Synthesis and antiangiogenic activity of 6-amido-2,4,5-trimethylpyridin-3- ols

Article abstract of DOI:10.1016/j.bmcl.2014.05.005

We recently reported that 6-aminoalkyl-2,4,5-trimethylpyridin-3-ols, novel series of 6-aminopyridin-3-ol-based antioxidants, have high antiangiogenic activities. In pursuit of wider variety in the analogues, we here report the synthesis and antiangiogenic activities of 6-amidoalkyl-2,4,5-trimethylpyridin- 3-ols, which would not be considered excellent antioxidants because of the poorer electron-donating effect of the C(6)-amido group than the corresponding C(6)-amino group. The selected 6-amido compounds showed up to several fold-higher antiangiogenic activities and up to an order of magnitude better antitumor activities in the chick embryo chorioallantoic membrane (CAM) assay than SU4312, a positive control. We also found that paracetamol, as a direct phenolic analogue of our simplest 6-amidopyridin-3-ol, showed a moderate level of antiangiogenic activity. We propose this study will offer a basis for a scaffold of novel angiogenesis inhibitors that can perturb angiogenesis-related pathologies.

Full text of DOI:10.1016/j.bmcl.2014.05.005

Accepted Manuscript
Synthesis and antiangiogenic activity of 6-amido-2,4,5-trimethylpyridin-3-ols
Hyunji Lee, Suhrid Banskota, Dong-Guk Kim, Jae-Hui Been, You-Jin Jin, Jaya
Gautam, Hyeonjin Jang, Tae-gyu Nam, Jung-Ae Kim, Byeong-Seon Jeong
PII:
S0960-894X(14)00492-2
DOI:
http://dx.doi.org/10.1016/j.bmcl.2014.05.005
BMCL 21618
Reference:
Bioorganic & Medicinal Chemistry Letters
To appear in:
Received Date:
Revised Date:
Accepted Date:
4 March 2014
23 April 2014
2 May 2014
Please cite this article as: Lee, H., Banskota, S., Kim, D-G., Been, J-H., Jin, Y-J., Gautam, J., Jang, H., Nam, T-g.,
Kim, J-A., Jeong, B-S., Synthesis and antiangiogenic activity of 6-amido-2,4,5-trimethylpyridin-3-ols, Bioorganic
& Medicinal Chemistry Letters (2014), doi: http://dx.doi.org/10.1016/j.bmcl.2014.05.005
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.

Graphical Abstract
Synthesis and antiangiogenic activity of 6-
amido-2,4,5-trimethylpyridin-3-ols
Leave this area blank for abstract info.
Hyunji Leea,‡, Suhrid Banskotaa,‡, Dong-Guk Kima, Jae-Hui Beena, You-Jin Jinb, Jaya Gautama, Hyeonjin Janga,
Tae-gyu Namb,∗, Jung-Ae Kim,a,∗ and Byeong-Seon Jeonga,∗
aCollege of Pharmacy and Institute for Drug Research, Yeungnam University, Gyeongsan 712-749, Republic of Korea
bDepartment of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 426-791, Republic of Korea

Bioorganic & Medicinal Chemistry Letters
jo u rn al h ome p ag e : w ww .e lse vie r .c om
Synthesis and antiangiogenic activity of 6-amido-2,4,5-trimethylpyridin-3-ols
Hyunji Leea,‡, Suhrid Banskotaa,‡, Dong-Guk Kima, Jae-Hui Beena, You-Jin Jinb, Jaya Gautama, Hyeonjin
Janga, Tae-gyu Namb,∗, Jung-Ae Kim,a,∗ and Byeong-Seon Jeonga,∗
aCollege of Pharmacy and Institute for Drug Research, Yeungnam University, Gyeongsan 712-749, Republic of Korea
bDepartment of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 426-791, Republic of Korea
ARTICLE INFO
ABSTRACT
Article history:
Received
We recently reported that 6-aminoalkyl-2,4,5-trimethylpyridin-3-ols, novel series of 6-
aminopyridin-3-ol-based antioxidants, have high antiangiogenic activities. In pursuit of wider
variety in the analogues, we here report the synthesis and antiangiogenic activities of 6-
amidoalkyl-2,4,5-trimethylpyridin-3-ols, which would not be considered excellent antioxidants
because of the poorer electron-donating effect of the C(6)-amido group than the corresponding
C(6)-amino group. The selected 6-amido compounds showed up to several fold-higher
antiangiogenic activities and up to an order of magnitude better antitumor activities in the chick
embryo chorioallantoic membrane (CAM) assay than SU4312, a positive control. We also found
that paracetamol, as a direct phenolic analogue of our simplest 6-amidopyridin-3-ol, showed a
moderate level of antiangiogenic activity. We propose this study will offer a basis for a scaffold
of novel angiogenesis inhibitors that can perturb angiogenesis-related pathologies.
Revised
Accepted
Available online
Keywords:
Amidopyridinol
Angiogenesis
Antiangiogenic
Antitumor
Chick chorioallantoic membrane assay
2009 Elsevier Ltd. All rights reserved.
Angiogenesis is a biological process where new blood vessels
branch out from the existing vasculature.1 This process is tightly
controlled for normal physiologies such as reproduction,
development, and wound repair. However, it becomes out of
control when it is implicated in diseases such as cancer, age-
related or diabetic retinopathy and so on.2 For example,
angiogenesis is significantly increased around solid tumor tissues
which require a high level of nutrients and oxygen to grow to a
considerable size. New blood vessels, in turn, enable cancer cells
to invade adjacent tissues and to migrate throughout the body
(metastasis). Significant efforts have been made to develop
angiogenesis inhibitors, which block tumor angiogenesis, for the
prevention and treatment of cancer.3 Synthetic antiangiogenic
drugs include sorafenib and sunitinib which were approved by
the FDA for the treatment of cancer.4 Various types of
angiogenesis inhibitors are currently being tested in clinical
trials.5 For example, thalidomide, once a tragic drug, has recently
received a great deal of attention as an antitumor agent due to its
excellent antiangiogenic activities.6
6-Aminopyridin-3-ol (1) has been known as
a novel
antioxidant scaffold for years, featuring enhanced air-stability by
virtue of the ring nitrogen and potent antioxidant activity toward
lipid peroxyl radical.7 Mono- and bicyclic analogues with
lipophilic side chains showed higher levels of antioxidant activity
and binding affinity (kd) to tocopherol transfer protein (TPP) than
α-tocopherol (2), the most effective natural lipophilic
antioxidant.7d-g Also, they protect the endogenous α-tocopherol
from oxidative consumption and do not participate in tocopherol
———
‡ These authors contributed equally to this work and should be considered co-first authors.
∗ Corresponding author (T.-g. Nam). phone: +82-31-400-5807; e-mail: tnam@hanyang.ac.kr
∗ Corresponding author (J.-A. Kim). phone: +82-53-810-2816; e-mail: jakim@yu.ac.kr
∗ Corresponding author (B.-S. Jeong). phone: +82-53-810-2814; e-mail: jeongb@ynu.ac.kr

mediated peroxidation process.7d,e We recently reported 6-
aminoalkyl-2,4,5-trimethylpyridin-3-ols (4, R1 or R2 = H or
alkyl) as novel series of 6-aminopyridin-3-ol antioxidants.7f,g
They were found to be good antioxidants with potent radical-
scavenging activities. A lipophilic analogue (i.e., R1 = n-C16H33,
R2 = H in 4) showed greater capacity to prevent plasma lipid
peroxidation and higher efficacy to protect cells from oxidative
injury than α-tocopherol. A hydrophilic, water-soluble analogue
(i.e., R1 = R2 = H in 4) acted as a co-antioxidant in a
heterogeneous system that may serve to extend the half-life of α-
tocopherol. Another profound feature of this series is the facile
synthetic method starting from pyridoxine hydrochloride (3)
which is readily available in quantity.
amides 10 which were next hydrogenolyzed to afford 6-amido-
2,4,5-trimethylpyridin-3-ols (5).
In an alternative approach shown in Scheme 2, the amino
group of 10 was introduced through a slightly different pathway.
First, C(3)-OH of compound 6 was benzylated to afford 11 in
71% yield. Then, the nitrogen of the pyridine ring of 11 was
oxidized to an N-oxide with m-CPBA to give 12 in 94% yield.
Subsequently, the treatment of 12 with p-toluenesulfonyl chloride
and phthalimide in the presence of Hünig's base gave 13 in 70%
yield,12 which was finally converted to the amine 9 in 90% yield
by a simple treatment with hydrazine.
Based on the notion that the electron donating groups at ortho-
and para-positions to –OH group can decrease bond dissociation
enthalpy of O–H bond of phenolic antioxidants,8 thereby
increasing H atom transfer to lipid peroxyl radicals, C(6)-amino
functions of 6-aminopyridin-3-ols (1 and 4) have almost always
been mono- or dialkylated or arylated in pursuit of high H-atom
donation ability as chain-breaking antioxidants. In parallel,
studies of their biological activities have focused largely on the
antioxidant activities to neutralize reactive oxygen species (ROS).
There are only a few reports on their pharmacological actions
against disease-related systems.9
However, we recently found for the first time that 6-
alkylamino-2,4,5-trimethylpyridin-3-ols (4) have very potent
antiangiogenic activity in the chick embryo chorioallantoic
membrane (CAM) assay.10 The best analogues showed more than
3-fold better ID50 than SU4312, a well-known angiogenesis
inhibitor.11 They also significantly inhibited angiogenic cancer-
formation in a cancer cell-inoculated CAM assay. Interestingly,
we have not observed a particularly good correlation between
antiangiogenic activities and antioxidant activities of 6-
Scheme 1. Synthesis of 6-amido-2,4,5-trimethylpyridin-3-ols.
Reagents and conditions: (a) SOCl2, DMF (cat.), reflux, 30 min,
93%; (b) Zn, AcOH, reflux, 3 h, 92%; (c) DBDMH, THF, r.t., 3 h,
80%; (d) PhCH2Cl, K2CO3, DMF, r.t., 12 h, 97%; (e)
benzophenone imine, Pd2(dba)3, BINAP, NaOtBu, toluene, reflux,
12 h, 83%; (f) HCl, MeOH-THF, r.t., 12 h, 83%; (g) acyl
chloride, Et3N, CH2Cl2, r.t.; (h) H2, Pd/C, MeOH, r.t. or BCl3,
CH2Cl2, 0 °C (for 5S).
alkylamino-2,4,5-trimethylpyridin-3-ols.
There
was
no
meaningful distinction in antiangiogenic activities between the
analogues with an electron donation group and the ones with an
electron withdrawing group on C(6)-amino moiety. In fact, the
best antiangiogenic analogues include the one with p-nitrophenyl
group attached to C(6)-amino group.
A variety of amide groups were introduced in 5 as R groups
shown in Scheme 1. R groups range from various alkyl chains
with various lengths, cycloalkanes, and aromatic rings with
various types of methylene spacers, electron donating groups,
electron withdrawing groups, and heteroatoms.
Inspired by this observation, we introduced 6-amido groups in
place of 6-amino groups, which would be poor substituents for
antioxidants, because they will cause the pyridinols to be electron
poorer and presumably less effective antioxidants. We report, in
fact, that 6-amido analogues 5, in general, have improved
antiangiogenic and antitumor activities compared to 6-amino
analogues 4. We also report that paracetamol, which is a well-
known active ingredient of an antipyretic and analgesic drug, as a
direct phenolic analogue of our simplest 6-amidopyridin-3-ol,
showed moderate antiangiogenic activity. We propose that this
study will offer the basis for a scaffold of novel angiogenesis
inhibitors that can perturb angiogenesis-related pathologies.
Scheme 2. An alternative synthesis of 6-amino-3-benzyloxy-
2,4,5-trimethylpyridin-3-ol (9). Reagents and conditions: (a)
PhCH2Cl, K2CO3, DMF, r.t., 12 h, 71%; (b) m-CPBA, CH2Cl2,
r.t., 1 h, 94%; (c) p-TsCl, i-Pr2NEt, phthalimide, CH2Cl2, r.t., 12
h, 70%; (d) H2NNH2, THF-EtOH, r.t., 1 h, 90%.
Shown in Scheme 1 is a synthesis of 6-amido-2,4,5-
trimethylpyridin-3-ol analogues (5) starting from pyridoxine
hydrochloride (3). Our initial synthetic pathway utilized 6-amino-
3-benzyloxy-2,4,5-trimethylpyridine (9) as a key intermediate.
Briefly, two primary alcohols of 3 were reductively removed via
chlorides to afford two methyl groups of 6. C(6)-position and
C(3)-OH of 6 were brominated and benzylated, respectively, in
consecutive manner, to afford 7. Then, for the installation of
amino group, benzophenone imine, as an ammonia equivalent,
was subjected to Buchwald-Hartwig amination condition to
afford a C(6)-benzophenone imine-installed derivative 8 in 83%
yield. It was then hydrolyzed to conveniently give 9 in 83%
yield.10 Various acid chlorides were reacted with 9 to give the
Angiogenesis inhibitory activities of 6-amido-2,4,5-
trimethylpyridin-3-ols (5) were evaluated using quantitative
CAM assay,13 which is one of the most useful in vivo assay
models of angiogenesis.14 In CAM assays, angiogenesis was
induced by treating CAMs with vascular endothelial growth
factor (VEGF), the best characterized proangiogenic factor, prior
to the compound treatment. Then, test compounds soaked in a
disk were treated on CAM. As shown in Table 1, treatment with

VEGF (20 ng/CAM) significantly enhanced the number of newly
formed blood vessel branch points compared to phosphate
buffered saline (PBS)-treated control group. At a fixed dose of
0.01 nmol/CAM,15 the 6-amido-2,4,5-trimethylpyridin-3-ols
(5A–S) significantly suppressed the VEGF-induced angiogenesis,
with compound 5A being the most effective one and compound
5G being the least effective one among the analogues.
53.2 11.5*
73.2 6.4*
81.8 8.4*
5G
5H
5I
Table 1. Inhibitory effects of 6-amido-2,4,5-trimethylpyridin-3-
ols (5A–S) on VEGF-induced angiogenesis in vivo.a
76.3 7.2*
5J
69.6 11.0*
74.2 3.9*
5K
5L
HO
O
N
N
H
77.3 13.1*
75.3 6.3*
5M
5N
Compound
Structure
Inhibition (%) at
0.01 nmol/CAMb
78.0 4.8*
SU4312
5O
5P
69.7 4.5*
74.2 7.0*
88.8 8.1*
Sunitinib
malate
77.9 10.6*
84.8 10.0*
Paracetamol
5A
64.8 17.4*
75.8 5.4*
5Q
5R
74.7 4.6*
57.4 10.0*
59.9 11.3*
70.2 4.6*
75.6 8.9*
5B
5C
5D
5E
5F
74.8 13.2*
5S
a Quantification of new branches formed from existing blood vessels was
performed. Photographs were imported into an Image software program,
to measure the new branch points. The data is expressed as the
mean S.E.M.of at least six chick embryos. Dose was 0.01 nmol/CAM
for both test compounds and SU4312, which is equivalent to 2–3
ng/CAM depending on the molecular weights.
b
Inhibition (%) = [(the number of vessel branch points induced by
−(the number of vessel branch
VEGF)
points induced by test compound
and VEGF)/(the number of vessel branch points induced by
VEGF)]×100.

*P<0.05 compared to the VEGF-treated CAM sample.
5.0
0.9
14.9
3.6
5C
5I
SU4312 and sunitinib were used as positive controls. SU4312
is known as a selective and potent VEGF-receptor (VEGFR)
tyrosine kinase inhibitor,11a-c whereas sunitinib, treated as its
malate salt in this study, is a multi-targeted receptor tyrosine
kinase inhibitor preventing the signalling of VEGFR, platelet-
derived growth factor receptor (PDGFR), Kit, colony stimulating
factor (CSF)-1R, and RET.11d In general, 6-amidopyridin-3-ols
(5) showed moderate to high levels of inhibitory activities at a
fixed dose (0.01 nmol/CAM). Among them, the simplest methyl
(5A) and cyclopentyl (5I) analogues were particularly strong
showing better activities than SU4312. Analogues with aromatic
groups (5K–S) generally showed strong activities regardless of
the existence of methylene spacer(s), electron-donating or
withdrawing group(s), heteroaromatic and bicyclic aromatic rings.
The analogues with n-alkyl substituents (5A–E) were also quite
strong but showed rather complex structure-activity relationships.
The simplest methyl analogue (5A) showed the best activity
while the longer alkyl analogues gradually lost the activity.
However, the analogues with branched alkyls (5F–H) and
cycloalkanes (5I, 5J) restored the activity except for the
relatively simple isopropyl (5G) substituent.
a
Each data point represents mean SEM (n, at least six) at indicated
compound doses. ID50's were calculated using Prizm (GraphPad
software).
We then examined dose-dependency and the 50% inhibitory
dose (ID50) of 5A, 5I (strong ones) and 5C (weak one), along
with paracetamol, in VEGF-induced angiogenesis. Paracetamol
can be considered the simplest phenolic analogue of 5A, from a
structural point of view, and can thereby provide some
information about the structure-activity relationship. It is a non-
selective cyclooxygenase inhibitor and one of the most widely
used antipyretic and analgesic drugs. It was found to share, in
part, a pharmacological mode of action with aminopyridinols by
which they inhibit cyclooxygenase- and lipoxygenase-mediated
lipid peroxidation.16 Table 2 displays dose-response curves and
remarkable ID50’s of the compounds. The order of ID50 of
SU4312, sunitinib malate, and the three selected 6-amidopyridin-
3-ols (5A, 5C, and 5I) is reasonably consistent with the trend
found in single-dose data shown in Table 1. In the current study,
we report for the first time that SU4312 was more potent
inhibitor of in vivo angiogenesis using CAM assay than sunitinib
malate. Significantly, 5A and 5I dose-dependently inhibited
angiogenesis and showed more than an order of magnitude better
ID50 than SU4312. It is remarkable that paracetamol showed
moderate level of antiangiogenic activity as a structural analogue
of 5A, indicating the potential roles of three ring methyl groups
and pyridine ring of 5A in the inhibition of angiogenesis.
Table 2 Dose-response curves and ID50 values of the selected
compounds.a
Cancer is one of the most serious disease conditions in which
angiogenesis is deeply involved.17 In order to examine if the
antiangiogenic activities of our compounds can also affected
tumorigenesis, 5A, 5C, and 5I were tested in cancer cell-
inoculated CAM assay. Implanted A549 human lung cancer cells
in a mixture of Matrigel onto CAM dramatically induced
angiogenesis and corresponding tumor growth (untreated
condition in Table 3). In contrast, all tested compounds (5A, 5C,
5I, and SU4312), treated once at the time of implantation,
showed potent and dose-dependent inhibition of cancer cell-
induced angiogenesis (Table 3), measured by the same methods
as Table 1. In line with our hypothesis for the antitumor activity,
test compounds that showed a significant level of angiogenesis
inhibition also suppressed the growth of tumors. It is notable that
more than one order of magnitude lower doses of 5A, 5C, and 5I
were required to achieve the same level of antitumor activity than
of SU4312 at low dose ranges (i.e., 0.19 and 1.9 pg/CAM for 5A).
At higher dosages (i.e., 19 and 190 pg/CAM for 5A), they
showed up to almost 2-fold better activity than SU4312. The
degrees of the reduction in size and weight of the excised tumors
shown in Table 3 were proportionate to the degrees of
angiogenesis inhibition by each compound. This result strongly
suggests that the antitumor activity of 5A, 5C, and 5I was due to
the suppression of angiogenesis. It also indicates that other
factors besides the electron density of the pyridinol ring, an
important property for antioxidant activity, dictate the inhibitory
activities against angiogenesis and thus tumor growth. Taken
together, the data warrant further studies to define the
pharmacophore in more detail and to elucidate the mode of action.
Compound
SU4312
ID50 (pg/CAM)
ID50 (fmol/CAM)
10.5
202.4
60.0
1.7
39.7
380.0
396.9
8.7
Sunitinib malate
Paracetamol
5A

Table 3. Antiangiogenic and antitumor effects of compounds 5A, 5C, 5I, and SU4312 on A549 human lung cancer cell-inoculated
CAMs.a
Compound
SU4312
5A
Treatment
Angiogenesis
Tumor
pg/CAM
pmol/CAM Vessel branch points Inhibition (%) Tumor weight Inhibition (%) Excised tumor
around tumor (No.)
124.2 4.5
98.4 1.7*
93.0 3.5*
79.2 2.4*
120.7 5.3
105.4 7.9
92.0 6.3*
84.0 4.4*
71.0 1.7*
120.7 5.3
106.0 5.3
99.0 3.8*
95.0 2.5*
90.9 2.6*
116.5 4.3
80.5 3.8*
60.2 1.8*
53.1 3.0*
48.8 2.9*
(mg)
untreated
2.6
–
–
17.6 1.8
14.8 3.6
13.5 1.6
12.9 0.9
16.7 1.5
13.3 1.1
11.0 0.9*
10.4 1.2*
8.8 1.4*
16.7 1.5
13.1 1.4
12.4 1.4
11.5 1.1*
10.3 1.3*
29.7 1.4
26.3 1.1
23.1 0.5*
16.7 1.0*
11.3 0.8*
–
0.01
0.1
1.0
–
20.8 1.4*
25.1 2.8*
36.2 1.9*
–
16.2 20.4
23.4 9.3
26.8 4.9
–
26
260
untreated
0.19
1.9
0.001
0.01
0.1
1.0
–
12.7 6.5
23.8 5.2*
30.4 3.7*
41.2 1.4*
–
20.3 5.9
34.2 5.3*
37.9 8.0*
47.7 4.1*
–
19
190
untreated
0.33
3.3
0.001
0.01
0.1
1.0
–
12.2 4.4
18.0 3.2*
21.3 2.0*
24.7 2.2*
–
21.7 8.9
26.0 10.0
31.3 7.3*
38.2 7.2*
–
5C
33
330
untreated
0.25
2.5
0.001
0.01
0.1
1.0
30.9 8.5*
48.4 4.1*
54.4 6.7*
58.1 6.8*
13.2 3.5
24.0 1.6*
45.1 3.1*
62.7 2.3*
5I
25
250
aA549 human lung cancer cells (2×106 cells/CAM) were inoculated on top of CAM, and different concentrations of 5A, 5C, 5I, and SU4312 were
treated. The number of new vessel branches was quantitated by the same method as described in Table 1.Tumor mass grown on top of CAM was
isolated and weighed. The data represent the means S.E.M. of at least six chick embryos.
*P<0.05 compared to the vehicle-treated group.
In summary, a new series of 6-amido-2,4,5-trimethylpyridin-
3-ols (5) were synthesized from pyridoxine·HCl (3). In this study,
5I inhibited VEGF-induced angiogenesis better than SU4312 and
sunitinib malate. In particular, compounds 5A and 5I showed
much better antiangiogenic antitumor activity than SU4312. It
indicates that their antitumor activities are correlated with the
antiangiogenic activities and that other factors might control the
antiangiogenesis-based activities besides the electron density of
the pyridinol ring. Further studies on the pharmacophore and the
mode of action are warranted.
(NRF) funded by the Ministry of Education, Science and
Technology (NRF-2012R1A1A2039174).
References and notes
1. (a) Risau W.; Flamme I. Annu. Rev. Cell Dev. Biol. 1995, 11, 73–
91. (b) Risau W. Nature 1997, 386, 671–674. (c) Carmeliet, P. Nat.
Med. 2000, 6, 389–395. (d) Carmeliet P. Nat. Med. 2003, 9, 653–
660. (e) Carmeliet P. Nature 2005, 438, 932–936.
2. (a) Folkman J. N. Eng. J. Med. 1971, 285, 1182–1186. (b)
Folkman J. Nat. Rev. Drug Discov. 2007, 6, 273–286.
3. Cook K. M.; Figg W. D. CA Cancer J. Clin. 2010, 60, 222–243.
4. (a) Shin T.; Lindley C. Clin. Ther. 2006, 28, 1779–1802. (b)
Gotink K. J.; Verheul H. M. Angiogenesis 2010, 13, 1–14.
5. Siemann D. W. Cancer Treat Rev. 2011, 37, 63–74.
6. (a) D'Amato R. J.; Loughnan M. S.; Flynn E.; Folkman J. Proc.
Natl. Acad. Sci. USA, 1994, 91, 4082–4085. (b) Masiero L.; Figg
Acknowledgments
This research was supported by Basic Science Research
Program through the National Research Foundation of Korea

W. D.; Kohn E. C. Angiogenesis 1997, 1, 23–35. (c) Rajkumar S.
V.; Witzig T. E. Cancer Treat Rev. 2000, 26, 351–362. (d)
Rajkumar S. V.; Gertz M. A.; Lacy M. Q.; Dispenzieri A.;
Fonseca R.; Geyer S. M.; Iturria N.; Kumar S.; Lust J. A.; Kyle R.
A.; Greipp P. R.; Witzig T. E. Leukemia 2003, 17, 775–779.
7. (a) Wijtmans M.; Pratt D. A.; Valgimigli L.; DiLabio G. A.;
Pedulli G. F.; Porter N. A. Angew. Chem. Int. Ed. 2003, 42, 4370–
4373. (b) Wijtmans M.; Pratt D. A.; Brinkhorst J.; Serwa R.;
Valgimigli L.; Pedulli G. F.; Porter N. A. J. Org. Chem. 2004, 69,
9215–9223. (c) Nam T.-g.; Wijtmans M.; Pratt D. A.; Porter N. A.
Synthesis 2005, 1397–1404. (d) Kim H.-Y.; Pratt D. A.; Seal J. R.;
Wijtmans M.; Porter N. A. J. Med. Chem. 2005, 48, 6787–6789.
(e) Nam T.-g.; Rector C. L.; Kim H.-Y.; Sonnen A. F.-P.; Meyer
R.; Nau W. M.; Atkinson J.; Rintoul J.; Pratt D. A.; Porter N. A. J.
Am. Chem. Soc. 2007, 129, 10211–10219. (f) Omata Y.; Saito Y.;
Yoshida Y.; Jeong B.-S.; Serwa R.; Nam T.-g.; Porter N. A.; Niki
E. Free Radical Biol. Med. 2010, 48, 1358–1365. (g) Serwa R.;
Nam T.-g.; Valgimigli L.; Culbertson S.; Rector C. L.; Jeong B.-
S.; Pratt D. A.; Porter N. A. Chem. Eur. J. 2010, 16, 14106–14114.
(h) Nam T.-g.; Ku J.-M.; Park H.-g.; Porter N. A.; Jeong B.-S. Org.
Biomol. Chem. 2011, 9, 1749–1755. (i) Nam T.-g.; Ku J.-M.;
Rector C. L.; Choi H.; Porter N. A.; Jeong B.-S. Org. Biomol.
Chem. 2011, 9, 8475–8482.
H. K.; Seruga B.; Knox J. J. Expert Opin. Invest. Drugs 2009, 18,
821–834.
12. Farrell R. P.; Elipe M. V. S.; Bartberger M. D.; Tedrow J. S.;
Vounatsos F. Org. Lett. 2013, 15, 168–171.
13. (a) Auerbach R.; Lewis R.; Shinners B.; Kubai L.; Akhtar N. Clin.
Chem. 2003, 49, 32–40. (b) Storgard C.; Mikolon D.; Stupack D.
G. Mol. Biol. 2005, 294, 123–136.
14. CAM and rabbit cornea assay are the most widely used assays as
an in vivo model for angiogenesis study. Of these, CAM provides
advantages of being simpler to use, reproducible, reliable, and less
expensive.
15. Each test compound was prepared in stock solution and diluted
with PBS in a concentration of 1.0 µM. 10 µL of this solution was
added directly to the disk on top of CAM. Since we measured the
blood vessels in the area under the disk, the antiangiogenic dose
was calculated as 10 µL/CAM × drug concentration (1.0 µM), i.e.
0.01 nmol/CAM.
16. Nam T.-g.; Nara S. J.; Zagol-Ikapitte I.; Cooper T.; Valgimigli L.;
Oates J. A.; Porter N. A.; Boutaud O.; Pratt D. A. Org. Biomol.
Chem. 2009, 7, 5103–5112.
17. (a) Zetter B. R. Annu. Rev. Med. 1998, 49, 407–424. (b) Kerbel R.
S. Carcinogenesis 2000, 21, 505–515. (c) Kerbel R. S. N. Eng. J.
Med. 2008, 358, 2039–2049. (d) Weis S. M.; Cheresh D. A. Nat.
Med. 2011, 17, 1359–1370.
8. (a) Pratt D. A.; DiLabio G. A.; Brigati G.; Pedulli G. F.;
Valgimigli L. J. Am. Chem. Soc. 2001, 123, 4625–4626. (b)
Valgimigli L.; Brigati G.; Pedulli G. F.; DiLabio G. A.;
Mastragostino M.; Arbizzani C.; Pratt D. A. Chem. Eur. J. 2003, 9,
4997–5010.
18. Colman R. W.; Pixley R. A.; Sainz I. M.; Song J. S.; Isordia-Salas
I.; Muhamed S. N.; Powell J. A.; Mousa S. A. J. Thromb.
Haemost. 2003, 1, 164–170.
19. (a) Kim J.-A.; Cho K. B.; Kim M. R.; Park B. C.; Kim S. K.; Lee
M. Y.; Kang K. W. Cancer Lett. 2008, 268, 225–232. (b) Thapa
D.; Lee J. S.; Heo S.-W.; Lee Y. R.; Kang K. W.; Kwak M.-K.;
Choi H. G.; Kim J.-A. Eur. J. Pharmacol. 2011, 650, 64–71.
9. (a) Khdour O. M.; Lu J.; Hecht S. M. Pharm. Res. 2011, 28,
2896–2909. (b) Cai X.; Khdour O. M.; Jaruvangsanti J.; Hecht S.
M. Biorg. Med. Chem. 2012, 20, 3584–3595. (c) Arce P. M.;
Goldschmidt R.; Khdour O. M.; Madathil M. M.; Jaruvangsanti J.;
Dey S.; Fash D. M.; Armstrong J. S.; Hecht S. M. Biorg. Med.
Chem. 2012, 20, 5188–5201.
Supplementary Material
10. Kim D.-G.; Kang Y.; Lee H.; Lee, E. K.; Nam T.-g.; Kim J.-A.;
Jeong B.-S. Eur. J. Med. Chem. 2014, 78, 126–139.
Experimental details along with 1H- & 13C-NMR spectra of all
new compounds are provided.
11. (a) Sun L.; Tran N.; Tang F.; App H.; Hirth P.; McMahon G.;
Tang C. J. Med. Chem. 1998, 41, 2588–2603. (b) Zaman G. J. R.;
Vink P. M. F.; van der Doelen A. A.; Veeneman G. H.;
Theunissen H. J. M. Biochem. Pharmacol. 1999, 57, 57–64. (c)
Kendall R. L.; Rutledge R. Z.; Mao X.; Tebben A. J.; Hungate R.
W.; Thomas K. A. J. Biol. Chem. 1999, 274, 6453–6460. (d) Gan