Identification of anticancer agents based on the thieno[2,3-b]pyridine and 1H-pyrazole molecular scaffolds

Article abstract of DOI:10.1016/j.bmc.2016.05.061

Structural similarity search of commercially available analogues of thieno[2,3-b]pyridine and 1H-pyrazole derivatives, known anticancer agents, resulted in 717 hits. These were docked into the phosphoinositide specific-phospholipase C (PLC) binding pocket, the putative target of the compounds, to further focus the selection. Thirteen derivatives of the thieno[2,3-b]pyridines were identified and tested against the NCI60 panel of human tumour cell lines. The most active derivative 1 was most potent against the MDA-MB-435 melanoma cell line with GI₅₀at 30?nM. Also, it was found that a piperidine moiety is tolerated on the thieno[2,3-b]pyridine scaffold with GI₅₀?=?296?nM (MDA-MB-435) for derivative 10 considerably expanding the structure activity relationship for the series. For the 1H-pyrazoles four derivatives were identified using the in silico approach and additionally ten were synthesised with various substituents on the phenyl moiety to extend the structural activity relationship but only modest anticancer activity was found.

Full text of DOI:10.1016/j.bmc.2016.05.061

Accepted Manuscript
Identification of anticancer agents based on the thieno[2,3-b]pyridine and 1H-
pyrazole molecular scaffolds
Chatchakorn Eurtivong, Inga Reynisdóttir, Stephanie Kuczma, Daniel P.
Furkert, Margaret A. Brimble, Jóhannes Reynisson
PII:
S0968-0896(16)30405-9
DOI:
http://dx.doi.org/10.1016/j.bmc.2016.05.061
BMC 13045
Reference:
Bioorganic & Medicinal Chemistry
To appear in:
Received Date:
Revised Date:
Accepted Date:
4 April 2016
24 May 2016
28 May 2016
Please cite this article as: Eurtivong, C., Reynisdóttir, I., Kuczma, S., Furkert, D.P., Brimble, M.A., Reynisson, J.,
Identification of anticancer agents based on the thieno[2,3-b]pyridine and 1H-pyrazole molecular scaffolds,
Bioorganic & Medicinal Chemistry (2016), doi: http://dx.doi.org/10.1016/j.bmc.2016.05.061
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Identification of anticancer agents based on the
thieno[2,3-b]pyridine and 1H-pyrazole molecular scaffolds
Chatchakorn Eurtivong1, Inga Reynisdóttir2, Stephanie Kuczma1, Daniel P.
Furkert1, Margaret A. Brimble1 and Jóhannes Reynisson1*
1School of Chemical Sciences, University of Auckland, New Zealand
2Cell Biology Unit, Department of Pathology, Landspítali University Hospital, Reykjavík,
Iceland
*To whom correspondence should be addressed: School of Chemical Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand.
E-mail: j.reynisson@auckland.ac.nz, Tel. 64-9-373-7599 ext. 83746, Fax. 64-9-373-7422
Abstract
Structural similarity search of commercially available analogues of thieno[2,3-b]pyridine and
1H-pyrazole derivatives, known anticancer agents, resulted in 717 hits. These were docked
into the Phosphoinositide specific-phospholipase C (PLC) binding pocket, the putative target
of the compounds, to further focus the selection. Thirteen derivatives of the thieno[2,3-
b]pyridines were identified and tested against the NCI60 panel of human tumour cell lines.
The most active derivative 1 was most potent against the MDA-MB-435 melanoma cell line
with GI50 at 30 nM. Also, it was found that a piperidene moiety is tolerated on the thieno[2,3-
b]pyridine scaffold with GI50 = 296 nM (MDA-MB-435) for derivative 10 considerably
expanding the structure activity relationship for the series. For the 1H-pyrazoles four
derivatives were identified using the in silico approach and additionally ten were synthesised
with various substituents on the phenyl moiety to extend the structural activity relationship
but only modest anticancer activity was found.
Keywords: Similarity searching; phospholipase C; molecular modelling; NCI60; MTT;
Structure Activity Relationship (SAR).
1

Introduction
The phospholipase C (PLC) family comprises a series of enzymes which regulate many
2
cellular growth functions, making them interesting targets for cancer therapy.1, The
thieno[2,3-b]pyridines and 1H-pyrazoles were initially discovered as potential inhibitors of
PLC isoforms by virtual high throughput screen (vHTS) using the available crystal structure
of the PLC-δ1 isoform.1 The molecular structures of the thieno[2,3-b]pyridines and 1H-
pyrazoles are shown in Figure 1. In vitro testing for the thieno[2,3-b]pyridines revealed that
the most potent analogues had growth inhibitory activity at low nanomolar concentrations
against the National Cancer Institute’s NCI60 human tumour cell line panel.3-7 The
administration of thieno[2,3-b]pyridines causes the breast cancer cell line MDA-MB-231 to
be severely growth restricted, rounded and blebbing of the plasma membrane, G2/M phase
population increase in the cell cycle and decrease in motility as reflected in slowed
proliferation in scratch assays. 8, 9 These effects on MDA-MB-231 are in line with inhibition
of the PLC-δ1 and δ2 isoforms making them the most plausible target for this class of
9
compounds.8, The thieno[2,3-b]pyridine structural motive appears in many bioactive
compounds with various mechanisms of action: antagonists of adenosine A2A receptor
antagonist (a G protein-coupled receptor),10 as inhibitors of copper trafficking interfaces of
Atox1 and CCS proteins, for inhibition of tumour growth and Wilson’s disease,11
hepatocellular carcinoma-specific anti-tumour activity12, 13 and tubulin inhibitors.14 The 1H-
pyrazoles also showed, albeit more modest, activity against the NCI60 human tumour cell
line panel.4
2

Figure 1. The basic molecular structures of the anticancer thieno[2,3-b]pyridines (3-amino-5-oxo-N-phenyl-
5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carboxamide (left) and 1H-pyrazoles (3-(chroman-6-yl)-1-
(phenylsulfonyl)-1H-pyrazoles), (right).
The aim of this project is to explore the chemical space around the active thieno[2,3-
b]pyridines and 1H-pyrazoles extending their structural activity relationship (SAR) profiles
by identifying their commercially available analogues using similarity searching and
substructure techniques. To focus the SAR study on the most promising analogues and reduce
the number of compounds for testing docking against the PLC-δ1 lipase was conducted.
Results and Discussion
Thieno[2,3-b]pyridines
Structural similarity search was conducted on eMolecules,15 a commercial compound
database using the thieno[2,3-b]pyridine structure shown in Fig. 1. Six hundred and fifty-four
(654) compounds were found, using similarity coefficient of 0.7, and docked against the
PLC-δ1 scaffold (see Methodology). Ligands with no or weak hydrogen bonding (HB < 1)
were eliminated as well as those with low predicted binding energies, (GS < 45, CS < 20,
ChemPLP < 45 and ASP < 25). The remaining candidates were checked for consensus for the
best predicted poses between the scoring functions used and whether a plausible binding
mode was predicted, e.g., unstrained poses and whether lipophilic moieties were jutting into
the aqueous phase causing entropic penalty. This resulted in identification of thirteen virtual
hits, which were tested using the NCI60 human tumour cell panel at 10 µM concentration.
Two distinct structural classes of thieno[2,3-b]pyridines (1-6 and 8-12) and two singletons (7
3

and 13) were found and their molecular structures are shown in Table 1 with their mean
growth of the NCI60 panel.
Table 1 Anti-proliferative activity of the thieno[2,3-b]pyridines.
R
H
H
H
H
X1
H
Et
Et
H
X2
Me
H
X3
H
H
H
Me
X4
H
H
Me
H
H
NCI Meana
29.9
1
2
25.4
25.2
H
3
4
Me
Acetyl
H
26.3
H
H
H
H
H
97.9b
99.0
5
6
Phenyl
H
-
-
-
-
-
101.6
7
Benzyl
Benzyl
Benzyl
Benzyl
Isopropyl
-
Me
H
H
H
Me
H
H
Me
H
H
27.3
100.6
52.7
59.4
98.8
8
Me
OMe
H
9
10
11
12
13
H
H
H
H
H
H
H
c
c
c
c
-
-
-
-
24.8
aValues represent relative growth (%) versus control as an average for 60 human tumour cell lines (NCI60). All
compounds were tested at 10 µM. bFrom ref.5 cNo phenyl moiety.
It is clear that derivatives 1 – 4, 8 and 13 are the most active with growth of ~25% as
compared to untreated cells (100%). When the substitution patterns of the phenyl rings are
4

considered for derivatives 1 - 6, it can be concluded that small alkyl substitutions at ortho
(X1) and meta (X2) positions are the most advantageous whilst electron withdrawing groups
such as acetyl (derivative 5) at the meta (X2) position is detrimental as compared to the un-
substituted derivative that has a relative growth of 30.2%.4 It has been previously reported
that substitution of on the ortho position gives good results such as with fluoro (33.3%) and
methyl (42.0%) groups but larger groups are not tolerated, e.g., CF3 (81.6%) and methoxy
(61.3%).4, 5 Furthermore, meta substitution is also favourable with fluoro at 31.4% and chloro
4, 5
at 36.3% relative growths.
This is in line with the results presented in Table 1.4, 5
Interestingly, methyl substitutions at both the meta (X2) and para (X3) positions as for
derivative 4 has similar effect as derivatives 1 - 3 suggesting the importance of alkyl
substitutions at the meta position (X2) to anticancer activity since it has been previously seen
that para substitution is clearly detrimental to the anticancer activity of the thieno[2,3-
b]pyridines, e.g., para methoxy and para chloro derivatives have no effect on the growth of
the tumour cells . 4, 5 No anticancer activity was found for the N,N-diphenyl derivative (6).
Derivative 7 is structurally unique in that it has a bicyclic instead of tricyclic ring system. It
exhibited no activity; apparently conserving the tricyclic ring system is important for
anticancer activity of this class of compounds as has been previously observed.7
In general, the thieno[2,3-b][1,6]naphthyridine derivatives 9 - 13 exhibited more modest
anticancer effects than the cyclohexanone-thieno[2,3-b]pyridines (1-6) with the exception of
derivatives 8 and 13, which had relative growth of 27% and 25%, respectively. In contrast to
the cyclohexanone-thieno[2,3-b]pyridines (1-6), methyl meta (X2) substitution is detrimental
to the anticancer activity of the thieno[2,3-b][1,6]naphthyridines as seen for derivative 9. A
possible explanation for this effect is that the two series are inhibiting different but related
enzyme classes. Changing the R group from benzyl to isopropyl (derivative 12) had a
detrimental effect indicating that the benzyl group is occupying a lipophilic pocket (see Fig.
5

2). Derivative 13 is different in that it does not have a phenyl group but a thiophenyl on the
pyridine moiety and can therefore be considered as a novel analogue in this chemical series.
Nevertheless, it is potent in reducing growth of the cancer cells.
Derivatives 1 – 4 and 8, 10, 11 and 13 were selected for dose response testing based on their
favourable growth inhibition at 10 µM and the results are given in Table 2. The Growth
Inhibition at 50% (GI50) and Total Growth Inhibition (TGI) were derived from these
measurements.3 GI50 is the concentration for 50% of maximal inhibition of cell proliferation
and therefore reflects the cytostatic concentration whereas TGI is the compound
concentration resulting in total growth inhibition. Five tumour cell lines were particularly
affected: MDA-MB-435 (melanoma), MDA-MB-468 (breast), A498 (renal), SF-539 (central
nervous system, CNS) and K-562 (leukaemia).
Table 2 The dose response for the most active compounds shown for five tumour cell lines in nano-molar (nM)
concentration.
MDA-MB-435
MDA-MB-468
A498
SF-539
K-562
GI50
a
TGIb
a
a
a
a
GI50
TGIb
GI50
TGIb
GI50
TGIb
GI50
TGIb
1c
2c
3c
4c
8
X/X
31/30
60/46
115/138 143/80
Y/2660
139/31
270/180
224/178
274/198
1310
701/915
237/167
335/416
320/334
404/443
2440
821/462
76/144
X/X
336/225 235/209 44700/Y
261/377 X/60600
44800/682
866/665
Y/658
7710
2690/3710 372/203
31800/15800
171/148 426/X
152/121 443/322 229/314
Y/Y
Y/Y
7790
6560
X
341/522
468/Y
903
35000/Y
Y/X
32200
61400
X
X
X
X
X
399
296
4380
11000
71600
X
1780
2600
17000
1750
3820
24400
Y
1990
530
10
11
13
3430
3130
1780
2780
9100
4990
4860
2580
7270
2350
6790
aGI50 (50% growth inhibition). TGI (total growth inhibition). Tested twice and both values are given.
b
c
X: TGI not achieved at 10 µM, Y: no data.
Considering the results in Table 2, it is clear that derivative 1 is the most active compound
particularly against MDA-MB-435 with an average GI50 of ~30 nM and inhibition in the 76 –
237 nM range for the other cell lines. The most active compound identified in this series has
an ortho methyl and meta chloro substitution on the phenyl ring with GI50 of 18.5 nM for the
MDA-MB-435 melanoma cell line and inhibition in the 23 – 38 nM range for the other cell
lines.5 Derivative 2 is second most active compound with activity in the 53 – 372 nM range
6

followed by derivatives 3 – 4. Even though the thieno[2,3-b][1,6]naphthyridines are less
active than their cyclohexanone-thieno[2,3-b]pyridine counterparts identifying them using the
combination of similarity search and molecular modelling demonstrates the effectiveness of
coupling these techniques together extending the SAR profile of the series.
Molecular modelling studies against PLC-δ1 showed that the cyclohexanone-thieno[2,3-
b]pyridines (1-6) have hydrogen bonding to two amino acids histidine (His311) via the
carboxamide and glutamic acid (Glu341) with the amine group. Also, arginine (Arg549) and
lysine (Lys438) interact with the ketone group in the cyclohexanone moiety and the phenyl
group is embedded into a lipophilic pocket. In general, the binding mode is the same as has
been previously reported on this chemical series.4, 5, 7, 8 The thieno[2,3-b][1,6]naphthyridine
family had a similar predicted hydrogen bonding pattern, i.e., His311 and His356 are
involved in hydrogen bonding to the carboxamide moiety, Glu341 to the amino group and the
phenyl moiety occupies the lipophilic pocket to the left hand site as shown in Figure 2A for
derivative 10. The benzyl extension to the right hand side fills another lipophilic pocket,
which could explain the reduction of activity for derivative 12 due to its smaller isopropyl
moiety.
His311
Glu341
His356
A
B
Figure 2. The docked configuration of derivative 10 in the PLC-δ1 binding site. (A) The phenyl group occupies
the lipophilic cavity to the left hand side and the benzyl moiety another pocket on the right hand side. Red
depicts a positive partial charge on the surface, blue depicts negative partial charge and grey shows
neutral/lipophilic regions. (B) Hydrogen bonds are depicted as green dotted lines between derivative 10 and
amino acids His311, Glu341 and His356.
7

1H-Pyrazoles
The 1H-pyrazoles derivative 14 (CCT129954 – see Table 3) has a measured IC50 ~ 7.5 µM
for PLC-γ2.1 Structural similarity search was conducted based on derivative 14 and sixty-
three compounds were found. These were docked to the PLC-δ1 binding pocket and four
virtual hits were identified (22-24 and 28, Table 3) using the same criteria as for the
thieno[2,3-b]pyridines. Unfortunately, no compounds with the tetrahydro-2H-pyran moiety
were found as in derivative 14, severely limiting the SAR study. In order to address this
shortcoming seven derivatives with the tetrahydro-2H-pyran moiety were synthesised (15-21)
with various substitutions on the phenyl ring as shown in Table 3. In particular, substitutions
on the para (X3) position on the phenyl ring were made since the hit (14) has a methoxy
group there, indicating that this position was important. Also, a derivative without any
substitions on the phenyl ring was made as a reference. Furthermore, for the hits 22- 24 three
close structural analogues were synthesised to extend the SAR study (25-27) with different
R1 substituents. The molecular structures are shown in Table 3 with the total growth of the
NCI60 panel at 10 µM as compared to untreated cells (100% growth).
Table 3 Anti-proliferative activity of the 1H-pyrazole structural derivatives. Derivative 14 (CCT129954) is the
lead compound for the 1H-pyrazole series.
8

R1
-
-
-
-
-
-
-
R2
-
-
-
-
-
-
-
X1
H
H
H
H
Cl
H
H
H
H
H
H
H
H
H
H
X2
H
H
H
H
H
H
OMe
Me
H
H
H
H
H
H
H
X3
OMe
H
CF3
t-Butyl
Cl
NHCOMe
OMe
H
X4
H
H
H
H
H
H
H
Me
H
H
H
H
H
H
H
NCI Meana
77.3b
76.5
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
89.8
83.9
87.9
64.5
72.4
85.5
85.0
102.2
87.5
84.2
81.8
87.0
81.9
-
(CH2)3F
Et
(CH2)3F
Me
-
H
NH2
H
H
H
H
-
Me
OMe
Br
Me
Me
Isopropyl
OMe
OMe
H
2,3-dihydrofuran
aValues represent relative growth (%) versus control as an average for 60 human tumour cell lines (NCI60). All
compounds were tested at 10 µM. bFrom Ref.4
As can been seen in Table 3 only modest reduction of growth is achieved by the 1H-
pyrazoles with only derivatives 19 and 20 with marginally better results than 14. Absence of
the tetrahydro-2H-pyran ring (22 - 27) and ring contraction from a six membered ring to five
membered tetrahydrofuran (28) did not result in improved anticancer activity. To further test
the potency of the 1H-pyrazoles, derivative 14 was tested with the MTT colorimetric assay,
which measures the activity of NAD(P)H-dependent redox enzymes in the cytosol reflecting
the viability of the cells.16 The breast cancer cell line MDA-MB-468 was incubated with 10
µM concentration of 14 and were compared to the activity of the anticancer drug
camptothecin (topoisomerase I poison). This tumour cell line was chosen due to its low
relative growth of 36.6% in the NCI60 panel.4 Minimal effect was observed (data not shown)
confirming the modest anticancer effect for this chemical class.
Chemical Space
The calculated molecular descriptors molecular weight, log P, hydrogen bond donors,
hydrogen bond acceptors, polar surface area and rotatable bonds for derivatives 1 – 28 are
given in Table S1 in the Supplementary Information. All are within the boundaries of ‘drug –
9

like’ chemical space with some of the properties dipping into lead-like space (for definition of
boundary see Table S2, Supplementary Information). It can therefore be concluded that the
compounds are within favourable property space for drug development.
Conclusion
The anticancer activity of the thieno[2,3-b]pyridine and 1H-pyrazole derivatives was
investigated. Tests against the NCI60 cancer cell panel revealed that the cyclohexanone-
thieno[2,3-b]pyridines were the most active with derivative 1 giving GI50 = 30 nM against the
MDA-MB-435 melanoma cell line emphasising the importance of meta substitution on the
phenyl ring moiety for this chemical series, which is in line with previous findings.4, 5, 7 By
applying a combination of similarity searching and molecular modelling the thieno[2,3-
b][1,6]naphthyridines were found to have anticancer activity extending the SAR. Finally, the
1H-pyrazoles only showed moderate growth inhibition for the NCI60 panel, which was
verified using the MTT assay.
Methodology
Modelling and Screening: The thieno[2,3-b]pyridine and 1H-pyrazoles derivatives, were
acquired from commercial sources using the eMolecules,15 web based compound library.
Substructure and Tanimoto similarity search methods were used to identify plausible
inhibitors.17 The structures shown in Figure 1 were used as initial search scaffolds with
similarity coefficient given at 0.7 and supplemented with substructure searches.
The compounds were docked to the crystal structure of PLC-δ1 (PDB ID: 1DJX, resolution
2.3 Å),18 which was obtained from the Protein Data Bank (PDB).19, 20 The Scigress Ultra
version 7.7.0.47 program21 was used to prepare the crystal structure for docking, i.e.,
hydrogen atoms were added, the co-crystallised ligand (D-Myo-Inositol-1,4,5-Triphosphate,
10

IP3) was removed as well as crystallographic water molecules. The Scigress software suite
was also used to build the inhibitors and the MM222 force field was used to optimise the
structures. The centre of the binding pocket was defined as the position of the Ca2+ ion (x =
126.257, y = 38.394, z = 22.370) with 10 Å radius. Fifty docking runs were allowed for each
ligand with default search efficiency (100%). The basic amino acids lysine and arginine were
defined as protonated. Furthermore, aspartic and glutamic acids were assumed to be
deprotonated. The GoldScore (GS),23 ChemScore (CS),24, 25 ChemPLP26 and ASP27 scoring
functions were implemented to validate the predicted binding modes and relative energies of
the ligands using the GOLD v5.2 software suite. The results were inspected visually and
seventeen virtual hits selected. The QikProp 3.228 software package was used to calculate the
molecular descriptors of the compounds. The reliability of the prediction power of QikProp is
established for the molecular descriptors used in this study.29
Synthetic chemistry: Preparation of test compounds 15-21, 25-27 was achieved via
sulfonation of the corresponding pyrazole intermediates with a library of sulfonyl chlorides.
Pyrazole S3, required for compounds 15-21, was prepared using the three-step route shown in
Scheme 3. The key propargylation-gold cyclisation sequence to convert 4′-
hydroxyacetophenone into chroman S2, once optimised, gave convenient and reliable access
to gram quantities of the intermediates required to carry out the study. Pyrazoles S4 and S5
required for synthesis of compounds 25-27 were prepared using analogous chemistry,
beginning from 4′-methoxy or 4′-isopropoxy acetophenone, respectively.
11

+
-
tBu
Au
SbF6
tBu
P
Cl
HO
i)
DBU, TFAA
CuCl2
O
O
O
CH2Cl2,10 min
66%
ii) H2, Pd/C, THF
rt, 2 h, 97%
MeCN, -10°C
80%
O
O
OH
S2
S1
X4
NMe2
OMe
ArSO2Cl
py, reflux
1 h
X3
MeO
i)
HN
N
SO2
N
120°C, 4 d
X2
N
X1
ii) H2NNH2.H2O
EtOH, reflux
45 min
O
96% for 2 steps
S3
O
13-24
Scheme 1. Preparation of derivatives 15-21 via chroman S3.
Scheme 2. Pyrazoles required for preparation of derivatives 25-27.
Full experimental procedures and all characterisation data for compounds S1-5, 15-21 and
25-27 are provided in the supporting information.
NCI60 assay: The compounds obtained were submitted to the National Cancer Institute’s
Developmental Therapeutic Program (DTP) where they were screened against a panel of
sixty human tumour cell lines first at 10 µM and for active ligands dose response curves were
generated (NCI60, for further information see ref.3, 30, 31 and references therein). Furthermore,
the full description of the protocol is given in the Supplementary Information.
MTT assay: The MDA-MB-468 breast cancer cell line was maintained in RPMI1640 medium
and 10% heat-inactivated foetal calf serum. Twenty-five thousand cells were seeded into each
well of a 96 well plate. After 24h, the cells were incubated in medium without phenol red
12

containing 10 µM of derivative 14 in 1% DMSO, each condition in triplicate. Camptothecin
(250 nM) was used as a positive control and 1% DMSO as a negative control. Following a
24h incubation, a standard MTT assay was performed: 20 µl of 5 mg/ml MTT were added to
each well and incubated for 3.5 h at 37°C, subsequent to medium removal solvent (4 mM
HCl, 0.1% NP40 (Nonidet P-40) dissolved in isopropanol) was added for 15 min with
agitation of the cells, followed by reading of the absorbance on a plate reader at 590 nm with
a reference filter at 620 nm.
Acknowledgements
Funding for this work was obtained from the Faculty Research Developmental Fund, Faculty
of Science, University of Auckland (Ref: 3700449).
References
1.
Reynisson, J.; Court, W.; O’Neill, C.; Day, J.; Patterson, L.; McDonald, E.;
Workman, P.; Katan, M.; Eccles, S. A. Bioorg. Med. Chem., 2009, 17, 3169-3176.
Kölsch, V.; Charest, P. G.; Firtel, R. A. J. Cell Sci., 2008, 121, 551-559.
Shoemaker, R. H. Nat. Rev. Drug Dis., 2006, 6, 813-823.
Feng, L.; Reynisdóttir I.; Reynisson, J. Eur. J. Med. Chem., 2012, 54, 463-469.
Arabshahi, H. J.; Leung, E.; Barker, D.; Reynisson, J. Med. Chem. Comm., 2014, 5,
186-191.
2.
3.
4.
5.
6.
Arabshahi, H. J.; van Rensburg, M.; Pilkington, L. I.; Jeon, C. Y.; Song, M.; Gridel,
L.-M.; Leung, E.; Barker, D.; Vuica-Ross, M.; Volcho, K. P.; Zakharenko, A. L.;
Lavrik, O. I.; Reynisson, J. Med. Chem. Comm., 2015, 6, 1987-1997.
Hung, J. M.; Arabshahi, H. J.; Leung, E.; Reynisson, J.; Barker, D. Eur. J. Med.
Chem., 2014, 86, 420-437.
7.
8.
Leung, E.; Hung, J. M.; Barker, D.; Reynisson, J. Med. Chem. Comm., 2014, 5, 99-
106.
9.
Reynisson, J.; Jaiswal, J. K.; Barker, D.; D’mello, S. A. N.; Denny, W. A.; Baguley,
B.; Leung, E. Cancer Cell Int., 2016, 16, 18.
10.
11.
Katritch, V.; Jaakola, V.; Lane, J. R.; Lin, J.; IJzerman, A. P.; Yeager, M.; Kufareva,
I.; Stevens, R. C.; Abagyan, R. J. Med. Chem., 2010, 53, 1799–1809.
Wang, J.; Luo, C.; Shan, C.; You, Q.; Lu, J.; Elf, S.; Zhou, Y.; Wen, Y.; Vinkenborg,
J. L.; Fan, J.; Kang, H.; Lin, R.; Han, D.; Xie, Y.; Karpus, J.; Chen, S.; Ouyang, S.;
Luan, C.; Zhang, N.; Ding, H.; Merkx, M.; Liu, H.; Chen, J.; Jiang, H.; He, C. Nature
Chem., 2015, 7, 968-979.
13

12.
Zeng, X.; Zheng, R.; Zhou, T.; He, H.; Liu, J.; Zheng, Y.; Tong, A.; Xiang, M.; Song,
X.; Yang, S.; Yu, L.; Wei, Y.; Zhao, Y.; Yang, L. Bioorg. Med. Chem. Lett., 2010, 20,
6282–6285.
13.
14.
Zhou, R.; Huang, W. J.; Guo, Z. Y.; Li, L.; Zeng, X. R.; Deng, Y. Q.; Hu, F. Y.;
Tong, A. P.; Yang, L.; Yang, J. L. Oncol. Rep., 2012, 28, 225-231.
Romagnoli, R.; Baraldi, P. G.; Salvador, M. K.; Preti, D.; Tabrizi, M. A.; Bassetto,
M.; Brancale, A.; Hamel, E.; Castagliuolo, I.; Bortolozzi, R.; Basso, G.; Viola, G. J.
Med. Chem., 2013, 56, 2606–2618.
15.
16.
17.
eMolecules, www.emolecules.com
Mosmann, T. J. Immun. Meth., 1983, 65, 55-63.
A. R. Leach and V. J. Gillet, 1. Representation and manipulation of 2D molecular
structures, in An Introduction to Chemoinformatics, Kluwer Academic Publisher,
Dordecht, 2003, pp. 1-26.
18.
Essen, L. O.; Perisic, O.; Katan, M.; Wu, Y.; Roberts, M. F.; Williams, R. L.
Biochemistry, 1997, 36, 1704-1718.
19.
20.
Berman, H.; Henrick, K.; Nakamura, H. Nat. Struct. Biol., 2003, 10, 980.
Berman, H. M.; Westbrook, J.; Feng, Z.; Gilliland, G.; Bhat, T. N.; Weissig, H.;
Shindyalov, I. N.; Bourne, P. E. Nuc.Acids Res., 2000, 28, 235-242.
Scigress Explorer Ultra Version 7.7.0.47, Fijitsu Limited, 2000 - 2007.
Allinger, N. L. J. Am. Chem. Soc., 1977, 99, 8127-8134.
Jones, G.; Willet, P.; Glen, R. C.; Leach, A. R.; Taylor, R. J. Mol. Biol., 1997, 267,
727-748.
21.
22.
23.
24.
25.
Eldridge, M. D.; Murray, C.; Auton, T. R.; Paolini, G. V.; Mee, P. M. J. Comp. Aid.
Mol. Design, 1997, 11, 425-445.
Verdonk, M. L.; Cole, J. C.; Hartshorn, M. J.; Murray, C. W.; Taylor, R. D. Proteins,
2003, 52, 609-623.
26.
27.
28.
29.
Korb, O.; Stützle, T.; Exner, T. E. J. Chem. Inf. Model., 2009, 49, 84-96.
Mooij, W. T. M.; Verdonk, M. L. Proteins, 2005, 61, 272-287.
QikProp v3.2, Schrödinger, New York, 3.2, 2009.
Ioakimidis, L.; Thoukydidis, L.; Naeem, S.; Mirza, A.; Reynisson, J. QSAR Comb.
Sci., 2008, 27, 445-456.
30.
Alley, M. C.; Scudiero, D. A.; Monks, P. A.; Hursey, M. L.; Czerwinski, M. J.; Fine,
D. L.; Abbott, B. J.; Mayo, J. G.; Shoemaker, R. H.; Boyd, M. R. Cancer Res., 1988,
48, 589-601.
31.
Boyd, M. R.; Paull, K. D. Drug Dev. Res., 1995, 34, 91-109.
14

15