Novel potent dual inhibitors of CK2 and Pim kinases with antiproliferative activity against cancer cells

Article abstract of DOI:10.1016/j.bmcl.2012.02.099

A novel family of potent dual inhibitors of CK2 and the Pim kinases was discovered by modifying the scaffolds of tricyclic Pim inhibitors. Several analogs were active at single digit nanomolar IC₅₀ values against CK2 and the Pim isoforms Pim-1

Full text of DOI:10.1016/j.bmcl.2012.02.099

Bioorganic & Medicinal Chemistry Letters 22 (2012) 3327–3331
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Novel potent dual inhibitors of CK2 and Pim kinases with antiproliferative
activity against cancer cells
⇑
Fabrice Pierre , Collin F. Regan, Marie-Claire Chevrel, Adam Siddiqui-Jain, Diwata Macalino,
Nicole Streiner, Denis Drygin, Mustapha Haddach, Sean E. O’Brien, William G. Rice, David M. Ryckman
Cylene Pharmaceuticals, 5820 Nancy Ridge Drive, Suite 200, San Diego, CA 92121, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
A novel family of potent dual inhibitors of CK2 and the Pim kinases was discovered by modifying the scaf-
folds of tricyclic Pim inhibitors. Several analogs were active at single digit nanomolar IC50 values against
CK2 and the Pim isoforms Pim-1 and Pim-2. The molecules displayed antiproliferative activity in various
cell phenotypes in the low micromolar and submicromolar range, providing an excellent starting point
for further drug discovery optimization.
Received 24 January 2012
Revised 25 February 2012
Accepted 28 February 2012
Available online 6 March 2012
Ó 2012 Elsevier Ltd. All rights reserved.
Keywords:
CK2
Pim
Multikinase inhibitors
Cancer
Kinase inhibitor
A significant proportion of kinase inhibitors approved for cancer
therapy are multikinase targeting agents able to simultaneously
modulate several biological processes of the disease.1 The pharma-
cologic benefits of multi-targeting include the blockage of redun-
dant compensatory pathways and the reduction of resistance
development through the modulation of several cancer hallmarks.2
Although many of these drugs were not deliberately created for
their multi-targeting profile, a more rational design of molecules
with predefined profiles has emerged.3
A group of enzymes suitable for multi-targeting comprises pro-
tein kinase CK24–6 (from the misnomer casein kinase 2) and the Pim
kinases7,8 (Proviral Integration site of moloney Murine leukemia
virus). These constitutively active serine/threonine kinases are
overexpressed in a number of tumors and are known to mediate
important hallmarks of cancer such as apoptosis resistance and cell
growth. Moreover, both enzymes share a relatively similar ATP
binding site, allowing small molecules to inhibit both proteins in
enzyme assays.9 The rational design of dual CK2/Pim inhibitors
for cancer therapy has been theorized in detail in a pioneering pa-
per by Lopez-Ramos et al.10 The best analog reported in that article
had IC50 values for CK2 and Pim-1 of 63 and 20 nM, respectively, but
was inactive in cells, as a likely result of poor cell penetration.
We have recently described CX-4945 1 (Fig. 1),11–13 the first
ATP-competitive inhibitor of CK2 to enter clinical trials for cancer.
CX-4945 was also a moderate inhibitor of Pim-1 and Pim-2
isoforms in enzyme assays (IC50 values of 0.048 and 0.186 lM,
respectively), albeit inactive against Pim in a functional cell-based
assay. Structural modification of 1 led to the discovery of 7-(4H-
1,2,4-triazol-3-yl)benzo[c][2,6]naphthyridine 2,14 a single digit
nanomolar inhibitor of Pim-1 and Pim-2, able to modulate cellular
phosphorylation of the Pim substrate Bad at serine 112, but inactive
against CK2.
As part of our continuing effort to develop this series of mole-
cules, we considered modifying the left pyridine ring of 2 to diver-
sify our pool of active molecules and optimize their drug like
properties. A series of more compact scaffolds bearing five-mem-
bered ring replacements of the pyridine was designed and deriva-
tized. These modifications maintained inhibition of the Pim
kinases, but also resulted in the restoration of potent CK2 inhibi-
tion. In this paper, we describe the preliminary SAR and character-
ization of the resulting dual inhibitors of CK2 and the Pim kinases.
A variety of scaffolds bearing sulfur or nitrogen five-membered
rings were prepared. The domino Suzuki coupling/intramolecular
amide formation used for the sulfur containing molecules is based
on the chemistry used to prepare similar molecules.11,14 Methyl 2-
amino-3-bromobenzoate 4 (Scheme 1, prepared according to Refs.
11 or 15) was converted to key-boronic ester 5 by a Miyaura boryla-
tion. Compound 5 was formed alongside a significant amount of the
reduced product methyl 2-aminobenzoate, which could be easily
separated from less polar 5 by flash chromatography on silica gel.16
Boronic ester 5 was coupled under palladium catalysis with var-
ious 2-bromo esters 3a–e to form the core molecules 6a–e. Reac-
tion with POCl3 led to compounds 7a–e, which were converted in
⇑
Corresponding author. Tel.: +1 858 622 0177; fax: +1 858 875 5101.
E-mail addresses: fpierre@cylenepharma.com, fpierre22@hotmail.com (F. Pierre).
0960-894X/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2012.02.099

3328
F. Pierre et al. / Bioorg. Med. Chem. Lett. 22 (2012) 3327–3331
O
Cl
O
N
N
a
NH
NH
HN
Cl
HN
CO2Me
S
N
5
S
H
N
N
N
N
6a
N
7
11
N
2
N
1
H
R2
R3
8
CO2H
N
Cl
N
1
2
N
N
N
c
N
b
N
Pim-1 IC50 = 0.001 µM
Pim-2 IC50 = 0.006 µM
CK2 IC50 > 0.5 µM
Pim-1 IC50 = 0.048 µM
Pim-2 IC50 = 0.186 µM
CK2 IC50 = 0.001 µM
S
N
S
N
H
H
Figure 1. Structure of CX-4945 111 and representative 7-(4H-1,2,4-triazol-3-
yl)benzo[c][2,6]naphthyridine 2 inhibitor of the Pim kinases.14
13a-y
12
Scheme 2. Reagents and conditions: (a) NaOH, H2O, EtOH, 80 °C, 92%; NH4Cl
HOBtꢀH2O, DIEA, EDCI, NMP, 80 °C, 97%; (MeO)2CHNMe2 neat, 80 °C then
NH2NH2ꢀH2O, AcOH, 80 °C, 89%; (b) POCl3, NEt3, ACN, 100 °C 88%; (c) HNR2R3 (for
various acids 8a–i through a two-step procedure. After amide cou-
pling leading to 9a–j, carboxamides 9a–i were converted to tria-
structure of R2 and R3, see Table 2), NMP,
TLC, 4–71%.
lwave 120–160 °C, preparative HPLC or
zoles 10a–i by
a two-step process utilizing DMF–DMA and
hydrazine.
The buildup of scaffolds bearing nitrogenous five-membered
rings started from ethyl 3-amino-2-nitrobenzoate 14, (Scheme 3)
prepared according to a published procedure.17,18 The amino func-
tion of 14 was expanded to an ethyl 1H-imidazole-5-carboxylate in
a process involving the reaction of TosMIC with the condensation
product of ethyl glyoxylate and 14 (using a procedure described
in Ref. 19). Iron reduction of the nitro group at 100 °C and intramo-
lecular addition of the aniline function on the ester resulted in the
formation of ethyl 4-oxo-4,5-dihydroimidazo[1,5-a]quinoxaline-6-
carboxylate 16. Chemical transformations similar to the previous
descriptions provided triazole analog 17.
The chemistry depicted in Scheme 2 was designed to study the
SAR of C-4 substituted 6-(4H-1,2,4-triazol-3-yl)thieno[3,2-c]quino-
lines. The ester 6a was converted to a triazole 11 in three steps, and
the central pyridone ring was transformed to a chloropyridine by
reacting with POCl3. The resulting crude 12 was reacted with var-
ious substituted amines leading to compounds 13a–y, isolated
after purification by chromatography.
CO2R1
CO2R1
Br
CO2Me
CO2Et
Me
3b
=
S
S
S
Br
Br
Br
3a
3d
3'c R1 = H
N
NO2
NO2
CO2Me
CO2Me
a
N
S
S
3c R1 = Me
a
H2N
CO2Et
N
CO2Et
3e
Br
Br
EtO2C
15
14
Cl
b
f,g,h
NH2
NH2
CO2R1
Br
O
Br
CO2Me
Bpin
CO2Me
b
+
N
NH
N
N
CO2Et
N
CO2Et
4
5
3a-e
O
Cl
16
18
d
NH
N
i,j,k,l
c
c,d,e
R3
CO2Me
CO2Me
R2
Cl
N
6a-e
R2
7a-e
m
N
N
N
N
N
N
R3
A
N
N
N
N
8a-i R4 = CO2H
N
H
H
e,f
g
h
N
9a-j R4 = CONHR5
R4
19
17
A = N
20a-c A = CH
N
N
10a-i R4 =
N
H
Scheme 3. Reagents and conditions: (a) EtO2CCHO, MeOH, Dean–Stark reflux, then
TosMIC, K2CO3, 50 °C, 15%; (b) HOAc, Fe, 100 °C, 27%; (c) (i) POCl3, NEt3, ACN, 100 °C,
Scheme 1. Reagents and conditions: (a) (COCl)2, DMF cat., CH2Cl2 then MeOH, 63%;
(b) PinBBPin, KOAc, PdCl2(dppf).CH2Cl2, toluene, 100 °C, 45%; (c) Cs2CO3,
PdCl2(dppf)ꢀCH2Cl2, dioxane/water (20:1, v/v) 100 °C, 57–83%; (d) POCl3, NEt3,
ACN, 100 °C, 48–95%; (e) HNR2R3 (for structure of R2 and R3 see Tables 1 and 3),
99%, (ii) HNR2R3, NMP,
lwave 140 °C, 50%, (iii) NaOH, H2O, EtOH, 80 °C, 60%; (d)
NH4Cl, HOBtꢀH2O, DIEA, EDCI, dioxane, 80 °C, 52%; (e) (MeO)2CHNMe2 neat, 80 °C
then NH2NH2ꢀH2O, AcOH, 80 °C, 26%; (f) 2,5-dimethoxytetrahydrofuran, 120 °C,
88%; (g) EtOH, Pd/C, H2 (40 psi), 91%; (h) triphosgene, toluene, 120 °C, 73%; (i)
NaOH, H2O, 80 °C, 91%; (j) NH4Cl, HOBtꢀH2O, DIEA, EDCI, dioxane, 80 °C; (k)
(MeO)2CHNMe2 neat, 80 °C then NH2NH2ꢀH2O, AcOH, 80 °C, 89% over two steps; (l)
POCl3, NEt3, ACN, 100 °C, 84%; (m) HNR2R3 (for structure of R2 and R3, see Table 1),
NMP,
lwave or conventional heating 120–140 °C; (f) NaOH, H2O, EtOH 60–80 °C,
22–91% over two steps; (g) NH4Cl or MeNH2ꢀHCl (R5 = Me, compound 9j),
HOBtꢀH2O, DIEA, EDCI, NMP or dioxane, 70–80 °C, 28–82%; (h) (R5 = H)
(MeO)2CHNMe2 neat, 80 °C then NH2NH2ꢀH2O, AcOH, 80 °C, 32–67%.
NMP, lwave 120–140 °C, preparative HPLC, 6–30%.

F. Pierre et al. / Bioorg. Med. Chem. Lett. 22 (2012) 3327–3331
3329
The aniline function of ethyl 3-amino-2-nitrobenzoate 14 could
form a pyrrole by a Paal–Knorr condensation with 2,5-dimethoxy-
tetrahydrofuran. Hydrogenation of the resulting intermediate and
reaction with triphosgene led to the isolation of cyclized interme-
diate ethyl 4-chloropyrrolo[1,2-a]quinoxaline-6-carboxylate 18.
After simultaneous hydrolysis of the ester and substitution of the
chlorine by a hydroxyl group in the presence of sodium hydroxide,
intermediate 19 was built using chemistries similar to those de-
picted in Scheme 2. Compounds 20a–c were prepared by substitut-
ing the chlorine of 19 with various anilines.
the chemistry described in Scheme 2. Alkyl secondary (13a) or ter-
tiary (13b) amines as well as benzyl (13c) or heteroaryl (13d–e)
amines reduced the activity against the three enzymes. When com-
pared to 10b, their ability to inhibit Pim-1 and Pim-2 ranged from
0.004 to 0.091
cantly higher range (0.048–0.216
l
M while for CK2 the IC50 values were in a signifi-
M).
l
As observed in similar molecules,11,14 aniline moieties at C-4
demonstrated the greatest activity against the three enzymes.
Unsubstituted aniline analog 10a was already very potent, having
IC50 values close to 20-chloro aniline 10b and 30-chloroaniline 13f.
Moving the chlorine atom to the para position of the aniline (13g)
lowered the affinity for the three targets. Other disubstituted ana-
logs bearing a chlorine atom in the 20-position (13h–k) were slightly
less potent against at least one of the enzymes. Compounds bearing
a fluorine atom on the phenyl ring were all very potent (10c, 13l–m)
and changing the position of the fluorine atom induced minimal
changes in activity. The 20-position appeared however to be the
most favorable for a fluorine atom, as confirmed by the highest po-
tency of ortho-fluoro disubstituted molecules 13n and 13o, in com-
parison with 13p and 13q. Interestingly, among the methoxy
analogs (13r–t), the para-methoxy aniline 13t was the most potent
molecule, displaying IC50 values below 6 nM for the three enzymes.
However, extension of the alkyl chain (13u) decreased the potency
of the drug. Finally, among several aniline bearing various groups in
the meta position (13v–x), the 3-acetylenyl-phenyl 13x was the
most potent modulator of the three enzymes.
All compounds20 were tested in a radiometric enzymatic assay
using recombinant human Pim-1, Pim-2 or CK2 holoenzyme
(
aabb)21 The structure–activity relationship (SAR) studies depicted
in Table 1 investigated variations of the left ring of various scaffolds
substituted on the upper position by aniline (compounds 10a, 10d,
10f and 20a) or by 20-halogeno anilines (10b–c, 10e, 10g–h, 20b–c
and 17), which were previously shown to increase potency against
the Pim kinases.14 Our first choice of thiophene analogs 10a–c pro-
vided potent inhibitors of Pim-1, Pim-2 and CK2. The analogs
substituted by a chlorine (10b) or a fluorine (10c) inhibited the 3
enzymes with single digit nanomolar IC50 values. Moving the sulfur
to various positions (10d–g) resulted in a slight decrease of affinity
for the three enzymes, regardless of the substitutions. A similar
trend was observed when adding a nitrogen atom within the five-
membered ring of the molecule. When comparing thiazole 10h
with thiophene analog 10b, IC50 values for the three enzymes tested
increased three to four fold. Finally, less lipophilic nitrogen-bearing
heterocycles in 20a–c and 17 decreased activity further to double
digit nanomolar values, with the exception of 20c which inhibited
Overall, the SAR of the C-4 position indicated that the three
tested proteins could accommodate anilines bearing small hydro-
phobic moieties at variable positions. A preliminary exploration
of other sites of the scaffold is reported in Table 3. While a carbox-
ylate on R3 significantly decreased inhibitory activity against the
three targets, carboxamides in 9a and 9j maintained single digit
nanomolar inhibition of the Pim-1 isoform. Adding a methyl on
R1 on the thiophene of fluoro aniline analog 10c gave 10i, which
preserved the potent inhibition of Pim-2 and Pim-1 and induced
a slight loss of CK2 modulation. This suggests that further explora-
tion of this position with larger moieties and solubilizing groups is
possible and may lead to improved drug properties.
the Pim-1 isoform with an IC50 value equal to 0.008 lM.
The potent activity of the 6-(4H-1,2,4-triazol-3-yl)thieno[3,2-
c]quinolines 10b and 10c against the three enzymes prompted us
to further explore this chemical series, and in particular the SAR
of analogs diversely substituted at C-4 by amines (Table 2), using
Table 1
Pim-1, Pim-2 and CK2 inhibitory activity of various tricyclic analogs
In our previous paper,14 we showed that several analogs of the
potent Pim inhibitor 2 also inhibited the kinase Flt-3 with IC50 val-
R1
ues ranging from 0.017 to 0.104
served with CK2 inhibitor CX-4945 1 (Flt-3 IC50 = 0.035
l
M, a property that is also ob-
M11).
HN
l
Selected triazoles 10b, e, g, 20b and methyl amide 9j were tested
N
N
N
against Flt-322 in an enzymatic assay (Table 4). The molecules
N
showed no activity at concentration below 5 lM, suggesting that
H
the present dual CK2/Pim inhibitors may have a kinase selectivity
profile different than 2 and its close analogs.14
Left ring
Compd R1 Pim-1 IC50
M)
Pim-2 IC50
M)
CK2 IC50
M)
The most potent dual Pim/CK2 inhibitors (Pim-1, Pim-2 and CK2
IC50<10 nM) and representative analogs of other scaffolds depicted
in Table 1 were tested for their antiproliferative activity against a
number of cancer cell lines (Table 5).23 All compounds were gener-
ally active in several cell lines with EC50 values in the low micro-
molar range. In the most sensitive leukemia cells MV-4-11,
several compounds were active at submicromolar concentration,
with IC50 values as low as 100 nM. This cell line carries the Flt-3
ITD activating mutation, and Pim-1 and Pim-2 are known to be
the principal kinases mediating the anti-apoptotic function of Flt-
3-ITD signaling,24,25 explaining the high sensitivity of this cell line
to Pim inhibitors.
(l
(l
(l
10a
10b
H
0.004
0.015
0.002
0.002
0.010
0.009
0.004
Cl 0.003
10c
F
0.002
0.027
S
S
10d
10e
H
0.017
0.008
0.010
0.020
Cl 0.007
10f
10g
H
0.016
0.014
0.006
0.030
0.021
S
Cl 0.004
N
S
10h
Cl 0.008
0.009
0.039
In summary, we have discovered a novel chemotype of potent
dual inhibitors of CK2 and the Pim kinases, of which several ana-
logs were active with single digit nanomolar IC50 values against
the three targets. The molecules displayed antiproliferative activity
in various cancer cells in the low micromolar and submicromolar
range, a result that brings a significant improvement over previ-
ously published dual inhibitors of these enzymes.
20a
20b
20c
H
0.014
0.030
0.041
0.020
0.101
0.089
0.021
Cl 0.012
N
F
F
0.008
0.038
N
N
17
0.043
0.035

3330
F. Pierre et al. / Bioorg. Med. Chem. Lett. 22 (2012) 3327–3331
Table 2
Pim-1, Pim-2 and CK2 inhibitory activity of various C-4 substituted 6-(4H-1,2,4-triazol-3-yl)thieno[3,2-c]quinolines
R2
R3
N
4
3
N
N
N
2
6
S
N
1
H
Compd
–NR2R3
Pim-1 IC50
(lM)
Pim-2 IC50
(lM)
CK2 IC50 (lM)
13a
13b
13c
13d
13e
10a
10b
13f
–NHc-Pr
–Morpholino
0.015
0.035
0.004
0.017
0.091
0.004
0.003
0.006
0.014
0.014
0.009
0.005
0.064
0.002
0.003
0.004
0.002
0.002
0.009
0.009
0.007
0.011
0.004
0.016
0.016
0.010
0.006
0.017
0.025
0.010
0.052
0.022
0.068
0.015
0.002
0.006
0.086
0.004
0.009
0.021
0.076
0.002
0.005
0.007
0.002
0.014
0.015
0.024
0.049
0.028
0.006
0.034
0.052
0.012
0.005
0.017
0.062
0.128
0.048
0.076
0.216
0.010
0.009
0.015
0.033
0.010
0.052
0.017
0.075
0.004
0.007
0.007
0.011
0.009
0.077
0.151
0.084
0.011
0.005
0.136
0.024
0.126
0.002
0.139
–NHBn
–NH(30-pyridyl)
–NH(40-pyridyl)
–NHphenyl
–NH(20-Cl-phenyl)
–NH(30-Cl-phenyl)
–NH(40-Cl-phenyl)
–NH(20-Cl, 40-OH-phenyl)
–NH(20-Cl, 40-F-phenyl)
–NH(20Cl, 30-OMe-phenyl)
–NH(20-Cl, 40-OCF3-phenyl)
–NH(20-F-phenyl)
13g
13h
13i
13j
13k
10c
13l
–NH(30-F-phenyl)
–NH(40-F-phenyl)
13m
13n
13o
13p
13q
13r
13s
13t
13u
13v
13w
13x
13y
–NH(20-F, 40-F-phenyl)
–NH(20-F,20-MeO-phenyl)
–NH(30-F, 40-F-phenyl)
–NH(30-F, 50-F-phenyl)
–NH(20-OMe-phenyl)
–NH(30-OMe-phenyl)
–NH(40-OMe-phenyl)
–NH(40-O(CH2)2NMe2-phenyl)
–NH(30-CF3-phenyl)
–NH(30-CN-phenyl)
–NH(30-acetylenyl-phenyl)
–NH(40-CONH2-phenyl)
Table 3
Pim-1, Pim-2 and CK2 inhibitory activity of various substituted N-phenylthieno[3,2-c]quinolin-4-amines
R2
HN
N
R1
R3
S
Compd
R1
R2
R3
Pim-1 IC50
(l
M)
Pim-2 IC50
(
lM)
CK2 IC50 (lM)
8a
9a
9j
10b
10c
10i
H
H
H
H
H
Me
Cl
Cl
Cl
Cl
F
CO2H
CONH2
CONHMe
C-(4H-1,2,4-triazol-3-yl)
C-(4H-1,2,4-triazol-3-yl)
C-(4H-1,2,4-triazol-3-yl)
0.069
0.005
0.005
0.003
0.002
0.015
0.121
0.012
0.028
0.002
0.002
0.006
0.139
0.022
0.048
0.009
0.004
0.026
F
Table 4
Flt-3 inhibitory activity of various thieno[3,2-c]quinolines
assessment of their kinase selectivity profile, as well as the corre-
lation of their kinase inhibitory activity with antiproliferative
properties. However, the lack of significant inhibitory activity
against Flt-3 (Table 4), one of the most frequently inhibited ki-
nases,26 suggests a reasonable selectivity profile for this new class
of molecules.
Compd
10g
10e
20b
10b
9j
Flt-3 IC50
(lM)
>10
>10
>10
>10
5.3
This work delivers interesting antiproliferative molecules for
the study of the dual inhibition of CK2 and the Pim kinases in can-
cer, and provides a useful starting point for lead optimization. A
fundamental aspect of their future characterization remains the
Finally, crystallographic studies will also be essential to assess
the structural features responsible for the intriguing increase in
CK2 inhibition induced by the modification of the left ring of tria-
zole 2, an observation implying the possibility of a binding mode

F. Pierre et al. / Bioorg. Med. Chem. Lett. 22 (2012) 3327–3331
3331
Table 5
Filippakopoulos, P.; Bullock, A. N.; Knapp, S.; Reiser, J. B.; Cochet, C. Faseb J.
2010, 24, 3171.
Antiproliferative activity of potent inhibitors (Pim-1, Pim-2 and CK2 IC50 <10 nM) and
of representative analogs of various scaffold depicted in Table 1
11. Pierre, F.; Chua, P. C.; O’Brien, S. E.; Siddiqui-Jain, A.; Bourbon, P.; Haddach, M.;
Michaux, J.; Nagasawa, J.; Schwaebe, M. K.; Stefan, E.; Vialettes, A.; Whitten, J.
P.; Chen, T. K.; Darjania, L.; Stansfield, R.; Anderes, K.; Bliesath, J.; Drygin, D.;
Ho, C.; Omori, M.; Proffitt, C.; Streiner, N.; Trent, K.; Rice, W. G.; Ryckman, D. M.
J. Med. Chem. 2011, 54, 635.
Compd
Cell viability EC50 (lM)
BxPC3
SUM-149PT
K-562
MDA-MB453
MV-4-11
12. Siddiqui-Jain, A.; Drygin, D.; Streiner, N.; Chua, P. C.; Pierre, F.; O’Brien, S. E.;
Bliesath, J.; Omori, M.; Ho, C.; Proffitt, C.; Schwaebe, M. K.; Ryckman, D. M.;
Rice, W. G.; Anderes, K. Cancer Res. 2010, 70, 10288.
13. Battistutta, R.; Cozza, G.; Pierre, F.; Papinutto, E.; Lolli, G.; Sarno, S.; O’Brien, S.
E.; Siddiqui-Jain, A.; Haddach, M.; Anderes, K.; Ryckman, D. M.; Meggio, F.;
Pinna, L. A. Biochemistry 2011, 50, 8478.
14. Pierre, F.; Stefan, E.; Nédellec, A.-S.; Chevrel, M.-C.; Regan, C. F.; Siddiqui-Jain,
A.; Macalino, D.; Streiner, N.; Drygin, D.; Haddach, M.; O’Brien, S. E.; Anderes,
K.; Ryckman, D. M. Bioorg. Med. Chem. Lett. 2011, 21, 6687.
15. Jacobs, R.T.; Folmer, J.J.; Simpson, T.R.; Chaudhari B.; Frazee, W.J.; Davenport,
T.W.; Sundarababu, G. U.S. patent 6,399,603 B1, 2002.
10b
10c
13x
13m
13l
13t
13n
10a
10e
10g
20c
10h
17
11.7
>30
24.6
>30
9.1
28.0
>30
>30
4.5
4.4
9.5
9.6
>30
8.1
8.2
>30
7.0
2.6
3.6
3.6
6.7
>10
>10
7.2
2.6
7.1
9.3
6.6
2.6
7.4
4.6
7.8
4.9
1.3
28.4
2.0
3.1
0.5
0.6
5.4
>10
4.6
6.5
1.7
2.0
0.6
3.2
3.7
4.7
0.1
4.8
6.1
>10
>10
8.2
>10
5.4
16.1
>30
2.8
2.6
22.8
12.6
5.4
16. Boronic ester 5: Rf = 0.5, methyl 2-aminobenzoate: Rf = 0.30, SiO2, 20% EtOAc in
hexanes. Compound 5 was isolated in 45% yield by flash chromatography on
silica gel using a 1.5–2.5% gradient of AcOEt in hexanes.
15.0
17. Staab, H. A.; Zipplies, M. F.; Mueller, T.; Storch, M.; Krieger, C. Chem. Ber. 1994,
127, 1667.
18. Yamasaki, N.; Imoto, T.; Murai, Y.; Hiramura, T.; Oku, T.; Sawada, K. U.S. patent
6,166,219, 2000.
19. Chen, B.-C.; Sundeen, J.E.; Bednarz, M.S.; Chen, P. PCT patent application
WO2004/078714 A2, 2004.
20. All final compounds were characterized by LC–MS and found to be P95% pure.
Selected compounds were characterized by NMR.
slightly distinct from that of CX-4945 1. The optimization and
structural biology exploration of these tricyclic molecules will be
the matter of further research.
21. CK2, Pim-1 and Pim-2 inhibitions were measured in radiometric assays using
References and notes
human recombinant CK2
RRRDDDSDDD), human recombinant Pim-1 at [ATP] = 30
RSRHSSYPAGT) and human recombinant Pim-2 at [ATP] = 5
(
aabb-holoenzyme) at [ATP] = 15
l
lM
l
M
(substrate
(substrate
M (substrate
1. Li, R.; Stafford, J. A. Kinase Inhibitor Drugs; John Wiley & Sons: New York, 2009.
2. Hanahan, D.; Weinberg, R. A. Cell 2011, 144, 646.
3. Morphy, R. J. Med. Chem. 2010, 53, 1413.
RSRHSSYPAGT). The IC50 values were derived from eight concentrations of test
inhibitors
4. Sarno, S.; Pinna, L. A. Mol. Biosyst. 2008, 4, 889.
22. The Flt-3 enzymatic assay was carried out at Millipore, Billerica, MA, using
their standard protocol.
5. Guerra, B.; Issinger, O. G. Curr. Med. Chem. 1870, 2008, 15.
6. Trembley, J. H.; Chen, Z.; Unger, G.; Slaton, J.; Kren, B. T.; Van Waes, C.; Ahmed,
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353.
23. Cell proliferation inhibition was determined by Alamar Blue assay, exposing
various cell lines to the tested compounds for 48 days.
24. Kim, K. T.; Levis, M.; Small, D. Br. J. Haematol. 2006, 134, 500.
25. Kim, K. T.; Baird, K.; Ahn, J. Y.; Meltzer, P.; Lilly, M.; Levis, M.; Small, D. Blood
2005, 105, 1759.
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Biotechnol. 2011, 29, 1039.
10. Lopez-Ramos, M.; Prudent, R.; Moucadel, V.; Sautel, C. F.; Barette, C.;
Lafanechere, L.; Mouawad, L.; Grierson, D.; Schmidt, F.; Florent, J. C.;