Synthesis and evaluation of a radioiodinated 4,6-diaryl-3-cyano-2-pyridinone derivative as a survivin targeting SPECT probe for tumor imaging

Article abstract of DOI:10.1016/j.bmcl.2015.12.046

Survivin is overexpressed in most of the cancerous tissues but not in terminally differentiated normal tissues, making it an attractive target for diagnosis and therapy of various types of cancers. In this study, we aimed to develop 4,6-diaryl-3-cyano-2-p

Full text of DOI:10.1016/j.bmcl.2015.12.046

Bioorganic & Medicinal Chemistry Letters xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis and evaluation of a radioiodinated 4,6-diaryl-3-cyano-2-
pyridinone derivative as a survivin targeting SPECT probe for tumor
imaging
a,
⇑
a
a
b
a
Takeshi Fuchigami , Tatsuya Mizoguchi , Natsumi Ishikawa , Mamoru Haratake , Sakura Yoshida ,
c
a,
⇑
Yasuhiro Magata , Morio Nakayama
a
Department of Hygienic Chemistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan
Medical Photonics Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
b
c
a r t i c l e i n f o
a b s t r a c t
Article history:
Survivin is overexpressed in most of the cancerous tissues but not in terminally differentiated normal tis-
sues, making it an attractive target for diagnosis and therapy of various types of cancers. In this study, we
aimed to develop 4,6-diaryl-3-cyano-2-pyridinone (DCP) derivatives, as novel cancer imaging probes that
target survivin. Chloro and iodo analogs of DCP (CDCP and IDCP, respectively) were successfully synthe-
sized by using a previously unreported carbon monoxide-free procedure. IDCP exhibited a slightly higher
Received 28 September 2015
Revised 3 December 2015
Accepted 15 December 2015
Available online xxxx
d d
binding affinity for recombinant human survivin (K = 34 nM) than that of CDCP (K = 44 nM).
Keywords:
Survivin
Cancer imaging
Fluorescence staining indicated that both CDCP and IDCP showed high signals in MDA-MB-231 cells with
high levels of survivin expression. Significantly low fluorescent signals were observed in MCF-10A cells,
1
25
which showed low levels of survivin expression. [ I]IDCP was synthesized for the application of IDCP to
single photon emission computed tomography (SPECT) imaging. Quantitative in vitro binding of [1 I]
IDCP in cell cultures showed results consistent to those observed after fluorescent staining. In vivo biodis-
tribution studies in tumor-bearing mice demonstrated that the tumor uptake of [1 I]IDCP increased
gradually with time and was 0.65% injected dose per gram (% ID/g) at 180 min. The maximum tumor/
blood and tumor/muscle ratio at 60 min were 0.87 and 2.27, respectively, indicating inadequate [1 I]
IDCP accumulation in tumors necessary for in vivo imaging. Although further structural modifications
are necessary to improve pharmacokinetic properties of IDCP, this study demonstrates the feasibility
of using the DCP backbone as a scaffold for the development of survivin-targeting tumor imaging probes.
Ó 2015 Elsevier Ltd. All rights reserved.
Single photon emission computed
tomography (SPECT)
25
25
25
7
Survivin is a 16.5 kDa intracellular protein, which belongs to the
inhibitors of apoptosis (IAP) family of proteins.1 It is the smallest
reported protein among the IAP family and has a baculovirus IAP
chromosome segregation and cytokinesis. Survivin is rarely over-
expressed in differentiated normal tissues, but overexpressed in
most cancerous tissues in esophageal, lung, ovarian, gliobastoma,
breast, colorectal, bladder, gastric, prostate, pancreatic, uterine,
2
repeat (BIR). It is also a nodal protein that can bind to X-linked
8
IAP (XIAP) and stabilize it against degradation by ubiquitin sys-
tems, thereby increasing the effects of XIAP mediated caspase inhi-
hepatocellular, and renal cancers. Additionally, survivin is one of
the most crucial biomarkers of poor prognosis and resistance to
radiation therapy and chemotherapy. Accordingly, survivin is con-
3
,4
9
bition.
However, the mechanistic details of anti-apoptosis
mediated by survivin have not yet been elucidated. Further, sur-
vivin is a singular protein, which has also been implicated in the
regulation of mitosis. It is found to associate with Borealin and
INCENP to form the chromosomal passenger complex (CPC), which
plays a key role in the regulation of mitotic procedures such as
sidered to be an ideal target for the specific diagnosis and treat-
ment of various types of cancers. Several cancer treatment
approaches such as the use of mRNA inhibitors, small-molecules
and immunotherapy, which target survivin have been
5
,6
1
0,11
12
reported.
Two series of compounds including S12 and 4,6-
diaryl-3-cyano-2-pyridinone (DCP) derivatives such as Abbott 8
1
3,14
⇑
Corresponding authors. Tel.: +81 95 819 2442; fax: +81 95 819 2893 (T.F.); tel.:
81 95 819 2441; fax: +81 95 819 2893 (M.N.).
E-mail addresses: t-fuchi@nagasaki-u.ac.jp (T. Fuchigami), morio@nagasaki-u.ac.
(Fig. 1)
were found to bind to near the dimer interface of sur-
+
vivin. In contrast to the Smac/DIABLO peptide binding BIR domain,
which is the common region among other IAP family proteins, the
jp (M. Nakayama).
http://dx.doi.org/10.1016/j.bmcl.2015.12.046
0
960-894X/Ó 2015 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Fuchigami, T.; et al. Bioorg. Med. Chem. Lett. (2015), http://dx.doi.org/10.1016/j.bmcl.2015.12.046

2
T. Fuchigami et al. / Bioorg. Med. Chem. Lett. xxx (2015) xxx–xxx
OH
Studies reporting on the synthesis of CDCP used carbon monox-
O
H
ide, which is hard to treat and high toxic, to form the aldehyde
group. Here, we considered more convenient alternative routes
N
O
13
O
O
Cl
for the synthesis of DCP derivatives (Scheme 1) that did not involve
the use of carbon monoxide. Acetylation of 4-chloro-o-cresol
resulted in acetate 1, which underwent a Fries rearrangement1
Br
HO
O
CN
6,17
N
H
3
to yield acetophenone 2. Methylation of 2 by means of CH I
afforded the methoxy derivative 3, which was brominated with
NBS and AIBN to provide the bromomethyl derivative 4.
S12
Abbott8
Nucleophilic substitution of
4
with methylamine yielded
methylamino derivative 5, whose condensation with 1-propy-
lpiperidine-4-carboxylic acid using HOAt and EDC resulted in the
amide derivative 6. Cyclocondensation of 6 with 2-chloro-5-(triflu-
oromethyl)-benzaldehyde and 2-cyanoacetamide under solvent-
free condition provided the 3-cyano-2-pyridone derivative 7.
Finally, the conversion of methoxy group in 7 to a hydroxyl group
using boron tribromide successfully yielded CDCP. The synthesis of
IDCP is outlined in Scheme 2. Demethylation of the methoxy
Figure 1. Chemical structures of low molecular compounds that bind near the
dimeric interface of survivin.
1
8
dimer interface of survivin is considered to be its specific ligand
binding domain. Although the therapeutic potential of targeting
the dimerization interface is still unclear, DCPs have been recently
reported to inhibit mitotic progression and caused mitotic defects
in proliferating cancer cells.14 Consequently, targeting survivin by
using nuclear medicine imaging techniques such as positron emis-
sion tomography (PET) and single photon emission computed
tomography (SPECT) could provide vital information about the
pathophysiology of related cancers in living systems as well as
aid specific diagnosis and characterization. Although SPECT imag-
ing probes for survivin were developed using antisense
oligodeoxynucleotides, nonspecific cellular accumulations resulted
in their ineffective application in in vivo imaging.15 Unfortunately,
further nuclear medicine imaging probes targeting survivin have
not yet been developed. We hypothesize that its dimer interface
domain may be an attractive target for nuclear medicine imaging.
3 2 2
derivative 6 with BBr in CH Cl resulted in the phenol derivative
8. 2-Bromo-5-(trifluoromethyl)benzaldehyde was converted to
the tributyltin derivative 9 using a bromo-to-tributyltin exchange
reaction catalyzed by Pd(0). Cyclocondensation of 8 with 9 using
NCCH CO Et and CH CO NH in EtOH yielded the 3-cyano-2-pyri-
2
2
3
2
4
done 10. Treatment of 10 with iodine led to the final product ICDP.
1
25
[
I]IDCP was synthesized by an iododestannylation reaction of
the trimethyltin derivative 10 with chloramine T as an oxidant
125
(Scheme 3). The radiochemical yield of [ I]IDCP was 13% with a
radiochemical purity of >95%.
It has been reported that DCPs exhibit increased fluorescence
1
3
intensity upon complex formation with survivin. Therefore, sur-
vivin binding affinity of the DCP derivatives was determined by
saturation binding assays, wherein fluorescence intensity was
monitored during the incubation of different compounds and the
recombinant human survivin. As shown in Figure 3, the saturated
binding curves and linear Scatchard plots indicated that both CDCP
and IDCP bound to the recombinant survivin, which suggested the
presence of high-affinity single binding sites for survivin on these
Wendt et al. reported that survivin displayed a high affinity, K
d
value of 37 nM, towards chloro analog of DCPs with N-propyl
piperidine (CDCP) (Fig. 2). This suggested that CDCP possessed
1
3
the most potent binding affinity for survivin within its series.
Since NMR analysis indicated a possible hydrophobic interaction
between the chlorine atom on the 3-phenyl ring of CDCP and the
broad binding pocket near the L14 residue of survivin,1 substitu-
tion of chlorine with other hydrophobic functional groups may
maintain its binding affinity for survivin. Accordingly, we designed
an iodine analog of DCP (IDCP), wherein the chlorine atom was
replaced with iodine at position 2 on the 3-phenyl ring of CDCP
for application as a SPECT imaging probe (Fig. 2). Herein, we syn-
3
d
derivatives. The K values of CDCP and IDCP for survivin were
44 nM ± 11 nM (n = 3) and 34 nM ± 6.2 nM (n = 3), respectively. A
slightly higher binding affinity of IDCP compared to CDCP indicated
that substitution from the chloro to iodo derivative improved the
binding affinity for survivin. To further characterize the binding
properties of DCP derivatives for intracellular survivin, two cell
lines (MDA-MB-231 and MCF-10A), with different expression
1
25
thesized CDCP and
I-labeled IDCP and characterized these
in vitro by evaluating their performance using cells expressing dif-
ferent levels of survivin. Further, in vivo performance of [1 I]IDCP
was evaluated in tumor-bearing mice.
25
19
levels of survivin were incubated with DCP derivatives (Fig. 4).
Both CDCP and IDCP showed significant signals and DCP derived
N
N
O
O
N
N
OH
H
OH
H
N
O
N
O
Cl
Cl
CN
CN
Cl
125I
CF3
CF3
[125I]IDCP
CDCP
Figure 2. Chemical structure of CDCP and design of radioiodinated IDCP for the application in SPECT imaging.
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T. Fuchigami et al. / Bioorg. Med. Chem. Lett. xxx (2015) xxx–xxx
3
Br
OH
OAc
OH
Ac
OMe
Ac
OMe
Ac
a
b
c
d
Cl
Cl
Cl
Cl
Cl
O
1
2
3
4
N
N
N
O
HN
O
N
N
OMe
Ac
N
e
f
g
h
OMe
OH
OMe
Ac
H
H
Cl
N
O
N
O
CN
Cl
Cl
5
Cl
CN
Cl
Cl
6
CF3
CF3
7
CDCP
Scheme 1. The synthesis of CDCP. Reagents and conditions: (a) AcCl, Et
3 2
N, CH Cl
2
, rt 15 h, 97%; (b) AlCl
3
, 160 °C, 6 h, 65%; (c) CH
3 2
I, K CO
3
, DMF, rt 4 h, 91%; (d) NBS, AIBN,
CCl , 80 °C, 3.5 h; (e) CH NH , CH CN, rt 4 h; (f) 1-propylpiperidine-4-carboxylic acid, HOAt, EDC, DMF, rt 4.5 h, 88%; (g) 2-chloro-5-(trifluoromethyl)-benzaldehyde,
4
3
2
3
NCCH
2
CONH
2
, NaOH, 1 h, 80 °C, 30%; (h) CH
Cl
2 2
3
, BBr , rt 6 h, 46%.
N
N
O
O
N
N
N
N
O
O
OMe
a
OH
N
N
Cl
Ac
6
Cl
Ac
OH
OH
8
H
H
N
O
N
O
c
d
Cl
Cl
CN
CN
Me Sn
I
3
CHO
CHO
Br
Me Sn
3
b
CF3
CF3
CF3
CF
3
10
IDCP
9
Scheme 2. The synthesis of IDCP. Reagents and conditions: (a) CH
2
Cl
2
, BBr
3
, rt, 48 h, 50%; (b) dioxane, (Me
3 2 3 4 3 2 2
Sn) , (Ph P) Pd, Et N, 110 °C, 7 h, 28%; (c) NCCH CO Et,
CH
3
CO
2
NH
4
, EtOH, 80 °C, 10 h, 25%; (d) I
2
, CHCl
3
, rt 9 h, 31%.
N
N
Negligible fluorescent signals were detected in the MCF-10A cells,
which displayed poor survivin expression. These results clearly
indicated that DCP derivative binding correlated with survivin
expression. It has been reported that the expression of survivin
in cancer cell lines is highest in the G2/M phase. Based on this,
we further characterized the binding interaction of IDCP and sur-
O
O
N
N
OH
H
OH
5
H
N
O
a
N
O
Cl
Cl
vivin by fluorescent staining of G
Clear IDCP fluorescence was observed in the cytoplasm of sur-
vivin-rich cells, presumably at the G /M phase (Fig. 5A). In con-
2
/M-synchronized HeLa cells.
CN
CN
Me Sn
125I
3
2
trast, lower fluorescence levels were observed to accumulate in
the survivin-poor cells, which were presumed to be in phases other
CF3
CF3
2
than the G /M phase (Fig. 5B). Corresponding quantitative plots
[125I]IDCP
1
0
demonstrated that IDCP accumulation in cells correlated well with
the expression levels of survivin, except at centromeres, which are
survivin abundant regions (Fig. 5C). Lower IDCP fluorescence sig-
nals at the centromeric regions may be attributed to successful
binding of the DCP derivative to the survivin dimer, but not to a
survivin monomer. Indeed, DCP derivatives have been reported
Scheme 3. Radiosynthesis of [125I]IDCP. Reagents and conditions: (a) [125I]NaI,
chloramine T, 1 M HCl, EtOH, 60 °C, 13%.
immunofluorescence co-localized with survivin in the MDA-MB-
31 cells, which displayed high survivin expression levels.
1
3
2
to bind near the dimer interface of survivin. It is also reported
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4
T. Fuchigami et al. / Bioorg. Med. Chem. Lett. xxx (2015) xxx–xxx
Figure 3. Representative saturation curves and Scatchard plots of CDCP (A) and IDCP (B) with recombinant survivin. Bound DCPs were quantified by measuring increase in
fluorescence intensity during incubation of each DCP (ꢀ10–320 nM) and the recombinant human survivin (10 M).
l
A
CDCP
Survivin
Merge
B
IDCP
Survivin
Merge
MDA-MB-
MDA-MB-
231
2
31
MCF-10A
MCF-10A
Figure 4. Representative confocal fluorescence microscopy images of MDA-MB-231 and MCF-10A cells. The cells labeled with CDCP (A) or IDCP (B) are shown in green, and
stained for survivin protein expression with monoclonal antibody D-8 to survivin (CF633) are shown in red. Merged images are shown with colocalization of CDCP (A) or IDCP
(
B) accumulation and survivin. Scale bar represents 100 lm.
C
D
A
IDCP
Survivin
IDCP
Survivin
Survivin
Distance(µm)
B
IDCP
IDCP
Survivin
Distance(µm)
Figure 5. Representative confocal fluorescence microscopic images of cross-sections indicating the co-localization of IDCP and the anti-survivin antibody in the areas of high
A), and low (B) survivin expression in HeLa cells synchronized in the G /M phase. Cells were labeled with IDCP (green), and stained for survivin protein expression using
monoclonal antibody (red). Scale bar represents 10 m. Line analysis of fluorescence images of IDCP and survivin protein expression levels (red arrow in A and B) in the areas
(
2
l
of high (C), and low (D) survivin expression in HeLa cells.
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T. Fuchigami et al. / Bioorg. Med. Chem. Lett. xxx (2015) xxx–xxx
5
the maximum tumor/blood and tumor/muscle ratios at 60 min
were 0.87 and 2.18, respectively, suggesting unsatisfactory tumor
*
1
25
6
5
4
3
2
1
00
00
00
00
00
00
0
accumulation properties of [ I]IDCP for in vivo imaging. For suc-
cessful in vivo imaging of survivin, it is recommended that survivin
specific nuclear medicine imaging probes should be cell membrane
permeable, should be able to bind survivin, and be retained inside
the cells during the acquisition periods. Here, several factors may
have correlated with the relatively low tumor uptake of [1 I]IDCP
in vivo, including insufficient tissue penetration, inadequate speci-
fic binding to survivin, as well as deiodination and rapid washout
into the intestine. In fact, in vitro studies demonstrated a non-
*
Control
+
CDCP (50 µM)
25
1
25
negligible nonspecific binding of [ I]IDCP to the MDA-MB-231
cells in the presence of as high as 50 M of CDCP (Fig. 6).
l
Nevertheless, the DCP backbone is an attractive scaffold for the
development of useful in vivo imaging probes targeting survivin.
Continued efforts should be concentrated on the development of
imaging probes displaying higher affinities and optimized in vivo
pharmacokinetics, which show superior tumor targeting efficien-
cies and higher signal to noise ratio. In general, passive diffusion
of small molecules through the membrane decreased with an
MDA-MB-231
MCF-10A
Figure 6. In vitro binding of [125I]IDCP in MDA-MB-231 cells and MCF-10A cells.
Nonspecific binding was determined by blocking experiments with CDCP (50
P <0.001 (ANOVA, Bonferroni t test). Values are means ± SEM, n = 5–7.
l
M).
⁄
2
0,21
125
increase in the molecular weight.
In addition, [ I]IDCP
Table 1
1
2
5
a
showed a non-negligible nonspecific binding to survivin-positive
cells and low in vivo uptake in the tumor tissues because of a high
logP. Accordingly, new imaging agents with decreased molecular
weight and lipophilicity should be developed while maintaining
the binding affinity for survivin.
B
i
o
d
i
s
t
r
i
b
u
t
i
o
n
o
f
[
I
]
I
D
C
P
i
n
M
D
A
-
M
B
-
2
3
1
t
u
m
o
r
-
b
e
a
r
i
n
g
m
i
c
e
Time after injection (min)
Organ
30
60
180
Blood
Liver
Kidney
Intestine
Spleen
1.36 (0.13)
16.3 (4.47)
3.02 (0.62)
10.1 (2.30)
2.27 (0.52)
2.25 (0.35)
3.54 (1.02)
2.22 (1.71)
0.84 (0.09)
0.07 (0.02)
0.42 (0.16)
0.51 (0.18)
0.37 (0.10)
1.34 (0.62)
0.72 (0.10)
10.01 (1.90)
1.50 (0.20)
25.3 (4.84)
1.10 (0.28)
1.43 (0.36)
5.33 (2.70)
0.55 (0.12)
0.53 (0.08)
0.06 (0.01)
0.29 (0.09)
0.63 (0.11)
0.87 (0.14)
2.27 (0.57)
0.99 (0.13)
5.68 (1.20)
1.22 (0.22)
21.5 (2.87)
0.71 (0.17)
1.35 (0.73)
6.21 (1.95)
0.61 (0.07)
0.51 (0.22)
0.05 (0.00)
0.33 (0.08)
0.65 (0.09)
0.66 (0.03)
2.08 (0.58)
In conclusion, we employed a convenient procedure for the suc-
125
cessful synthesis of [ I]IDCP as a candidate survivin imaging
probe. IDCP demonstrated a high binding affinity for recombinant
survivin and exhibited localization consistent to the levels of sur-
vivin expression in vitro. However, IDCP demonstrated poor tumor
accumulation in vivo. Although further structural modifications are
necessary to improve pharmacokinetic properties of IDCP, this
study demonstrated the feasibility of using the DCP backbone as
a scaffold for development of survivin-targeting tumor imaging
probes.
Lung
Stomach
Pancreas
Heart
Brain
Muscle
Tumor
Tumor/Blood ratio
Tumor/Muscle ratio
a
Expressed as % of injected dose per gram (% ID/g). Each value represents mean
SD) for three mice at each interval (n = 3).
Acknowledgments
(
Financial support was provided by a Grant-in-Aid for Young
Scientists (B) (Grant No. 21791180), a Grant-in-Aid for Scientific
Research (C) from Japan Society for the Promotion of Science (JSPS)
and a grant from Takeda Science Foundation.
that survivin is present in a monomeric state at the chromosomal
passenger complex. Accumulation of IDCP in survivin-poor cells
7
was significantly lower compared to survivin-rich cells (Fig. 5D).
1
25
Next, we evaluated the quantitative in vitro binding of [ I]IDCP
to MDA-MB-231 and MCF-10A cells (Fig. 6). MDA-MB-231 cells
showed significantly higher uptake of [1 I]IDCP compared to
MCF-10A cells (416% ID/mg protein vs. 100% ID/mg protein,
P <0.001). Specificity of [1 I]IDCP uptake was examined by a
Supplementary data
25
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.bmcl.2015.12.
25
0
46.
blocking study using CDCP (50 lM), which led to a significantly
loss of radioactive uptake in the MDA-MB-231 cells (416% ID/mg
protein vs. 221% ID/mg protein, P <0.001). These results were con-
References and notes
sistent with those of fluorescent staining experiments, indicating
1. Ambrosini, G.; Adida, C.; Altieri, D. C. Nat. Med. 1997, 3, 917.
2. Salvesen, G. S.; Duckett, C. S. Nat. Rev. Mol. Cell Biol. 2002, 3, 401.
in vitro survivin binding specificity of [125I]IDCP.
Further we assessed the in vivo biodistribution of [125I]IDCP at
3.
Dohi, T.; Okada, K.; Xia, F.; Wilford, C. E.; Samuel, T.; Welsh, K.; Marusawa, H.;
Zou, H.; Armstrong, R.; Matsuzawa, S.; Salvesen, G. S.; Reed, J. C.; Altieri, D. C. J.
Biol. Chem. 2004, 279, 34087.
3
0, 60, and 120 min after tail vein injection in BALB/c mice bearing
125
4
5
.
.
Dohi, T.; Xia, F.; Altieri, D. C. Mol. Cell 2007, 27, 17.
Li, F.; Ambrosini, G.; Chu, E. Y.; Plescia, J.; Tognin, S.; Carlomarchisio, P.; Altieri,
D. C. Nature 1998, 396, 580.
MDA-MB-231 xenografts (Table 1). [ I]IDCP showed rapid blood
clearance, resulting in low levels of radioactivity in blood and mus-
cles (1.36% ID/g and 0.42% ID/g, respectively) as demonstrated at
6. Deveraux, Q. L.; Reed, J. C. Genes Dev. 1999, 13, 1253.
7. Jeyaprakash, A. A.; Klein, U. R.; Lindner, D.; Ebert, J.; Nigg, E. A.; Conti, E. Cell
3
0 min after injection. A significant radioactivity uptake was
2007, 131, 271.
retained in the intestine (21.5% ID/g at 180 min after injection).
Uptake of the radiotracer in the stomach was 6.2% ID/g at
8
9
.
.
Fukuda, S.; Pelus, L. M. Mol. Cancer Ther. 2006, 1087, 5.
Singh, N.; Subramanian, K.; Kanwar, R. K.; Cheung, C. H.; Kanwar, J. R. Drug
Discovery Today 2015, 20, 578.
1
80 min after injection, indicating deiodination of a certain level
1
25
10. Coumar, M. S.; Tsai, F. Y.; Kanwar, J. R.; Sarvagalla, S. Cancer Treat. Rev. 2013, 39,
02.
of [ I]IDCP. Further, radiotracer uptake in the MDA-MB-231
tumor showed a gradual time-dependent increase and reached a
maxima (0.65% ID/g) at 180 min after injection. On the other hand,
8
11. Athanasoula, K. Ch.; Gogas, H.; Polonifi, K.; Vaiopoulos, A. G.; Polyzos, A.;
Mantzourani, M. Cancer Lett. 2014, 347, 175.
Please cite this article in press as: Fuchigami, T.; et al. Bioorg. Med. Chem. Lett. (2015), http://dx.doi.org/10.1016/j.bmcl.2015.12.046

6
T. Fuchigami et al. / Bioorg. Med. Chem. Lett. xxx (2015) xxx–xxx
1
1
2. Berezov, A.; Cai, Z.; Freudenberg, J. A.; Zhang, H.; Cheng, X.; Thompson, T.;
16. Chen, F. C.; Chang, C. T. J. Chem. Soc. 1958, 146.
17. Bennett, C. J.; Caldwell, S. T.; McPhail, D. B.; Morrice, P. C.; Duthie, G. G.;
Hartley, R. C. Bioorg. Med. Chem. 2004, 12, 2079.
18. Rong, L. C.; Han, H. X.; Jiang, H.; Shi, D. Q.; Tu, S. J. Synth. Commun. 2008, 38,
217.
19. Yang, L.; Cao, Z.; Yan, H.; Wood, W. C. Cancer Res. 2003, 63, 6815.
20. Artursson, P.; Ungell, A. L.; Löfroth, J. E. Pharm. Res. 1993, 10, 1123.
21. Artursson, P.; Palm, K.; Luthman, K. Adv. Drug Deliv. Rev. 2001, 46, 27.
Murali, R.; Greene, M. I.; Wang, Q. Oncogene 1938, 2012, 31.
3. Wendt, M. D.; Sun, C.; Kunzer, A.; Sauer, D.; Sarris, K.; Hoff, E.; Yu, L.;
Nettesheim, D. G.; Chen, J.; Jin, S.; Comess, K. M.; Fan, Y.; Anderson, S. N.; Isaac,
B.; Olejniczak, E. T.; Hajduk, P. J.; Rosenberg, S. H.; Elmore, S. W. Bioorg. Med.
Chem. Lett. 2007, 17, 3122.
1
4. Chettiar, S. N.; Cooley, J. V.; Park, I. H.; Bhasin, D.; Chakravarti, A.; Li, P. K.; Li, C.;
Jacob, N. K. Bioorg. Med. Chem. Lett. 2013, 23, 5429.
1
5. Wang, Y.; Liu, X.; Zhang, Y.; Liu, G.; Rusckowski, M.; Hnatowich, D. J. Nucl. Med.
Biol. 2007, 34, 47.
Please cite this article in press as: Fuchigami, T.; et al. Bioorg. Med. Chem. Lett. (2015), http://dx.doi.org/10.1016/j.bmcl.2015.12.046