Synthesis and in vitro evaluation of potential anticancer activity of mono- and bis-1,2,3-triazole derivatives of bis-alkynes

Article abstract of DOI:10.1016/j.ejmech.2012.12.025

In order to find new molecules with cytotoxic activity against cancer cells, we prepared bis-akyne amides derived from propiolic acid. The bis-alkynes were then transformed in their mono-1,2,3-triazole analogs onto the amide side, due to its greater reactivity, using a catalyst-free Huisgen's reaction. The mono-triazoles were then subjected to the copper (I)-catalyzed version of the previous reaction (CuAAC), using a supported catalyst, to produce bis-triazoles. All products were obtained pure after simple trituration or filtration procedures. All synthetic compounds were tested in vitro for their cytotoxic activity using B16 melanoma cells. Four compounds (7, 23, 25 and 33) showed activities in the micromolar range (<21 μM) whereas three compounds (3, 22 and 38) presented activity at low micromolar concentrations (<10 μM), and two analogs (2 and 13) were active at nanomolar levels (<1 μM).

Full text of DOI:10.1016/j.ejmech.2012.12.025

Accepted Manuscript
Synthesis and in vitro evaluation of potential anticancer activity of mono- and
bis-1,2,3-triazole derivatives of bis-alkynes
Hichem Elamari, Riadh Slimi, Guy G. Chabot, Lionel Quentin, Daniel Scherman,
Christian Girard
PII:
S0223-5234(12)00747-7
10.1016/j.ejmech.2012.12.025
EJMECH 5896
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 26 September 2012
Revised Date: 10 December 2012
Accepted Date: 12 December 2012
Please cite this article as: H. Elamari, R. Slimi, G.G. Chabot, L. Quentin , D. Scherman, C.
Girard, Synthesis and in vitro evaluation of potential anticancer activity of mono- and bis-1,2,3-
triazole derivatives of bis-alkynes, European Journal of Medicinal Chemistry (2013), doi: 10.1016/
j.ejmech.2012.12.025.
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Synthesis and in vitro evaluation of potential
anticancer activity of mono- and bis-1,2,3-
triazole derivatives of bis-alkynes
Leave this area blank for abstract info.
H. Elamari, R. Slimi, G. G. Chabot , L Quentin, D. Scherman and C. Girard
CNRS UMR8151, INSERM U1022, Unité de Pharmacologie Chimique, Génétique & Imagerie, Ecole Nationale
Supérieure de Chimie de Paris and Université Paris Descartes, Paris, France
1. R1N3
O
O
O
neat or acetone
R2N3
R
R
R
N
N
N
H
H
H
R2
N
N
N
1 N
1 N
N
A-21•CuI
CH2Cl2
2. EtOH
trituration
R
R
N
N
N
1-3
4-12
13
-
37

ACCEPTED MANUSCRIPT
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Preliminary communication
Synthesis and in vitro evaluation of potential anticancer activity of mono- and bis-
1,2,3-triazole derivatives of bis-alkynes
Hichem Elamaria , Riadh Slimia , Guy G. Chabotb, , Lionel Quentinb , Daniel Schermanb and Christian
Girarda,
aCNRS UMR8151, INSERM U1022, Unité de Pharmacologie Chimique, Génétique & Imagerie, Ecole Nationale Supérieure de Chimie de Paris (Chimie
ParisTech), PSL,11 rue Pierre & Marie Curie, Paris 75005, France
b CNRS UMR8151, INSERM U1022, Faculté de Pharmacie, Université Paris Descartes, Sorbonne Paris Cité, 4 avenue de l'Observatoire, 75006 Paris, France
TN QTAB LE 2ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
In order to find new molecules with cytotoxic activity against cancer cells, we prepared bis-
akyne amides derived from propiolic acid. The bis-alkynes were then transformed in their mono-
1,2,3-triazole analogs onto the amide side, due to its greater reactivity, using a catalyst-free
Huisgen's reaction. The mono-triazoles were then subjected to the copper (I)-catalyzed version
of the previous reaction (CuAAC), using a supported catalyst, to produce bis-triazoles. All
products were obtained pure after simple trituration or filtration procedures. All synthetic
compounds were tested in vitro for their cytotoxic activity using B16 melanoma cells. Four
compounds (7, 23, 25 and 33) showed activities in the micromolar range (< 21 µM) whereas
three compounds (3, 22 and 38) presented activity at low micromolar concentrations (< 10 µM),
and two analogues (2 and 13) were active at nanomolar levels (< 1 µM).
Available online
Keywords:
Alkyne
Triazole
Click chemistry
Anticancer
B16 melanoma
2012 Elsevier Masson SAS, All rights reserved.
1. Introduction
structures incorporating this nucleus as mono- and bis-triazoles
prepared from bis-alkynes was undertaken [16].
Cancer is already the leading cause of death in many high-
income countries and is set to become a major cause of morbidity
and mortality in the next decades in every region of the world [1].
Death rate for cancer remains approximately the same worldwide
and did not appear to decrease in recent years. Indeed, it is
predicted that by 2030, approximately 20 million new cancer
cases will be diagnosed worldwide and that about 13 million
cancer patients will die from this disease [1,2]. Therefore, there is
an urgent need for novel and more efficacious compounds in
order to try to reduce the cancer mortality rate.
This communication reports our findings following the in
vitro biological evaluation of all derivatives synthesized in this
study using the murine B16 melanoma cell line. The choice of
the B16 melanoma model is based on the urgent need to find new
active compounds against metastatic melanoma which is
particularly resistant to chemotherapy in humans [17]. The B16
melanoma is considered a good model of the human disease
because it is highly invasive and can metastasize when grafted
into syngeneic mice [18]. This melanoma model is also
particularly refractory to chemotherapy, just like the human
disease [19]. This model has also recently been shown to express
alpha v beta 3 and E-selectin which are particularly important
targets for antiangiogenic cancer therapy [20]. In addition, B16
melanoma has been used extensively in preclinical studies
worlwide including the National Cancer Institute, and therefore
allows a good comparison basis to numerous other published
preclinical studies. Another important point is that first line
interesting results obtained with this cell line in vitro can readily
In our sustained endeavor to find new methods for the
synthesis of biologically active compounds against cancer [3-13],
based on our experience in the synthesis of 1,4-disubstituted bis-
1,2,3-triazole [14] and previous results of triazolic analogs of
Combretastatin A4 [15], we became interested in the evaluation
of other triazolic derivatives. Since 1,2,3-triazoles are recognized
as important and efficient pharmacophores, investigation of new
———
C. Girard. Tel.: +3-144-276-748; e-mail: christian-girard@chimie-paristech.fr
G. G. Chabot. Tel.: +33-153-739-571; e-mail: guy.chabot@parisdescartes.fr

ACCEPTED MANUSCRIPT
be tested in vivo in mice to further evaluate the lead compounds
detected in vitro.
Scheme 2. Copper(I)-catalyzed synthesis of triazoles 39-41
from propiolamide of aniline (38) and azides.
In the present study, we found out that the triazolic derivatives
possessed biological activity, some in the micromolar and
nanomolar range, and that, surprisingly, some of the starting bis-
alkynes themselves showed interesting cytotoxicity against B16
melanoma cells.
3. Biological activity
The cytotoxic activity of compounds 1-41 on B16 melanoma
cells is presented in Table 1.
We first analyzed our biological results with the bis-alkynes 1-
3 and the mono-alkyne 38, in order to include the starting
materials. To our surprise, the alkynes did possess interesting
activities. The amide derived from propargyl amine 1 presented
an IC50 of 38 µM. The replacement of the propargyl side chain in
1 by a m-ethynylphenyl to yield compound 2 caused a 127-fold
increase in biological activity with an IC50 of 0.3 µM. The
presence of an aromatic "linking" ring also increased the
cytotoxic activity of 1, as shown for the para-analog 3 and the
2. Chemistry
The compounds required for this study were synthesized
according to our previously published procedure [14]. Briefly,
the starting bis-alkyne amides 1-3 were prepared by classical
DCC coupling between propiolic acid and propargyl amine for 1,
and m- and p-ethynylanilines for 2 and 3, respectively (Scheme
1).
phenyl substituted derivative 38, which both presented
a
The bis-alkynes 1-3 were then reacted with various organic
azides to afford the corresponding mono 1,4-disubstituted 1,2,3-
triazoles 4-12. This first Huisgen's reaction was conducted
without catalyst and without solvent for the propiolic acid
propargyl amide (1), or in acetone under reflux for the propiolic
acid m-ethynylphenyl (2) and m-ethynylphenyl (3) amides
[21,22]. All reactions gave good yields of a mixture of the 1,4-
and 1,5-isomers of the triazole in ratio around 80 : 20,
respectively. The reaction was selective for the alkyne conjugated
with the carbonyl group (activated alkyne). The 1,4-isomers 4-12
were obtained pure and in fair yields after a simple trituration in
ethanol, leaving the 1,5-isomers, together with a few 1,4-ones, in
the filtrate.
cytotoxic activity of 6 µM. Although compounds 3 and 38
showed a 6-fold increase in cytotoxicity compared to 1, these
IC50 values were twenty times lower than the IC50 value obtained
with compound 2.
Introduction of the first triazole ring had a deleterious effect
on the activities of the four precited compounds (1-3 and 38).
The propargyl derivative 1 (38 µM) was about two times more
potent than the benzyl-substituted triazole at the R1 position of 4
(65 µM).
The presence at this position of a benzyloxycarbonylmethyl in
5, and acetoxyethyl in 6, gave compounds with activities higher
than 100 µM. The same series of couplings on the meta-
derivative 2 (0.3 µM) gave also mono-triazoles with lower
activities: around fifty to three-hundred times decrease for
compounds 7, 8 and 9, with IC50 of 14.5, 91.0 and 25.1 µM,
respectively.
The mono-triazole-alkynes 4-12 were then subjected to a
second Huisgen's reaction using its copper (I)-catalyzed version
[23-26], or copper-catalyzed alkyne-azide coupling (CuAAC),
using our polymer-supported catalyst Amberlyst A-21•CuI in
methylene chloride at room temperature [27,28]. This reaction
gave exclusively the 1,4-isomers of the second triazole ring onto
the inactivated alkyne in very good yield. The products 13-37
being obtained pure after a simple filtration and evaporation
procedure.
This effect was also observed for the para-derivative 3 and the
phenyl substituted 38. For the bis-alkyne 3 (6.3 µM), the
cytotoxic activity was over 100 µM for 10 and 11, and was 79
µM for 12. The phenyl substituted propiolamide 38 (6.2 µM)
exhibited the same decrease in activities with an IC50 of 93 µM
for 39, and over 100 µM for 40 and 41.
In order to make some comparison between the different
products and to study the influence of the second triazole ring,
we also synthesized propiolic acid phenyl amide (38) from
propiolic acid and aniline (Scheme 2). The alkyne 38 was then
reacted with organic azides using the A-21•CuI CuAAC
procedure to afford the triazoles 39-41 with the same selectivity
and good yields.
When considering the results for the introduction of the
second triazole ring in molecules 13-37, some interesting
modifications of the biological activity of the mono-triazoles
derivatives 4-12 were observed.
In the R1 = benzyl series (molecules 4, 7 and 10), we were
surprised to observe an amelioration of activity when going from
4 to 13 (with R2 = benzyl). The bis-triazole 13 had an IC50 = 0.3
µM, which was two-hundred and thirty times the activity of 4 and
the same as the one of the bis-alkyne 2. Introduction of this R1 =
benzyl in 22, starting from 7, gave also an increase in activity
going from 14.5 to 4.5 µM (three times).
R1N3
O
O
N
N
H
H
N
1 N
A-21•CuI
CH2Cl2
R
N
39 : R1 = Bn
38
40 : R1 = CH2CO2Et
41 : R1 = (CH2)2OAc

ACCEPTED MANUSCRIPT
1. R1N3
neat or
22 : R = m-Ph, R1 = R2 = Bn
23 : R = m-Ph, R1 = Bn, R2 = CH2CO2Et
24 : R = m-Ph, R1 = Bn, R2 = (CH2)2OAc
25 : R = m-Ph, R1 = CH2CO2Et, R2 = Bn
26 : R = m-Ph, R1 = R2 = CH2CO2Et
27 : R = m-Ph, R1 = CH2CO2Et, R2 = (CH2)2OAc
28 : R = m-Ph, R1 = (CH2)2OAc, R2 = Bn
29 : R = m-Ph, R1 = (CH2)2OAc, R2 = CH2CO2Et
30 : R = m-Ph, R1 = R2 = (CH2)2OAc,
31 : R = p-Ph, R1 = R2 = Bn
32 : R = p-Ph, R1 = Bn, R2 = CH2CO2Et
33 : R = p-Ph, R1 = Bn, R2 = (CH2)2OAc
34 : R = p-Ph, R1 = CH2CO2Et, R2 = (CH2)2OAc
35 : R = p-Ph, R1 = (CH2)2OAc, R2 = Bn
36 : R = p-Ph, R1 = (CH2)2OAc, R2 = CH2CO2Et
37 : R = p-Ph, R1 = R2 = (CH2)2OAc
O
O
O
R2N3
acetone, ∆
R
R
R
N
N
N
H
H
H
N
1 N
R2
N
N
1 N
N
2. EtOH
trituration
A-21•CuI
CH2Cl2
R
N
R
N
N
1
2
3
: R = CH2
: R = m-Ph
: R = p-Ph
4
5
6
7
8
9
: R = CH2, R1 = Bn
13 : R = CH2, R1 = R2 = Bn
: R = CH2, R1 = CH2CO2Bn
: R = CH2, R1 = (CH2)2OAc
: R = m-Ph, R1 = Bn
14 : R = CH2, R1 = Bn, R2 = CH2CO2Et
15 : R = CH2, R1 = Bn, R2 = (CH2)2OAc
16 : R = CH2, R1 = CH2CO2Bn, R2 = Bn
17 : R = CH2, R1 = CH2CO2Bn, R2 = CH2CO2Et
18 : R = CH2, R1 = CH2CO2Bn, R2 = (CH2)2OAc
19 : R = CH2, R1 = (CH2)2OAc, R2 = Bn
20 : R = CH2, R1 = (CH2)2OAc, R2 = CH2CO2Et
21 : R = CH2, R1 = R2 = (CH2)2OAc
: R = m-Ph, R1 = CH2CO2Et
: R = m-Ph, R1 = (CH2)2OAc
10 : R = p-Ph, R1 = Bn
11 : R = p-Ph, R1 = CH2CO2Et
12 : R = p-Ph, R1 = (CH2)2OAc
Scheme 1. Two steps synthesis triazoles: Uncatalyzed first step to form mono-triazoles 4-12 and polymer-supported copper(I)-
catalyzed second step (A-21•CuI) to access bis-triazoles 13-37, strating from the bis-alkynes 1-3 and corresponding azides.
Table 1. In vitro biological activity (IC50) against B16 melanoma cells for molecules 1-41 produced via Schemes 1 and 2a
N°
1
R
R1
R2
IC50 (µM)b
N°
R
R1
R2
IC50 (µM)b
4.5 ± 0.3
21.0 ± 2
CH2
m-Ph
p-Ph
CH2
CH2
CH2
–
–
38.0 ± 0.4
22 m-Ph Bn
Bn
2
–
–
0.3 ± 0.008 23 m-Ph Bn
CH2CO2Et
3
–
–
6.3 ± 0.3
65 ± 5
24 m-Ph Bn
(CH2)2OAc 25.1 ± 03
4
Bn
–
25 m-Ph CH2CO2Et
26 m-Ph CH2CO2Et
27 m-Ph CH2CO2Et
Bn
20.4 ± 0.4
> 100
5
CH2CO2Bn
(CH2)2OAc
–
> 100
CH2CO2Et
6
–
> 100
(CH2)2OAc > 100
7
m-Ph Bn
–
14.5 ± 0.7
91.0 ± 6
25.1 ± 0.1
> 100
28 m-Ph (CH2)2OAc Bn
> 100
8
m-Ph CH2CO2Et
m-Ph (CH2)2OAc
–
29 m-Ph (CH2)2OAc CH2CO2Et
63.0 ± 9
9
–
30 m-Ph (CH2)2OAc (CH2)2OAc > 100
10 p-Ph
11 p-Ph
12 p-Ph
13 CH2
14 CH2
15 CH2
16 CH2
17 CH2
18 CH2
19 CH2
20 CH2
21 CH2
Bn
–
31 p-Ph
32 p-Ph
33 p-Ph
Bn
Bn
> 100
CH2CO2Et
(CH2)2OAc
Bn
–
> 100
Bn
CH2CO2Et
36.3 ± 0.8
–
79.0 ± 2
Bn
(CH2)2OAc 13.2 ± 0.3
(CH2)2OAc > 100
Bn
0.3 ± 0.003 34 p-Ph
CH2CO2Et
Bn
CH2CO2Et
35.0 ± 1
35 p-Ph
36 p-Ph
37 p-Ph
38 Phc
39 Phc
40 Phc
41 Phc
(CH2)2OAc Bn
> 100
> 100
Bn
(CH2)2OAc 28.0 ± 1
(CH2)2OAc CH2CO2Et
CH2CO2Bn Bn
22.4 ± 0.5
> 100
(CH2)2OAc (CH2)2OAc > 100
CH2CO2Bn CH2CO2Et
–
–
–
–
–
6.2 ± 0.05
93.0 ± 2
> 100
CH2CO2Bn (CH2)2OAc > 100
Bn
(CH2)2OAc Bn
> 100
> 100
CH2CO2Et
(CH2)2OAc
(CH2)2OAc CH2CO2Et
> 100
(CH2)2OAc (CH2)2OAc > 100
a B16 melanoma cells were exposed for 48 h to the test compound and cytotoxicity was assayed using the MTT assay, as described in the General Procedures
section.
b Compound concentration (µM) required to kill 50% of B16 murine melanoma cells (IC50). Mean ± SEM of at least 3 determinations.
c Propiolic acid phenyl amide (38) derivatives, without a second ethynyl substituent.
However, the same effect was not observed when introducing
this second triazole in 31, obtained from 10, since they had both
IC50 > 100 µM. Also in this R1 = benzyl series, the introduction
of another type of chain like ethoxycarbonylmethyl and
acetoxyethyl, had positive effects on the biological activity, but
not as important as for 13. Bis-triazoles 14, 15, 23, 24, 32 and 33;
synthesized from molecules 4, 7 and 10, presented activities in
the range of 15-35 µM. Increase in activity was observed for
propargylic-issued molecules 5 and 6 (both over 100 µM), giving
14 (38 µM) and 15 (28 µM), respectively. The same increased
activity was not encountered in the meta derivative for the
transformation from 7 (14 µM) to 23 (21 µM) and 24 (25 µM).
However, the para-ethynyl derivative 10 (> 100 µM) also gave
more active bis-triazoles 32 (36 µM) and 33 (13 µM).
In the R1 = benzyl / ethyloxycarbonyl (5, 8 and 11) and
acetoxyethyl (6, 9, 12) series, the introduction of another triazole

ACCEPTED MANUSCRIPT
< 1 µM :
ring only yielded compounds with IC50 > 100 µM. The only
O
exceptions were the followings: preparation of 16 (22 µM)
showed an increased biological activity from 5 (> 100 µM);
compound 25 (20 µM) was 4.6-fold more cytotoxic than 8 (91
µM); and, 29 (63 µM) presented a 2.5-fold decreased in activity
from 9 (25 µM).
O
N
N
H
N
N
Bn
N
N
H
Bn
N
N
2
: 0.3 µM
13 : 0.28 µM
< 10 µM :
4. Discussion
O
When considering the unexpected results obtained for the bis-
alkynes 1-3 and 38, it appears that the presence of a phenyl ring
between the two alkynes yielded compounds with higher
cytotoxic activities (Figure 1). However, the presence of the
phenyl ring itself does not seem to be the only influence in this
dramatic increase in activity. When the ethynyl group was in a
para position like in 3 (6.3 µM), or absent like in 38 (6.2 µM),
the activity was better than for 1 (38 µM), but lower than 2 (0.3
µM), where the ethynyl was in meta position. It thus seems that
the presence of an ethynyl group in a meta position was
necessary for a strong activity.
N
H
O
38 : 6.16 µm
N
H
N
N
Bn
N
N
Bn
N
N
O
22 : 4.5 µM
N
H
3
: 6.3 µM
< 20 µM :
(CH2)2OAc
N
N
N
By comparing the structure of the more potent compounds, a
further tentative of structure-activity relationship can be drawn
for this small series of molecules. The bis-triazole 13 (0.3 µM),
in which two benzyl substituents were on the triazoles gave an
activity similar to 2 (0.3 µM), without any structural correlations.
However, the same double substitution by benzylic substituents
was found in the bis-triazole 22 (4.5 µM) derived from 2.
Replacement of one of the benzyl groups by another one, e.g.
ethoxycarbonylmethyl like in 23 (21 µM) and 25 (20.4 µM), also
issued from 2, increased the IC50. Interestingly for these two
compounds, the replacement of the benzylic substituent on one or
the other triazole gave products with the same activity.
Introduction of a triazole bearing a benzyl substituent, onto the
activated alkyne of 2, gave the triazole-alkyne 7 with a good
activity (14.5 µM). Once again, the benzylic part was found in
the derivative, as well as a meta substitution. The benzyl group
was also present in 33 (13.2 µM), derived from the para-bis-
alkyne 3.
O
O
N
N
H
H
N
N
N
N
Bn
Bn
N
N
33 : 13.2 µM
7
: 14.5 µM
O
N
H
R2
N
N
N
N
R1
N
N
23 : R1= Bn, R2= CH2CO2Et : 21 µM
25 : R1= CH2CO2Et , R2= Bn : 20.4 µM
Figure 1. Representative active compounds (2, 3, 7, 13, 22,
23, 25, 33 and 38) against B16 melanoma included in the
range inferior to 1 µm to inferior or equal to 20 µM.
5. Conclusion
From this preliminary study, we can hypothesize that for the
bis-alkynes, an aromatic "spacer" as well as a meta-substitution
was required for the highest activity, as seen for 2. When one or
two triazoles were formed on the starting bis-alkynes, it seemed
that the presence of a benzylic part onto the nitrogen-1 of the
cycle was responsible for an activity ranging from good to
excellent as for 2. This was observed for compounds 13, 22, 23,
25 and 33, for bis-triazole, and 7 for the mono-triazoles.
In this preliminary communication we presented our findings
on the potential anticancer activity of bis-alkyne amides and their
mono- and bis-triazolic derivatives. Some of the synthesized
products showed noteworthy activity against B16 melanoma
cells. Interestingly, one of the bis-alkynes was very potent, as
well as a bis-triazole prepared from another less active mono-
triazole. A tentative SAR was formulated as a starting point
aiming at better understanding the required substituents for
biological activity in this series of compounds. Further work onto
the activity and mechanism of action of these compounds is
warranted.
Considering the drug-like properties of our best compounds 2
and 13, they were shown to meet the Lipinski's rule of 5 criteria,
i.e., a molecular mass ≤ 500, a log P ≤ 5 and a H donor count ≤ 5,
indicating favorable properties for drug development [29].
Furthemore, potential molecular targets were also searched for,
using the in silico bioactivity score developed by Molinspiration
[30]. By comparison to large databases, the results showed that
three potential pathways could significantly be involved in
compound 2 mechanism of action (but not for 13): G protein
coupled receptor (GPCR) ligand, kinase inhibitor and enzyme
inhibitor. Of course, those potential targets identified in silico
would need further in vitro validation.
6. General Procedures
6.1. Catalyst free Huisgen's reaction (for the R1 group)
To the neat bis-alkyne 1 (0.5 mmol), in an opened test tube,
was added the needed organic azide (0.55 mmol). The mixture
was stirred at room temperature for 18 h. The crude products
were triturated in EtOH (8 mL) and filtrated to obtain the solid
1,4-isomer of the mono-triazoles 4-6. For the reactions ran in
solution, i.e. for bis-alkynes 2-3, the alkyne was dissolved in
acetone (4 mL), the azides added, and the solution was heated
under reflux (65°C) for 24 h. The same work-up was conducted
after acetone removal under vacuum to afford mono-triazoles 7-
12.

ACCEPTED MANUSCRIPT
6.2. Amberlyst A-21•CuI CuAAC reaction (for the R2 group)
[12] A. Arezki, G. G. Chabot, L. Quentin, D. Scherman, G. Jaouen, E. Brule,
Med. Chem. Comm. 2 (2011) 190-195.
[13] M. Arthuis, R. Pontikis, G. G. Chabot, J. Seguin, L. Quentin, S. Bourg,
L. Morin-Allory, J.-C. Florent, Chem. Med. Chem. 6 (2011) 1693-1705.
[14] H. Elamari, F. Meganem, J. Herscovici, C. Girard, Tetrahedron Lett. 52
(2011) 658-660.
[15] N. M. Blanch, G. G. Chabot, L. Quentin, D. Scherman, S. Bourg, D.
Dauzonne, Eur. J. Med. Chem. 54 (2012) 22-32.
[16] S. G. Agalave, S. R. Maujan, V. S. Pore, Chem. Asian J. 6 (2011) 2696-
2718.
[17] G. M. Boyle, Expert Rev. Anticancer Ther. 11 (2011) 725-737.
[18] D. P. Griswold, Cancer Chemother. Reports Part 2 Supplement 3 (1972)
315-324.
The mono-triazoles 4-12 – or mono-alkyne 38 – (0.2 mmol)
were dissolved in CH2Cl2 (2 mL) and treated with the desired
azide (0.22 mmol) in the presence of Amberlyst A-21•CuI (12
mg, 8 mol%). The suspension was gently stirred at room
temperature in a closed vessel until complete reaction (16-48 h),
filtered and the polymer rinsed with CH2Cl2 (2 x 1 mL).
Evaporation of the solvent gave the bis-triazoles 13-41.
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96-well plates at 5000 cells per well in 100 µl of culture medium.
Twenty-four h after plating, 100 µl of medium containing the
compound at final concentrations ranging from 0.01 to 100 µM
were added to the wells (in triplicate) containing the cells, and
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microplate reader (BioKinetics Reader, EL340). Appropriate
controls with DMEM only and MTT were run to subtract
background absorbance. The concentration of compound that
inhibited cell viability by 50% (inhibitory concentration for 50%
of cells, or IC50) was determined using the GraphPad Prism
software.
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This work was financially supported by the Centre National de la
Recherche Scientifique (CNRS, UMR8151), the Institut National
de la Santé et de la Recherche Médicale (INSERM, U1022), and
by a grant from the Institut National du Cancer to G. G. Chabot
(INCa, Boulogne-Billancourt, France). H. Elamari and R. Slimi
were supported in part by the Ministère de l'Enseignement
Supérieur of Tunisia, and by the host laboratory during their
Ph.D. studies.
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ACCEPTED MANUSCRIPT
Synthesis and in vitro evaluation of potential anticancer activity of mono- and bis-1,2,3-
triazole derivatives of bis-alkynes
H. Elamari, R. Slimi, G. G. Chabot , L Quentin, D. Scherman and C. Girard
CNRS UMR8151, INSERM U1022, Unité de Pharmacologie Chimique, Génétique & Imagerie, Ecole
Nationale Supérieure de Chimie de Paris and Université Paris Descartes, Paris, France
1. R1N3
O
O
O
neat or acetone
R2N3
R
R
R
N
N
N
H
H
H
R2
N
N
N
N
1 N
N
R1
R
2. EtOH
trituration
A-21•CuI
CH2Cl2
N
N
N
1-3
4-12
13
-
37
•
•
•
•
•
The compounds were prepared by a regioselective synthesis using click chemistry
This was done by a solvent / catalyst free and a solid phase supported steps
All synthetic compounds were tested: alkynes, mono and bistriazoles
Some compounds reached micro to nanomolar cytotoxicities agains B13 melanoma
We made a Structure-Activity Relationship tentative for the series