Design, click conventional and microwave syntheses, DNA binding, docking and anticancer studies of benzotriazole-1,2,3-triazole molecular hybrids with different pharmacophores

Article abstract of DOI:10.1016/j.molstruc.2020.129192

Despite the availability of some drugs, there is an urgent need for effective anti-cancer medication. It is due to various side effects and non-functionality of the present drugs; especially at the late stage of cancer. Therefore, three series (4a-e, 6a-e and 8a-j; 21 compounds) of benzotriazole-1,2,3-triazole hybrids (carrying different pharmacophores) have been designed and synthesized (by both conventional and microwave syntheses) through the Cu(I)-catalyzed click 1,3-dipolar cycloaddition reaction of the propargylated benzotriazole with the appropriate aliphatic, aromatic and phenyl/benzyl acetamide azides. The syntheses times were from 6 to 12 h and 4 to 8 min in conventional and microwave syntheses. The yields were 80 to 86percent and 89 to 95percent in conventional and microwave syntheses; confirming microwave synthesis as an economic and eco-friendly method. These compounds were characterized by proper spectroscopic methods. The anticancer activities with A549 and H1299 lung cancer cell lines were in the range of 70.0 to 90.0percent for 4a-e series, 78.0 to 90.0percent for 6a-e series and 81.0 to 90.0percent for 8a-j series. The reported compounds showed good DNA binding constants in the range of 1.3 × 10³ to 11.90 × 10⁵ M^?1. The docking results suggested strong DNA bindings of the reported compounds in the minor grooves of DNA; through hydrogen bonding and hydrophobic interactions. The quite good anticancer activities and high DNA binding constants have indicated that the reported molecules may be future anticancer agents.

Full text of DOI:10.1016/j.molstruc.2020.129192

Journal of Molecular Structure 1225 (2021) 129192
Contents lists available at ScienceDirect
Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstr
Design, click conventional and microwave syntheses, DNA binding,
docking and anticancer studies of benzotriazole-1,2,3-triazole
molecular hybrids with different pharmacophores
Shaya Yahya Alraqaa, Khalid Alharbia, Ateyatallah Aljuhania, Nadjet Rezkia,
Mohamed Reda Aouada, Imran Alia,b,∗
a Department of Chemistry, College of Science, Taibah University, Al-Madinah Al-Munawarah 30002, Saudi Arabia
b Department of Chemistry, Jamia Millia Islamia (A Central University), New Delhi 110025, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Despite the availability of some drugs, there is an urgent need for effective anti-cancer medication. It
is due to various side effects and non-functionality of the present drugs; especially at the late stage
of cancer. Therefore, three series (4a-e, 6a-e and 8a-j; 21 compounds) of benzotriazole-1,2,3-triazole hy-
brids (carrying different pharmacophores) have been designed and synthesized (by both conventional and
microwave syntheses) through the Cu(I)-catalyzed click 1,3-dipolar cycloaddition reaction of the propar-
gylated benzotriazole with the appropriate aliphatic, aromatic and phenyl/benzyl acetamide azides. The
syntheses times were from 6 to 12 h and 4 to 8 min in conventional and microwave syntheses. The yields
were 80 to 86% and 89 to 95% in conventional and microwave syntheses; confirming microwave synthesis
as an economic and eco-friendly method. These compounds were characterized by proper spectroscopic
methods. The anticancer activities with A549 and H1299 lung cancer cell lines were in the range of 70.0
to 90.0% for 4a-e series, 78.0 to 90.0% for 6a-e series and 81.0 to 90.0% for 8a-j series. The reported com-
Received 6 May 2020
Revised 29 August 2020
Accepted 1 September 2020
Available online 2 September 2020
Keywords:
Benzotriazole-1,2,3-triazole
Conventional and microwave synthesis
DNA binding
Docking study
Anticancer activity
pounds showed good DNA binding constants in the range of 1.3 × 103 to 11.90 × 105
M
−1. The docking
results suggested strong DNA bindings of the reported compounds in the minor grooves of DNA; through
hydrogen bonding and hydrophobic interactions. The quite good anticancer activities and high DNA bind-
ing constants have indicated that the reported molecules may be future anticancer agents.
© 2020 Elsevier B.V. All rights reserved.
1. Introduction
quite interesting that the 1,2,3-triazoles can form non-covalent in-
teractions like hydrogen bonds, hydrophobic interactions, Van der
Cancer is one of the most deadly diseases and the leading cause
of a large number of global deaths. As per the World Health Orga-
nization (WHO) 2018, the latest estimate is 9.6 million deaths and
18.1 million clinical cases, which are in constant increase; espe-
cially in developing countries [1]. Although great efforts have been
made in the field of cancer prevention and treatment over the last
few decades yet success remains a challenge. Azoles derivatives
are one of the crucial structural nitrogen-containing heterocycles,
which exhibited numerous biological activities and have attracted
considerable attention from medicinal chemists. In particular, the
five-membered ring triazoles including 1,2,3-triazole, 1,2,4-triazole
and benzofused triazole as well as their derivatives usually have
remarkable pharmacological properties such as anticancer [2,3],
antifungal [4], antibacterial [5,6] and antiviral [7] activities. It is
Waal’s forces and dipole-dipole bonds with DNA and other cell bio-
molecules; altering biological activities [8].
Recently, molecular hybridization is a well-known and effective
linking approach in the medicinal chemistry, which consists of the
combination of two or more bioactive molecules in a new sin-
gle chemical framework. It is capable to modulate multiple targets
of interest in the development of new synthetic hybrid molecules
called drug-like-properties [9,10]. Thus, to address the challenge
in this strategy, the selection of the privileged core from linker-
to fragment-based hybrids was the critical issue for impacting the
synergetic effect of the right target combination compared to the
parental compounds [11–16]. Up to date, there are several hybrid
molecules, which have been launched to the clinical trials for the
conduct of various diseases. Hybridization of 1,2,3-triazole frame-
work with other pharmacophores has become progressively useful
and significant in building bioactive and useful molecules [17–19].
∗
Corresponding author.
E-mail addresses: drimran.chiral@gmail.com, drimran_ali@yahoo.com (I. Ali).
https://doi.org/10.1016/j.molstruc.2020.129192
0022-2860/© 2020 Elsevier B.V. All rights reserved.

2
S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
the literature [32]. The IR spectrum showed the absence of the -NH
absorption band and the appearance of two characteristic sharp
absorption bands at 2150 and 3300 cm−1 credited to the alkyne
(-C C-) and ( C H) group, respectively. In addition, the 1H NMR
≡
≡ –
spectrum also revealed the disappearance of the benzotriazole -
≡ –
NH proton and the presence of the diagnostic propargyl C H and
-NCH2 protons as two singlets at δH 3.61 and 5.74 ppm. The sig-
≡
nals belonging to these carbons (-NCH2 and -C C-) resonated at δC
37.77, 77.38 and 77.66 ppm, respectively. These results confirmed
the incorporation of a propargyl group in the structure of benzo-
triazole.
Scheme 1. Propargylation of the benzotriazole 1.
The click 1,3-dipolar cycloaddition reaction of benzotriazole-
based alkyne 2 with several un/functionalized aromatic azides 3a-
e; catalyzed by copper sulfate and sodium ascorbate in DMSO:H2O
(1:1, v/v) at room temperature for 12 hr; afforded the targeted
benzotriazole-1,2,3-triazole molecular conjugates 4a-e in 80–83%
yields (Scheme 2). It should be noted that the aromatic azides 3a-e
were prepared according to the reported procedure [33] via diazo-
tization of the respective anilines by sodium nitrite in HCl followed
by treatment with sodium azide.
The main efforts in our laboratory have been focused on the
development of new methodologies for the syntheses of new het-
erocyclic hybrid molecules starting from some biologically active
functionalized moieties and chiral separation [22–25]. Amongst
these, the benzotriazole [20,21] and 1,2,3-triazole derivatives [22–
24] were selected as privileged scaffolds for library design and de-
velopment of targeted drug candidates. Moreover, the presence of
several functionalities in their structures becomes a subject of cur-
rent interest for exalting their biological properties [26]. In this
respect, we report herein the hybridization of benzotriazole and
1,2,3-triazoles with several functionalities, including amide, ke-
tone, ester and/or carboxylic acid; via click conventional and mi-
crowave routes, as a continuation of our previous work on the use
of microwave technology in our laboratory [27,28,29,30,31]. These
molecules were screened for their anticancer activities on the dif-
ferent cell lines. To determine the anti-cancer mechanism DNA
binding and docking studies are also performed. The results re-
ported herein.
The structures of the click products 4a-e have been recognized
on the basis of their spectroscopic data. In their IR spectra, the
≡
absence of the characteristic alkyne absorption bands (-C C and
≡ –
C H) of their precursor 2 established the achievement of the click
reaction. The 1H NMR spectra also confirmed the disappearance of
≡ –
the alkyne proton C H and the appearance of a distinct singlet
attributable to the 1,2,3-triazole proton at δH 9.06–9.19 ppm. Also,
the presence of a phenyl ring in the structure of the 1,2,3-triazole
4a-e at position N-1 was clearly evidenced through the appearance
of 3 to 4 additional aromatic protons in the aromatic region. The
involvement of the alkyne group in the click reaction was also sup-
ported by 13C NMR analysis which exposed the vanishing of the
2. Results and discussion
≡
signals assigned to the -C C- carbons and the appearance of extra
2.1. Chemistry
aromatic signal carbons.
The synthesis of the benzotriazole-1,2,3-triazole hybrids (carry-
ing un/functionalized alkyl side chain 6a-e) required first the syn-
thesis of the appropriate alkyl azides 5a-e through the azidolysis
of their alkyl halide analogs with sodium azide in acetone:water
(1:1) according to the previous procedure [34]. Then, the click liga-
tion of the azide building block of the freshly prepared alkyl azides
5a-e with the alkyne group of compound 2; using the same Cu(I)-
catalyzed click synthesis described previously; led to the formation
of the benzotriazole-based click products 6a-e in 83–86% yields
(Scheme 3).
In the present work, the click synthetic methodology has been
adopted for the synthesis of
a series of novel benzotriazole-
1,2,3-triazole hybrids carrying different pharmacophoric center un-
der conventional and microwave circumstances, as illustrated in
Schemes 1,2,3,4.
2.1.1. Conventional assisted organic synthesis
The click reaction required first the synthesis of the propargy-
lated benzotriazole 2 via base assisted alkylation of benzotriazole
(1) with propargyl bromide in the attendance of potassium carbon-
ate as base and DMF as solvent (Scheme 1). The reaction required
heating 2 hr at 80 °C to afford alkyne derivative 2 in 90% yield.
The structure of compound 2 has been deduced from its spec-
tral data (IR, 1H NMR and 13C NMR), which are in agreement with
The formation of the click products 6a-e has been shown by
1H NMR analyses through the absence of the terminal hydrogen
≡ –
of the C H group and the presence of a diagnostic singlet in the
aromatic region at δH 8.21–8.30 ppm typical for the C-5H proton of
Scheme 2. Click synthesis of benzotriazole-1,2,3-triazole hybrids carrying un/functionalized aromatic side-chain 4a-e.

S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
3
Scheme 3. Click synthesis of benzotriazole-1,2,3-triazole hybrids carrying un/functionalized alkyl side chain 6a-e.
Scheme 4. Click synthesis of benzotriazole-1,2,3-triazole hybrids carrying un/functionalized phenyl and/or benzyl acetamide side-chain 8a-j.
the triazole ring. Besides, the spectra of compounds 6c-e exposed
the attendance of two singlets at δH 6.09–6.13 and 5.36–6.14 ppm
assigned to the protons bonded to NCH2 and NCH2CO, respectively.
Four extra aromatic protons were also recorded in the aromatic
region related to the p-substituted phenyl ring for compounds 6d
and 6e. The success of the click synthesis for the formation of the
1,2,3-triazole scaffold 6a-e was also confirmed by 13C NMR analy-
cleophilic acylation of the appropriate anilines and/or ben-
zyl amines with chloroacetyl choride followed by azidolysis of
the resulting chloroacetamide intermediates with sodium azide
[36].
The 1H NMR spectra of all amide-based click products 8a-j were
investigated by the presence of a diagnostic signal in the downfield
area at δH 8.76–11.09 ppm connected to the amide -NH proton.
Besides, three to five extra protons were recorded in the aromatic
region assignable to the aryl side chain appended to the acetamide
linkage. The 13C NMR analysis also evidenced the success of the
click reaction via the appearance of the characteristic acetamide
methylene (-CH2) and carbonyl (-C = O) carbon at δC 52.04–52.78
and 164.31–165.92 ppm, respectively.
≡
sis where the absence of the -C C- carbons was obvious in their
spectra. The spectra also revealed the appearance of new signals at
δC 56.15–56.31 and 190.76–192.41 ppm, which were attributed, re-
spectively, to the methylene (-CH2) and carbonyl (-C = O) carbons
of the phenacyl side chains in compounds 6d and 6e. It should be
noted that compound 6a has been previously reported in the lit-
erature with similar proton NMR pattern to that reported in the
present manuscript [35].
2.1.2. Microwave assisted organic synthesis
On the other hand, a series of novel amide based benzotriazole-
1,2,3-triazole molecular conjugates 8a-j have been successfully
synthesized in 80–84% yields; under the same optimized Cu(I)-
catalyzed click conditions; through the coupling of the propar-
Microwave-assisted propargylation of benzotriazole (1) for
2 min afforded the desired benzotriazole-based alkyne 2 in 98%
yield (Table 1). On the other hand, the benzotriazole-1,2,3-triazole
hybrids 4a-e, 6a-e and 8a-j were prepared in respectable yields
(89–95%) when the click reactions were assisted by microwave ir-
radiations for 4–8 min (Table 1).
gylated benzotriazole
2 with different phenyl and/or ben-
zyl acetamide azides 7a-j. The latter was prepared by nu-

4
S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
Table 1
ergy, man-power, costly chemicals and operational simplicity. This
microwave-assisted method may be highly useful as an alternative
eco-friendly source of energy characterized by a significant reduc-
tion in reaction time and improvement of reaction yield, as well as
high purity.
MAOS versus conventional synthesis of 1,2,3-triazoles 4a-e, 6a-e and 8a-j: times
and yields.
Compound
No
Conventional
procedure (CP)1
Microwave
procedure (MWI)2
Time (h)
Yield (%)
Time (min)
Yield (%)
2.2. DNA binding study
2
2
90
82
81
83
80
81
86
85
86
83
84
83
84
84
82
82
84
83
80
81
81
2
8
8
8
8
8
4
4
4
6
6
6
6
6
6
7
7
7
7
7
7
98
90
89
90
89
89
95
94
94
93
94
93
94
93
91
91
94
93
91
92
91
4a
4b
4c
4d
4e
6a
6b
6c
6d
6e
8a
8b
8c
8d
8e
8f
12
12
12
12
12
6
The UV spectra of Ct-DNA in buffer presented 2 peaks at 280
and 260 nm in the ratio of 1.9:1.0 which showed protein-free na-
ture [37]. The concentration of DNA was estimated by molar ab-
sorption coefficient ε260 = 6600 L mol−1.cm−1 [38]. The equal
quantity of DNA was added to both reference and the other solu-
tions for the removal of DNA absorbance. The absorption titration
trials were led by variable the amount of DNA with a fixed amount
of compounds.
6
6
8
8
8
DNA is an important pharmacological target of drugs in sev-
eral diseases chiefly cancer. There are numerous methods to study
DNA and drug interactions but, absorption spectroscopy is a mod-
est and powerful instrument. The absorption spectra of the most
active compounds of 4e, 6b and 8d are given in Fig. 1, whereas
the others are stated in the supplementary information. In the ab-
sence of Ct-DNA, the compounds showed absorbance in the range
of 262–302 nm in tris-buffer at biological pH. With adding of dif-
ferent amounts (1.5 × 10−5, 1.3 × 10−5 and 1.1 × 10−5) of Ct-
DNA to the fixed amount of compounds (1.6 × 10−4 M), the ab-
sorption strength of these compounds showed both hypochromism
and hyperchromism and varied from one compound to other. Nor-
mally, both hypochromism and hyperchromism are the features
detected in spectrophotometric titration of minor molecules with
Ct-DNA [39–42]. Hypochromism is usually characterized by non-
covalently intercalative bindings of the complexes with DNA [43],
while hyperchromism most possibly is related to hydrogen bond-
ings or electrostatic [44]. The compounds showing hyperchromism
to DNA are detected in grooves binding cases. The binding co-
efficients of compounds were intended using Benesi–Hildebrand
equation [45]. The compounds 4e and 6b showed hyperchromism
while compound 8d showed hypochromism (Fig. 1). It is clear
from the spectra that the variation in λmax was from 265 to
266 nm (total change 1 nm) with 86.82% hyperchromism for com-
8
8
8
10
10
10
10
10
10
8 g
8h
8i
8j
1
CP: alkyne 2 (1 equiv.), azides3a-e, 5a-e and 7a-j (1 equiv.), copper sulfate (0.4
eq), sodium ascorbate (0.75 eq), DMSO: H2O (1:1), room temperature.
2
MWI: alkyne 2 (1 equiv.), azides3a-e, 5a-e and 7a-j (1 equiv.), copper sulfate
(0.4 eq), sodium ascorbate (0.75 eq), DMSO: H2O (1:1), 300 W, 80 °C.
2.1.3. Comparison of conventional and microwave assisted organic
syntheses
A comparison of the click conventional and microwave-assisted
syntheses is given in Table 1, which showed clearly that the time
required for completion of the reactions in click conventional syn-
theses were varied from 6 to 12 h while these times in click mi-
crowave syntheses were ranged from 4 to 8 min. Besides, the per-
cent yields were from 80 to 86% in click conventional synthe-
ses while the values of yield were varied from 89 to 95%. There-
fore, it may be mentioned here that microwave-assisted synthe-
ses of the reported molecules are highly economic saving en-
Table 2
Wavelength shifts, % hypochromism and binding constants of 2, 4a-e, 6a-e and 8a-j.
c
Compound
λmax (free)
λmax (bound to DNA)
Change
%Chromisma,b
Kb (M−1
)
2
212 nm
216 nm
214 nm
267 nm
261 nm
265 nm
212 nm
212 nm
270 nm
213 nm
213 nm
214 nm
214 nm
214 nm
217 nm
217 nm
217 nm
215 nm
275 nm
214 nm
213 nm
212 nm
217 nm
214 nm
267 nm
261 nm
266 nm
212 nm
214 nm
273 nm
212 nm
213 nm
214 nm
214 nm
214 nm
220 nm
219 nm
217 nm
215 nm
271 nm
215 nm
213 nm
0
0.00a
1.3 × 105
1.57 × 105
2.6 × 105
3.33 × 105
11.9 × 105
7.0 × 105
6.0 × 105
7.5 × 105
10.2 × 105
2.0 × 105
5.5 × 105
3.4 × 105
1.9 × 105
2.7 × 105
3.8 × 105
4.5 × 105
4.0 × 105
8.6 × 105
10.1 × 105
6.57 × 105
7.2 × 105
4a
4b
4c
4d
4e
6a
6b
6c
6d
6e
8a
8b
8c
8d
8e
8f
1
37.81a
46.55a
59.03a
4.00a
0
0
0
1
86.82a
a
0
36.81
2
74.44a
24.95a
27.78a
36.26a
26.45b
36.97a
29.21a
45.46b
45.31a
39.14a
47.59a
119.34b
49.58a
31.51a
3
−1
0
0
0
0
3
2
0
8 g
8h
8i
0
−4
1
8j
0
a
% Hyperchromicity (H%)= [Af − Ab)/Af] × 100, where Af and Ab represent the absorbance of free
and bound compounds and.
b
Hyporchromicity.
c
Binding constants.

S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
5
Fig. 1. DNA binding curves for 4e, 6b and 8d compounds.
pound 4e. Likewise, for 6b showed the variation in λmax from
2.3. Anticancer study
212 to 214 nm (total change 2 nm) with 74.44% hyperchromism.
Contrarily, 8d showed hypochromism of 45.46% with changes in
λmax from 217 to 220 (total change 3 nm). All these compounds
showed bathochromic shifts. These variations showed that these
compounds (4e, 6b and 8d) have interacted with Ct-DNA via non-
covalently intercalations, which could be owing to the stacking
interactions between two chromophores. The intrinsic DNA bind-
ing coefficients were calculated for all compounds ranging from
1.3 × 103 to 11.90 × 105 M−1 (Table 3). In addition to these
three compounds, the compounds 2, 4a, 4b, 4c, 4d, 6a, 6c, 6d,
6e, 8b, 8c, 8e, 8f, 8 g, 8i and 8j showed hypochromism while
hyperchromism was shown by 8a and 8 h compounds. The hyp-
sochromic shift was shown by 6d and 8 h compounds while
the bathocromic shift was shown by 4a, 6b, 6c, 8e, 8i com-
pound. These changes are the signs of the sensible bindings of
compounds with DNA. Lastly, high values of Kb confirmed that
the compounds have a good attraction towards Ct-DNA. It can
be said that they showed a slight effect in the case of bind-
ing with DNA. These can be measured as non-covalent binders
[46,47,48,49].
In vitro% inhibitions of A549 and H-1229 lung cancerous cells
were determined at 50, 100, 200, 300 and 400 μg/mL amounts of
the compounds. The outcomes are given in Figs. 2 and 3 (% via-
bility). Initially, the molecules were dissolved in 0.1% DMSO and
the cells with DMSO were applied as vehicle controllers. Then,
the growth of the molecules was delayed until the control cells
touched at the sluggish phase. The cells were counted after 24 hrs.
The propagation step for the cells was increased with growing
concentrations of the compounds. The results showed the impor-
tant reticence in cancer cell proliferation. Three series of the com-
pounds i.e. 4a-e, 6a-e and 8a-j were screened. The activities of
the reported compounds were compared with the concentration of
400 μg/mL.
It is clear from Fig. 2 that the percentage viability for 4a-e se-
ries was in the range of 16 to 22% (% inhibition 78 to 84%) with
A549 cell line with minimum viability by compound 4e (16%). In
the series of 6a-e the percentage viability was ranging from 11 to
22% (% inhibition 78 to 89) with A549 cell line with minimum vi-
ability by compound 6b (11%). Similarly, the percentage viability in

6
S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
Table 3
The docking results of the reported compounds.
Compounds No
2
Binding energy (kcal mol−1
)
No. of H bonds
Residues involved in H-bonding (Bond length)
Hydrophobic interaction
−3.6
2
244/B/DC‘13/O2::N of
-N= group (3.5)
dt8::C1,C2,C3&C4
dc9:: C3,C5,C6,C8 & N2
dc15::C3&C6
016/A/DG‘12/N1::N of
-N= group (3.5)
4a
4b
−4.6
−4.8
1
1
624/B/DC‘15/OP2:: O of
-NO2 group (3.5)
dt8::C2,C3,C12,C6,C10 & N7
dc9:: C2 & C3
dc13:: O2,N3,O1 & C7
dc15::C11, C13 & C15
dt8::C2,C4,C13,C11 & N6
dc9:: C2 & C4
263/A/DG‘10/O6::N of
-N= group (3.4)
dc13:: C11 & C12
dc15::C12, C14& C15
dg14::C7
4c
4d
4e
6a
6b
−4.7
−4.7
−4.4
−4.5
−4.8
1
1
1
2
2
624/B/DG‘14/OP2:: N of -N= group (3.5)
dt8::C1 & C2
dc9:: C1 & C2
dg10:: C17
dg14::C3,C4,C5,C6,C9 & C10
dc15::C4,C6 & C13
dt8::C1 & C2
624/B/DC‘15/OP2:: O of
-NO2 group (3.3)
dc9:: C1,C2 & C7
dg14:: C3,C4,C5,C6,C9,C10 & C12
dc15::C12
dg10::C15
624/B/DC‘15/OP2:: O of
dt8::C8,N2 & N3
dc9:: N2 & C17
-COO- group (3.3)
dg10:: C13
dc15::C5,C6,C9,C10,C11,C13& C18
dg14:: C3,C5,C9,C16 & C18
dt8::N3
127/A/DC‘9/N4::N of
-N= group (3.5)
dc13:: C3,C8 & C1
dg10:: C15
.127/B/DC‘15/N4::N of
-N= group (3.6)
dc15::C4,C10,C11,C12 & C13
dg14:: C15
127/B/DC‘15/N4::N of
-N= group (3.6)
dt8::C1 &C3
dc9:: C2,C3 & C6
dg10:: C17 & C11
dc15::C3,C4,C5,C9,C12 & C17
dg14:: C12,C15 & C17
dg16::C1
.624/B/DG‘14/OP2::O of
-O- group (3.3)
6c
−4.1
1
624/B/DC‘15/OP2:: O of
dt8::C1,C2,C3&C4
dc9:: C4 & N3
-COO- group (3.5)
dg10:: C5
dc15::C9
dg13:: C10 & O2
dg14::C5,C10 & N2
dt8::C3,C17,C18 & O1
dc9:: C12,C17 & N5
dg10:: C12,C14 & C15
dc15::C7,C10,C16 & O2
dg14:: C1,C2 & C5
dt8::N2
6d
6e
−4.5
−5.1
1
1
263/A/DG‘10/O6::N of
-N= group (3.6)
127/B/DC‘15/N4:: O of
-CO- group (3.4)
dc9:: C15,C16 & N15
dg10:: C7 & C15
dc15::C3,C4,C10,C11,C13 & C18
dg14:: C2,C7 & C10
dc13::C1 & C2
8a
8b
−5.1
−4.7
1
1
127/B/DC‘15/N4:: O of -CONH- group (3.3)
dt8::C5,C10&N3
dg10:: C14 & C16
dc15::C2,C3,C4,C7 & C8
dg14:: C15 & C18
dt8::N1 & C16
263/A/DG‘10/O6:: H of
-CONH- group (2.3)
dc9:: C12
dg10:: N7
dc15::C7,C13&N3
dg14:: C1,C2,C8,C10,C15& C17
dc13::C3& C5
8c
−5.4
2
263/A/DG‘10/O6:: O of
dt8::C7 & N13
-CONH- group (3.4).263/B/DG‘14/O6:: O of
-CONH- group (3.5)
dg10:: C13 & C16
dc15::C1,C2,C3,C9,C8 & C15
dg14:: C14,C18 & N2
(continued on next page)

S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
7
Table 3 (continued)
Compounds No
8d
Binding energy (kcal mol−1
)
No. of H bonds
Residues involved in H-bonding (Bond length)
Hydrophobic interaction
−5.2
2
127/B/DC‘15/N4::N of
-N= group (3.5)
dt8::C1,N3&C9
dg10:: C16
624/B/DC‘15/OP2::O of
-CONH- group (3.4)
dc15::C1,C4,C6,C7 & C10
dg14:: C1,C15,C17 & N2
dg16::C1
8e
8f
−5.0
−4.7
−4.9
−4.8
2
4
1
2
263/A/DG‘10/O6::N of
-N= group (3.3)
dt8::C2 & C8
dc9:: C3 & C8
.263/B/DG‘14/O6::N of
-N= group (3.4)
dg10:: C11,C13&C15
dc15::C4,C5,C7,C8,C11&C16
dg14:: C16
dg16::C8& C14
dt8::N2
263/A/DG‘10/O6::N of
-N= group (3.5) 127/A/DC‘9/N4::N of
-N= group (3.6)
dc9:: C13&C15
dg10::C15,C13&C4
dc15::O
263/B/DG‘14/O6::O of
-CONH- group (3.1).263/A/DG‘10/O6::O of -CONH-dg14::C2,C3,C7 &C8
group (3.3)
dc13::C1& C2
8 g
263/A/DG‘10/O6:: O of
-CONH- group (3.2)
dt8::N2,N6,O & C16
dc9:: C9,N4
dg10:: C3,C11&C15
dc15:: N5
dg14:: C2,C3,C13 & C14
dc13::C1 & C2
8h
624/B/DG‘14/OP2:: O of -NO2 group
dt8::N2
ꢀ
(3.3).218/B/DC‘13/O5 :: O of -NO2 group (3.6)
dc9:: C14,C15&N4
dg10:: C7,C14&C15
dc15::C12,C18,N5 & O1
dg14:: C2,C3,C4,C6,C7 & C9
dc13::C1,C4 & O2
dt8::C1,C6&N2
8i
8j
−5.1
−5.0
1
2
127/A/DC‘9/N4::N of
-N= group (3.4)
dc9::N1&N8
dg10:: C15&C11
dc15::C14,C17,O3&N3
dg14:: C4& C9
263/A/DG‘10/O6::N of
dt8::C1,C8&N3
-N= group (3.4) 0.127/A/DC‘9/N4::N of
-N= group (3.5)
dc9:: N1,N7&N3
dg10:: C15&C12
dc15::C3 & C9
dg14:: C6,C16 & C17
dc13::C16,C17 & O
No. of hydrogen bond and residues involved were determined by PyMol.
Hydrophobic interactions by Ligplots.
the series of 8a-j ranged from 11 to 19 (% inhibition 81 to 89) with
maximum inhibition by compound 8d (11%). A comparison of the
percentage viability in H-1229 cell line by the reported compounds
is carried out and given in Fig. 3. It is clear from Fig. 3 that the
percent viability for 4a-e series was in the range of 10 to 30 (%
inhibition 70 to 90) with A549 cell line with maximum inhibition
by compound 4e (10%). In the series of 6a-e the percent viability
was ranging from 10 to 12 (% inhibition 78 to 90) with H-1229 cell
line with maximum inhibition by compound 6b (10%). Similarly,
the percent viability in the series of 8a-j ranged from 8 to 25 (%
inhibition 75 to 92) with maximum inhibition by compound 8 h
(8%).
cell lines. Furthermore, maximum inhibition was 70.0 to 90.0% for
4a-e series, 78.0 to 90.0% for 6a-e series and 81.0 to 90.0% for 8a-
j series of the reported compounds. The percentage reticence was
found to be good for 4e, 6b, 8d and 8 h compounds and, hence,
these compounds may be the imminent molecules for giving
cancer.
2.4. Docking study
The efforts were made to determine the interaction mechanism
of the reported molecules with DNA by docking study. The differ-
ent binding energies are given in Table 3. This article describes
twenty-one compounds and the binding study was performed with
all these compounds. The binding energies of the compounds with
DNA ranged from −3.6 to −5.2 kcal/mol because of the differ-
ent structures of the organic molecules. Also, DNA bond estab-
lishment with hydrogen was based on the different structures of
the molecules. In these compounds, there were different num-
bers of hydrogen bonds in the structures. The structures of 4a-
e, 6c, 6d, 6e, 8a, 8b, 8 g and 8i have one hydrogen bond, while
2, 6a, 6b, 8c, 8d, 8e, 8 h and 8j structures formed two hydro-
gen bonds. One the other hand, 8f structure formed four hydro-
gen bonds. Besides, hydrophobic interactions were also different in
different structures. Afterward hydrogen bond establishment study,
the hydrophobic connections were seen utilizing ligplot software.
The above paragraph explains both viability and inhibition of
the reported drugs with both A549 and H-1229 cell lines. The max-
imum percentage inhibitions of 4a-e series with A549 and H-1229
cell lines were 84.0% (4e) and 90.0%, (4e). The order of the anti-
cancer activities was 4e > 4d > 4c > 4a > 4b and 4e > 4d > 4a
> 4c > 4b. High percentage inhibitions of 6a-e series with A549
and H-1229 cell lines were 89.0% (6b) and 90.0% (6b). The order of
the anticancer activities with these cell lines was 6b > 6c> 6d >
6a> 6e and 6b > 6d > 6a > 6c > 6e. The maximum percentage in-
hibitions of 8a-j series with A549 and H-1229 cell lines were 89.0%
(8d) and 92.0% (8 h), respectively. The order of the anticancer ac-
tivities with these cell lines was 8d > 8e> 8 g> 8 h > 8b> 8f >
8i > 8c> 8j > 8a and 8 g > 8d> 8c> 8i> 8 h > 8f > 8e> 8j > 8a
> 8b. All the compounds showed more than 50% inhibition of the

8
S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
Fig. 2. Anticancer activities of the reported compounds on A549 cell line.
Fig. 3. Anticancer activities of the reported compounds on H1299 cell line.
The collective residues of DNA involved with the reported com-
pounds were dc9, dc13, dc14, dc15, dg10, dg13, dg14, dg16 and
dt8. The interactions models of the most active compounds (4e,
6b and 8d) are given in Fig. 4, whereas rests are listed in the sup-
plementary information. It is observed from docking models that
all the molecules favored DNA minor grooves for the interactions.
It was also seen that all the molecules oriented themselves in such
a fashion that their active sites were inside the minor grooves. The
results of DNA binding study were in good agreement with those
of the docking study. It is very significant to observe that all the
molecules showed different docking results; confirming their dif-
ferent anticancer activities.

S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
9
Fig. 4. The docking models of 4e, 6b and 8d compounds.
3. Conclusion
the reported compounds may be used as promising anti-cancer
drugs.
Newer series of benzotriazole-1,2,3-triazole hybrids carrying
different pharmacophores 4a-e, 6a-e and 8a-j were designed and
prepared. The yields were 80 to 87% in click conventional synthe-
ses while the values of yields were varied from 89 to 96% in mi-
crowave synthesis. The time required for the completion of the re-
actions in click conventional syntheses were varied from 6 to 20 h
while these times in click microwave syntheses were ranged from
2 to 8 min. Besides, the percent yields were from 80 to 87% in
click conventional syntheses while the values of yields were var-
ied from 89 to 96%. Therefore, it is concluded that the microwave-
assisted synthesis of the reported molecules is highly economic
saving energy, man-power and costly chemicals. These microwave-
assisted methods may be the choice for the industries. Presently,
the world is running under strong economic pressure and un-
der such situations, the reported procedures may be highly use-
ful for the production of the reported molecules at the industrial
level. The reported compounds showed good DNA binding con-
4. Experimental section
4.1. Synthesis and characterization of
1-(prop–2-yn-1-yl)−1H-benzo[d][1,2,3]triazole (2)
Conventional procedure: To a mixture of benzotriazole (1)
(10 mmol), potassium carbonate (11 mmol) and DMF (20 ml) were
added with stirring propargyl bromide (12 mmol). The mixture
was stirred at 80 °C for 2 h until the intake of the starting material
exhausted; as indicated by TLC (hexane-ethyl acetate). The reaction
mixture was poured into crushed ice and the resulting solid was
composed and recrystallized from ethanol to afford the targeted
propargylated benzotriazole 2 as colorless crystals in 90% yield,
mp: 55–56 °C (Lit. mp: 57–58 °C [50]). IR (υ, cm−1): 1570 (C = C),
2150 (C C), 2930 (C H al), 3040 (C H ar), 3300 ( CH). 1H NMR
≡
–
–
≡
≡
(400 MHz, DMSO–d6): δH 3.61 (s, 1H, CH), 5.74 (s, 2H, NCH2),
stants in the range of 1.3 × 103 to 11.90 × 105
M
−1. The an-
7.45 (t, 1H, J = 8.0 Hz, Ar-H), 7.61 (t, 1H, J = 8.0 Hz, Ar-H), 7.93
(d, 1H, J = 8.0 Hz, Ar-H), 8.10 (d, 1H, J = 8.0 Hz, Ar-H). 13C NMR
ticancer activities were in the range of 86.0 to 90.0% for 4a-e,
89.0 to 90.0% for 6a-e series and 89.0 to 90.0% for 8a-j series.
The docking results suggested strong DNA bindings of the reported
compounds in minor grooves of DNA; through hydrogen bond-
ings and hydrophobic interactions. These results indicated that
≡
(100 MHz, DMSO–d6): δC 37.77 (NCH2); 77.38, 77.66 (C C); 111.12,
119.77, 124.77, 128.15, 132.77, 145.72 (Ar-C). The spectral data of
compound 2 are in agreement with the literature [32]. Anal. Calcd.
for C9H7N3: C, 68.78; H, 4.49; N, 26.74. Found: C, 68.61; H, 4.55;
N, 26.67.

10
S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
Microwave procedure: Benzotriazole (1) (1 mmol), potassium
200, 100, and 50, μg/mL) of the reported compounds and permit-
ted to incubate for the next 24 h. The cells were examined by
adding 15.0 μL (5.0 mg/mL MTT). At 37 °C for 4 h, the individual
medium from each well was cleared. The cells were re-suspended
in 100 μL of DMSO and the plate directly covered with aluminum
foil, shadowed by mild shaking on a shaker for around 15 min. Ab-
sorbance was recorded at 540 nm [45] and the percent stop in pro-
liferation was intended by the formula in Eq. (2).
carbonate (1.1 mmol), propargyl bromide (1.2 mmol) and DMF
(5 mL) were kept in locked borosilicate glass container fitted with
a silicone cap and open to irradiation for 2 min at 50 °C by means
of a microwave reactor at 300 W. The reaction was treated as de-
fined in the conventional process previously given for alkyne 2
(98% yield).
ꢂꢀ
ꢁ
ꢃ
4.2. General click procedure for the synthesis of 1,2,3-triazoles 4a-c,
6a-c and 8a-j
% Inhibition = AControl − ASample /AControl × 100
The detailed procedure is given in Supplementary information.
(2)
Conventional procedure: A solution of copper sulfate (0.10 g)
and sodium ascorbate (0.15 g); in water (10 mL); was added to
a solution of alkyne 2 (1 mmol) in DMSO (10 mL) with stirring.
Thereafter, an appropriate azide (1 mmol) was added, and the re-
action mixture was stirred at room temperature for 4–10 h. The
reaction was monitored via TLC (hexane-ethyl acetate), and after
the completion of the reaction, iced-water was added in the mix-
ture. The precipitate made was collected by filtration, treated with
a saturated solution of NH4Cl and recrystallized from ethanol/DMF
to give the targeted 1,2,3-triazoles 4a-c, 6a-c and 8a-j.
4.5. Docking study
The docking studies of 1,2,3- triazole complexes were done by
Intel® dual CPU (1.86 GHz) with Windows XP operating system.
Marwin Sketch software was utilized to draw the structures of
1,2,3- triazole compounds. The structures were cleaned to 3D and
saved in PDB file format [53]. After that, the structure of DNA
(pdb ID: 1bna) was downloaded from protein data bank. Using
AutoDock Tools (ADT) 4.2 the structure of DNA to be docked was
prepared by assigning Gastegier charges, merging non-polar hydro-
gen atoms and saving it in PDBQT file format. Docking was per-
formed with AutoDock 4.2 (Scripps Research Institute, USA) con-
sidering all the rotatable bonds of the ligand as rotatable and the
receptor as rigid [54]. Using the same tool, an 1,2,3-triazole com-
pounds (as a ligand) were edited to be saved in PDBQT formate.
The grid box size of 60 × 80 × 110 Aᵒ with 0.375 Aᵒ spacing was
used. After saving both files in PDBQT formate, vina software was
used to get binding energy/affinity between receptor (DNA) and
ligand (1,2,3-triazole compounds). After using vina software, the
output file was opened in PyMOL to carry out the molecular dock-
ing, virtual screening and binding site analysis and to get an image
of interaction and the bond length of the hydrogen bonds between
DNA and 1,2,3- triazole compounds.(Table 2)
Microwave procedure: Alkyne
2 (1 mmol), copper sulfate
(0.10 g) and sodium ascorbate (0.15 g) in water (10 mL) and an ap-
propriate azide (1 mmol) and DMSO (10 mL) were placed in shut
borosilicate glass container fitted with a silicone cap and open to
irradiation for 3–8 min using a microwave reactor. The reaction
was managed as defined in the conventional procedure outlined
earlier to give the same click products 4a-c, 6a-c and 8a-j.
The characterization of the compounds is given in supplemen-
tary information
4.3. DNA binding study
DNA binding study is one of the significant tools to assess
the activities of the newly synthesized molecules. It is because
the cancer is directly associated with DNA activities in the body.
The reported compounds interactions were determined with Ct-
DNA (at pH 7.4) in a solution of distilled water comprising tris-
(hydroxymethyl)-amino methane buffer (Tris, 10−2 M). Originally,
the concentration of newly prepared Ct-DNA solution was deter-
mined on UV–Vis absorption spectrophotometry at a wavelength
of 260 nm (ε = 6600 M−1cm−1) by knowing its absorbance [51].
The absorption spectra of newly prepared compounds at a fixed
concentration of (1.6 × 10−4 M) were taken separately and then
with the different amounts of DNA (1.5 × 10−5, 1.3 × 10−5 and
1.1 × 10−5) were added. The λmax was noted and the absorbance of
the mixture i.e. with each dissimilar solution of DNA and the com-
pounds was also dignified. To produce constant results, the experi-
ments were repeated five times (n = 5). The intrinsic DNA binding
coefficients (Kb) were resolved by Benesi-Hilderbrand equation (eq.
4.6) as by Wolfe et al. [52]. The equation is as follows:
Declaration of Competing Interest
The authors declare that they have no known competing finan-
cial interests or personal relationships that could have appeared
to influence the work reported in this paper. The authors declare
the following financial interests/personal relationships which may
be considered as potential competing interests: Design, click con-
ventional and microwave syntheses, DNA binding, docking and an-
ticancer studies of benzotriazole-1,2,3-triazole molecular hybrids
with different pharmacophores
Supplementary materials
Supplementary material associated with this article can be
found, in the online version, at doi:10.1016/j.molstruc.2020.129192.
ꢀ
ꢁ
ꢀ
ꢁ
ꢀ
ꢁ
DNA / ε − ε = DNA / ε − ε + 1/K εb − εf
(1)
[
]
[
]
a
a
f
f
CRediT authorship contribution statement
Where, absorption coefficients, εa, εf, and εb represents
Aobs/[compound], extinction coefficient for the complex and
the extinction coefficient for the complex in the completely
bound form. The intrinsic binding coefficients for the dissimilar
compounds (Kb) were dogged by the division of slopes and the
intercepts of the plots of [DNA] / (εa - εf) vs [DNA].
Shaya Yahya Alraqa: Conceptualization, Methodology. Khalid
Alharbi: Methodology, Data curation. Ateyatallah Aljuhani:
Methodology, Software. Nadjet Rezki: Software. Mohamed Reda
Aouad: Methodology, Writing - original draft. Imran Ali: Method-
ology, Writing - review & editing.
4.4. Anticancer study
References
[1] F. Bray, J. Ferlay, I. Soerjomataram, R.L. Siegel, L.A. Torre, A. Jemal, Global can-
cer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide
for 36 cancers in 185 countries, CA Cancer J. Clin. 68 (6) (2018) 394–424.
[2] D. Dheer, V. Singh, R. Shankar, Medicinal attributes of 1,2,3-triazoles: current
developments, Bioorg. Chem. 71 (2017) 30–54.
The anti-proliferative activities of the compounds were per-
formed with 2 lung cancer cell lines (A549 and H-1229). These
cells were sowed in a 96 well plate and incubated. At around 61–
71% confluence, the cells were preserved with concs. (400, 300,

S.Y. Alraqa, K. Alharbi and A. Aljuhani et al. / Journal of Molecular Structure 1225 (2021) 129192
11
[3] Nadjet Rezki, Amjad M. Al-Yahyawi, Sanaa K. Bardaweel, Fawzia F. Al-Blewi,
Mohamed R. Aouad, Synthesis of novel 2,5-disubstituted-1,3,4-thiadiazoles
clubbed 1,2,4-triazole, 1,3,4-thiadiazole, 1,3,4-oxadiazole and/or Schiff base
as potential antimicrobial and antiproliferative agents, Molecules, 20, 2015,
16048–16067.
[4] P. Xin-Mei, C. Gui-Xin, Z. Cheng-He, Recent developments in azole compounds
as antibacterial and antifungal agents, Curr. Top. Med. Chem. 13 (16) (2013)
1963–2010.
[30] A.H. Albalawi, W.S. El-Sayed, A. Aljuhani, S.M. Almutairi, N. Rezki, M.R.
Aouad, M. Messali, Microwave-assisted synthesis of some potential bioactive
imidazolium-based room temperature ionic liquids, Molecules, 23, 2018, 1727–
1741.
[31] A. Aljuhani, M.R. Aouad, N. Rezki, O.A. Aljaldy, S.A. Al-Sodies, M Messali, I. Ali,
Novel pyridinium based ionic liquids with amide tethers: microwave assisted
synthesis, molecular docking and anticancer studies, J. Mol. Liq. 285 (2019)
790–802.
[5] R. Kaushik, M. Chaud, S.C. Jain, Synthesis and antibacterial evaluation of ni-
trogen containing novel heterocyclic chalcones, Synth. Comm. 48 (11) (2018)
1308–1315.
[32] L.A. Perego, R. Blieck, J. Michel, I. Ciofini, L. Grimaud, M. Taillefer, F. Monnierc,
Copper-Catalyzed Hydroamination of N-Allenylazoles: access to Amino-Substi-
tuted N-Vinylazoles, Adv. Synth. Catal. 359 (2017) 4388–4392.
[6] M.R. Aouad, M.M. Mayab, A. Naqvi, S.K. Bardaweel, F.F. Al-blewi, M. Messali,
N. Rezki, Design, synthesis, in-silico and in-vitro antimicrobial screenings of
novel 1,2,4-triazoles carrying 1,2,3-triazole scaffold with lipophilic side chain
tether, Chem. Cent. J. 11 (2017) 117–129.
[33] M.J. Minvielle, C.A. Bunders, C. Melander, Indole-triazole conjugates are selec-
tive inhibitors and inducers of bacterial biofilms, Med. Chem. Comm. 6 (2013)
916–919.
[34] N. Devender, S. Gunjan, R. Tripathi, R.P. Tripathi, Synthesis and antiplasmodial
activity of novel indoleamide derivatives bearing sulfonamide and triazole
pharmacophores, Eur. J. Med. Chem. 131 (2017) 171–184.
[35] O.N. Verkhozina, V.N. Kizhnyaev, L.I. Vereshchagin, A.V. Rokhin, A.I. Smirnov,
Synthesis of Polynuclear Nonfused Azoles, Russ. J. Org. Chem. 39 (12) (2003)
1792–1796.
[7] D.J. Zhang, W.F. Sun, Z.J. Zhong, R. Me. Gao, H. Yi, Y.H. Li, Z.G. Peng, Z.R. Li, Syn-
thesis and broad-spectrum antiviral activity of some novel benzo-heterocyclic
amine compounds„ Molecules 19 (2014) 925–939.
[8] A. Lauria, R. Delisi, F. Mingoia, A. Terenzi, A. Martorana, G. Barone,
A.M. Almerico, 1,2,3-Triazole in heterocyclic compounds, endowed with biolog-
ical activity, through 1,3-dipolar cycloadditions, Eur. J. Org. Chem. 2014 (2014)
3289–3306.
[36] G. Wang, Z. Peng, J. Wang, X. Li, J. Li, Synthesis, in vitro evaluation and
molecular docking studies of novel triazine-triazole derivatives as potential
α-glucosidase inhibitors, Eur. J. Med. Chem. 125 (2017) 423–429.
[37] J. Marmur, A procedure for the isolation of deoxyribonucleic acid from mi-
croorganisms, J. Mol. Biol. 3 (1961) 208–218.
[9] C. Viegas-Junior, A. Danuello, V.S. Bolzani, E.J. Barreiro, C.A.M. Fraga, Molecular
hybridization: a useful tool in the design of new drug prototypes, Curr. Med.
Chem. 14 (2007) 1829–1852.
[10] G. Bérubé, An overview of molecular hybrids in drug discovery, Expert Opin.
Drug Discov. 11 (2016) 281–305.
[38] I. Ali, M. Nadeem Lone, Z.A. Al-Othman, A. Al-Warthan, Insights into the phar-
macology of new heterocycles embedded with oxopyrrolidine rings: DNA bind-
ing, molecular docking, and anticancer Studies, J. Mol. Liq. 234 (2017) 391–402.
[39] K. Saleem, W.A. Wani, A. Haque, M.N. Lone, M.-.F. Hsieh, I. Ali, Synthesis, DNA
binding, hemolysis, and anticancer profiles of copper (II), nickel(II) and iron(III)
complexes of a pyrazoline based ligand, Fut. Med. Chem. 5 (2013) 135–146.
[40] I. Ali, M.N. Lone, M.-.F. Hsieh, N-Substituted (Substituted-5-Benzylidine) Thi-
azolidine-2,4-Diones: crystal structure, In silico, DNA binding, and anticancer
studies, Biointerface Res. Appl. Chem. 6 (2016) 1356–1379.
[11] N. Rezki, A Green ultrasound synthesis, characterization and antibacterial eval-
uation of 1,4-disubstituted 1,2,3-triazoles tethering bioactive benzothiazole nu-
cleus, Molecules 21 (2016) 505–517.
[12] N. Rezki, M.R. Aouad, Green ultrasound-assisted three-component click
synthesis of novel 1H-1,2,3-triazole carrying benzothiazoles and fluorinat-
ed-1,2,4-triazole conjugates and their antimicrobial evaluation, Acta Pharma-
ceutica 67 (2017) 309–324.
[13] M.R. Aouad, M.A. Soliman, M.O. Alharbi, S.K. Bardaweel, P.K. Sahu, A.A. Ali,
M. Messali, N. Rezki, Y.A. Al-Soud, Design, synthesis and anticancer screening
of novel benzothiazole-piperazine-1,2,3-triazole hybrids, Molecules 23 (2018)
2788–2801.
[14] M.R. Aouad, M.A. Almehmadi, N. Rezki, F. Faleh Al-blewi, M. Messali, I. Ali,
Design, click synthesis, anticancer screening and docking studies of novel ben-
zothiazole-1,2,3-triazoles appended with some bioactive benzofused heterocy-
cles, J. Mol. Struct. 1188 (2019) 153–164.
[41] I. Ali, W.A. Wani, K. Saleem, M.F. Hseih, Design and synthesis of thalidomide
based dithiocarbamate Cu(II), Ni(II) and Ru(III) complexes as anticancer agents,
Polyhedron 56 (2013) 134–143.
[42] I. Ali, K. Saleem, D. Wesselinova, A. Haque, Synthesis, DNA binding, hemolytic
and anticancer assays of curcumin I based ligands and their ruthenium (III)
complexes, Med. Chem. Res. 22 (2013) 1386–1398.
[43] S. Chandrasekaran, Y. Sameena, I.V.M.V. Enoch, Modulation of the interaction
of coumarin 7 with DNA by β-cyclodextrin, J. Incl. Phenom. Macrocycl. Chem.
81 (2015) 225–236.
[15] I. Ali, Nano anti-cancer drugs: pros and cons and future perspectives, Curr.
Cancer Drug Targets 11 (2011) 131–134.
[44] I. Ali, W.A. Wani, A. Khan, A. Haque, A. Ahmad, K. Saleem, N. Manzoor, Syn-
thesis and synergistic antifungal activities of a pyrazoline based ligand and its
Copper (II) and Nickel (II) complexes with conventional antifungals, Microb.
Pathogen. 53 (2012) 66–73.
[16] I. Ali, M.N. Lone, Z.A. Al-Othman, A. Al-Warthan, Heterocyclic scaffolds: cen-
trality in anticancer drug development, Curr. Drug Target 16 (2015) 711–734.
[17] Z. Xu, S.J. Zhao, Y. Liu, 1,2,3-Triazole-containing hybrids as potential anticancer
agents: current developments, action mechanisms and structure-activity rela-
tionships, Eur. J. Med. Chem. 183 (2019) 111700–111737.
[18] K. Bozorov, J. Zhao, H.A. Aisa, 1,2,3-Triazole-containing hybrids as leads in
medicinal chemistry: a recent overview, Bioorg. Med, Chem 27 (16) (2019)
3511–3531.
[45] X. Shui, M.E. Peek, L.A. Lipscomb, Q. Gao, C. Ogata, B.P. Roques, C.G. Jau-
reguiberry, A.P. Wilkinson, L.D. Williams, Effects of cationic charge on three-di-
mensional structures of intercalative complexes structure of a bis-intercalated
DNA complex solved by MAD phasing, Curr. Med. Chem. 7 (2000) 59–71.
[46] M.J. Waring, C. Bailly, The purine 2-amino group as a critical recognition ele-
ment for binding of small molecules to DNA, Gene 149 (1994) 69–79.
[47] C. Rehn, U. Pindur, Molecular modeling of intercalation complexes of antitu-
mor active 9-aminoacridine and a [d,e]-anellatedisoquinoline derivative with
base paired deoxytetranucleotides, Monatsh. Chem. 127 (1996) 645–658.
[48] M. Baginski, F. Fogolari, J.M. Briggs, Electrostatic and non-electrostatic contri-
butions to the binding free energies of anthracycline antibiotics to DNA, J. Mol.
Biol. 274 (1997) 253–267.
[19] M.E. Welsch, S.A. Snyder, B.R. Stockwell, Privileged scaffolds for library design
and drug discovery, Curr. Opin. Chem. Biol. 14 (2010) 347–361.
[20] S. Briguglio, P. Piras, E. Corona, M. Gavini, G. Nieddu, A. Boatto, Carta, Benzo-
triazole: an overview on its versatile biological behavior, Eur. J. Med. Chem. 97
(2015) 612–648.
[21] B.V. Suma, N.N. Natesh, V. Madhavan, Benzotriazole in medicinal chemistry: an
overview, J. Chem. Pharm. Res. 3 (6) (2011) 375–381.
[22] E. Bonandi, M.S. Christodoulou, G. Fumagalli, D. Perdicchia, G. Rastelli, D. Pas-
sarella, The 1,2,3-triazole ring as a bioisostere in medicinal chemistry, Drug
Discov. Today 22 (10) (2017) 1572–1581.
[49] I. Ali, M.N. Lone, H.Y. Aboul-Enein, Imidazoles as potential anticancer agents,
Med. Chem. Commun. 8 (2017) 1742–1773.
[50] A. Khalafi-Nezhada, A. Zareb, A. Parhamia, M.N. Soltani Rad, G.R. Nejabat,
Highly Regioselective N-Alkylation of Benzotriazole under Solvent-Free Condi-
tions, J. Iran. Chem. Soc. 4 (3) (2007) 271–278.
[23] Z. Xu, S.–J. Zhao, Y. Liu, 1,2,3-Triazole-containing hybrids as potential anti-
cancer agents: current developments, action mechanisms and structure-activ-
ity relationships, Eur. J. Med. Chem. 183 (2019) 111700.
[24] R. Kharb, P. Chander Sharma, M. Sh, Yar, Pharmacological significance of tria-
zole scaffold, J, Enzy. Inhib. Med. Chem. 26 (1) (2011) 1–21.
[51] N. Ataci, E. Ozcelik, N. Arsu, Spectrophotometric study on binding of 2-thiox-
anthone acetic acid with ct-DNA, Spectrochimica Acta Part A: mol, Biomol.
Spectr. 204 (2018) 281–286.
[25] H.Y. Abou-Enein, I. Ali, 25 newHPLC enantiomeric resolution of nebivolol on
normal and reversed amylose based chiral phases, Pharmazie 56 (3) (2001)
214–216.
[52] A. Wolfe, G.H. Shimer Jr., T. Meehan, Polycyclic aromatic hydrocarbons phys-
ically intercalate into duplex regions of denatured DNA, Biochem. 26 (1987)
6392–6396.
[26] D. Dheer, V. Singh, R. Shankar, Medicinal attributes of 1,2,3-triazoles: current
developments, Bioorg. Chem. 71 (2017) 30–54.
[53] M.F. Sanner, Python: a programming language for software integration and de-
velopment, J. Mol. Graph. Model. 17 (1999) 57–61.
[27] N. Rezki, M.R. Aouad, M. Messali, E.S.H. El Ashry, Regioselective (2,3-e-
poxy)propylation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-thione
and synthesis of triazolo[2,1-b]thiazine analogs under conventional and mi-
crowave irradiation, Lett. Org. Chem. 12 (6) (2015) 418–423.
[54] G.M. Morris, D.S. Goodsell, R.S. Halliday, R. Huey, W.E. Hart, R.K. Belew, A.J. Ol-
son, Automated docking using a lamarckian genetic algorithm and and empir-
ical binding free energy function, J. Comput. Chem. 19 (1998) 1639–1662.
[28] N. Rezki, Green microwave synthesis and antimicrobial evaluation of novel tri-
azoles, Org. Prep. Proced. Int. 49 (2017) 525–541.
[29] A. Aljuhani, W.S. El-Sayed, P.K. Sahu, N. Rezki, M.R. Aouad, R. Salghi, M. Mes-
sali, Microwave-assisted synthesis of novel imidazolium, pyridinium and pyri-
dazinium-based ionic liquids and/or salts and prediction of physico-chemical
properties for their toxicity and antibacterial activity, J. Mol. Liq. 249 (2018)
747–753.