Found, C, 64.43; H, 4.24; N, 16.87.

JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
871
3–(2-(4–(4-Chlorophenyl)thiazol-2-yl)hydrazono)indolin-2-one (10c). 1H, H-7 isatin), 7.37 (dd, J ¼ 8.5, 2.0 Hz, 1H, H-6 isatin), 7.53 (d,
Yield 73%, m.p. 295–297 ꢀC; IR (KBr, ꢀ cmꢁ1): 3257 (NH), 1693 J ¼ 2.0 Hz, 1H, H-4 isatin), 7.61 (d, J ¼ 8.5 Hz, 2H, H-3 and H-5 of 4-
(C¼O), 1618 (C¼N); 1H NMR (DMSO-d6) d: 6.95 (d, J ¼ 7.5 Hz, 1H,
H-7 isatin), 7.06 (t, J ¼ 7.5 Hz, 1H, H-5 isatin), 7.32 (t, J ¼ 7.5 Hz, 1H,
H-6 isatin,), 7.45 (d, J ¼ 8.5 Hz, 2H, H-3 and H-5 of 4-Cl-C6H4), 7.51
(d, J ¼ 8.0 Hz, 1H, H-4 isatin), 7.67 (s, 1H, H-5 thiazole), 7.90 (d,
J ¼ 8.5 Hz, 2H, H-2 and H-6 of 4-Cl-C6H4), 11.24 (s, 1H, NH), 13.33
(s, 1H, NH); 13C NMR (DMSO-d6) d: 107.9, 111.5, 120.2, 120.3, 122.9,
127.8, 127.9, 128.9, 129.1, 130.1, 130.9, 132.7, 133.3, 141.8, 150.3,
163.6, 166.7 (C¼O); MS m/z: 354 [Mþ]; Anal. Calcd for
C17H11ClN4OS (354.81) C, 57.55; H, 3.12; N, 15.79; Found, C, 57.76;
H, 3.17; N, 15.66.
Br-C6H4), 7.75 (s, 1H, H-5 thiazole), 7.85 (d, J ¼ 8.5 Hz, 2H, H-2 and
H-6 of 4-Br-C6H4), 11.37 (s, 1H, NH), 13.34 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 108.5, 113.1, 120.0, 121.9, 122.0, 126.7, 128.1, 128.3,
130.6, 131.2, 132.1, 132.3, 133.6, 140.4, 150.4, 163.5, 166.7 (C¼O);
MS m/z: 433 [Mþ]; Anal. Calcd for C17H10BrClN4OS (433.71) C,
47.08; H, 2.32; N, 12.92; Found, C, 46.87; H, 2.29; N, 13.11.
5-Bromo-3–(2-(4-phenylthiazol-2-yl)hydrazono)indolin-2-one (10i).
Yield 83%, m.p. 285–287 ꢀC; IR (KBr, ꢀ cmꢁ1): 3169 (NH), 1685
1
(C¼O), 1614 (C¼N); H NMR (DMSO-d6) d:6.91 (d, J ¼ 8.0 Hz, 1H, H-7
isatin), 7.42–7.84 (m, 6H, Ar-H), 7.90 (d, J ¼ 8.0Hz, 1H, Ar-H), 8.53 (d,
J ¼ 8.0 Hz, 1H, H-4 isatin), 11.37 (s, 1H, NH), 13.32 (s, 1H, NH); 13C
NMR (DMSO-d6) d: 107.8, 112.0, 113.5, 114.7, 122.4, 122.5, 126.1,
128.5, 129.2, 129.4, 131.3, 133.1, 134.4, 140.7, 151.6, 163.3, 166.3
(C¼O); MS m/z: 399 [Mþ]; Anal. Calcd for C17H11BrN4OS (399.26) C,
51.14; H, 2.78; N, 14.03; Found, C, 51.37; H, 2.72; N, 13.88.
3–(2-(4–(4-Bromophenyl)thiazol-2-yl)hydrazono)indolin-2-one
(10d). Yield 75%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3259 (NH), 1689
1
(C¼O), 1618 (C¼N); H NMR (DMSO-d6) d: 6.95 (d, J ¼ 7.5 Hz, 1H, H-7
isatin), 7.09 (t, J¼ 7.5 Hz, 1H, H-5 isatin), 7.33 (t, J ¼ 7.5 Hz, 1H, H-6
isatin), 7.52 (d, J ¼ 7.5 Hz, 1H, H-4 isatin), 7.60 (d, J ¼ 8.0 Hz, 2H, H-3
and H-5 of 4-Br-C6H4), 7.68 (s, 1H, H-5 thiazole), 7.84 (d, J¼ 8.5 Hz,
2H, H-2 and H-6 of 4-Br-C6H4), 11.25 (s, 1H, NH), 13.34 (s, 1H, NH);
13C NMR (DMSO-d6) d: 108.1, 111.5, 120.2, 120.4, 121.5, 122.9, 128.0,
128.2, 131.0, 131.9, 132.1, 132.7, 133.6, 141.8, 150.3, 163.7, 166.2
(C¼O); MS m/z: 399 [Mþ]; Anal. Calcd for C17H11BrN4OS (399.26) C,
51.14; H, 2.78; N, 14.03; Found, C, 50.89; H, 2.81; N, 14.14.
5-Bromo-3–(2-(4–(4-tolyl)thiazol-2-yl)hydrazono)indolin-2-one (10j).
Yield 80%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3157 (NH), 1685 (C¼O),
1618 (C¼N); 1H NMR (DMSO-d6) d: 2.38, 2.39 (2s, 3H, CH3), 6.80,
6.92 (2 ꢂ d, J ¼ 8.0 Hz, 1H, H-7 isatin), 7.18, 7.24 (2 ꢂ d, J ¼ 7.5 Hz,
2H, H-3 and H-5 of 4-CH3-C6H4), 7.41, 7.49 (2 ꢂ dd, J ¼ 8.0, 2.0 Hz,
1H, H-6 isatin), 7.59 (s, 1H, H-5 thiazole), 7.63, 8.52 (2 ꢂ d,
J ¼ 2.0 Hz, 1H, H-4 isatin), 7.72, 7.78 (2 ꢂ d, J ¼ 8.0 Hz, 2H, H-2 and
H-6 of 4-CH3-C6H4), 10.62, 11.37 (2s, 1H, NH), 12.97, 13.32 (s, 1H,
NH); 13C NMR (DMSO-d6) d: 21.3 (CH3), 106.9, 113.5, 114.7, 122.4,
122.5, 126.0, 126.1, 129.8, 129.9, 131.2, 131.7, 133.0, 137.9, 140.7,
151.7, 163.3, 166.2 (C¼O); MS m/z: 413 [Mþ]; Anal. Calcd for
C18H13BrN4OS (413.29) C, 52.31; H, 3.17; N, 13.56; Found, C, 52.59;
H, 3.14; N, 13.48.
5-Chloro-3–(2-(4-phenylthiazol-2-yl)hydrazono)indolin-2-one (10e).
Yield 80%, m.p. 292–294 ꢀC; IR (KBr, ꢀ cmꢁ1): 3169 (NH), 1707
1
(C¼O), 1612 (C¼N); H NMR (DMSO-d6) d:6.95 (d, J ¼ 7.5 Hz, 1H, H-
7 isatin), 7.30–7.60 (m, 6H, Ar-H), 7.68 (s, 1H, H-5 thiazole), 7.84 (d,
J ¼ 7.5 Hz, 1H, H-4 isatin), 11.25 (s, 1H, NH), 13.34 (s, 1H, NH); 13C
NMR (DMSO-d6) d: 108.1, 111.5, 120.2, 120.4, 121.5, 122.9, 128.19,
131.0, 132.1, 132.7, 133.6, 141.8, 150.3, 163.7, 166.7 (C¼O); MS m/z:
354 [Mþ]; Anal. Calcd for C17H11ClN4OS (354.81) C, 57.55; H, 3.12;
N, 15.79; Found, C, 57.73; H, 3.07; N, 15.64.
5-Bromo-3–(2-(4–(4-chlorophenyl)thiazol-2-yl)hydrazono)indolin-2-
one (10k). Yield 84%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3159 (NH),
1687 (C¼O), 1614 (C¼N); 1H NMR (DMSO-d6) d: 6.92 (d, J ¼ 8.5 Hz,
1H, H-7 isatin), 7.48–7.57 (m, 4H, Ar-H), 7.64 (s, 1H, H-5 thiazole),
7.92 (d, J ¼ 8.5 Hz, 2H, H-2 and H-6 of 4-Cl-C6H4), 11.37 (s, 1H, NH),
13.32 (s, 1H, NH); 13C NMR (DMSO-d6) d: 108.8, 113.4, 115.1, 122.2,
122.5, 127.9 (2 ꢂ C), 129.2, 129.8, 131.5, 132.9, 133.1, 133.2, 140.9,
150.3, 163.4, 166.5 (C¼O); MS m/z: 433 [Mþ]; Anal. Calcd for
C17H10BrClN4OS (433.71) C, 47.08; H, 2.32; N, 12.92; Found, C,
47.15; H, 2.35; N, 12.81.
5-Chloro-3–(2-(4-(p-tolyl)thiazol-2-yl)hydrazono)indolin-2-one (10f).
Yield 78%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3155 (NH), 1685 (C¼O),
1618 (C¼N); 1H NMR (DMSO-d6) d: 2.38, 2.40 (2s, 3H, CH3), 6.85,
6.97 (2 ꢂ d, J ¼ 8.5 Hz, 1H, H-7 isatin), 7.28–7.38 (m, 3H, Ar-H), 7.52,
7.58 (2s, 1H, H-5 thiazole), 7.71, 7.78 (2 ꢂ d, J ¼ 8.5 Hz, 2H, H-2 and
H-6 of 4-CH3-C6H4), 8.34, 8.41 (2 ꢂ d, J ¼ 2.0 Hz, 1H, H-4 isatin),
10.62, 11.36 (2s, 1H, NH), 13.34 (s, br, 1H, NH); 13C NMR (DMSO-d6)
d: 21.3 (CH3), 106.9, 111.5, 113.0, 119.8, 121.9, 126.0, 126.1, 127.0,
129.8, 129.9, 131.3, 131.7, 137.9, 140.3, 151.6, 163.5, 166.2 (C¼O);
MS m/z: 368 [Mþ]; Anal. Calcd for C18H13ClN4OS (368.84) C, 58.61;
H, 3.55; N, 15.19; Found, C, 58.77; H, 3.51; N, 15.07.
5-Bromo-3–(2-(4–(4-bromophenyl)thiazol-2-yl)hydrazono)indolin-2-
one (10l). Yield 90%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3157 (NH),
1685 (C¼O), 1614 (C¼N); 1H NMR (DMSO-d6) d: 6.93 (d, J ¼ 8.5 Hz,
1H, H-7 isatin), 7.50–7.87 (m, 6H, Ar-H), 8.52 (s, 1H, H-4 isatin),
11.38 (s, 1H, NH), 13.33 (s, 1H, NH); 13C NMR (DMSO-d6) d: 108.7,
113.6, 114.6, 121.7, 122.3, 122.8, 128.1, 128.2, 131.4, 132.1, 133.1,
133.6, 140.9, 142.1, 150.3, 163.4, 166.5 (C¼O); MS m/z: 478 [Mþ];
Anal. Calcd for C17H10Br2N4OS (478.16) C, 42.70; H, 2.11; N, 11.72;
Found, C, 42.52; H, 2.09; N, 11.78.
5-Chloro-3–(2-(4–(4-chlorophenyl)thiazol-2-yl)hydrazono)indolin-2-
one (10g). Yield 85%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3215 (NH),
1695 (C¼O), 1620 (C¼N); 1H NMR (DMSO-d6) d: 6.98 (d, 1H, H-7
isatin, J ¼ 8.5 Hz), 7.37 (dd, J ¼ 8.5, 2.0 Hz, 1H, H-6 isatin), 7.48 (d,
J ¼ 8.5 Hz, 2H, H-3 and H-5 of 4-Cl-C6H4), 7.53 (d, J ¼ 2.0 Hz, 1H, H-
4 isatin), 7.74 (s, 1H, H-5 thiazole), 7.92 (d, J ¼ 8.5 Hz, 2H, H-2 and
H-6 of 4-Cl-C6H4), 11.37 (s, 1H, NH), 13.34 (s, 1H, NH); 13C NMR
(DMSO-d6) d: 108.5, 113.1, 119.8, 121.9, 127.1, 127.8, 127.9, 129.2,
129.5, 130.3, 131.6, 132.3, 133.2, 140.4, 150.3, 163.5, 166.5 (C¼O);
MS m/z: 389 [Mþ]; Anal. Calcd for C17H10Cl2N4OS (389.26): C, 52.45;
H, 2.59; N, 14.39; Found, C, 52.67; H, 2.62; N, 14.53.
Biological evaluation
In vitro anti-proliferative activity. The anti-proliferative activity of
the title compounds 3a-e, 5a-e, 7a-c, and 10a-l towards cancer
cell lines, normal cell lines, and multidrug-resistant lung cancer
NCI-H69AR cell line was determined using CellTiter-GloTM
3–(2-(4–(4-Bromophenyl)thiazol-2-yl)hydrazono)-5-chloroindolin-2-
one (10h). Yield 90%, m.p. >300 ꢀC; IR (KBr, ꢀ cmꢁ1): 3250 (NH), Luminescent cell viability assay according to the previously pub-
1690 (C¼O), 1620 (C¼N); 1H NMR (DMSO-d6) d: 6.97 (d, J ¼ 8.0 Hz, lished procedures14,15
.

872
W. M. ELDEHNA ET AL.
Cell cycle effects. Cell cycle effects of the synthesised compounds accomplished via refluxing indoline-2,3-diones with hydrazine
hydrate in ethanol. Further condensation of hydrazones 1a-c with
7b and 10e were determined adopting the reported procedures14,15
.
benzaldehydes (2a, b), thiazole-2-carbaldehydes (4a, b), or 1H-pyr-
azole-5-carbaldehyde (6) in methyl alcohol in the presence of a
catalytic amount of glacial acetic acid afforded the target deriva-
tives 3a-e, 5a-e, and 7a-c, respectively, in 65–85% yield
(Scheme 1).
Results and discussion
Chemistry
Our proposed synthetic strategy to the target hydrazonoindolin-2-
The assigned structures of compounds 3a-e, 5a-e, and 7a-c
were confirmed by IR, 1H and 13C NMR spectra. Their IR spectra
ones 3a-e, 5a-e, 7a-c, and 10a-l is depicted in Schemes 1 and 2.
The synthesis of the 3-hydrazonoindolin-2-ones 1a-c was showed absorption bands around 3200 cmꢁ1 for the (NH) groups
R1
R1
N
N
O
3
a
b
c
d
e
R
R1
H COMe
H COOMe
Cl COOMe
Br COMe
R
2a,b
O
N
H
3a-e
Br COOMe
R1
N
R1
N
S
N
N
NH2
O
S
4a, b
N
R
R
H
R1
Me
5
O
i
R
a
b
c
d
e
O
Cl H
Cl Me
Br H
N
H
5a-e
N
H
1a-c
Br Me
1
a
b
c
R
H
Cl
Br
HN
N
HN
N
N
N
R
O
6
O
7
R
H
Cl
Br
N
H
7a-c
a
b
c
Scheme 1. Synthesis of the hydrazonoindolin-2-ones 3a-e, 5a-e, and 7a-c. Reagents and conditions: (i) Methanol, glacial acetic acid (cat.), reflux, 4 h.
Ar
10
a
b
c
d
e
f
g
h
i
R
Ar
H
C6H5
S
N
NH2
H
H
H
4-CH3-C6H4
4-Cl-C6H4
4-Br-C 6H4
C6H5
4-CH3-C6H4
4-Cl-C6H4
4-Br-C6H4
C6H5
O
S
NH
Br
N
NH
N
Ar
R
Cl
Cl
Cl
Cl
Br
Br
Br
Br
R
9a-d
O
O
i
N
N
H
H
9
a
b
c
d
Ar
-C6H5
4-CH3 -C6H4
4-Cl-C6H4
4-Br-C6H4
8a-c
10a-l
j
k
l
4-CH3-C6H4
4-Cl-C6H4
4-Br-C6H4
8
a
b
c
R
H
Cl
Br
Scheme 2. Synthesis of thiazoles 10a-l. Reagents and conditions: (i) Ethanol, reflux, 3 h.

JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
873
Table 1. Anti-proliferative (cell growth inhibitory activity at 30 mM concentration)
activity of the target compounds 3a-e, 5a-e, 7a-c, 10a-l, and Sunitinib towards
HT-29, ZR-75, and A-549 cell lines.
of the indolin-2-one moiety, in addition to the absorption bands
1
of (C¼O) groups in the region of 1660–1751 cmꢁ1. H NMR spectra
of compounds 3a-e, 5a-e, and 7a-c revealed the presence of a
singlet signal in the region d 10.93–11.11 corresponding to NH
proton of isatin moiety, in addition to the singlet signal of the
methine (–CH¼N–) proton in the region d 8.55–8.82. Also, com-
pounds 7a-c displayed additional signal attributable to the NH
proton of the pyrazole ring at d 13.17–13.62. Moreover, the 13C
NMR spectra of these compounds displayed signals resonating
around d 164 corresponding to the amidic (C¼O) carbons.
Growth inhibition %
Average growth
inhibition %
Compound No.
A-549
ZR-75
HT-29
3a
3b
3c
3d
3e
5a
5b
5c
5d
5e
7a
7b
7c
10a
10b
12.7 7.1
68.1 2.8
93.5 2.8
17.3 10.2
ꢁ4.2 9.3
2.4 5.0
29.6 24.4
80.6 7.0
98.9 2.1
53.9 14.4
55.9 18.2
40.8 25.7
95.0 8.2
98.0 2.6
96.4 1.5
96.9 2.4
60.1 5.8
82.3 15.2
19.2 22.8
76.9 7.1
62.1 10.7
77.1 10.9
53.8 19.2
89.3 7.2
50.3 33.6
52.8 9.4
9.0 19.2
97.5 3.1
73.1 3.5
50.6 11.5
40.9 16.7
90.7 4.5
53.6 12.2
92.3 3.7
95.9 4.7
56.8 15.1
26.3 24.4
37.9 26.3
96.2 4.5
96.4 4.8
98.5 3.1
99.0 1.1
60.8 13.1
94.9 1.8
28.8 17.3
91.2 8.3
33.9 21.2
85.4 7.0
20.6 26.9
85.7 10.2
54.4 19.5
34.4 23.6
ꢁ8.3 43.8
96.3 5.9
90.1 5.3
66.8 19.1
27.8 4.3
85.7 2.7
32.0
80.3
96.1
42.7
41.1
27.0
94.9
97.7
96.6
97.1
43.0
89.6
26.9
79.6
40.1
64.6
28.9
85.1
44.0
35.4
9.0
On the other hand, the condensation of indoline-2,3-diones
with thiosemicarbazide in refluxing ethanol containing a catalytic
amount of acetic acid yielded the corresponding thiosemicarba-
zones 8a-c. The second targeted isatin-based derivatives 10a-l
were obtained in good yields (67–90%) through the reaction of
the key intermediates 8a-c with the appropriate phenacyl bromide
9a-d in refluxing absolute ethyl alcohol (Scheme 2).
93.6 5.4
98.8 1.5
94.8 2.5
95.3 3.1
8.2 15.1
91.5 1.3
32.8 8.9
70.7 5.7
24.4 14.1
31.4 9.1
12.3 11.3
80.4 6.0
27.4 5.8
18.9 3.2
ꢁ2.6 7.5
92.3 6.2
85.9 9.1
72.4 3.5
ꢁ20.1 5.9
59.5 2.3
IR spectra of the compounds 10a-l displayed the characteristic
absorption bands in the regions 3136–3315 cmꢁ1 and 10c
1685–1707 cmꢁ1 corresponding to the (NH) and (C¼O) groups,
10d
10e
10f
10g
10h
10i
10j
10k
respectively, while their 1H NMR spectra were characterised by the
presence of three singlets in the regions d 11.24–11.38, 13.32–13.36,
and 7.58–7.75 which were assigned to two NH groups and H-5 of
the thiazole ring, respectively. Besides, 13C NMR spectra of these
compounds showed characteristic signals resonating around d 166
which was attributed to (C¼O) carbon. It is worth noting that some
derivatives are existing in E/Z geometrical isomerism in the DMSO-
solution state, such as compounds 5e, 10f, and 10j17.
95.4
83.0
63.3
34.4
78.7
10l
Sunitinib
Table 2. Inhibitory concentration 50% (IC50) of anti-proliferative activity of the
tested compounds 3b-e, 5b-e, 7a, 7b, 10a-k, and Sunitinib toward HT-29, ZR-75,
and A-549 cell lines.
Biological evaluation
In vitro anti-proliferative activity
IC50 (mM)a
The cancer cell growth inhibitory activity of the synthesised 25
compounds 3a-e, 5a-e, 7a-c, and 10a-l was evaluated in vitro
towards three human cancer cell lines, namely lung cancer A-549,
human colon cancer HT-29, and breast cancer ZR-75 cell lines
using CellTiter-GloTM Luminescent cell viability assay30. Sunitinib
was included in this assay as a reference drug.
The prepared hydrazonoindolin-2-ones were first evaluated at
preliminary anti-proliferative assay against the three cancer cell
lines in quadruplicate at a single concentration of 30 mM. The data
presented as percentage growth inhibition (GI%) caused by the
test compounds (Table 1).
The tested hydrazonoindolin-2-ones displayed different levels
of anti-proliferative activity and possessed a distinctive pattern of
selectivity against the tested cancer cell lines with average growth
inhibition in the range of 9.0–97.7%. Close examination of the GI%
values in Table 1, revealed that compounds 3b, 3c, 5b-e, 7b, 10e,
10i, and 10j are the most active analogs in this study, showing
broad spectrum activity toward the tested cell lines with average
GI% values >80%. On the other hand, compounds 3a, 5a, 7c, 10d,
10h, and 10l displayed modest growth inhibitory activity (GI% val-
ues <35%). It is noteworthy to mention that compounds 3e and
10l stimulated the growth of the A-549 cell line and compound
10h stimulated the growth of both A-549 and HT-29 cell lines.
Compound No.
A-549
ZR-75
HT-29
Average IC50 (mM)
3b
4c
4d
3e
5b
5c
11.25 1.45
6.07 0.90
26.09 4.47
NAb
4.87 0.49
2.15 0.23
9.72 2.52 21.05 1.86
14.01
6.25
>28.69
>27.77
4.37
4.20 0.57
NAb
23.33 0.0
2.09 0.12
1.16 0.39
8.49 1.01
NAb
NAb
6.15 0.51
4.29 0.25
2.53
5d
5e
7a
7b
10a
10b
10c
10e
10f
10g
10i
10j
10k
Sunitinib
12.53 1.73 12.68 2.40 15.32 1.93
13.51
7.49
>27.65
2.14
11.07
>28.19
>17.36
4.66
>25.38
>12.65
5.45
3.54 0.42
22.94 3.51
2.29 0.21
9.41 1.29
NAb
17.2 2.56
4.79 0.45
22.72 3.71
6.07 7.41
6.13 0.76
2.93 0.46
8.51
NAb
NAb
1.37 0.23
4.35
24.59
4.89
1.95 1.03
23.41
2.75 0.31
19.44 1.03
NAb
NAb
7.25 0.83
NAb
1.87 0.26
1.96 0.85
NAb
8.26 0.86
12.84 1.40 10.91 2.81 15.22 1.10
12.99
14.49
8.11
20.13 3.81
10.14 0.8
3.61
8.31 2.4
19.75 1.63
5.87 0.3
aIC50 values are the mean SD of four separate experiments.
bNA: Compounds having IC50 value >30 lM.
Investigations of the anti-proliferative activity against A-549
The quantitative inhibitory concentration 50% (IC50) values indicated that compounds 5b, 5c, 5e, 7b, and 10e
were evaluated for the active members that displayed effective (IC50 ¼ 4.87 0.49, 2.15 0.23, 3.54 0.42, 2.29 0.21, and
growth inhibition toward the three cancer cell lines (GI% values 4.79 0.45 mM, respectively) were found to be the most potent
>35%) in the preliminary single high dose (30 mM) screening counterparts as they were 2, 4.7, 2.8, 4.4 and 2.1 times, respect-
(Table 2). From the displayed results in Table 2, it was obvious ively, more active than Sunitinib (IC50 ¼ 10.14 0.8 mM). Besides,
that several of the synthesised hydrazonoindolin-2-ones possessed compounds 3c, 10a, 10g, and 10i possessed excellent anti-prolif-
excellent to moderate growth inhibitory activity against the tested erative activity against A-549 cells (IC50 ¼ 6.07 0.90, 9.41 1.29,
cancer cell lines.
6.07 7.41, and 6.13 0.76 mM, respectively) which are better than

874
W. M. ELDEHNA ET AL.
7b
10e
800
600
400
200
0
800
600
400
24h
48h
200
24h
48h
0
0.01
0.01
0.1
1
10
100
0.1
1
10
100
Concentration (µM)
Concentration (µM)
100%
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
G2/M
S
G2/M
S
G1
G1
Figure 3. Effects on number and cell cycle distribution. A-549 cells were treated with dose curve. Compound 7b (left) or 10e (right). Cell number per cell cycle was
determined by DNA content by DAPI fluorescent labeling and imaging cytometry following 48 h treatment.
the used reference drug Sunitinib. On the other hand, compounds compounds 5a-e with 4-methyl group resulted in an increase
3e and 10b showed weak activity with IC50 >30 mM. Concerning of the anti-proliferative activity (compound 5b; average
activity against ZR-75 cells, compounds 3c, 5b, 5c, 5e, 7b, 10a, IC50 ¼ 4.37 mM vs. compound 5c; average IC50 ¼ 2.53 mM).
10c, 10e, 10g, 10i, and 10k displayed excellent anti-proliferative
Regarding phenylthiazolyl series, compounds 10a-l, the impact
activity superior to that of Sunitinib with IC50 range 1.16–4.89 mM. of the substitution on the 4-phenyl group was examined. The
Whereas, compounds 3d and 7a possessed weak activity with IC50 decreased average IC50 values of compounds 10a, 10e, and 10i
>30 mM. Moreover, anti-proliferative evaluation in HT-29 cell line (11.07, 4.66 and 5.45 mM, respectively) which incorporated an
revealed that two members, 5c and 7b, only showed superior unsubstituted phenyl moiety than that of their corresponding
activity to Sunitinib (IC50 ¼ 4.29 0.25 and 2.75 0.31 mM, respect- members 10b, 10f, and 10j (>28.19, >25.38, and 12.99 mM,
ively). Also, compounds 3c, 5b, 5e, 10e, and 10i were moderately respectively), with 4-methyl substituted phenyl moiety, and their
active with IC50 range of 6.15–8.49 mM.
corresponding members 10c, 10g, and 10k (>17.36, >12.65, and
Compound 7b was the most active congener in the synthes- 14.49 mM, respectively), with 4-chloro substituted phenyl moiety,
ised Schiff bases 3a-e, 5a-e, and 7a-c with an average IC50 value indicated that unsubstitution of the phenyl moiety is advanta-
of 2.14 mM toward the tested human cancer cell lines being nearly geous. On the other hand, substitution with 4-bromo substituent
four-fold more potent than the positive control, Sunitinib (average (compounds 10d, 10h, and 10l) diminished the activity. Finally,
IC50 value ¼8.11 mM). Whereas, compound 10e was the most we explored the effect of the substitution of the indolin-2-one
active candidate in the arylthizole derivatives 10a-l with an appar- moiety. Interestingly, grafting 5-chloro substituent was found to
ent average IC50 value of 4.66 mM against the tested cell lines.
be more beneficial for the activity rather than unsubstituted or 5-
bromo substituted indolin-2-one moieties throughout the study.
In conclusion, we can deduce that replacing the phenyl moiety
of compounds 3a-e with 2-thiazolyl ring, 5-pyrazolyl ring, or its
substitution with alipophilic ester group greatly enhances the anti-
proliferative activity. In addition, hybridisation of the indolin-2-one
moiety with 4-phenylthiazolylmoiety, compounds 10a-l seems to
be a prosperous approach.
Structure activity relationship
Observing the results, we could deduce valuable data about the
structure activity relationship (SAR). Firstly, investigation of the
impact of the substitution on the pendant phenyl group in com-
pounds 3a-e revealed that grafting an ester group (compound 3b;
average IC50 ¼ 14.01 mM) is more beneficial for activity than acetyl
group (compound 3a; average IC50 > 30 mM). The effect of bioisos-
teric replacement of the pendant phenyl ring in compounds 3a-e
Cell cycle effects
with 2-thiazolyl ring, compounds 5a-e, or 5-pyrazolyl ring, com- The cell cycle consists of a number of complex biochemical path-
pounds 7a-c was explored. Both 2-thiazolyl moiety (compound 5c; ways and controlled by numerous mechanisms to ensure correct
average IC50 ¼ 2.53 mM) and 5-pyrazolyl moiety (compound 7b; cell division. An important role is played by cyclin/cyclin-depend-
average IC50 ¼ 2.14 mM) resulted in remarkable increase in the ent kinase (CDK) complexes, which are critical regulators of cell
activity in comparison to compounds 3a-e (compound 3c; average cycle progression and RNA transcription. Deregulation of the cell
IC50 ¼ 6.25 mM). Also, substitution of the 2-thiazolyl ring in cycle underlies the aberrant cell proliferation which characterises

JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
875
7b
10e
1000
800
600
400
200
0
1000
800
600
400
24h
48h
200
24h
48h
0
0.01
0.1
1
10
100
0.01
0.1
1
10
100
Concentration (µM)
Concentration (µM)
1000
800
600
400
200
0
24h
48h
0.01
0.1
1
10
100
Concentration (µM)
Sunitinib
Figure 4. Dose-dependent changes in total levels of phosphorylated Rb protein of 7b, 10e and Sunitinib.
loss of cell cycle checkpoint control and cancer31,32
.
Retinoblastoma protein (pRb), a cell cycle regulatory molecule,
plays a critical role in control of the G1-to-S phase checkpoint of
the cell cycle. pRb suppresses the activity of E2F transcription fac-
tors thereby inhibiting transcription of cell cycle promoting genes,
in its hypophosphorylated state. Upon phosphorylation, mainly via
CDKs, phosphorylated pRb dissociates from E2F and permits cell
cycle progression33,34. In the current medical era, therapeutic strat-
egies directed against critical cell cycle regulators have stood out
as an attractive approach for discovering therapies for many
human malignancies.
In this study, cancer cells derived from lung adenocarcinoma
(A-549) were used to evaluate the effects of compounds 7b and
10e on various aspects of the cell cycle progression. Both
immunofluorescent imaging of phosphorylated Rb protein and
total DNA content of each cell were explored to determine the
activity of compounds 7b and 10e over a range of concentrations
less than 100 nM to 50 mM (Figures 3–5).
Compound 7b caused a dose-dependent reduction in the total
cell number after 48 h of treatment with IC50 value ¼8.08 mM,
while compound 10e caused a dose-dependent reduction in the
total cell number after 24 h of treatment with IC50 value ¼7.38 mM
(Table 3).
Moreover, compound 7b caused a decrease in the percentage
of cells in the G1 phase of the cell cycle with corresponding
increase in the G2/M-phases. Arrest in G2 may represent a check-
point blockade whereas mitotic arrest may, in some cases, lead to
mitotic catastrophe and subsequent programed death of cells with
multiple or aberrant nuclei. In contrast, compound 10e caused an
increase in the percentage of cells in the G1 phase of the cell
cycle with corresponding decreases in S- and G2/M phases. This
Figure 5. Immunofluorescent imaging of phosphorylated Rb protein for 7b, 10e,
and Sunitinib.
attributable to a decreased rate of progression through the cell
cycle and corresponding decreases in proliferation.
However, levels of phosphorylated Rb protein were significantly
reduced in a dose-dependent manner by the control and the test
compounds 7b and 10e (Figure 4). The IC50 values were consistent
with the IC50 values for reductions in cell number caused by each
compound after 24 h of treatment while the correlation is less
apparent after 48 h of treatment (Table 3). This may support the
hypothesis that inhibition of cyclin-dependent kinases by isatin
suggests that part of the compound effects on growth may be compounds plays a vital role in their growth inhibitory activity.

876
W. M. ELDEHNA ET AL.
Table 3. IC50 for reductions in the total cell number and cell cycle effects of compounds 7b, 10e, and Sunitinib.
IC50 (mM) for reductions in the
IC50 (mM) for reduction in Rb
total cell number
phosphorylation
Compound No.
24 h
48 h
24 h
48 h
Cell cycle effects
7b
10e
Sunitinib
12.67 13.6
7.38 1.04
12.54 9.82
8.08 0.95
7.27 1.15
3.48 0.61
12.07 0.6
7.59 0.38
3.18 0.07
13.56 0.6
12.46 2.1
14.01 0.6
G1 decreased and G2/M-phases increased
G1 increased and G2/M-phases decreased
G1 decreased and G2/M-phases increased
7b
10e
100
80
60
40
20
0
Sw3t3
IEC-6
MCF-10A
A-549
100
Sw3t3
IEC-6
MCF-10A
A-549
80
60
40
20
0
0.01
0.1
1
10
0.01
0.1
1
10
Concentration (µM)
Concentration (µM)
100
80
60
40
20
0
Sw3t3
IEC-6
MCF-10A
A-549
0.01
0.1
1
10
Concentration (µM)
Sunitinib
Figure 6. Selectivity profile of 7b, 10e, and Sunitinib.
Table 4. Selectivity for compounds 7b, 10e, and Sunitinib towards tumor and non-tumorigenic cell lines.
IC50 (mM) SD
NSCLC
A-549
Mean
tumor selectivity
Compound No. Intestine IEC-6 Breast MCF-10A Fibroblast Swiss-3t3
7b
10e
Sunitinib
8.70 4.32
8.98 1.25
4.56 0.54
3.42 0.45
5.37 0.61
4.43 0.23
6.85 0.76
8.51 1.01
4.07 0.75
3.84 0.67
4.13 0.61
3.06 0.9
1.6
1.8
1.4
Selectivity
Table 5. Cancer cell growth inhibitory activity of compounds 7b, 10e, and
Sunitinib towards sensitive (A-549) and resistant (NCI-H69AR) cell lines.
The cell growth inhibitory activity of compounds 7b and 10e was
examined towards three non-tumorigenic cell lines to estimate
their selectivity for tumor cells. A-549 human non-small cell lung
cancer (NSCLC) cell line was included in the assay for comparison.
Cultures derived from human fibrocystic mammary tissue (MCF-
10A) are non-tumorigenic and exhibit features of primary cultures
of breast tissue including dome formation35. IEC-6 cells derived
from rat intestine show morphologic and karyotypic features of
normal intestinal epithelial cells36. Fibroblasts derived from embry-
onic tissue from mice (Swiss-3t3) are both non-tumorigenic and
contact inhibited37. Compounds 7b and 10e were tested quadru-
plicate at maximum concentrations of 25 mM, with subsequent 10
serially diluted concentrations.
IC50 (mM)
Compound No.
Sensitive A-549
Resistant NCI-H69AR
Fold resistant
7b
10e
Sunitinib
3.8 0.67
4.1 0.61
3.1 0.9
16.0
16.6
5.8 0.52
4.2
4.0
1.9
(NCI-H69AR), which expresses the ABCC1 efflux pump protein.
Table 5 and Figure 7 revealed that both 7b and 10e displayed
growth inhibitory activity towards NCI-H69AR cells with IC50 values
of 16.0 mM. Accordingly, the NCI-H69AR cells were about four-fold
less sensitive than A-549 cells, suggesting that these compounds
might be subjected to efflux by ABCC1. Furthermore, the H69AR
cells manifested a lesser degree of resistance to the reference
drug, Sunitinib (1.9-fold less sensitive).
The results were displayed in Figure 6, while the IC50 values
and mean selectivity index were listed in Table 4. Both com-
pounds 7b and 10e displayed mean tumor selectivity index (1.6
and 1.8, respectively) higher than that of Sunitinib (1.4).
Conclusion
Multidrug resistant lung cancer cell line (NCI-H69AR)
In summary, herein, we report the design and synthesis of differ-
The anti-proliferative activity of compounds 7b and 10e was ent series of hydrazonoindolin-2-ones 3a-e, 5a-e, 7a-c, and 10a-l.
evaluated towards multidrug resistant lung cancer cell line All the prepared hydrazonoindolin-2-ones were examined for their

JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
877
7b
10e
100
80
60
40
20
0
100
80
60
40
20
0
H69AR
A-549
H69AR
A-549
0.01
0.1
1
10
0.01
0.1
1
10
Concentration (µM)
Concentration (µM)
100
H69AR
80
60
40
20
0
A-549
0.01
0.1
1
10
Sunitinib Concentration (µM)
Figure 7. Activity of 7b, 10e, and Sunitinib towards sensitive and resistant cancer cell lines.
anti-proliferative activity towards three cell lines, namely lung A-
549, colon r HT-29, and breast ZR-75 human cancer cell lines using
CellTiter-GloTM Luminescent cell viability assay. Compounds 5b, 5c,
7b, and 10e were the most potent members with average IC50
values of 4.37, 2.53, 2.14, and 4.66 mM, respectively, which are
superior to Sunitinib (average IC50 ¼ 8.11 mM). The SAR study sug-
gested that replacing the phenyl moiety of compounds 3a-e with
2-thiazolyl ring, 5-pyrazolyl ring, or its substitution with a lipophilic
ester group greatly enhances their anti-proliferative activity. In
addition, hybridisation of the indolin-2-one moiety with 4-phenyl-
thiazolyl moiety, compounds 10a-l, seems to be a prosperous
approach. Furthermore, compounds 7b and 10e were evaluated
for their effects on cell cycle progression and levels of phosphory-
lated retinoblastoma (Rb) protein in the A-549 human cancer cell
line. Moreover, 7b and 10e inhibited the cell growth of the multi-
drug-resistant lung cancer NCI-H69AR cell line with IC50 ¼ 16 mM.
Finally, the cytotoxic activities of 7b and 10e were assessed
towards three non-tumorigenic cell lines (Intestine IEC-6, Breast
MCF-10A, and Fibroblast Swiss-3t3) where both compounds dis-
played mean tumor selectivity index (1.6 and 1.8) higher than that
of Sunitinib (1.4).
2. Szakacs G, Ludwig JA, Booth-Genthe C, et al. Targeting mul-
tidrug resistance in cancer. Nat Rev Drug Disc 2006;5:
219–34.
3. Kathawala RJ, Gupta P, Ashby Jr CR, et al. The modulation of
ABC transporter-mediated multidrug resistance in cancer: a
review of the past decade. Drug Resist Update 2015;18:1–7.
4. Kidwai M, Jahan A, Mishra NK. Isatins: a diversity orientated
biological profile. Med Chem 2014;4:451–68.
5. Al-Wabli RI, Zakaria AS, Attia MI. Synthesis, spectroscopic
characterization and antimicrobial potential of certain new
isatin-indole molecular hybrids. Molecules 2017;22:1958.
6. Eldehna WM, Al-Ansary GH, Bua S, et al. Novel indolin-2-one-
based sulfonamides as carbonic anhydrase inhibitors: synthe-
sis, in vitro biological evaluation against carbonic anhydrases
isoforms I, II, IV and VII and molecular docking studies. Eur J
Med Chem 2017;127:521–30.
7. Sridhar SK, Ramesh A. Synthesis and pharmacological
activities of hydrazones, Schiff and Mannich bases of isatin
derivatives. Biol Pharm Bull 2001; 24:1149–52.
8. Eldehna WM, Fares M, Abdel-Aziz MM, et al. Design, synthe-
sis and antitubercular activity of certain nicotinic Acid hydra-
zides. Molecules 2015;20:8800–15.
9. Dhillon S. Nintedanib: a review of its use as second-line
treatment in adults with advanced non-small cell lung can-
cer of adenocarcinoma histology. Target Oncol 2015;10:
303–10.
10. Rossi A, Latiano TP, Parente P, et al. The potential role of
nintedanib in treating colorectal cancer. Expert Opin
Pharmacother 2017;18:1153–62.
11. Cutsem EV, Yoshino T, Hocke J, et al. Rationale and design
for the LUME-Colon 1 Study: a randomized, double-blind,
placebo-controlled phase III trial of nintedanib plus best sup-
portive care versus placebo plus best supportive care in
patients with advanced colorectal cancer refractory to stand-
ard treatment. Clin Colorectal Cancer 2016;15:91–4.
12. Quintela-Fandino M, Urruticoechea A, Guerra J, et al. Phase I
clinical trial of nintedanib plus paclitaxel in early HER-2-
negative breast cancer (CNIO-BR-01-2010/GEICAM-2010-10
study). Br J Cancer 2014;111:1060–4.
Acknowledgements
The authors would like to extend their sincere appreciation to the
Deanship of Scientific Research at King Saud University for its
funding of this research through the Research Group Project no.
RG-1438–083.
Disclosure statement
No potential conflict of interest was reported by the authors.
References
1. Avendano C, Menendez JC. Medicinal chemistry of anti-
cancer drugs. 1st ed. Chapter 1. Amsterdam: Elsevier; 2008.
13. Goodman VL, Rock EP, Dagher R, et al. Approval summary:
sunitinib for the treatment of imatinib refractory or

878
W. M. ELDEHNA ET AL.
intolerant gastrointestinal stromal tumors and advanced 24. Kondratieva ML, Pepeleva AV, Belskaia NP, et al. A new syn-
renal cell carcinoma. Clin Cancer Res 2007;13:1367–73.
thetic method for the 2H-[1, 2, 3]thiadiazolo [5, 4-b]indoles.
Tetrahedron 2007;63:3042–8.
25. Dahiya R, Narayan S, Bindal V, et al. Heterocyclic systems
containing bridgehead nitrogen atom. Part 60. Synthesis of
thiazolo[20, 30: 3, 4][1, 2, 4]triazino[5, 6-b]indoles. Indian J
Chem Sect B 1987;26B:535–8.
26. Pal R, Jain K, Gupta G, et al. Heterocyclic systems containing
bridgehead nitrogen atom. lxxii: reaction of 5H-2,3-dihydro-
[1, 2, 4]triazino[5, 6-b]indole-3-thiones with phenacyl brom-
ide, 1, 2-dibromoethane and chloroacetic acid. Indian J
Chem Sect B 1991;30B:1098–103.
27. Mohan J, Anjaneyulu G, Kiran K. Heterocyclic systems con-
taining bridgehead nitrogen atom: Synthesis of thiazolo [30,
20: 2, 3][1, 2, 4]triazino [5, 6-b]indoles and isomeric thiazolo
[20, 30: 3, 4][1, 2, 4]triazino[5, 6-b]indoles. Indian J Chem Sect
B 1988;27B:346–9.
14. Attia MI, Eldehna WM, Afifi SA, et al. New hydrazonoindolin-2-
ones: synthesis, exploration of the possible anti-proliferative
mechanism of action and encapsulation into PLGA micro-
spheres. PLoS One 2017;12:e0181241.
15. Abdel-Aziz HA, Eldehna WM, Keeton AB, et al. Isatin-benzoa-
zine molecular hybrids as potential antiproliferative agents:
synthesis and in vitro pharmacological profiling. Drug Des
Devel Ther 2017;11:2333.
16. Eldehna WM, Almahli H, Al-Ansary GH, et al. Synthesis and
in vitro anti-proliferative activity of some novel isatins conju-
gated with quinazoline/phthalazine hydrazines against triple-
negative breast cancer MDA-MB-231 cells as apoptosis-
inducing agents. J Enz Inhib Med Chem 2017;32:600–13.
17. Eldehna WM, Fares M, Ceruso M, et al. Amido/ureidosubsti-
tuted benzenesulfonamides-isatin conjugates as low nano-
molar/subnanomolar inhibitors of the tumor-associated
28. Xie Z, Wang G, Wang J, et al. Synthesis, biological evalu-
ation, and molecular docking studies of novel isatin-thiazole
derivatives as a-glucosidase inhibitors. Molecules 2017;
22:659.
carbonic anhydrase isoform XII. Eur
J
Med Chem
2016;110:259–66.
18. Eldehna WM, Fares M, Ibrahim HS, et al. Synthesis and cyto-
toxic activity of biphenylurea derivatives containing indolin-
2-one moieties. Molecules 2016;21:762.
19. Eldehna WM, Altoukhy A, Mahrous H, et al. Design, synthesis
and QSAR study of certain isatin-pyridine hybrids as poten-
tial anti-proliferative agents. Eur J Med Chem 2015;90:
684–94.
20. Fares M, Eldehna WM, Abou-Seri SM, et al. Design, synthesis
and in vitro antiproliferative activity of novel isatin–quinazo-
line hybrids. Arch Der Pharm 2015;348:144–54.
21. Eldehna WM, Fares M, Ibrahim HS, et al. Indoline ureas as
potential anti-hepatocellular carcinoma agents targeting
VEGFR-2: synthesis, in vitro biological evaluation and
molecular docking. Eur J Med Chem 2015;100:89–97.
22. (a) Eldehna WM, EL-Naggar DH, Hamed AR, et al. One-pot
three-component synthesis of novel spirooxindoles with
potential cytotoxic activity against triple-negative breast can-
29. Meleddu R, Distinto S, Corona A, et al. (3Z)-3-(2-[4-(aryl)-1,3-
thiazol-2-yl]hydrazin-1-ylidene)-2,3-dihydro-1H-indol-2-one
derivatives as dual inhibitors of HIV-1 reverse transcriptase.
Eur J Med Chem 2015;93:452–60.
30. Hannah R, Beck M, Moravec R, et al. CellTiter-GloTM
Luminescent cell viability assay:
a sensitive and rapid
method for determining cell viability. Promega Cell Notes
2001;2:11–13.
31. Collins K, Jacks T, Pavletich NP. The cell cycle and cancer.
Proc Natl Acad Sci USA 1997;94:2776–8.
32. De Falco M, De Luca A. Cell cycle as a target of antineoplas-
tic drugs. Curr Pharm Des 2010; 16:1417–26.
33. Weinberg RA. The retinoblastoma protein and cell cycle con-
trol. Cell 1995;81:323–30.
34. Woitach JT, Zhang M, Niu C-H, et al. A retinoblastoma-bind-
ing protein that affects cell-cycle control and confers trans-
forming ability. Nat Genet 1998;19:371.
35. Soule HD, Maloney TM, Wolman SR, et al. Isolation and
characterization of a spontaneously immortalized human
breast epithelial cell line, MCF-10. Cancer Res 1990;50:
6075–86.
36. Quaroni A, Wands J, Trelstad RL, et al. Epithelioid cell
cultures from rat small intestine. Characterization by mor-
phologic and immunologic criteria. J Cell Biol 1979;80:
248–65.
cer MDA-MB-231 cells.
J
EnzInhib Med Chem
2018;33:309–18; (b) Eldehna WM, Abo-Ashour MF, Ibrahim
HS, et al. Novel [(3-indolylmethylene)hydrazono]indolin-2-
ones as apoptotic anti-proliferative agents: design, synthesis
and in vitro biological evaluation. J Enz Inhib Med Chem
2018;33:686–700; (c) Abdel-Aziz HA, Eldehna WM, Hamed
AR, et al. Synthesis, crystal structure, and biological activity
of cis/trans amide rotomers of (Z)-N0-(2-oxoindolin-3-ylide-
ne)formohydrazide. J Chem 2014;2014:760434.
23. Gabr MT, El-Gohary NS, El-Bendary ER, et al. Isatin-b-thiocar-
bohydrazones: microwave-assisted synthesis, antitumor activ-
ity and structure-activity relationship. Eur J Med Chem
2017;128:36–44.
37. Todaro GJ, Green H. Quantitative studies of the growth of
mouse embryo cells in culture and their development into
established lines. J Cell Biol 1963;17:299–13.