Triazole and benzotriazole derivatives as novel inhibitors for p90 ribosomal S6 protein kinase 2: Synthesis, molecular docking and SAR analysis

Article abstract of DOI:10.1002/cjoc.201300443

A series of triazole and benzotriazole derivatives as novel p90 ribosomal S6 protein kinase 2 (RSK2) inhibitors were designed and synthesized. The in vitro activities against RSK2 were evaluated, and among 14 compounds, compounds 5, 6, 11, 12, 13 and 14 exhibited enzyme IC₅₀ values of 8.91, 2.86, 3.19, 3.05, 4.49 and 2.09 μmol/L respectively. The proposed binding modes were simulated using molecular docking method, and the docking results coupled with the structure-activity relationship (SAR) analysis indicated that all these active compounds bound to the RSK2 ATP binding site at NTKD, and the electron-donating groups on the 4-position of phenyl were the determinant point for the inhibitory activity. In the present study, a series of triazole and benzotriazole derivatives as novel p90 ribosomal S6 protein kinase 2 (RSK2) inhibitors were designed and synthesized. The in vitro activities of the 14 compounds against RSK2 were evaluated, among which, compounds 5, 6, 11, 12, 13 and 14 exhibited enzyme IC₅₀ values of 8.91, 2.86, 3.19, 3.05, 4.49 and 2.09 μmol/L respectively. The proposed binding modes were simulated using molecular docking method, and the docking results coupled with the structure-activity relationship (SAR) analysis indicated that all our active compounds bound to the RSK2 ATP binding site at NTKD, and the electron-donating groups on the 4-position of phenyl were the key point for the inhibitory activity. Copyright

Full text of DOI:10.1002/cjoc.201300443

FULL PAPER
DOI: 10.1002/cjoc.201300443
Triazole and Benzotriazole Derivatives as Novel Inhibitors for
p90 Ribosomal S6 Protein Kinase 2: Synthesis,
Molecular Docking and SAR Analysis
Jun Yuan,† Ye Zhong,† Shiliang Li, Xue Zhao, Guoqin Luan,
Zhenjiang Zhao, Jin Huang,* Honglin Li,* and Yufang Xu*
Shanghai Key Laboratory of New Drug Design, State Key Laboratory of Bioreactor Engineering,
School of Pharmacy, East China University of Science & Technology, Shanghai 200237, China
A series of triazole and benzotriazole derivatives as novel p90 ribosomal S6 protein kinase 2 (RSK2) inhibitors
were designed and synthesized. The in vitro activities against RSK2 were evaluated, and among 14 compounds,
compounds 5, 6, 11, 12, 13 and 14 exhibited enzyme IC50 values of 8.91, 2.86, 3.19, 3.05, 4.49 and 2.09 μmol/L re-
spectively. The proposed binding modes were simulated using molecular docking method, and the docking results
coupled with the structure-activity relationship (SAR) analysis indicated that all these active compounds bound to
the RSK2 ATP binding site at NTKD, and the electron-donating groups on the 4-position of phenyl were the deter-
minant point for the inhibitory activity.
Keywords RSK2, structure-activity relationships, molecular docking
Introduction
PDK1 that can phosphorylate the NTKD at Ser227.[9]
The activated NTKD will phosphorylate various down-
stream substrates sequentially.[10] Therefore, RSK2 of-
fers two logical sites for inhibition, which are the
ATP-binding sites in the CTKD and the NTKD, respec-
tively.[10,11]
So far, dozens of potent RSK2 inhibitors have been
reported (Figure 1) and most of them bind to RSK2 at
the ATP binding site.[7] Among them, SL0101 is the first
reported specific inhibitor for RSK2 with an IC50 value
of 90 nmol/L.[12] In addition, a few classical kinase in-
hibitors are also found to inhibit RSK2, such as PKC
inhibitors GF109203X and Ro31-8220.[13] Besides,
FMK can irreversibly bind to the CTKD of RSK2 and
exhibits a potent inhibitory activity with an IC50 of 15
nmol/L.[14]
Recently, using the ligand-based virtual screening
program SHAFTS, a 3D similarity based computational
virtual screening procedure combining shape compari-
son with chemical feature superposition, several inhibi-
tors for the NTKD region of RSK2 kinase with novel
scaffolds have been reported by our group.[15] Among
them, compounds with the peculiar triazole and benzo-
triazole scaffolds inspired us to perform structural
modifications to improve the RSK2 inhibitory activity.
Here, we report a series of triazole and benzotriazole
derivatives synthesized from the lead compound 1 with
The p90 ribosomal S6 protein kinase 2 (RSK2) is a
member of RSKs family, which belongs to the ser-
ine/threonine kinases.[1] There are four isoforms identi-
fied in mammals and each is expressed by a separate
gene. RSKs lie downstream in the mitogen-activated
protein kinase (MAPK) signaling cascades, which regu-
late cellular growth and differentiation by phosphoryla-
tion on many pivotal cellular components like transcrip-
tion factors and histones.[2] Among these, RSK2 has
been reported in connection with Coffin-Lowry syn-
drome (CLS)[2d] and other human diseases, such as
HIV,[3] myocardial ischemia,[4] and myeloid leukemia.[5]
Moreover, it is overexpressed in human breast cancer,
prostate cancer and lung cancer.[6] The above studies
indicate that RSK2 is a promising anti-cancer target,
which is of great interest to develop novel and potent
RSK2 inhibitors.[7]
RSKs are rather different from other kinases.[7] In
details, there are two catalytically functional domains,
the C-terminal kinase domain (CTKD), and the
N-terminal kinase domain (NTKD), which is linked by
a domain with about 100 residues.[8] Taking RSK2 as an
example, stimulation of the Ras-ERK signaling pathway
will result in the activation of the CTKD by ERK 1/2,
which will lead to the autophosphorylation of Ser386 in
the linker region of RSK2 and provide a binding site for
*
E-mail: hlli@ecust.edu.cn. † The first two authors contributed equally to this work.
Received May 31, 2013; accepted June 30, 2013; published online July 19, 2013.
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cjoc.201300443 or from the author.
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Triazole and Benzotriazole Derivatives as Novel Inhibitors for p90 Ribosomal S6 Protein Kinase 2
scribed previously.[15b] Derived from the previously
OH
F
discovered lead compound 1, structural optimizations
underwent two phases. Firstly, common substituent
groups were introduced into the benzene ring. Secondly,
the triazole moiety would be modified with similar sub-
stituent groups for diversity. The structures of inhibitors
with inhibitory activities of them against RSK2 are
listed in Table 1.
OH
N
N
N
HO
O
O
N
O
O
OH
OH
OAc
O
OAc
FMK IC50: 15 nmol/L
SL0101 IC50: 90 nmol/L
Scheme 1 The synthesis routes of triazole and benzotriazole
derivatives
O
R5
R1
O
HN
HOAc (cat.)
EtOH, reflux
HN
N
N
N
NH
R4
H2N
N
CHO
O
O
R3
R4
R5
R2
R1
N
S
NH
NH2
R3
N
N
Ro31-8220 IC50: 36 nmol/L
N
GF109203x IC50: 310 nmol/L
N
N
N
I
R2
OH
-
compounds 1 4
N
N
O
N
N
O
N
NH2NH2
EtOH, 90 o
CS2, KOH
NHNH
2 EtOH, 80 oC
Lead compound 1 IC50: 16.18 μmol/L
C
N
C
O
Figure 1 The reported RSK2 inhibitors, and the lead compound
1.
SH
intermediate 1a
IC50 value of 16.18 μmol/L[15b] (Figure 1). The structure
activity relationship (SAR) was summarized, and the
potential binding modes of these inhibitors were eluci-
dated by docking simulations with the RSK2 NTKD
homology model built in our previous work.[15c] Since
only three RSK2 NTKD complexed with SL0101 and
its analogues have been released to the PDB database
presently,[16] the homology modeling and ligand-based
methods are still useful for the discovery of novel RSK2
inhibitors.[11,15c,17]
N
N
N
Aromatic aldehydes
N
N
N
CH3COOH, 120 oC, 10 min
N
SH
H2N
SH
R
intermediate 2a
-
compunds 5 7
NH2
N
N
N
N
R
N
+
CH O
+
2
methanol
r.t.
N
H
R
N
H
-
compounds 8 14
Results and Discussions
In comparison with compounds 1 and 2 in Table 1,
conclusion could be drawn that the substituent groups
on the phenyl contributed much to the inhibitory activity,
in which electron-donating groups like OH and OCH3
would be beneficial to activities. In the meantime, in the
cases of compounds 1 and 7, halogen atoms could be
tolerated at the 3-position on the benzyl, which did not
affect the RSK2 inhibitory activities efficiently. While
turning to the 4-position, it was found that a OH sub-
stituent was essential, and if it was replaced by electron-
withdrawing groups, such as Cl (compound 3), or other
electron-donating ones, such as OCH3 (compound 4),
the derivatives would lose RSK2 inhibitory activities.
Moreover, structural optimization was introduced to
the triazole moiety for further investigations. In general,
substituents on the triazole were not key factors for
RSK2 inhibitory activities, even a smaller group like a
Chemistry
Triazoles 1－7 in Table 1 were synthesized accord-
ing to Scheme 1 by coupling of 1,2,4-triazol-4-amine
derivatives and substituted benzaldehyde in ethanol and
a catalytic amount of HOAc. The Schiff bases were
separated and purified by recrystallization or gel chro-
matography. Benzotriazoles in Table 2 were synthesized
according to Scheme 1 by condensation of benzotriazole
with 40% aqueous formaldehyde and substituted aniline
in methanol. These compounds had been reported else-
where,[18] and the structures of these compounds in this
work were characterized by NMR confirmation (see the
Supporting Information).
Biological activity and SAR
The kinase inhibition assay was performed as de-
Chin. J. Chem. 2013, 31, 1192—1198
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Table 1 The structures of triazole derivatives with inhibitory activities against RSK2
R3
R4
R5
R1
N
N
N
N
R2
IC50b/(μmol•L−1)
Compound
R1
R2
R3
R4
R5
Inhibitiona/%
1
2
3
4
5
6
7
H
H
H
I
OH
OH
Cl
OCH3
H
51.51
30.15
4.86
16.18
ND
H
H
H
H
H
H
ND
H
H
H
OCH3
OH
OH
OH
H
2.02
ND
SH
SH
SH
CH3
benzyl
benzyl
H
OCH3
OCH3
Br
60.86
62.53
48.87
8.91
2.86
ND
OCH3
Br
a Inhibition rates were determined at the concentration of 10 μmol/L; b IC50 values were calculated if the inhibition rate at 10 μmol/L was
larger than 50%. ND, not determined.
methyl (compound 5) or a larger one like a benzyl
(compound 6) at the 2-position likewise would result in
equivalent activities. Still, substituents on the phenyl
moiety, especially the 4-OH had been pivotal to the
binding affinities, while substituents at other positions
of phenyl moiety were not the key factors to the RSK2
inhibitory activities.
Replacing 1,2,4-triazole with benzotriazole, a series
of benzotriazole derivatives were synthesized and the
structural optimizations were focused on the substituent
group of the phenyl moiety. Their RSK2 inhibitory ac-
tivities were evaluated and the results are listed in Table
2.
tion to the inhibitory activity, in which electron-donat-
ing groups like OH, OCH3 and morpholinyl would be
beneficial to activities. That is, compound 11 and com-
pound 12, which had OH introduced at different posi-
tions of the aniline, were both superior to unsubstituted
compound 8, but had a similar activity as compounds 13
and 14, which were also introduced with electron-do-
nating groups. When the substituent groups were re-
placed by electron-withdrawing groups, such as NO2
and Cl (compounds 9 and 10), both of them lost RSK2
inhibitory activities.
Binding mode analysis
To investigate the structural basis for the binding
modes of these novel inhibitors in the RSK2 ATP-
binding site, we have scrutinized the binding poses re-
sulting from molecular docking stimulations. The pre-
dicted binding modes of compounds 6, 11, 12 and 14 are
shown in Figure 2. As we reported previously,[15a,15b,19]
all of them bind to RSK2 NTKD in the ATP binding site.
Meanwhile, each triazole group in the four compounds
occupies the adenine binding pocket of the enzyme and
forms important hydrogen bonds with the residue Leu
150 within the hinge region. However, compound 6
(Figure 2A) displays a slightly different binding style
compared with the other three compounds. With the
polyphenol group orienting in the hydrophobic pocket,
the phenolic hydroxyl group may form an additional
H-bond with the nitrogen atom of Asn 198. Thus when
the phenolic hydroxyl group is replaced by electron-
withdrawing groups, such as Cl (compound 3), or other
electron-donating ones like OCH3 (compound 4), the
H-bond aforementioned would abort. At the same time,
the two methoxyl groups fit well with the pocket, and if
any of the methoxyl group is substituted by halogen
atoms of I and Br (compounds 1 and 7), the shape
matching profile will be destroyed which further results
in a decrease in activity against RSK2. Besides, a sulf-
Table 2 The structures of benzotriazoles with inhibitory activi-
ties against RSK2
N
R
N
N
N
H
Compound
R
Inhibitiona/%
IC50b/(μmol•L−1)
8
H
12.84
0.00
ND
ND
9
4-NO2
4-Cl
10
13.73
82.09
72.94
77.02
76.06
98.21
ND
11
4-OH
3.19
3.05
4.49
2.09
0.01
12
13
2-OH
4-OCH3
4-morpholinyl
14
Ro31-8220
a
Inhibition rates were determined at the concentration of 10
b
μmol/L; IC50 values were calculated if the inhibition rate at 10
μmol/L was larger than 50%. ND, not determined.
The substitution of benzotriazoles derivatives shared
a similar pattern with 1,2,4-triazole derivatives. The
substituent groups on the phenyl made great contribu-
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Chin. J. Chem. 2013, 31, 1192—1198

Triazole and Benzotriazole Derivatives as Novel Inhibitors for p90 Ribosomal S6 Protein Kinase 2
Figure 2 The predicted binding modes for representative compounds (stick, green carbon) 6 (A), 11 (B), 12 (C) and 14 (D) in the RSK2
NTKD model (surface and cartoon, purple carbon). The important residues are shown in yellow thin stick, and the nitrogen and oxygen
atoms are colored in blue and red, respectively. Potential intermolecular hydrogen bonds are shown in orange dashed lines.
hydryl group at the 1-position of the triazole scaffold
appears to be tolerated (compounds 5－7).
lead compound 1 from our previous study, a series of
triazole and benzotriazole derivatives were designed and
synthesized to attain more potent RSK2 inhibitors.
Among these, compounds 5, 6, 11, 12, 13 and 14 exhib-
ited better inhibition against RSK2 with the IC50 values
of 8.91, 2.86, 3.19, 3.05, 4.49 and 2.09 μmol/L respec-
tively. The SAR was summarized and the proposed
binding modes were explored to further elucidate the
SAR. To our knowledge, this is the first report that tria-
zole and benzotriazole derivatives could be used as
RSK2 kinase inhibitors. Therefore, the above com-
pounds might be served as new lead compounds to sup-
press cell migration, especially to treat cancers in fur-
ther drug developments.
While turning to the benzotriazoles, it is found that
they bind to the ATP binding site stretching along the
hinge region, which not only provide hydrogen bond
interactions with Leu 150 and VDW interactions with
the residues Val 82, Ala 98, Leu 147 and Leu 200 by the
benzotriazole moiety, but also contact the enzyme with
a potential hydrogen bond by substituent groups on the
phenyl (Figure 2B－2D). But differently, the 4-OH of
11 could form a H-bond with the residue Lys 72 (Figure
2B), while the 2-OH of 12 (Figure 2C) and the
4-morpholinyl of 14 (Figure 2D) form H-bond interac-
tions with Leu 74 and Asp 154, respectively. When the
4-OH is replaced by electron-withdrawing groups, such
as NO2 (compound 9), the electronic distribution in the
whole conjugate system would be reduced efficiently to
attenuate the key hydrogen bond to Leu 150, and further
result in a sharp decrease in activities. Meanwhile, if it
is substituted by 4-Cl or unsubstituted (compounds 10
and 8), the abortion of the H-bond aforementioned
would also lead to inferior activities, but the 4-OCH3
substituent (compound 13) could retain the RSK2 in-
hibitory activity which can still form the H-bond with
Lys 72 with the 4-OCH3 as a H-bond acceptor.
Experimental
NMR spectra were recorded on a Bruker AV-400
spectrometer with TMS as an internal standard. Melting
points were measured on an X-6 micro-melting point
apparatus. All the reactions were monitored by
thin-layer chromatography (TLC). Column chromatog-
raphy was performed using silica gel (Hailang, Qingdao)
200－300 mesh.
In vitro kinase inhibition assay
The inhibitory ratio values of these compounds
against RSK2 were performed in 384-well flat-bottom
plates using the ADP Quest (DiscoveRx). The kinase
Conclusions
In summary, through structural optimization of the
Chin. J. Chem. 2013, 31, 1192—1198
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Yuan et al.
FULL PAPER
(15 ng, Millipore) in 30 μL assay buffer (15 mmol/L
HEPES, pH 7.4, 20 mmol/L NaCl, 1 mmol/L EGTA,
0.02% Tween 20, 10 mmol/L MgCl2, and 0.1 mg/mL
BGG (bovine-γ-globulins)) containing 25 μmol/L S6
peptide (AKRRRLSSLRA, Anaspec) was incubated for
20 min at room temperature with the indicated
concentrations of the compounds to be tested. Reactions
were initiated by the addition of 5 μL of ATP to a final
concentration of 5 μmol/L and terminated after 60 min
at room temperature by adding 10 μL of ADP reagent A
and 20 μL of ADP reagent B. Ro31-8220 was used as
the positive control. Compound dilutions were prepared
from stock in DMSO and diluted with assay buffer for
inhibition assay. The fluorescence signal detecting the
amount of ADP produced as a result of enzyme activity
was recorded on the SynergyTM 2 multimode micro-
plate reader (BioTek) at an excitation wavelength of 530
nm and an emission wavelength of 590 nm at 30 min
after the addition of the ADP reagent B. The inhibition
rate (%) was calculated using the following equation:
4-(((3-Mercapto-5-methyl-4H-1,2,4-triazol-4-yl)-
imino)methyl)-2-methoxyphenol (5): Acetohydrazide
(0.15 g, 2.0 mmol) and KOH (0.17 g, 3.0 mmol) were
dissolved in 50 mL absolute ethanol. CS2 (0.18 mL, 3.0
mmol) was added dropwise. The mixture was refluxed
for 8 h, and then distilled under reduced pressure. The
residue was added into distilled water and the solid
formed was filtered. The filtrate was acidified and set to
pH＝1 with 2 mol/L HCl solution. The product was ob-
tained by filtration and dissolved in ethyl acetate. The
solution was dried with MgSO4 and evaporated by vac-
uum. The intermediate 1a was obtained. The mixture of
intermediate 1a (0.36 g, 2.0 mmol), 80% hydrate hydra-
zine aqueous solution (0.4 mL, 2.5 mmol) and absolute
ethanol (20 mL) was refluxed at 90 ℃ for 8 h. Then
the mixture was cooled and evaporated by vacuum.
Crystallization of the product from ethanol gave pink
solid of intermediate 2a. 4-Hydroxy-3-methoxybenzaldehyde
(0.31 g, 2.0 mmol) and intermediate 2a (0.38 g, 2.0
mmol) were added. The reaction mixture was refluxed
for 10 min. Then the mixture was cooled and the solid
separated was filtered and washed with ethanol. After
drying, compound 5 was obtained. Yield 66%. m.p.
⎛
⎞
F
590,cmpd.
Inhibition＝ 1－
×100%
⎜
⎟
⎟
⎜
⎝
F
1
＞300 ℃ (m.p. ＞300 ℃[18b]); H NMR (400 MHz,
590,control
⎠
CD3OD) δ: 9.72 (s, 1H), 7.57 (s, 1H), 7.35 (dd, J1＝8.0
Hz, J2＝1.6 Hz, 1H), 6.93 (d, J＝8.4 Hz, 1H), 3.95 (s,
3H), 2.42 (s, 3H).
4-(((3-Mercapto-5-phenyl-4H-1,2,4-triazol-4-yl)imino)-
methyl)-2,6-dimethoxyphenol (6): A procedure similar
Unless otherwise stated, all reagents were purchased
from Sigma-Aldrich and used without further purifica-
tion.
Synthesis
to the preparation of 5. m.p. ＞300 ℃ (m.p. ＞300
℃
1
[18b]); Yield 80%. H NMR (400 MHz, CD3OD) δ:
4-(((4H-1,2,4-Triazol-4-yl)imino)methyl)phenol (2):
4-Hydroxybenzaldehyde (0.12 g, 1.0 mmol), 4H-1,2,4-
triazol-4-amine (0.084 g, 1.0 mmol) and ethanol (10 mL)
were put into a 25 mL round-bottomed flask, and then
2－3 drops of HOAc were added as the catalyst. The
reaction was refluxed and monitored by TLC. After that
the raw material was completely consumed, then the
mixture was cooled and evaporated by vacuum. The
residue was alkalized and set to pH＝7 with saturated
solution of Na2CO3 and extracted with DCM (50 mL×
2). The combined organic layers were washed with
brine, dried over Na2SO4, and concentrated. The crude
was purified by silica column chromatography or re-
crystallized in ethanol to give compound 2 as a white
powder. Yield 72%. m.p. 142.0－143.1 ℃ (m.p. 140.0
9.53 (s, 1H), 7.94 (dd, J1＝7.2 Hz, J2＝1.6 Hz, 2H),
7.52 (d, J＝7.6 Hz, 3H), 7.25 (s, 2H), 3.92 (s, 6H).
2,6-Dibromo-4-(((3-mercapto-5-phenyl-4H-1,2,4-
triazol-4-yl)imino)methyl)phenol (7): Yield 77%. m.p.
1
＞300 ℃ (m.p. ＞300 ℃[18b]); H NMR (400 MHz,
DMSO-d6) δ: 14.25 (s, 1H), 9.51 (s, 1H), 8.06 (s, 2H),
7.83－7.86 (m, 2H), 7.54－7.56 (m, 3H).
N-((1H-Benzo[d][1,2,3]triazol-1-yl)methyl)aniline
(8): A mixture of benzotriazole (0.60 g, 5.0 mmol), 40%
aqueous formaldehyde solution (0.38 g, 5.0 mmol) and
aniline (0.47 g, 5.0 mmol) in methanol (60 mL) was
stirred at room temperature for 2 h. With the process of
reaction, a white solid was separated out. The precipi-
tate was filtered off, washed with cool methanol and
dried in vacuo to yield product, 1.0 g; yield: 90%. m.p.
141.9－143.0 ℃ (m.p. 141－143 ℃[21]); 1H NMR
(400 MHz, DMSO-d6) δ: 8.06 (d, J＝8.4 Hz, 1H), 8.01
(d, J＝8.4 Hz, 1H), 7.54 (t, J＝7.6 Hz, 1H), 7.38 (t, J＝
7.6 Hz, 1H), 7.27 (t, J＝7.2 Hz, 1H), 7.07 (t, J＝7.6 Hz,
2H), 6.82 (d, J＝8.0 Hz, 2H), 6.59 (t, J＝7.2 Hz, 1H),
6.12 (d, J＝7.2 Hz, 2H).
℃
[20]); 1H NMR (400 MHz, DMSO-d6) δ: 10.34 (s, 1H),
9.07 (s, 2H), 8.93 (s, 1H), 7.71 (d, J＝8.8 Hz, 2H), 6.92
(d, J＝8.8 Hz, 2H).
N-(4-Chlorobenzylidene)-4H-1,2,4-triazol-4-amine
(3): A same procedure as to the preparation of 2. Yield
68%. m.p. 191.7－192.1 ℃ (m.p. 185 ℃[20]); 1H
NMR (400 MHz, DMSO-d6) δ: 9.15 (s, 2H), 9.11 (s,
1H), 7.87 (d, J＝8.4 Hz, 2H), 7.65 (d, J＝8.4 Hz, 2H).
N-(4-Methoxybenzylidene)-4H-1,2,4-triazol-4-amine
N-((1H-Benzo[d][1,2,3]triazol-1-yl)methyl)-4-nitro-
aniline (9): A procedure similar to the preparation of 8.
(4): Yield 70%. m.p. 144.5 －144.8 ℃ (m.p. 164
℃
Yield 91%. m.p. 210.1－212.0 ℃ (m.p. 210－213
℃
1
[20]); H NMR (400 MHz, DMSO-d6) δ: 9.10 (s, 2H),
1
[22]); H NMR (400 MHz, DMSO-d6) δ: 8.50 (t, J＝
9.00 (s, 1H), 7.81 (d, J＝8.8 Hz, 2H), 7.12 (d, J＝8.8
Hz, 2H), 3.85 (s, 3H).
6.8 Hz, 1H), 8.05－8.03 (m, 4H), 7.61－7.57 (m, 1H),
7.43－7.40 (m, 1H), 6.99 (d, J＝8.0 Hz, 1H), 6.27 (d,
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Chin. J. Chem. 2013, 31, 1192—1198

Triazole and Benzotriazole Derivatives as Novel Inhibitors for p90 Ribosomal S6 Protein Kinase 2
J＝6.8 Hz, 1H).
compound ranked by GlideScore were remained for
N-((1H-Benzo[d][1,2,3]triazol-1-yl)methyl)-4-chloro-
aniline (10): Yield 92%. m.p. 164.4－166.0 ℃ (m.p.
further analysis.
1
165－167 ℃[22]); H NMR (400 MHz, DMSO-d6) δ:
Acknowledgements
8.04－8.01 (m, 2H), 7.55 (t, J＝7.6 Hz, 1H), 7.45 (t,
J＝7.2 Hz, 1H), 7.39 (t, J＝7.8 Hz, 1H), 7.11 (d, J＝8.8
Hz, 2H), 6.84 (d, J＝8.8 Hz, 2H), 6.12 (d, J＝7.2 Hz,
2H).
The research is supported in part by the Fundamental
Research Funds for the Central Universities, the Na-
tional Natural Science Foundation of China (Nos.
81222046, 21236002 and 81230076), and the Shanghai
Committee of Science and Technology (Nos.
11DZ2260600, 12401900801).
4-(((1H-Benzo[d][1,2,3]triazol-1-yl)methyl)amino)-
phenol (11): Yield 83%. m.p. 168.5－169.9 ℃ (m.p.
1
169 ℃[22]); H NMR (400 MHz, DMSO-d6) δ: 8.51 (s,
1H), 8.04 (d, J＝8.4 Hz, 1H), 7.99 (d, J＝8.4 Hz, 1H),
7.52 (t, J＝7.2 Hz, 1H), 7.37 (t, J＝7.2 Hz, 1H), 6.73 (t,
J＝7.6 Hz, 1H), 6.65 (d, J＝8.4 Hz, 2H), 6.51 (d, J＝
8.8 Hz, 2H), 6.05－6.03 (m, 2H).
2-(((1H-benzo[d][1,2,3]triazol-1-yl)methyl)amino)-
phenol (12): Yield 76%. m.p. 151.5－152.9 ℃ (m.p.
155 ℃[22]); 1H NMR (400 MHz, CDCl3) δ: 8.03 (d, J＝
8.4 Hz, 1H), 7.89－7.86 (m, 1H), 7.63 (d, J＝8.4 Hz,
1H), 7.47－7.45 (m, 1H), 7.41－7.32 (m, 2H), 6.97 (d,
J＝8.0 Hz, 1H), 6.79 (t, J＝7.2 Hz, 2H), 6.73－6.67 (m,
1H), 6.12－6.11 (m, 2H).
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Molecular docking simulation
To explore the potential binding modes, molecular
docking method was employed for compounds 6, 11, 12
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previous study was used for protein preparation.[15c]
Hydrogen atoms and charges were added to the receptor
using the Protein Preparation workflow in Maestro
(Schrödinger Inc, version 9.0). The grid-enclosing box
was centered on the centroid of ligand (Staurosporine)
and defined so as to enclose residues located within 20
Å around the ATP binding site, and a scaling factor of
1.0 was set to van der Waals (VDW) radii of those re-
ceptor atoms with the partial atomic charge less than
0.25. Then compounds 6, 11, 12 and 14 were prepared
by the LigPrep module in Maestro, and Epik method
was selected to predict the ionization as well as the
tautomerization states of the compounds within the de-
fault pH range of 7.0±2.0. Finally, Extra-Precision (XP)
mode in Glide was used to perform the molecular dock-
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FULL PAPER
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© 2013 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2013, 31, 1192—1198