Structure-activity relationships study of neolamellarin A and its analogues as hypoxia inducible factor-1 (HIF-1) inhibitors

Article abstract of DOI:10.1016/j.bmcl.2019.06.017

The novel marine pyrrole alkaloid neolamellarin A derived from sponge has been shown to inhibit hypoxia-induced HIF-1 activity. In this work, we designed and synthesized neolamellarin A and its series of derivatives by a convergent synthetic strategy. The HIF-1 inhibitory activity and cytotoxicity of these compounds were evaluated in Hela cells by dual-luciferase reporter gene assay and MTT assay, respectively. The results showed that neolamellarin A 1 (IC₅₀ = 10.8 ± 1.0 μM) and derivative 2b (IC₅₀ = 11.9 ± 3.6 μM) had the best HIF-1 inhibitory activity and low cytotoxicity. Our SAR research focused on the effects of key regions aliphatic carbon chain length, aromatic ring substituents and C-7 substituent on biological activity, providing a basis for the subsequent research on the development of novel pyrrole alkaloids as HIF-1 inhibitors and design of small molecule probes for target protein identification.

Full text of DOI:10.1016/j.bmcl.2019.06.017

Accepted Manuscript
Structure-Activity Relationships Study of Neolamellarin A and Its Analogues
as Hypoxia Inducible Factor-1 (HIF-1) inhibitors
Guangzhe Li, Huijuan Dong, Yao Ma, Kun Shao, Yueqing Li, Xiaodan Wu,
Shisheng Wang, Yujie Shao, Weijie Zhao
PII:
S0960-894X(19)30397-X
https://doi.org/10.1016/j.bmcl.2019.06.017
BMCL 26495
DOI:
Reference:
Bioorganic & Medicinal Chemistry Letters
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Revised Date:
Accepted Date:
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23 May 2019
14 June 2019
Please cite this article as: Li, G., Dong, H., Ma, Y., Shao, K., Li, Y., Wu, X., Wang, S., Shao, Y., Zhao, W., Structure-
Activity Relationships Study of Neolamellarin A and Its Analogues as Hypoxia Inducible Factor-1 (HIF-1)
inhibitors, Bioorganic & Medicinal Chemistry Letters (2019), doi: https://doi.org/10.1016/j.bmcl.2019.06.017
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Structure-Activity Relationships Study of
Neolamellarin A and Its Analogues as
Hypoxia Inducible Factor-1 (HIF-1)
inhibitors
Leave this area blank for abstract info.
Guangzhe Li a,b, Huijuan Dong a, Yao Ma c, Kun Shao b, Yueqing Li a,b, Xiaodan Wu a ,Shisheng Wang
a,b*, Yujie Shao a, Weijie Zhao a,b
1

Bioorganic & Medicinal Chemistry Letters
Structure-Activity Relationships Study of Neolamellarin A and Its Analogues as
Hypoxia Inducible Factor-1 (HIF-1) inhibitors
Guangzhe Li a,b, Huijuan Dong a, Yao Ma c, Kun Shao b, Yueqing Li a,b, Xiaodan Wu a ,Shisheng Wang a,b*,
Yujie Shao a, Weijie Zhao a,b
aDepartment of Pharmacy, School of Chemical Engineering, Dalian University of Technology, Dalian 116023, China
bState Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116023, China
cDalian Hospital of Obstetrics and Gynaecology, Dalian 116083, China
ARTICLE INFO
ABSTRACT
Article history:
Received
Revised
Accepted
Available online
The novel marine pyrrole alkaloid neolamellarin A derived from sponge has been shown to
inhibit hypoxia-induced HIF-1 activity. In this work, we designed and synthesized neolamellarin
A and its series of derivatives by a convergent synthetic strategy. The HIF-1 inhibitory activity
and cytotoxicity of these compounds were evaluated in Hela cells by dual-luciferase reporter
gene assay and MTT assay, respectively. The results showed that neolamellarin A 1 (IC50 = 10.8
± 1.0 μM) and derivative 2b (IC50 = 11.9 ± 3.6 μM) had the best HIF-1 inhibitory activity and
low cytotoxicity. Our SAR research focused on the effects of key regions aliphatic carbon chain
length, aromatic ring substituents and C-7 substituent on biological activity, providing a basis
for the subsequent research on the development of novel pyrrole alkaloids as HIF-1 inhibitors
and design of small molecule probes for target protein identification.
Keywords:
Anti-tumor
Hypoxia inducible factor (HIF)-1
Marine alkaloids
2009 Elsevier Ltd. All rights reserved.
Neolamellarin A
Structure-activity relationship
Hypoxia-inducible factor-1 (HIF-1) is a transcription factor
with a basic helix-loop-helix (bHLH) structure, which forms a
heterodimer with the HIF-1α subunit and constitutively active
HIF-1β. Normal cells are in a normoxic condition, and O2-
regulated HIF-1α undergoes a continuous degradation process in
which proline residues 402 and 564 in the oxygen-dependent
degradation (ODD) domain are hydroxylated by prolyl
hydroxylase (PHD) and lysine residue 532 is acylated by
acetyltransferase-1 (ARD-1), then recognized by the tumor
suppressor protein von Hippel−Lindau (VHL). Subsequently it is
ubiquitinated by the E3 ubiquitin-protein ligase, causing the rapid
degradation of HIF-1α. That is, in a normoxic environment, the
expression and degradation of HIF-1α are in a dynamic
(VEGF), erythropoietin (EPO), glucose transporters (GLUT),
glycolytic enzymes, etc. All of these genes play a vital role in
many key aspects of tumor hypoxia adaption, including
angiogenesis, metabolic reprogramming, immortalization self-
renewal autocrine growth/survival epithelial-mesenchymal and
increased cell proliferation & survival [2]. In recent years,
extensive experimental and clinical data have validated HIF-1 as
a therapeutic target for cancer, leading to the exploration of many
small molecule inhibitors targeting HIF-1 signaling pathway for
seeking excellent clinical candidates [3-5]
.
Natural products have the advantages of chemical structure
diversity, biological activity diversity and good drug-likeness
properties. Therefore, to discover and modify lead compounds
with good activity from natural products has become a main
means of developing HIF-1 inhibitors. Many of natural products
equilibrium [1]
.
Tumor cells are often in a hypoxic microenvironment due to
the abnormal structure and function of their blood vessels. Under
a hypoxic condition, the oxygen-dependent hydroxylation of
HIF-1α is limited, resulting in stabilization of HIF-1α. Then HIF-
1α in the cytoplasm accumulates and translocates to the nucleus
where it dimerizes with HIF-1β to form HIF-1. HIF-1 combines
with transcriptional activator p300/cap binding protein (CBP)
and then binds to the hypoxic response element (HRE) of the
downstream target genes, like vascular endothelial growth factor
and their derivatives reported in recent years have exhibited good
[6-8]
HIF-1 inhibitory activity, such as Moracin O and Moracin P
,
Chaetocin [9, 10], Manassantin A [11-14], Curcumin [15, 16], Caulerpin
[17], Shikonin [18, 19] and Orobanone [20]
.
Lamellarins are a class of marine alkaloids with a pyrrole core
found in many marine organisms, such as molluscs, ascidians,
and sponges. These Alkaloids reported previously can be divided
into two broad categories, pentacyclic condensed scaffold with
Corresponding author. Tel.: +86-0411- 84986200; fax: +86-0411- 84986200; e-mail: wangss@dlut.edu.cn
2

benzopyrano-pyrrolo-isoquinolinone nucleus (type I, including
the influence of the substituents on the aromatic ring (R1 and
R2), the length of the aliphatic carbon chain and the substituent at
the C-7 position (R3) on the HIF-1 inhibitory activity. In this
synthetic approach, 3,4-diarylpyrrole is the key intermediate and
can yield the target products by N-acylation with different acid
chlorides.
type Ia and Ib) and tri-substituted open forms containing a 3,4-
[21]
diaryl substituted pyrrole core (type II
, Figure 1). These
compounds possess a wide range of biological activities,
including cytotoxicity against tumor cells, HIV-1 integrase
inhibition, multidrug resistance reversal activity and
[23]
immunomodulatory activity [22]. In 2007, Liu et al
first
The key intermediate 3,4-diarylpyrrole was prepared
reported two novel lamellarin-like phenolic pyrroles
neolamellarin A and 7-hydroxyneolamellarin A, which showed
good HIF-1 inhibitory potency in a reporter gene assay based on
T47D human breast tumor cells. This type of skeleton consists of
a substituted pyrrole ring, an aliphatic carbon chain and an
aromatic ring (Figure 2), but lacks a carboxyl moiety at the C-2
position of the substituted pyrrole ring and has a different carbon
chain compared to the type II compounds mentioned above, like
lamellarin O and R (Figure 1). Based on this background, M.
Khaled Arafeh et al achieved the first total synthesis of
neolamellarin A in 2009 [24]. Then Jiang et al. designed and
according to the method previously described by Fukuda et al [30]
.
(Scheme 1). Iminodiacetic acid, the low-cost starting material
was esterified and amidated followed by condensation with 4,4’-
dimethoxybenzil (benzil) under basic conditions to obtain 7a and
7b. The target 3,4- diarylpyrrole 8a and 8b were obtained via
high-temperature decarboxylation (Scheme 1).
synthesized a series of neolamellarin A derivatives and
[25-27]
investigated the SAR of their Hsp 90 inhibitory activity
.
However, the SAR and mechanism of these compounds as HIF-
1inhibitors remain unclear up to now.
Scheme 1. Synthesis of 3,4-diaryl pyrroles. Reagents and conditions: (a)
SOCl2, MeOH, -10 °C 0.5 h then r.t. overnight, 99%; (b) Ac2O, Et3N, 0 °C
0.5 h then r.t. 4 h, 82%; (c) 5, NaOMe, MeOH, reflux, 2 h; H2O, reflux, 1 h,
7a: 89%, 7b: 59% ; (d) 2-aminoethan-1-ol, 180 °C, 2 h, 8a: 84%, 8b: 45%.
A series of acyl chlorides with different carbon chain length
were then prepared from carboxylic acids 9a-d, 12, 18, 21 and
oxalyl chloride in anhydrous CH2Cl2 under the catalysis of DMF
(Schemes 2-4), and the crude products were immediately
subjected to the next amidation reaction with 3,4-diarylpyrroles 8
in the presence of n-butyllithium to obtain different methoxy-
substituted derivatives 2d, 2e, 2g, 2i and 2j, followed by
demethylation using boron tribromide to give neolamellarin A (1)
and other hydroxy-substituted derivatives 2f, 2h and 2k (Scheme
2).
Figure 1. Structure of type-II lamellarin-like new type pyrrole alkaloids from
sponge Dendrilla nigra.
In recent years, we have been dedicated to develop excellent
[20, 28,
HIF-1 inhibitors
29]. Neolamellarin A has attracted our
interest due to its unique skeleton and inhibitory potency against
HIF-1. In this work, we synthesized neolamellarin A and its
derivatives, evaluated their effects on HIF-1 by dual-luciferase
reporter assay and investigated their SAR.
Scheme 2. Synthesis of neolamellarin A (1) and compound 2d-k. Reagents
and conditions: (a) oxalyl chloride, DMF, anhydrous CH2Cl2, r.t., 1h; (b) (i)
n-BuLi, THF, -78 °C then r.t. 0.5 h (ii) 10a-d, r.t., 2 h, 2d: 64%, 2e: 73%, 2g:
67%, 2i: 64%; 2j: 69%; (c) BBr3, anhydrous CH2Cl2, 0 °C then r.t. 2.5 h, 2f:
69%, 2h: 63%, 1: 49%; 2k: 48%.
Figure 2. A convergent synthetic approach to neolamellarin A and its
analogues (2).
Using a convergent synthetic strategy (Figure 2), we have
easily prepared neolamellarin A and its derivatives to investigate
3

In order to introduce a trans double bond to change the linking
mode of the aliphatic carbon chains, we synthesized 2l and 2m
with 3,4-bis (4-methoxyphenyl)-1H-pyrrole (8a) and (E)-3-(4-
methoxyphenyl) propenoyl chloride (21) in the presence of
sodium hydride (Scheme 3).
respectively to give benzyloxycarbonyl protected acid chloride
15. P-methoxyphenylacetic acid was esterified, brominated and
substituted
to
obtain
methyl-2-methoxy-2-(4-
methoxyphenyl)acetate 19, then hydrolyzed by LiOH•H2O to
obtain a carboxylic acid, followed by treatment with oxalyl
chloride to give the methoxy-substituted acid chloride 21. 3,4-
bis(4-methoxyphenyl)-1H-pyrrole 8a was amidated with 15 or 21
in the presence of n-butyllithium in anhydrous THF to give 2a or
2c respectively. By palladium-catalyzed reduction, 2a was
converted to a 7-hydroxy substituted derivative 2b (Scheme 4).
We evaluated the hypoxia-induced HIF-1 inhibitory activity of
neolamellarin A and its derivatives using a cell-based dual-
luciferasereporter assay in Hela cells, which expressed both
HRE-dependent firefly luciferase reporter gene and constitutively
CMV-driven Renilla luciferase reporter gene. Inhibition of cell
growth (GI50) of synthetic compounds against Hela cells under
normoxia was determined by MTT assay. Compound 22
(phenoxyacetanilide), a previously reported HIF-1 inhibitor, was
used as a positive control [29]. All of the results are summarized in
Table 1.
Scheme 3. Synthesis of compound 2l and 2m. Reagents and conditions: (a)
oxalyl chloride, DMF, anhydrous CH2Cl2, r.t., 1h; (b) (i) NaH, r.t., 1 h (ii) 21,
DMF, 35 °C, 2 h, 74%; (c) BBr3, anhydrous CH2Cl2, r.t., 2 h, 63%.
The result showed that compound 22 exhibited the best HIF-1
inhibitory activity (IC50 = 6.7 ± 1.1 μM) among all tested
compounds. Although all synthesized compounds exhibited
weaker HIF-1 inhibitory activity than 22, C-7 hydroxy-
substituted analogue 2b (IC50 =11.9 ± 3.6 μM) showed
comparable potency with neolamellarin A (IC50 =10.8 ± 1.0 μM) ,
and specially, these two compounds were much less cytotoxic
against HeLa cells than compound 22 (GI50 of 1: 59.5 ± 0.5 μM
and 2b: 44.2 ± 1.6 μM vs 22: 9.3 ± 1.7 μM) under normoxia
condition.
Finally, we prepared neolamellarin A derivatives with
hydroxyl or methoxyl substituents at the C-7 position to
investigate the effect of the C-7 substituents on HIF-1 inhibitory
activity. According to our convergent synthesis strategy, the acid
chloride intermediates with different substituents at -C is the
Comparing the IC50 values of compounds 1, 2h and 2k (10.8,
18.8 and 14.7 μM, respectively) with different length of aliphatic
chain suggested that a two-carbon aliphatic carbon chain linker
was more favorable to HIF-1 inhibitory activity than a single or
triple carbon chain. In addition, the introduction of a trans-olefine
on the aliphatic chain resulted in a sharp decrease in inhibitory
activity (2l, IC50 > 50 μM), which may be due to the increased
rigidity of the skeleton.
The substituent on the three benzene rings seemed to produce
a noteworthy influence on HIF-1 inhibitory activity. Comparing
the IC50 values of 2j with 2k (26.8 and 14.7 μM), 2g with 2h
(24.4 and 18.8 μM) and 2l with 2m (>100 and 16.6 μM), it
indicated that compounds with p-hydroxyl group exhibit more
potent HIF-1 inhibitory activity than the corresponding
compounds with p-methoxyl groups, whereas their cytotoxic
effects were also higher than those of methoxyl-substituted
derivatives.
In addition, compound 2b, the 7-hydroxy substituted
derivative, showed higher activity than compound 2i (IC50 = 11.9
vs 22.5 μM), suggesting the benefit of 7-hydroxy to HIF-1
inhibition, which was evidenced by the fact that the methylation
of 7-hydroxy of 2b sharply reduced the inhibitory activity (IC50
of 2c > 50 μM). All the compounds we synthesized had no
significant cytotoxicity at the concentrations they effectively
inhibited HIF-1 activation.
Scheme 4. Synthesis of compound 2b and 2c. Reagents and conditions: (a)
TBAB, CHCl3, NaOH, 45 °C, 2.5 h, 49%; (b) CbzCl, TMEDA, CH2Cl2, 0 °C
0.5 h then r.t. 2h, 37%; (c) Oxalyl chloride, DMF, anhydrous CH2Cl2, r.t., 1 h,
99%. (d) SOCl2, MeOH, 0 °C 0.5 h then r.t. 1 h, 99%; (e) AIBN, NBS, CCl4,
80 °C, 4 h, 99%; (f) MeONa, MeOH, 65 °C, 3 h, 81%; (g) LiOH•H2O,
MeOH/H2O, 30 °C, 1 h, 60%; (h) oxalyl chloride, DMF, anhydrous CH2Cl2,
r.t., 1 h, 99%.. (i) (i) n-BuLi, THF, -78 °C then r.t. 0.5 h (ii) 13 or 19, r.t., 2 h,
2a: 40%, 2c: 56%; (j) H2, Pd/C, MeOH/THF, 25 °C, 24 h, 58%.
In conclusion, neolamellarin A, a novel marine pyrrole
alkaloid derived from sponge, has been shown to inhibit hypoxia-
induced HIF-1 activity. In this work, we have succeeded in
synthesizing neolamellarin A and its derivatives by a convergent
synthetic strategy and evaluated their HIF-1 inhibitory potent
using a cell-based dual-luciferasereporter assay in Hela cells. Of
all the compounds, neolamellarin A (1) and its 7-hydroxy
derivative 2b exhibited significant HIF-1 inhibitory activity and
key step. Under
a
strong alkaline condition, p-
methoxybenzaldehyde 13 reacted with chloroform via
condensation reaction to obtain α-hydroxy acid 14, which was
treated with benzyloxycarbonyl chloride and then oxalyl chloride
4

low cytotoxicity. In addition, the SAR study of neolamellarin A
and its analogues provided valuable insights into further
structural optimization of novel pyrrole alkaloids as HIF-1
inhibitors. The action mechanism of neolamellarin A and its
analogues against HIF-1 signal pathway is under study.
Table 1. Inhibition of HIF-1 transcriptional activity in HeLa cell-based HRE and CMV dual-luciferase assay and cell growth
inhibition by MTT assay
Entry
1
Compound
IC50 (µM)a
6.7 ± 1.1
10.8 ± 1.0
11.9 ± 3.6
> 50
GI50 (µM)b
9.3 ± 1.7
59.5 ± 0.5
44.2 ± 1.6
> 100
22
1
2
3
2b
2c
2d
2e
2f
4
5
16.0 ± 2.4
14.6 ± 5.4
16.8 ± 4.2
24.4 ± 1.4
18.8 ± 4.4
22.5 ± 2.4
26.8 ± 4.2
14.7 ± 1.4
> 100
67.1 ± 1.5
> 100
6
7
32.9 ± 0.6
> 100
8
2g
2h
2i
9
76.0 ± 0.6
> 100
10
11
12
13
14
2j
> 100
2k
2l
51.5 ± 1.6
> 100
2m
16.6 ± 2.0
27.3 ± 0.6
a
HeLa cells expressing HRE-dependent firefly luciferase reporter construct (HRE-Luc) and constitutively expressing CMV-driven Renilla luciferase reporter
with SureFECT Transfection Reagent were established with Cignal™ Lenti Reporter (SABiosciences, Frederick, MD) according to the manufacturer’s
instructions. The consensus sequence of HRE was 5′-TACGTGCT-3′ from the erythropoietin gene. Cells stably expressing the HRE-reporter gene were selected
with puromycin. The cells were seeded in 96-well plates and incubated for 12 h, and then treated with serially diluted compounds. After 1 hour of normoxia and
12 hours of hypoxia (1% O2) incubation, the luciferase assay was performed using a Luciferase Assay System (Promega, Madison, WI) according to the
manufacturer’s instructions. The drug concentration required to inhibit the relative light units by 50% (IC50) was determined from semi-logarithmic dose–
response plots, and the results represent means ± SD of triplicate samples.
b HeLa cells were incubated for 60 h with various concentrations (100 nM to 100 μM) of compounds under the normoxic condition, and viable cells were tested
by the MTT assay. The drug concentration required to inhibit cell growth by 50% (GI50) was determined from semi-logarithmic dose–response plots, and results
represent means ± SD of triplicate samples.
Acknowledgments
References and notes
We gratefully acknowledge the financial support of the
National Natural Science Foundation of China (No. 21606036)
and the Fundamental Research Funds for the Central Universities
(DUT16RC(3)007, DUT18LK11).
1.
2.
Y. Xia,H. K. Choi,K. Lee, European Journal of Medicinal
Chemistry. 49(2012)24-40.
https://doi.org/10.1016/j.ejmech.2012.01.033.
G. L. Semenza, Trends in Pharmacological Sciences.
33(2012)207-214. https://doi.org/10.1016/j.tips.2012.01.005.
5

3.
4.
5.
D. Bhattarai,X. Xu,K. Lee, Medicinal Research Reviews.
5(2017)1-39. https://doi.org/10.1002/med.21477.
T. Yu,B. Tang,X. Sun, Yonsei Medical Journal. 58(2017)489-
496. https://doi.org/10.3349/ymj.2017.58.3.489.
H. S. Ban,Y. Uto,M. Won,H. Nakamura, Expert Opinion on
Therapeutic Patents. 26(2016)1-14.
https://doi.org/10.1517/13543776.2016.1146252.
N. T. Dat,X. Jin,K. Lee,Y. S. Hong,Y. H. Kim,J. J. Lee, Journal
of Natural Products. 72(2009)39-43.
18. W. Wang,M. Dai,C. Zhu,J. Zhang,L. Lin,J. Ding,W. Duan,
Bioorganic & Medicinal Chemistry Letters. 19(2009)735-737.
https://doi.org/10.1016/j.bmcl.2008.12.032.
19. Z. Rao,X. Liu,W. Zhou,J. Yi,S. S. Li, European Journal of
Medicinal Chemistry. 46(2011)3934-3941.
https://doi.org/10.1016/j.ejmech.2011.05.065.
20. Y. Li,G. Li,Y. Dong,X. Ma,H. Dong,Q. Wu,W. Zhao, Bioorganic
Chemistry. 85(2019)357-363.
https://doi.org/10.1016/j.bioorg.2019.01.013.
21. D. Imbri,J. Tauber,T. Opatz, Marine Drugs. 12(2014)6142-6177.
https://doi.org/10.3390/md12126142.
22. C. Bailly, Marine Drugs. 13(2015)1105-1123.
https://doi.org/10.3390/md13031105.
23. R. Liu,Y. Liu,Y. D. Zhou,D. G. Nagle, Journal of Natural
Products. 70(2007)1741-1745.
6.
7.
8.
9.
https://doi.org/10.1021/np800491u.
N. Kaur,X. Yan,Y. Jin,T. D. Nguyen,K. Gajulapati,Y. Choi,Y. S.
Hong,J. J. Lee,K. Lee, Cheminform. 40(2009)1879-1881.
https://doi.org/10.1002/chin.200934206.
Y. Xia,Y. Jin,N. Kaur,Y. Choi,K. Lee, European Journal of
Medicinal Chemistry. 46(2011)2386-2396.
https://doi.org/10.1016/j.ejmech.2011.03.022.
C. R. Isham,J. D. Tibodeau,W. Jin,R. Xu,M. M. Timm,K. C.
Bible, Blood. 109(2007)2579-2588.
https://doi.org/10.1021/np070206e.
24. K. M. Arafeh,N. Ullah, Natural Product Communications.
4(2009)925-926.
https://doi.org/10.1182/blood-2006-07-027326.
25. Z. Meng,R. Yin,Y. Zhang,H. Cui,L. Zhang,J. Tao, Journal of
Ocean University of China. 17(2018)967-972.
https://doi.org/10.1007/s11802-018-3530-x.
26. L. Jiang,R. Yin,X. Wang,J. Dai,J. Li,T. Jiang,R. Yu, European
Journal of Medicinal Chemistry. 135(2017)24-33.
https://doi.org/10.1016/j.ejmech.2017.04.019.
27. R. Yin,L. Jiang,S. Wan,T. Jiang, Journal of Ocean University of
China. 14(2015)329-334. https://doi.org/10.1007/s11802-015-
2372-z.
28. G. Li,S. Azuma,S. Sato,H. Minegishi,H. Nakamura, Bioorganic
& Medicinal Chemistry Letters. 25(2015)2624-2628.
https://doi.org/10.1016/j.bmcl.2015.04.088.
29. G. Li,S. Azuma,H. Minegishi,H. Nakamura, Journal of
Organometallic Chemistry. 798(2015)189-195.
https://doi.org/10.1016/j.jorganchem.2015.05.029.
30. Tsutomu Fukuda,Yasuyuki Koga,Masatomo Iwao,,
HETEROCYCLES. 76(2008)1237-1248.
10. K. M. Block,H. Wang,L. Z. Szabo,N. W. Polaske,L. K.
Henchey,R. Dubey,S. Kushal,C. F. Laszlo,J. Makhoul,Z. Song,
Journal of the American Chemical Society. 131(2009)18078-
18088. https://doi.org/10.1021/ja807601b.
11. T. W. Hodges,C. F. Hossain,Y. P. Kim,Y. D. Zhou,D. G. Nagle,
Journal of Natural Products. 67(2004)767-771.
https://doi.org/10.1021/np030514m.
12. C. F. Hossain,Y. P. Kim,S. R. Baerson,L. Zhang,R. K. Bruick,K.
A. Mohammed,A. K. Agarwal,D. G. Nagle,Y. D. Zhou,
Biochemical & Biophysical Research Communications.
333(2005)1026-1033. https://doi.org/10.1016/j.bbrc.2005.05.191.
13. A. C. Kasper,E. J. Moon,X. Hu,Y. Park,C. M. Wooten,H. Kim,W.
Yang,M. W. Dewhirst,J. Hong, Bioorganic & Medicinal
Chemistry Letters. 19(2009)3783-3786.
https://doi.org/10.1016/j.bmcl.2009.04.071.
14. D. Y. Kwon,H. E. Lee,D. H. Weitzel,K. Park,H. L. Sun,C. T.
Lee,T. Stephenson,H. Park,M. C. Fitzgerald,J. T. Chi, Journal of
Medicinal Chemistry. 58(2015)7659-7671.
https://doi.org/10.3987/com-08-s(n)86.
https://doi.org/10.1021/acs.jmedchem.5b01220.
15. H. Choi,Y. S. Chun,S. W. Kim,M. S. Kim,J. W. Park, Molecular
Pharmacology. 70(2006)1664-1671.
Supplementary Material
https://doi.org/10.1124/mol.106.025817.
Supplementary data (Synthesizing procedures and NMR,
HRMS/MS characterization of the compounds mentioned above.
Experimental procedures for cell-based dual-luciferase reporter
gene assay and MTT assay.) associated with this article can be
found in the online version.
16. H. Liu,Y. Liang,L. Wang,L. Tian,R. Song,T. Han,S. Pan,L. Liu,
Plos One. 7(2012)e48075.
https://doi.org/10.1371/journal.pone.0048075.
17. Y. Liu,J. B. Morgan,V. Coothankandaswamy,R. Liu,M. B.
Jekabsons,F. Mahdi,D. G. Nagle,Y. D. Zhou, Journal of Natural
Products. 72(2009)2104-2109.
https://doi.org/10.1021/np9005794.
6

Highlights:
 Neolamellarin A and its twelve
derivatives were designed and
synthesized.
 Brief analysis of the SAR
of Neolamellarin A and its analogues
for HIF-1 inhibition based on a cell-
based dual luciferase reporter assay.
 Neolamellarin A and derivative 2b
showed high HIF-1 inhibitory
activity (IC50 =10.8 ± 1.0 μM and
11.9 ± 3.6 μM, respectively) and low
cytotoxicity.
7