Hydrazide-integrated carbazoles: Synthesis, computational, anticancer and molecular docking studies

Article abstract of DOI:10.1039/c9nj01912j

A new class of carbazole-based hydrazides 6a-c, synthesized from carbazole by employing a multistep synthetic strategy, has been described. Detailed insight into their structures (6a-c) has been elucidated by UV-Vis, FT-IR and NMR (¹H and ¹³C) spectroscopic studies. Theoretical investigation of the molecules 6a-c has been accomplished utilizing DFT and TD-DFT techniques with the B3LYP/6-311++G(d,p) method. Theoretical findings such as optimized structural, vibrational, and electronic properties, and proton and carbon chemical shifts of the targets 6a-c are in harmony with their experimental results and/or structurally related reported ones. Cytotoxicity of the target hydrazides 6a-c has been evaluated using human pancreatic cancer cells (AsPC1 and SW1990). The hydrazides 6a-c displayed a significant in vitro cytotoxic effect against both the pancreatic cancer cells AsPC1 (concentration that inhibits 50% cell viability, IC₅₀: 3.42 ± 0.41 μM for 6a) and SW1990 (IC₅₀: 22.42 ± 1.40 μM for 6a). The superior binding energy resulting from the in silico molecular docking approach of the hydrazide 6a indicates its greater affinity towards the receptor (binding energy: -8.63 kcal mol^-1 and IC₅₀: 475.05 nM). Thus, the hydrazide 6a could serve as a new lead for the development of anticancer agents.

Full text of DOI:10.1039/c9nj01912j

View Article Online
View Journal
NJC
New Journal of Chemistry
Accepted Manuscript
A journal for new directions in chemistry
This article can be cited before page numbers have been issued, to do this please use: G. Kannan, P.
Ashothai, P. Krishnaraj, W. Lim, C. Mai, P. V. Thanikachalam and R. Chennan, New J. Chem., 2019, DOI:
10.1039/C9NJ01912J.
Volume 42
This is an Accepted Manuscript, which has been through the
Number
6
21 March 2018
Pages 3963-4776
Royal Society of Chemistry peer review process and has been
accepted for publication.
NJC
New Journal of Chemistry
rsc.li/njc
A journal for new directions in chemistry
Accepted Manuscripts are published online shortly after acceptance,
before technical editing, formatting and proof reading. Using this free
service, authors can make their results available to the community, in
citable form, before we publish the edited article. We will replace this
Accepted Manuscript with the edited and formatted Advance Article as
soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes to the
text and/or graphics, which may alter content. The journal’s standard
Terms & Conditions and the Ethical guidelines still apply. In no event
shall the Royal Society of Chemistry be held responsible for any errors
or omissions in this Accepted Manuscript or any consequences arising
from the use of any information it contains.
ISSN 1144-2546
PAPER
Chechia Hu, Tzu-Jen Lin et al.
Yellowish and blue luminescent graphene oxide quantum dots
prepared via a microwave-assisted hydrothermal route using
H2O2 and KMnO4 as oxidizing agents
rsc.li/njc

Please do not adjust margins
Page 1 of 10
New Journal of Chemistry
1
2
3
4
5
6
7
View Article Online
DOI: 10.1039/C9NJ01912J
ARTICLE
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Hydrazide integrated carbazoles: synthesis, computational,
anticancer and molecular docking studies
Received 00th January 20xx,
Accepted 00th January 20xx
Kannan Gokula Krishnan,a Pathinettampadi Ashothai,b Krishnaraj Padmavathy,a Wei-Meng Lim,c
Chun-Wai Maic,d Punniyakoti V Thanikachalamc and Chennan Ramalingana*
DOI: 10.1039/x0xx00000x
A new class of carbazole based hydrazides 6a-c, synthesized from carbazole by employing multistep synthetic strategy, has
been described. The detailed insight into its structures (6a-c) has been elucidated by UV-Vis, FT-IR and NMR (1H and 13C)
spectroscopic studies. Theoretical investigation of the molecules 6a-c has been accomplished utilizing DFT and TD-DFT
techniques with B3LYP/6-311++G(d,p) method. Theoretical findings such as optimized structural, vibrational, electronic
properties, proton and carbon chemical shifts of the targets 6a-c are in harmony with their experimental results and /
structurally related reported ones. Cytotoxicity of the target hydrazides 6a-c has been evaluated using human pancreatic
cancer cells (AsPC1 and SW1990). The hydrazide 6a-c displayed significant in-vitro cytotoxic effect against both the
pancreatic cancer cells AsPC1 (concentration that inhibits 50% cell viability, IC50: 3.42 ± 0.41 µM for 6a) and SW1990 (IC50:
22.42 ± 1.40 µM for 6a). The superior binding energy resulted from the in silico molecular docking approach of the
hydrazide 6a indicates its greater affinity towards the receptor (binding energy: -8.63 kcal/mol and IC50: 475.05 nM). Thus,
the hydrazide 6a could serve as a new lead for the development of anticancer agents.
heterocyclic intermediates with massive applications in
different fields of research.6 It has also been found in nature
sources as bio-pertinent stuffs used as traditional medicine.7
Introduction
Cancers - the leading death causing diseases- induced by
uncontrolled growth of abnormal cells which potentially
spread anywhere in the body.1 There are more than 200 types
of cancer cells have been identified, which affects the major
part of organs including bladder, breast, colorectal, kidney,
leukemia, lymphoma, prostate and uterine.2 The cells growth
of abnormal ones have high proliferative index as compared to
normal cells.3 Therefore the control of infected cell growth
cycle is one of the biggest challenges in modern era of
oncologists. Current psychoanalysis for cancer is mainly based
on treatment with surgery, radiation therapy and
chemotherapy.4 These therapies are existence to treat only the
most suspected cancer tissue in order to retard the
development of resistance to them.5 Thus it is vital to develop
new structural scaffolds which possess superior anticancer
action quite the analogues existing ones.
These categories of molecules are biologically potent, having
noteworthy anti-carcinogenic, antibiotic, antiviral, antitumor
and antiinflammatory properties.8-12 Over the past years,
several studies have highlighted the importance of carbazole
based compounds as promising lead for the treatment of
cancer.13 Because of its fluorescent nature, carbazole skeleton
is a structural motif of several molecules utilized in electronics
in connection with electroluminescent materials production,14
polymers15 or dyes.16 In addition, incorporation of alkyl groups
would help in increasing solubility of the compounds owing to
hydrophilic/hydrophobic balance of the structures.17
Hydrazides are recognized as a nitrogen-nitrogen structural
entity possessing four substituents, of those a minimum of one
must be benzoyl/acyl moiety.18 The focus towards the
development of novel hydrazide analogues is enthused by the
hydrazone category of compounds owning a variety of
Carbazoles are one of the valuable and versatile
pharmacological
profiles
including
antimicrobial,
anticonvulsant, antioxidant, antiinflammatory, antitumor and
antiviral.19-24 Further, the hybrid of isoniazid with various
aldehydes and ketones exhibited selective Mycobacterium
tuberculosis activity.25 Hence, integration of two or more
active structural motifs could possibly enhance the bioactivity
and thus, it was of interest to hybrid the carbazole nucleus
with hydrazide fragment through an imine bridge hoping to
develop a potent anticancer agent.
a.Department of Chemistry, School of Advanced Sciences (SAS), Kalasalingam
Academy of Research and Education (Deemed to be University), Krishnankoil - 626
126, Tamilnadu, India.
E-Mail: ramalinganc@gmail.com; c.ramalingan@klu.ac.in
b.Department of Chemistry, Lady Doak College, Madurai - 625 002, Tamilnadu,
India.
c. School of Pharmacy, International Medical University, 126 Jalan Jalil Perkasa 19,
57000, Bukit Jalil, Kuala Lumpur, Malaysia
.
d.Center for Cancer and Stem Cell Research, Institute for Research, Development
and Innovation (IRDI), International Medical University, 126, Jalan Jalil Perkasa
19, 57000, Bukit Jalil, Kuala Lumpur, Malaysia.
The extensive range of application of organic chemical
entities incorporated with carbazole and hydrazide structural
Electronic Supplementary Information (ESI) available:SeeDOI: 10.1039/x0xx00000x
Please do not adjust margins

Please do not adjust margins
New Journal of Chemistry
Page 2 of 10
ARTICLE
Journal Name
1
2
3
4
5
6
7
8
9
cores available in the literature stimulated us to investigate a aforementioned carbaldehydes 4a-c through condensation
View Article Online
new system possessing these couple of structural units. Herein reaction with isoniazid (5) in good yields. DOI: 10.1039/C9NJ01912J
we report synthesis, in-vitro anticancer activity, molecular
The structures of the newly synthesized carbazolyl
docking and computational studies of new class of methylene isonictinohydrazides 6a-c have been deduced by
a
molecules, carbazolylmethylene isonictinohydrazides.
UV-Vis, FT-IR and NMR (1H and 13C) spectroscopy techniques.
In the FT-IR spectra, the molecules 6a-c showed strong
absorptions in the double bond region of 1637-1643 cm-1,
reflect the presence of carbonyl group (C=O) of hydrazones. An
absorption band at 1587-1589 cm-1 reveals the presence of
imino group (C=N) in the molecules, which confirms the
formation of hydrazide. A collection of bands observed in the
region of 3587-3405 and 3213-2868 cm-1 are because of the
presence of N-H and C-H stretching (aromatic and aliphatic)
Results and discussion
Synthesis
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Initially, alkylations of 9H-carbazole
1 have been preceded
with 1-bromoalkanes 2a-b in THF at room temperature for 24
hours according to the method shown in Scheme 1
.
1
vibrations, respectively. In H NMR spectra, a singlet (sharp)
appeared in the farthest downfield region around 12.0 ppm
with an integral of one proton owing to labile proton of NH,
and this farthest downfield absorption is due to the
deshielding effect of -C=O, C=N- functionalities over the NH
proton. In 13C NMR, signals of the compounds 6a-c resulted in
the downfield region around 150.7 (C=N) and 161.8 (C=O) ppm
further confirm the formation of title hydrazides. A typical
absorption maximum attained in the UV-Vis spectra, in
dichloromethane, around 340 nm confirm the transition of
n→π* of the carbonyl (C=O) and imine (C=N) functionalities
present in the molecules. All the key distinguishing
band/signals resulted from UV-Vis, FT-IR, and NMR,
unquestionably validate the structure of the newly synthesized
hydrazides 6a-c
.
Structural Analysis
Scheme 1. Synthesis of hydrazide integrated carbazoles.
Figure 1 Optimized structure of hydrazide integrated carbazoles 6a-c.
Then the 9-alkyl-9H-carbazoles 3a-b react with Vilsmeier-
Haack reagent at cooled to refluxed condition for 5-6 hours to
yield the precursors, 9-alkyl-9H-carbazole-3-carbaldehydes 4a-
Carbazole containing hydrazides 6a-c have been optimized in
ground state acquired by B3LYP [6-311++G(d,p)] technique.
The optimized molecular structure of the compounds 6a-c are
visualized in Figure 1 and their structural features are
furnished in Table S1. As the hydrazides 6a-c are new ones, it
is obviously clear that the exact data resulted from
experiments on the structural parameters of the same would
b
in good yields. On the other hand, 6-bromo-9-butyl-9H-
carbazole-3-carbaldehyde 4c has been prepared from 9-butyl-
9H-carbazole-3-carbaldehyde 4a using NBS as a brominating
agent at room temperature. In the eventual step, bio-pertinent
carbazole
integrated
molecules,
carbazolylmethylene
isonictinohydrazides 6a-c have been constructed from the
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 10
New Journal of Chemistry
Please do not adjust margins
Journal Name
ARTICLE
1
2
3
4
5
6
7
8
9
not be accessible from the literature. Hence, it would not be computed are in accord with each other and thVeiewreAsrtuiclltesOnalirnee
DOI: 10.1039/C9NJ01912J
feasible to compare the results of computation with the tabulated in Tables S2
experiment. Consequently, the crystal information of strongly
-S4, respectively.
The aromatic stretching vibrations of C-H are normally
related molecules such as 3-(9-ethyl-9H-carbazol-3-yl)-1-(2- expected to appear in the region 3100-3000 cm-1.28 The
hydroxyphenyl)prop-2-en-1-one26 and 3-(9-hexyl-9H-carbazol- absorption bands resulted in the infrared spectra of hydrazides
3-yl)acrylic acid27 have been compared with that of the title 6a-c at 3213-2935 cm-1 are corresponding to stretching
molecules.
vibrations of C-H. These values show good conformity with the
As can be seen in the Figure 1, the core motif, carbazole of theoretically computed ones, observed at 3263-3123/3262-
the investigated hydrazides 6a-c is planar. The alkyl side chain 3178/3130-3104 cm-1 in B3LYP calculations. Further, it is
and N-isonicotinoyl group attached to the carbazole core are known that the stretching vibrations of alkyl moieties typically
making the molecules a co-planar conformation with slight arise at reasonably lesser frequencies than those present in
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
deviation from the main plane. Since the co-planarity of the the aromatic rings. In the infrared spectra of hydrazides 6a-c
,
molecules normally enhances the transfer of electron, the the C-H stretching vibrations of butyl/hexyl side chains are
molecules would enhance the physiochemical properties of resulted as medium and weak bands at 2953-2868 cm-1
the compounds. For instance, as a result of enhanced transfer whereas in the parallel computational infrared spectra, these
of electrons, the electron density over the atoms/groups of C-H stretching vibrations are found in the region 3119-
electron withdrawing capacity of a molecule would increase 3035/3119-3025/3098-2916 cm-1. Hence, the theoretical
thereby enhances its affinity towards the host (proteins / results are in accord with the experimental ones.
amino acids) in biological systems. The optimized angles and
lengths of bonds in the ground state of the calculated
hydrazides 6a-c are alike with each other. This signifies that
both the elongation of the side chain and incorporation of
substituent have small effect on these parameters of
geometry. The computed angles and lengths of bonds are in
accord with analogous molecules reported in the
literature.26,27 Further, the calculated bond lengths of C=O, N-N
and C=N fall at 1.220, 1.360 and 1.282 Å, respectively, realized
by the method of B3LYP, which are in good conformity with
those of experimental bond lengths.
Vibrational Analysis
The hydrazides 6a-c have 50/56/50 atoms, the molecules have
normal modes of vibrations 144/162/144 and belong to C1
symmetry. All the 144/162/144 vibrational modes are equally
disseminated as 53/59/53 stretching, 44/50/44 bending and
47/53/47 torsion vibrations in the computed spectrum. The
experimental FT-IR of the hydrazides 6a-c and their related
computed ones under investigation are sketched in Figure 2
.
The experimental and computed vibrational frequencies in
addition to their relative intensities and plausible assignments
of the hydrazides 6a-c are furnished in Tables S2-S4
,
respectively.
The aromatic and heteroaromatic ring systems undergo
coupled vibrations, hence original locations of these vibration
modes are difficult to determine by nature of the substituent.
The coupled vibrations of aromatic ring are commonly arising
in the area between 1625 and 1400 cm-1.28 In the infrared
spectra of the hydrazides 6a-c, the observed frequencies
between 1587 and 1438 cm-1 are due to stretching vibrations
of C-C. The subsequent computed frequencies predicted from
the method of B3LYP [6-311++G(d,p)] are 1607-1558/1607-
1546/1603-1547 cm-1. The experimental C-C-C out-of-plane
and in-plane bending vibrations of the hydrazides 6a-c have
been observed at 842-611 cm-1 while the computed C-C-C out-
of-plane and in-plane bending vibrations are also in a similar
area, reflecting that both the vibrations of experimental and
Figure 2 Experimental and Simulated FT-IR spectra of hydrazide integrated
carbazoles 6a-c.
In the hydrazides 6a-c, the C=O stretching vibrational
bands have easily been recognized from the FT-IR spectra due
to the conjugation degree, polarizations and strength.
Generally, the stretching vibrations of carbonyl are predictable
in the area from 1750 to 1650 cm-1.29 In the current
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
New Journal of Chemistry
Page 4 of 10
ARTICLE
Journal Name
1
2
3
4
5
6
7
8
experimental case, the region of carbonyl stretching form of dichloromethane, which appear due to n→π* tranVsiietwioAnrtsicleinOntlhinee
the hydrazides 6a-c seems at 1641/1637/1643 cm-1. On the visible region and π→π* transitions at shorter wavelengths. A
DOI: 10.1039/C9NJ01912J
other hand, in the computational case, the carbonyl stretching typical absorption maximum observed around 340 nm in the
bands arise at 1689/1689/1692 cm-1. The experimentally solvents utilized corresponding to the transition n→π* of the
obtained carbonyl stretching frequencies are in harmony with carbonyl (C=O) and imine (C=N) groups present in the molecules.
their theoretically computed counterparts.
On the other hand, the later one of strong intense absorption
Besides, the stretching vibrations of C-N are frequently maxima around 300 nm owing to transitions π→π* of carbazole and
more complicated to identify in the FT-IR spectra since the isoniazid rings. The experimentally obtained these absorption bands
band is of uneven intensity and may be present over the broad are well correlated by the results of computation, provided bands
region from 1360 to 1080 cm-1.29 The C-N absorption modes in around 370, 330 and 320 nm, respectively. The resulted broad one
the hydrazides 6a-c are found to be 1587/1587/1589 cm-1 band in the theoretical UV-Vis spectra of the molecules 6a-c, unlike
while the corresponding computed frequencies lie at the observed two distinct bands in the experimental UV-Vis spectra,
1624/1624/1625 cm-1. The results reflect that the computed may probably be due to anhormonic effect.
frequencies are aligned with their experimental ones.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
The vibrational assignment of N-H stretching is normally
exhibits as broad band in the higher energy region 3500-3250
cm-1.28 In the experimental infrared spectra of hydrazides 6a-c
,
the strong and broad bands occurred at 3405/3587/3400 cm-1
are due to N-H stretching frequencies of the investigated
molecules. The computationally calculated frequencies of the
bands arrived at 3499/3500/3361 cm-1 with 100 % PED by DFT
method are coincide well with the experimental results.
UV-Vis Spectral Studies
The theoretical UV-Vis absorption of the hydrazides 6a-c has
been calculated by the method of TD-DFT with the basis set
B3LYP/6-311++G(d,p). The electro-optic properties viz.,
energies of band gap and excitation along with strengths of
oscillator of compounds 6a-c in solvent phase
(dichloromethane) are presented in Table 1. The experimental
UV-Vis studies of the hydrazides 6a-c have been carried out in
dichloromethane. The experimental and calculated UV-Vis
spectra of the hydrazides 6a-c are depicted in Figure 3
.
Table 1. Experimental and calculated electronic transition of hydrazide integrated
carbazoles 6a-c in solution phase
Hydrazide 6a
Expt.
λ (nm)
344
Calc.
Solvent
DCM
λ (nm)
E (eV)
3.28
3.73
3.84
f
377 (98→99)
332 (97→99)
322 (97→100)
Hydrazide 6b
377 (106→107)
332 (105→107)
322 (105→107)
Hydrazide 6c
0.35
0.04
0.02
293
337
301
DCM
3.28
3.73
3.84
0.35
0.04
0.02
Figure 3 Experimental and Simulated UV-Vis spectra of hydrazide integrated
carbazoles 6a-c.
Expt.
λ (nm)
333
Calc.
Solvent
DCM
λ (nm)
E (eV)
3.31
3.60
3.84
f
374 (115→116)
344 (114→116)
322 (114→116)
0.35
0.02
0.02
HOMO-LUMO Analysis
299
As it is known, both molecular orbitals of highest occupied and
lowest unoccupied (MOs) are significant quantum chemical
factors to take part in the chemical reactivity and kinetic
stability of a molecule. Energy difference between HOMO and
LUMO is a vital parameter in deciding the excitability of a
As seen in the Figure 3, the absorption wavelengths of the
hydrazides 6a-c have been found to be a couple of characteristic
bands accomplished in wavelength at ̴ 340 and ̴ 300 nm for
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 10
New Journal of Chemistry
Please do not adjust margins
Journal Name
ARTICLE
1
2
3
4
5
6
7
8
9
molecule; smaller the energy, there is a decline in the The MEP is easily deduced as a color spectrum, as a result, it is
View Article Online
topological resonance energy.30 The patterns of the HOMO very valuable in research of molecular structure with its
DOI: 10.1039/C9NJ01912J
and LUMO of the hydrazides 6a-c have been computed by a relationship of physiochemical and also H-bond interactions. A
method of B3LYP [6-311++G(d,p)], which are displayed in model of electrostatic potential of the hydrazides 6a-c
Figure 4, while their related energy values are given in Table 2 computed at the 0.002 a.u isodensity surface are furnished in
The positive and negative phases are symbolized with red and Figure 5. The colour code of MEP maps ranges from -9.893 to
,
.
green, respectively.
+9.893 kcal/mol with dark-blue colour denotes extremely
electron-deficient areas and red colour denotes electron rich
areas.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
In the Figure 5, the negative region is largely concentrates
on the carbonyl part of isoniazid moiety. The utmost positive
region is typically distributed on the N9-H and N10 of
hydrazone part. These locations provide the information about
the area from where the compound can be devised the
intermolecular interactions. The MEP maps indicate, the
probable reactive position of the hydrazides 6a-c, in favour of
electrophilic attack is at C1=O8, while the most feasible areas
which could be involved in nucleophilic process are at N9-H
and N10.
Figure 4 3D plots of frontier molecular orbitals (FMOs) of hydrazide integrated
carbazoles 6a-c.
Table 2. Calculated frontier molecular orbitals energies of hydrazide integrated
carbazoles 6a-c
Compounds
HOMO
-7.90
-7.90
-7.56
LUMO
-5.36
-5.36
-5.35
Energy gap (eV)
6a
6b
6c
2.54
2.54
2.21
As seen in the figures, the carbazole ring in the HOMO is
more populated than the isoniazid core. In contrast, the LUMO
distributes slightly more in the isoniazid moiety. Hence, the
electronic transition to the LUMO (excited state) from the
HOMO (ground state) is primarily flowing of electrons from the
carbazole moirty to the isoniazid unit. The band gap energies
(∆E) of the hydrazides 6a-c are about 2.54, 2.54 and 2.21 eV. In
general, compounds hold higher energy gap reveal lower
chemical reactivity while compounds possess lower energy gap
reveal higher chemical reactivity. Since the energy gap of the
hydrazides 6a-c is small, the molecules are further polarizable
and are usually connected with low kinetic stability, high
chemical reactivity, and are also known as soft molecules. In
the case of 6a-c, since the energy gap is small, the existence of
electron density over the hydrazide motif would probably be
more; as a result, this motif would play a better role in binding
with the host (proteins / aminoacids).
Figure 5 Molecular surfaces achieved by B3LYP/6-311++G(d,p) level of hydrazide
integrated carbazoles 6a-c.
NMR Spectral Studies
In the proton NMR of hydrazides 6a-c, the signals with one
proton integral appeared in the extreme downfield region 12.0
ppm are assigned to labile NH proton. Since the
electronegative moieties -C=O, C=N- are adjacent to the NH
groups, they deshield the NH proton (supplementary Figures
S1 – S3; Table S5).
The chemical shift value of this proton is virtually in-line
with the calculated one. A group of signals resonated in the
downfield region 7.2-8.8 ppm with twelve protons integral
owing to the existence of N-isonicotinoyl group, carbazole
moiety and the proton attached to imino carbon of in the
molecules. All these signals resulted through experimental are
found to well synchronize with the computed ones. A triplet
(sharp) seemed in the shielded region 0.86/0.78/0.88 ppm
with three proton integral owing to methyl protons of
hexyl/butyl moiety. The experimental values of these protons
Molecular Electrostatic Potential Analysis
The MEP has widely been known as a technique for mapping
electrostatic potential onto the iso-electron density surface.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
New Journal of Chemistry
Page 6 of 10
ARTICLE
Journal Name
1
2
3
4
5
6
7
8
9
are in good conformity with their calculated ones. The signals significantly induced more apoptotic nucleosomes in all
View Article Online
for the protons of methylene groups existing in the butyl/hexyl pancreatic cancer cells (3.4- to 4.2-folds)DwOhI:i1le0.1IC03509/(C395N-J4001µ91M2J)
side chain resonate in the upfield region 1.2/1.2/1.3, of gemcitabine only induced 1.9- to 2.5-folds of apoptotic
1.7/1.7/1.7, and 4.3/4.4/4.4 ppm, respectively, as unresolved nucleosomes. This result suggests compound 6a has potential
multiplets. The signals obtained from the experimental study apoptotic induction in human pancreatic cancer.
are well coherent with the corresponding signals resulted at
computed chemical shifts. The comparative experimental and
computed proton chemical shifts are furnished in Table S5
.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
In the carbon NMR spectra of hydrazides 6a-c, all the
carbon atoms of aromatic core together resonate between
110.1 to 141.7 ppm. These aromatic carbon signals are in-line
with the theoretically obtained ones. The C=N and C=O
carbons appear in the downfield region at 150.7 and 161.8
ppm, respectively (supplementary Figures S4 - S3; Table S6).
These characteristic signals obtained from experimental are in
harmony with the signals resulted from computational studies.
In the upfield region, signals in connection with the alkyl side
chains attached to 9H-carbazole (i.e., in 6a/6b/6c) are
observed at 14.1/14.2/14.1, 20.2/22.4/20.2, --/26.5/--, --
/28.9/--, 31.1/31.4/31.1 and 42.6/42.8/42.6 ppm. The
computed chemical shifts of the alkyl side chains are in accord
with their experimental results. The comparative experimental
Figure
6 Enrichment factor induced by vehicle control, gemcitabine and
compound 6a on human pancreatic cancer cells. Apoptotic nucleosomes were
collected after cells were treated at IC50 (22.4 µM for SW1990 and 3.4 µM for
AsPC1) for 72 hours. Enrichment factor was quantified based on the
absorbance of cells treated with compound or gemcitabine over absorbance of
cells treated with vehicle control (0.1% DMSO) using Cell Death Detection
ELISAPLUS kit (Roche Diagnostics, Indianapolis, U.S.A.)
and computed carbon chemical shifts are provided in Table S6
.
In-vitro anticancer activity
The synthesized hydrazides 6a-c have been evaluated for their
in vitro anticancer activity against two human pancreatic
cancer cell lines (AsPC1 and SW1990), human non-cancerous
retinal endothelial cells (ARPE19) and human non-cancerous
lung fibroblast cells (MRC5) using Cell-Titre Glo Luminescent
Cell Viability Assay. The obtained results against the tested
chemical entities as well as positive control (gemcitabine) are
furnished in Table 3. As seen in the Table 3, all the tested
hydrazides 6a-c showed appreciable anticancer activities
against both the tested cell lines. Among them, the one
possessing butyl substituent on the nitrogen of the carbazole
structural motif (6a) exhibited highest activity against the
cancer cell line AsPCl and SW1990.
Molecular Docking
Molecular docking of the most active hydrazide 6a with active
sites of BCL-2 (B-cell lymphoma 2), taken from PDB was
performed using Autodock 4.0 version to realize the plausible
molecular basis of interactions and binding affinity and the
results are provided in Figure 7
.
The binding energy of 6a is calculated as -8.63 Kcal/mol
while the predicted IC50 value of the same is resulted as 475.1
nM. The chemical entity 6a shows two hydrogen bonds with
polar hydrophilic amino acids such as glutamine and
glutamate; the N-H and C=O groups of amide scaffold
participated in the hydrogen bonding. The ligand exhibits van
der Waals interactions with two polar hydrophilic amino acids
such as arginine and glutamate two non polar hydrophobic
amino acids such as phenyl alanine and valine. Besides, the
molecule 6a displays four alkyl interactions between the
methyl group of alkyl chain attached to the nitrogen of the
carbazole structural unit and non polar hydrophobic amino
acids such as leucine, phenyl alanine and valine. Further, there
are five π-alkyl interactions between the carbazole / pyridine
structural motifs of the chemical entity 6a and non polar
hydrophobic amino acids alanine / methionine observed in
addition to a π-π interaction between phenyl alanine, a non
polar hydrophobic amino acid and one of the fused phenyl
rings of carbazole scaffold as well as a π-σ interaction between
methionine, a non polar hydrophobic amino acid and other
fused phenyl moiety of carbazole scafold of 6a. In addition, a
Table 3. Anticancer activity of hydrazide integrated carbazoles 6a-c.
Inhibition concentration; IC50 (µM)
Chemical
entities
MRC5
ARPE19
SW1990
22.42 ±
1.40
AsPC1
3.42 ±
0.41
6a
64.79 ±
5.91
65.57 ±
3.21
6b
6c
23.11 ±
3.28
25.28 ±
5.40
4.11 ±
0.69
4.69 ±
0.69
73.27 ±
3.19
52.22 ±
1.55
83.11 ±
3.09
63.33 ±
1.01
Gemcitabine
35.11 ±
2.22
40.19 ±
4.30
14.11 ±
3.20
19.77 ±
1.90
Cell death assay
To determine the mode of cell deaths induced by compound
6a, we quantified the apoptotic nucleosomes induced by 0.1%
DMSO, and compound 6a at IC50 22.4 µM (for SW1990) and 3.4
µM (for AsPC1). As shown in Figure 6, compound 6a
6 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 7 of 10
New Journal of Chemistry
Please do not adjust margins
Journal Name
carbon hydrogen interaction between imino carbon of the
synthesized ligand and a negatively charged polar hydrophilic
amino acid aspartate has also been noticed.
ARTICLE
1
2
3
4
5
6
7
8
Conclusions
View Article Online
DOI: 10.1039/C9NJ01912J
A series of bio-pertinent carbazole integrated molecules,
carbazolylmethylene isonictinohydrazides 6a-c has been
synthesized by employing multistep synthetic strategy.
Computational calculations have been performed on the
hydrazides 6a-c and their appropriate outcomes are compared
with the experimentally obtained results. In-vitro anticancer
evaluation of hydrazides 6a-c has been executed and the most
active ones among them are identified as 6a against AsPCl and
SW1990 (IC50 of 3.42 ± 0.41 µM and 22.42 ± 1.40 µM,
respectively). The 6a also showed selective anticancer effect
and sparing the non-cancerous cells (MRC5 and ARPE19). The
superior binding energy resulted from the in silico molecular
docking approach of the hydrazide 6a indicates its greater
affinity towards the receptor (binding energy: -8.63 kcal/mol
and IC50: 475.05 nM). Molecular docking study reveals that the
hydrazide 6a has higher binding energy indicating its greater
affinity towards the receptor. With a view to enhance the
anticancer activity further, the following structural
modifications on 6a would be suggested: a) alkyl substitution
on the nitrogen of the carbazole moiety may be reduced to
fewer numbers of carbons (i.e., <4), b) electron releasing
substituents may be incorporated at the peripheral of
carbazole unit, c) bromo susbstituent may be replaced by
other halogens, and d) various substituents may be integrated
on the other carbons of the aromatic structural motifs.
Besides, anticancer evaluation of the most active chemical
entity 6a could be executed against other types of cancer cells
as well. Research focusing on the aforementioned suggestions
is under progress in our laboratory with a view to develop a
potent anticancer drug molecule.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 7a. 3D interaction of 6a with BCL-2.
Experimental Section
General
Sigma melting point apparatus was utilized to measure melting
points and they are uncorrected. Shimadzu IR Tracer-100
(range, 400-4000 cm-1) with KBr pellet was used to record FT-
IR spectra of the synthesized compounds. The spectral
characteristics are expressed in wavenumber (cm-1). Bruker
400 and 100 MHz spectrometer was utilized to acquire 1H and
13C NMR spectra (internal standard, tetramethylsilane).
Chemical shifts are denoted in ppm from TMS. 1H NMR
splitting patterns are designated as singlet (s), broad singlet (br
s), doublet (d), triplet (t) and multiplet (m). JASCO V-650
spectrophotometer was used to record UV-Vis spectra,
acquired in dichloromethane (range, 200-800 nm). For
microanalyses, Vario MICRO system was used.
The precursors, carbazole based carbaldehydes 4a-c were
synthesized by adopting literature methods.16
Figure 7b. 2D interaction of 6a with BCL-2.
General procedure for synthesis of hydrazide integrated
carbazoles 6a-c
A mixture of carbazole-3-carbaldehydes 4a-c (0.002 mol) and
isoniazid (0.0022 mol) in ethanol (10 mL) was subjected to
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

Please do not adjust margins
New Journal of Chemistry
Page 8 of 10
ARTICLE
Journal Name
1
2
3
4
5
6
7
8
9
reflux for 2 h. The reaction progress was checked by TLC. The Computations of the novel hydrazides 6a-c ViehwaAvreticlebOenleinne
31
DOI: 10.1039/C9NJ01912J
reaction mass was cooled after the completion of the reaction accomplished utilizing Gaussian 09 software. The hybrid
and, a solid was formed which was separated by filtration. functional, Becke3-Lee-Yang-Parr correlation function32 has
After washing well with water, it was subjected to been employed. The frequencies of vibration computed at the
recrystallization utilizing ethanol as a solvent to get a pure mentioned levels have some logical errors (known). The scaling
sample.
factor33 of 0.96 has been utilized in order to fetch the
frequencies of theoretical in close proximity to the frequencies
of experimental. The absorption spectra (UV-Vis) have been
computed in solution phases by DFT (time dependent) with
B3LYP [6-311++G(d,p)] basis set. The chemical shifts of NMR
have been calculated at B3LYP [6-311++G(2d,p)] level
employing GIAO technique.34 The isotropic chemical shifts of
1H and 13C have been referenced with TMS, which has been
computed at the same level of theory.
Hydrazide integrated carbazole 6a
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
The compound 4a (0.5 g, 0.002 mol) was reacted with
compound
5 (0.3 g, 0.0022 mol) to form 6a as pale yellow
solid. Yield: 84%; Melting point: 165-167 °C; IR (KBr): νmax/cm-1,
3405, 3221, 3070, 2953, 2868, 1641, 1587, 1554, 1489, 1465,
1438, 1408, 1381, 1352, 1328, 1298, 1278, 1240, 1211, 1147,
975, 931, 891, 842, 798, 748, 680, 611, 426; UV (λmax, nm,
DCM): 344, 293; 1H NMR (400 MHz, CDCl3) δ 12.03 (1H, s), 8.80
(2H, d, J=4.4Hz), 8.79 (1H, s), 8.64 (1H, s), 7.22-8.51 (8H, m),
Cell lines and cell culture
4.38 (2H, t, J=6.9Hz), 1.70 (2H, m), 1.24 (2H, m), 0.87 (3H, t, Two human pancreatic cancer cells (AsPC1 and SW1990) were
J=6.8Hz); 13C NMR (100 MHz, CDCl3) 161.8, 150.7, 150.0, 141.7, purchased from the American Type Culture Collection, ATCC,
141.2, 140.9, 126.7, 125.3, 125.1, 123.7, 122.7, 122.4, 121.1, USA. All cells were cultured in RPMI-1640 medium
120.8, 119.8, 110.3, 110.1, 42.6, 31.1, 20.2, 14.1; Anal. Cald for supplemented with 10% fetal bovine serum, 100 IU/mL of
C23H22N4O: C, 74.57; H, 5.99; N, 15.12. Found: C, 74.76; H, 5.84; penicillin and 100 μg/mL of streptomycin (Sigma-Aldrich, St.
N, 15.01.
Louis, MO, USA). All pancreatic cancer cells were maintained at
an incubator maintained at 37 °C in 5% CO2, using the standard
in vitro cell culture method established previously.35-39
Hydrazide integrated carbazole 6b
The compound 4b (0.55 g, 0.002 mol) was reacted with
Cell viability assay
compound
5 (0.3 g, 0.0022 mol) to form 6b as pale yellow
solid. Yield: 87%; Melting point: 158-160 °C; IR (KBr): νmax/cm-1, In order to assess the anti-tumor effects of the synthetic
3587, 3213, 2960, 2935, 1637, 1587, 1548, 1490, 1465, 1436, compounds, all compounds were reconstituted to 100 mM
1386, 1354, 1327, 1303, 1280, 1247, 1217, 1149, 1066, 975, stock solution using dimethylsulfoxide, further diluted to
891, 846, 798, 750, 688, 611, 522; UV (λmax, nm, DCM): 337, sterile phosphate buffer saline to the highest effective
1
301; H NMR (400 MHz, CDCl3) δ 12.03 (1H, s), 8.80 (2H, d, concentration, 0.001 to 0.1 mM. The cells were treated based
J=4.0Hz), 8.64 (1H, s), 8.50 (1H, s), 7.23-8.29 (8H, m), 4.40 (2H, on the previously published cell viability assay.35,40 Briefly, all
br s), 1.76 (2H, br s), 1.21 (6H, br s), 0.78 (3H, t, J=6.9Hz); 13
C
cells were then seeded (1500 cells/well) in 384-well plates for
NMR (100 MHz, CDCl3) 161.8, 150.7, 150.0, 141.7, 141.2, 24 hours before treated with compounds for 72 hours. Cell
140.9, 126.7, 125.3, 125.1, 123.7, 122.7, 122.4, 122.0, 121.1, viability was quantified using the Cell-Titre Glo Luminescent
120.8, 119.8, 110.3, 110.1, 42.8, 31.4, 28.9, 26.5, 22.4, 14.2; Cell Viability Assay (Promega, USA). The luminescence readings
Anal. Cald for C25H26N4O: C, 75.35; H, 6.58; N, 14.06. Found: C, were recorded using SpectraMax M3 microplate reader
75.54; H, 6.67; N, 13.92.
(Molecular Devices Corporation, USA). IC50, concentration that
inhibits 50% cell viability was determined from three
independent dose response studies. The gold standard
chemotherapy for pancreatic cancer, gemcitabine was served
as positive control while DMSO (0.1%) served as vehicle
control in this study.
Hydrazide integrated carbazole 6c
The compound 4c (0.66 g, 0.002 mol) was reacted with
compound
5 (0.3 g, 0.0022 mol) to form 6c as pale yellow
solid. Yield: 79%; Melting point: 176-178 °C; IR (KBr): νmax/cm-1,
3400, 3221, 2953, 2870, 1643, 1589, 1555, 1491, 1468, 1439,
1408, 1383, 1352, 1329, 1298, 1281, 1244, 1213, 1148, 976, Cell death assay
932, 843, 799, 748, 683, 426; UV (λmax, nm, DCM): 333, 299; 1H
In order to quantify the degree of apoptotic cell death induced
NMR (400 MHz, CDCl3) δ 12.02 (1H, s), 8.79 (2H, d, J=4.4Hz),
8.63 (1H, s), 8.50 (1H, s), 8.25 (1H, d, J=7.6Hz), 7.24-7.93 (6H,
m), 4.44 (2H, t), 1.77 (2H, m), 1.31 (2H, m), 0.88 (3H, t,
J=6.4Hz); 13C NMR (100 MHz, CDCl3) 161.8, 150.7, 150.0,
141.7, 141.4, 141.2, 140.9, 126.7, 125.4, 125.1, 124.0, 123.7,
122.7, 122.4, 122.0, 121.1, 120.8, 119.8, 110.2, 110.1, 42.6,
31.1, 20.2, 14.1; Anal. Cald for C23H21BrN4O: C, 61.48; H, 4.71;
N, 12.47. Found: C, 61.63; H, 4.60; N, 12.34.
by the compounds 6a, human pancreatic cancer cells (SW1990
and AsPC1) were treated for 72 hours and the nucleosomes
were quantified by sandwich enzyme immunoassay principle
using the Cell Death Detection ELISAPLUS kit (Roche Diagnostics,
Indianapolis, U.S.A.) as described in previous study.38 The
enrichment factors of apoptosis were quantified based on the
absorbance of cells treated with compound over absorbance
of cells treated with vehicle control (0.1% DMSO).
Computational details
8 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 9 of 10
New Journal of Chemistry
Please do not adjust margins
Journal Name
ARTICLE
1
2
3
4
5
6
7
8
9
18 R. Narang, B. Narasimhan and S. Sharma, Curr.VMieweAdr.ticClehOenmlin.e,
2012, 19, 569-612.
Conflict of interest
The authors declare no conflict of interest.
19 P. Vicini, F. Zani, P. Cozzini and I. DoyDtcOhIi:n1o0.v1a0,39E/uCr9.NJJ.0M19e12dJ.
Chem., 2002, 37, 553-564.
20 J. R. Dimmock, S. C. Vashishtha and J. P. Stables, Eur. J. Med.
Chem., 2000, 35, 241-248.
21 N. Belkheiri, B. Bouguerne, F. Bedos-Belval, H. Duran, C.
Bernis, R. Salvayre, A. Negre-Salvayre and M. Baltas, Eur. J.
Med. Chem., 2010, 45, 3019-3026.
22 U. Salgın-Goksen, N. Gokhan-Kelekci, O. Goktas, Y. Koysal, E.
Kilic, S. Isik, G. Aktay and M. Ozalp, Bioorg. Med. Chem.,
2007, 15, 5738-5751.
23 H. He, X. Wang, L. Shi, W. Yin, Z. Yang, H. He and Y. Liang,
Bioorg. Med. Chem. Lett., 2016, 26, 3263-3270.
24 O. I. El-Sabbagh and H. M. Rady, Eur. J. Med. Chem., 2009,
44, 3680-3686.
Acknowledgements
Financial assistance provided by the Indian Council of Medical
Research, New Delhi (No.58/16/2013BMS) and Kalasalingam
Academy of Research and Education (PDF to KG) is gratefully
acknowledged.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Notes and references
1
Cancer
-
World
Health
Organization,
25 P. P. T. Sah and S. A. Peoples, J. Pharm. Sci., 1954, 43, 513-
524.
26 D.-X. Cao, G.-Z. Li, G. Xue, W.-T. Yu and Z.-Q. Liu, Acta
Crystallogr., 2005, E61, o977-o979.
http://who.int/cancer/en (accessed January 2019).
2
National Cancer Institute:
Comprehensive Cancer
Inormation, http://www.cancer.gov (accessed on January
2019).
A. I. Baba, Comparative Oncology, Chapter 3, Bucharest: The
Publishing House of the Romanian Academy, Romania, 2007.
R. V. J. Chari, Acc. Chem. Res., 2008, 41, 98-107.
Y. Cheng, L. Zhao, Y. Li, T. Xu, Chem. Soc. Rev., 2011, 40
2673-2703.
27 W. Sun, W.-M. Liu and S.-L. Li, Acta Crystallogr., 2014, E70
,
3
o884.
28 B. H. Stuart, Infrared Spectroscopy: Fundamentals and
Applications, John Wiley and Sons, Chichester, UK, 2004.
29 G. Socrates, Infrared and Raman Characteristic group
Frequencies, Tables and Charts, 3rd Ed., Wiley, Chichester,
2001.
30 I. Fleming, Frontier orbitals and organic chemical reactions,
Wiley-Blackwell, New York, 1976.
31 M. J. Frisch, Gaussian 09, Revision E.01, Gaussian, Inc.,
Wallingford, CT, 2009.
32 (a) C. Lee, W. Yang and R. G. Parr, Phys. Rev., 1988, B37, 785-
789; (b) A. D. Becke, J. Chem. Phys., 1993, 98, 5648-5652.
33 G. Rauhut and P. Pulay, J. Phys. Chem., 1995, 99, 3093-3100.
34 K. Wolinski, J. F. Hinton and P. Pulay, J. Am. Chem. Soc.,
1990, 112, 8251-8260.
4
5
,
6
7
(a) A. Gluszynska, Eur. J. Med. Chem., 2015, 94, 405-426; (b)
F.-F. Zhang, L.-L. Gan and C.-H. Zhou, Bioorg. Med. Chem.
Lett., 2010, 20, 1881-1884; (c) L. Hu, Z.-R. Li, Y. Li, J. Qu, Y.-H.
Ling, J.-D. Jiang and D. W. Boykin, J. Med. Chem., 2006, 49
,
6273-6282.
(a) S.-P.Tan, A. Manaf Ali, M. A. Nafiah, K. Awang and K.
Ahmad, Tetrahedron, 2015, 71
, 3946-3953; (b) A. W.
Schmidt, K. R. Reddy and H.-J. Knolker, Chem. Rev., 2012,
112, 3193-3328; (c) H.-J. Knolker and K. R. Reddy, Chem.
Rev., 2002, 102, 4303-4428.
H. Hagiwara, T. Choshi, H. Fujimoto, E. Sugino and S. Hibino,
Tetrahedron, 2000, 56, 5807-5811.
C. Sherer and T. J. Snape, Eur. J. Med. Chem., 2015, 97, 552-
560.
8
9
35 J. L. Er, P. N. Goh, C. Y. Lee, Y. J. Tan, L.-W. Hii, C. W. Mai, F.
F.-L. Chung and C.-O. Leong, Apoptosis, 2018, 23, 343-355.
36 F. F.-L. Chung, P. F. T. M. Tan, V. J. Raja, B.-S. Tan, K.-H. Lim,
T.-S. Kam, L.-W. Hii, S. H. Tan, S.-J. See, Y.-F. Tan, L.-Z. Wong,
W. K. Yam, C. W. Mai, T. D. Bradshaw and C.-O. Leong, Sci
10 R. Sancho, M. Medarde, S. Sanchez-Palomino, B. M.
Madrigal, J. Alcami, E. Munoz and A. S. Feliciano, Bioorg.
Med. Chem. Lett., 2004, 14, 4483-4486.
11 L. Hu, Z.-R. Li, Y. Li, J. Qu, Y.-H. Ling, J.-D. Jiang and D. W.
Boykin, J. Med. Chem., 2006, 49, 6273-6282.
12 B. P. Bandgar, L. K. Adsul, H. V. Chavan, S. S. Jalde, S. N.
Shringare, R. Shaikh, R. J. Meshram, R. N. Gacche and V.
Masand, Bioorg. Med. Chem. Lett., 2012, 22, 5839-5844.
13 (a) C. Asche and M. Demeunynck, Anti-Cancer Agents Med.
Rep., 2017,
7, 1-13.
37 K. Y. Yeong, S. C. Tan, C.
‐
W. Mai, C.‐O. Leong, F. F.‐L. Chung,
Y. K. Lee, C. F. Chee and N. A. Rahman, Chem. Biol. Drug Des.,
2018, 91, 213-219.
38 C.‐W. Mai, Y.‐B. Kang, V. D. Nadarajah, A. S. Hamzah and M.
R. Pichika, Phytother. Res., 2018, 32, 1108-1118.
39 C. W. Mai, K. S. I. Yap, M. T. Kho, N. H. Ismail, K. Yusoff, K
Shaari, S. Y. Chin and E. S. H. Lim, Front. Pharmacol., 2016, 7,
Chem., 2007, 7, 247-267; (b) A. Caruso, D. Iacopetta, F. Puoci,
A. R. Cappello, C. Saturnino and M. S. Sinicropi, Mini Rev.
Med. Chem., 2016, 16, 630-643.
1-11.
40 H.-C. Soo, F. F.-L. Chung, K.-H. Lim, V. A. Yap, T. D. Bradshaw,
L.-W. Hii, S.-H. Tan, S.-J. See, Y.-F. Tan, C.-O. Leong and C.-W.
Mai, PLoS One, 2017, 12, 1-20.
14 K. R. Justin Thomas, J. T. Lin, Y.-T. Tao and C.-H. Chuen,
Chem. Mater., 2004, 16, 5437-5444.
15 J. Kim, Y. S. Kwon, W. S. Shin, S.-J. Moon and T. Park,
Macromol., 2011, 44, 1909-1919.
16 (a) A. Karuppasamy, K. Stalindurai, J. D. Peng, K.-C. Ho and C.
Ramalingan, Electrochim. Acta, 2018, 268, 347-357; (b) K.
Stalindurai, A. Karuppasamy, J.-D. Peng, K.-C. Ho, A.
Tamilselvan and C. Ramalingan, Tetrahedron, 2017, 73, 278-
289; (c) K. Stalindurai, A. Karuppasamy, J.-D. Peng, K.-C. Ho
and C. Ramalingan, Electrochim. Acta, 2017, 246, 1052-1064;
(d) A. Karuppasamy, K. Stalindurai, J. D. Peng, K.-C. Ho and C.
Ramalingan, Phys. Chem. Chem. Phys., 2016, 18, 30105-
30116.
17 P. D. McCrary, P. A. Beasley, G. Gurau, A. Narita, P. S.
Barber, O. A. Cojocaru and R. D. Rogers, New J. Chem., 2013,
37, 2196-2202.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 9
Please do not adjust margins

New Journal of Chemistry
Page 10 of 10
1
2
3
4
View Article Online
DOI: 10.1039/C9NJ01912J
Table of content
5
6
7
8
9
Hydrazide integrated carbazoles: synthesis, computational, anticancer and
molecular docking studies
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Kannan Gokula Krishnan, Pathinettampadi Ashothai, Krishnaraj Padmavathy, Wei-Meng Lim,
Chun-Wai Mai, Punniyakoti V Thanikachalam Chennan Ramalingan*
Novel carbazolylmethylene isonictinohydrazides have been synthesized as anticancer agents against
pancreatic cancer cells.