Synthesis and biological evaluation of 2-quinolineacrylamides

Article abstract of DOI:10.1016/j.bmc.2019.115250

A series of C6-substituted N-hydroxy-2-quinolineacrylamides (3–15), with four types of bridging groups have been synthesized. Most of these compounds exhibit antiproliferative activity against A549 and HCT116 cells and Western blot analysis revealed that they are able to inhibit HDAC. Measurement of the HDAC isoform activity of ether-containing compounds showed that compound 9 has distinct HDAC6 selectivity, more than 300-fold over other isoforms. This paper describes the development of 6-aryloxy-N-hydroxy-2-quinolineacrylamides as potential HDAC6 inhibitors.

Full text of DOI:10.1016/j.bmc.2019.115250

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Synthesis and Biological Evaluation of 2-Quinolineacrylamides
Shih-Wei Wang, Mei-Hsiang Lin, Fu-Chun Hsu, Mei-Chuan Chen, Jing-Ping
Liou, Yi-Ting Liu, Shiou-Sheng Chen, Hsueh-Yun Lee
PII:
S0968-0896(19)31375-6
https://doi.org/10.1016/j.bmc.2019.115250
BMC 115250
DOI:
Reference:
To appear in:
Bioorganic & Medicinal Chemistry
Received Date:
Revised Date:
Accepted Date:
15 August 2019
29 November 2019
1 December 2019
Please cite this article as: S-W. Wang, M-H. Lin, F-C. Hsu, M-C. Chen, J-P. Liou, Y-T. Liu, S-S. Chen, H-Y.
Lee, Synthesis and Biological Evaluation of 2-Quinolineacrylamides, Bioorganic & Medicinal Chemistry (2019),
doi: https://doi.org/10.1016/j.bmc.2019.115250
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Synthesis and Biological Evaluation of 2-
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a, b
c
c
d
c
Shih-Wei Wang , Mei-Hsiang Lin , Fu-Chun Hsu , Mei-Chuan Chen , Jing-Ping Liou , Yi-Ting
c
e, f
c, g, *
Liu , Shiou-Sheng Chen and Hsueh-Yun Lee
a
Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung,
b
Taiwan
c
School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan
Ph.D. Program for the Clinical Drug Discovery from Botanical Herbs, College of Pharmacy, Taipei Medical
d
University, Taiwan
e
Department of Urology, National Yang-Ming University School of Medicine, Taipei, Taiwan
f
Division of Urology, Taipei City Hospital HepingFuyou Branch, Taipei, Taiwan
g
Ph.D Program in Biotechnology Research and Development, College of Pharmacy, Taipei Medical University,
Taipei 11031, Taiwan.
Ullmann reaction
improved by N,N-dimethylglycine
Wittig olefination
O
H
N
H3CO
N
OH
O
Compound 9
HDAC6 IC50 = 20.7 nM
Doebner-Miller reaction

Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com
Synthesis and Biological Evaluation of 2-Quinolineacrylamides
a, b
c
c
d
c
c
Shih-Wei Wang , Mei-Hsiang Lin , Fu-Chun Hsu , Mei-Chuan Chen , Jing-Ping Liou , Yi-Ting Liu ,
e, f
c, g, *
Shiou-Sheng Chen and Hsueh-Yun Lee
a
Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
b
c
School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan
d
Ph.D. Program for the Clinical Drug Discovery from Botanical Herbs, College of Pharmacy, Taipei Medical University, Taiwan
Department of Urology, National Yang-Ming University School of Medicine, Taipei, Taiwan
e
f
Division of Urology, Taipei City Hospital HepingFuyou Branch, Taipei, Taiwan
g
Ph.D Program in Biotechnology Research and Development, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan.
ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
A series of C6-substituted N-hydroxy-2-quinolineacrylamides (3-15), with four types of bridging
groups have been synthesized. Most of these compounds exhibit antiproliferative activity against
A549 and HCT116 cells and Western blot analysis revealed that they are able to inhibit HDAC.
Measurement of the HDAC isoform activity of ether-containing compounds showed that
compound 9 has distinct HDAC6 selectivity, more than 300-fold over other isoforms. This paper
describes the development of 6-aryloxy-N-hydroxy-2-quinolineacrylamides as potential HDAC6
inhibitors.
Available online
Keywords:
Histone deacetylase
2
009 Elsevier Ltd. All rights reserved.
2
-Quinolineacrylamide
Ullmann reaction
S
1
. Introduction
H
O
S
O
O
H
N
H
H
H
N
N
In the structure of nucleosomes, histones are wrapped around
N
OH
N
NH
H
HN
O
S
OH
H
O
O
O
O
DNA and covalent binding exists between lysine residues and
O
O
N
H
SAHA
1
H
DNA. The resultant compact structure of the nucleosome helps
O
PXD-101
it fit within the cell nucleus. The acetylation of lysine residues of
the histone masks the covalent binding and consequently, the
condensed DNA is loosened and the replication process is
launched. The acetylation status of the lysines is regulated by two
enzymes: histone acetyltansferase (HAT) and histone deacetylase
FK-228
O
OH
N
N
H
N
H
H
NH
HN OH
O
N
N
S
OH
HN
O2
CH3
O
2
,3
(
HDAC). This acetylation is clearly correlated with epigenetic
LBH589
1
2
modification, which regulates gene expression without changing
DNA sequence. Abnormal epigenetic modification is responsible
Figure 1. FDA-approved and previously synthesized quinoline-containing
4
HDAC inhibitors.
for the development of many diseases including cancer ,
5
6
inflammation , and neurodegenerative diseases. Consequently
HDAC, with its significant role in epigenetic modification is a
therapeutic target. To date, several HDAC inhibitors have entered
the clinic, including SAHA, FK-228, PXD-101, and LBH5897-10
Bioactive
molecules
with
similar
pharmacological
mechanisms share common structural features or moieties. The
recognition of a specific characteristic often opens an avenue for
subsequent relevant research. Because HDAC is a zinc-catalyzed
enzyme, several HDAC inhibitors carrying hydroxamic acid and
(Figure 1). The therapeutic potential of this target has attracted
our attention.
2
-aminobenzamide were designed to interfere with this catalytic
1
1
interaction. The current study took advantage of hydroxamic
acid as the significant moiety in an attempt to develop anti-
HDAC activity. In addition to the zinc-binding motif, HDAC
inhibitors also possess two additional structural features, a linker

part and a surface recognition group, which contribute to the
diverse structures. Quinoline-containing derivatives have been
found to have promising biological properties such as
which were subsequently hydrolyzed by TFA to give the
corresponding hydroxamic acids (3-7).
O
Br
Br
antimalarial,
antibiotic,
antituberculosis,
antiplasmodial,
a
b
1
2-15
R
antitumor and anti-inflammatory activity.
Quinoline has also
NH2
N
CH3
N
CH3
been utilized in the development of HDAC inhibitors; for
instance, Finn et al. synthesized various carbamic acid
derivatives with diverse bicyclic heteroaryl groups including
quinoline, quinoxaline, benzoxazole, and benzothiazole.16 In
addition, our previous study in 2-sulfonylquinolines derived from
the combination of N-hydroxylacrylamide and quinoline found
that compound 1 acts as a potent HDAC inhibitor (Figure 1).17 In
1
6
17
18a: R = 4-F
18b: R = 4-CH3
18c: R = 4-OCH3
18d: R = 3,4-OCH3
18e: R = 3,4,5-OCH3
O
O
c
d
R
R
H
OH
N
N
other
hydroxyaminocarbonyl)benzylamino
−NHCH
work
a
combination
of
the
4-(N-
group
O
O
1
1
9a: R = 4-F
9b: R = 4-CH3
19c: R = 4-OCH3
20a: R = 4-F
20b: R = 4-CH3
20c: R = 4-OCH3
20d: R = 3,4-OCH3
20e: R = 3,4,5-OCH3
(
2
PhCONHOH) with quinoline led to compound 2 as a
1
1
9d: R = 3,4-OCH3
9e: R = 3,4,5-OCH3
potent HDAC6 inhibitor that is able to ameliorate the symptoms
of Alzheimer’s disease.18 These efforts encouraged us to continue
exploration of combinations of quinoline and a zinc-binding
hydroxamic acid motif. In an attempt to define the structural
features of HDAC inhibitors, the quinoline moiety is considered
as a linker part in combination with various replacements at C6
position as the surface recognition group, which provides a series
of C6-substituted N-hydroxy-2-quinolineacrylamides (3-15,
Figure 2). In addition, there are four bridging groups
O
e
R
H
N
N
OH
O
3: R = 4-F
: R = 4-CH3
4
5
: R = 4-OCH3
6: R = 3,4-OCH3
: R = 3,4,5-OCH3
7
Scheme 1. Synthetic approach to the designed 6-aroyl-N-hydroxy-2-
quinolineacrylamides 3-7: a. crotonaldehyde, 6 N HCl, toluene, reflux,
5.5%; b. i. n-BuLi, substituted benzaldehydes, THF, 0 oC to rt; ii. PDC,
molecule sieves, CH Cl , rt, 42-85%; c. SeO , xylene, reflux, 55-95%; d. i.
methyl (triphenylphosphor-anylidene)acetate, CH Cl , rt; ii. KOH, MeOH,
(sulfonamide, carbonyl, ether, and a simple bond) which link the
aryl/heteroaryl motif to the quinoline, which may shed light on
their influence on biological activity. In addition, the biological
activity and mechanism of action of these compounds are
discussed.
1
2
2
2
2
2
reflux, 79-100%; e. i. NH
TFA(aq), MeOH, rt, 9-20%.
2
OTHP, EDC·HCl, TEA, CH
2
Cl
2
, rt; ii. 10%
3
: X = -CO-, R = 4-F
Surface
recognition
area
Zn2+
4: X = -CO-, R = 4-CH3
5: X = -CO-, R = 4-OCH3
-
Linker
binding
6
7
8
9
: X = -CO-, R = 3,4,-OCH3
: X = -CO-, R = 3,4,5-OCH3
: X = -O-, R = 3-OCH3
Br
O
a
b
R
X
N
CH3
N
CH3
: X = -O-, R = 4-OCH3
R
H
N
10: X = -O-, R = 3,4,5-OCH3
N
OH
17
21a: R = 3-OCH3
21b: R = 4-OCH3
1c: R = 3,4,5-OCH3
1d: R = 4-CH(CH3)2
1
1
1
1: X = -O-, R = 4-CH(CH3)2
2: X = -O-, R = 4-NO2
3: X = -SO2NH-, R = 4-OCH3
O
2
2
H3CO
21e: R = 4-NO2
O
O
O
NHOH
NHOH
N
N
R
c
R
H
OH
O
O
O
N
N
O
1
4
15
2
2
2
2
2a: R = 3-OCH3
2b: R = 4-OCH3
2c: R = 3,4,5-OCH3
23a: R = 3-OCH3
23b: R = 4-OCH3
23c: R = 3,4,5-OCH3
23d: R = 4-CH(CH3)2
23e: R = 4-NO2
Figure 1. Designed N-hydroxy-2-quinolineacrylamides (3-15).
2d: R = 4-CH(CH3)2
2
. Results and discussion
22e: R = 4-NO2
2
.1. Chemistry
O
d
R
H
N
The synthesis of compounds 3-7 which possess a carbonyl
N
OH
O
group linking quinoline to a substituted phenyl ring is shown in
Scheme 1. 4-Bromoaniline (16) underwent a Doebner–Miller
reaction with crotonaldehyde under acidic conditions, affording
the corresponding 6-bromo-2-methylquinoline (17). Treatment of
compound 17 with n-BuLi followed by addition of substituted
benzaldehydes generated the corresponding secondary alcohol
which was subjected to oxidation by pyridinium dichromate
8
9
: R = 3-OCH3
: R = 4-OCH3
10: R = 3,4,5-OCH3
1: R = 4-CH(CH3)2
2: R = 4-NO2
1
1
Scheme 2. Synthetic approach to ether-containing N-hydroxy-2-
quinolineacrylamides (8-12): a. substituted phenols, CuI, Cs CO , N,N-
dimethylglycine, DMF, reflux, 64-95%; b. SeO , xylene, reflux, 65-92%; c. i.
methyl (triphenylphosphoranylidene)acetate, CH Cl , rt; ii. KOH, MeOH,
OTHP, EDC·HCl, TEA, CH Cl , rt; ii. 10%
2
3
2
(
PDC) to afford the corresponding 6-aroylquinolines (18a-18e).
2
2
The C2-methyl group of 18a-18e was oxidized by SeO to afford
2
reflux, 70-100%; d. i. NH
TFA(aq), MeOH, rt, 8-33%.
2
2
2
compounds 19a-19e. The resulting compounds underwent Wittig
olefination with methyl (triphenylphosphoranylidene)acetate to
give the acrylates which were subjected to hydrolysis by KOH to
obtain the corresponding carboxylic acid 20a-20e. The amidation
of compounds 20a-20e was carried out using O-(tetrahydro-2H-
The preparation of compounds 8-12, containing an ether
linkage is illustrated in Scheme 2. The reaction of compound 17
with 4-methoxyphenol in the presence of CuBr under Ullmann
conditions generated 21b in 28% yield. The low reaction yield
was also observed in the synthesis of compounds 21a-21e, but
can be overcome by addition of N,N-dimethylglycine while
pyran-2-yl)hydroxylamine (NH
2
OTHP) in the presence of
coupling agents such as EDC·HCl to afford N-protected amides

conducting the Ullmann reaction.19 Compound 17 reacted with
substituted phenols in the presence of CuI and N,N-
dimethylglycine to give compounds 21a-21e with satisfactory
yields. The resulting products underwent subsequent reactions
were subjected to hydrolysis by KOH to obtain the corresponding
carboxylic acids (31a-31b). Amidation of compounds 31a-31b
was carried out using NH OTHP in the presence of coupling
2
agents such as EDC·HCl to afford N-protected amides which
such as oxidation by SeO
conversion into hydroxamic acid similar to that shown in Scheme
to obtain compounds 8-12. Scheme 3 depicts the synthesis of
2
, Wittig olefination, hydrolysis, and
were subsequently hydrolyzed by TFA to give the corresponding
hydroxamic acids 14 and 15.
1
compound 13 which has a sulfonamide linkage between
quinoline and phenyl ring. 6-Nitro-2-methylquinoline (25) was
prepared from 4-nitroaniline (24) via a Doebner–Miller reaction
with crotonaldehyde. The nitro group of 25 was reduced by
palladium-catalyzed hydrogenation, and the corresponding amine
was subjected to a reaction with 4-methoxybenzenesulfonyl
chloride to yield compound 26. The following synthetic route
from compound 26 to the designed N-hydroxyacrylamide (13) is
similar to that used for the conversion of 18a to 3 shown in
Scheme 1.
Table 1. Antiproliferative activity (GI50) of compounds 3-15
and SAHA.
a
GI50 ± SD (μM)
Compd
A549
HCT116
3
4
1.26  0.22
2.58  0.2
1.89  0.2
3.31  0.31
3.35  0.5
4.35  0.07
3.2  0.56
2.43  0.77
3.28  0.18
1.84  0.06
2.51  0.1
2.3  0.1
5
H3CO
O2N
O2N
a
b
H
N
S
6
1.78  0.19
2.62  0.2
2.74  0.26
1.82  0.07
0.74  0.17
4.08  0.46
1.00  0.05
6.68  0.52
1.47  0.29
1.56  0.18
0.44  0.03
NH2
N
CH3
O2
N
CH3
7
24
25
26
8
H3CO
H3CO
H
N
H
c
d
N
9
S
S
O2
O2
H
OH
N
N
10
O
O
28
27
1
1
H3CO
12
1
.63  0.23
H
e
N
S
H
N
1
3
4.31  0.13
2.35  1.12
1.92  0.49
2.62  1.37
O2
N
OH
O
14
15
13
Scheme 3. Synthetic approach to compound 13: a. crotonaldehyde, 6 N
HCl, toluene, reflux, 55.8%; b. i. Pd/C,
methoxybenzenesulfonyl chloride, pyridine, CH
H
2
,
MeOH, rt; ii. 4-
SAHAb
2
Cl
2
, rt, 55.9%; c. SeO ,
2
xylene, reflux, 67.1%; d. i. methyl (triphenylphosphoranylidene)acetate,
Tubastatin
>
5
> 5
c
CH
CH
2
Cl
Cl
2
, rt; ii. KOH, MeOH, reflux, 28.3%; e. i. NH
, rt; ii. 10% TFA(aq), MeOH, rt, 20.5%.
2
OTHP, EDC·HCl, TEA,
A
a
2
2
SD: standard deviation. All experiments were independently performed at
b
c
least three times. data from reference 20. data from reference 21.
Br
Br
R
a
b
H
N
CH3
N
H
N
2
.2. Biological evaluation
O
O
17
29
3
3
0a: R = 4-methoxyphenyl
0b: R = 3-furanyl
The synthesized compounds (3-15) were tested for their
antiproliferative activity in two cell lines, A549 and HCT116
(Table 1). The results showed that most of this series of
compounds have similar cellular activity with GI50 values in
single digit μM range. Among them, compound 10 with an ether
bridge linking 3,4,5-trimethoxyphenyl group to quinoline had the
most potent antiproliferative activity against the growth of
HCT116 cells with an GI50 value of 0.74 μM. The 3,4,5-
trimethoxyphenyl moiety of 10 contributed to slight increase of
antiproliferative activity as compared with 9 which has a 4-
methoxyphenyl group. The effect of substitution on cellular
activity is ambiguous. The result from compounds 5, 9, 13, and
R
R
c
d
H
OH
N
N
N
OH
O
O
3
3
1a: R = 4-methoxyphenyl
1b: R = 3-furanyl
14: R = 4-methoxyphenyl
15: R = 3-furanyl
Scheme 4. Synthetic approach to the designed 6-aryl-N-hydroxy-2-
quinolineacrylamides (14 and 15): a. SeO , xylene, reflux, 60.3%; b.
Pd(PPh , 4-methoxyphenylboronic acid or furan-3-ylboronic acid, TBAB,
O, MW, 120 oC, 66-80%%; c. i. methyl
CO dioxane,
triphenylphosphoranyl-idene)acetate, CH Cl , rt; ii. KOH, MeOH, reflux,
9-44%; d. i. NH OTHP, EDC·HCl, TEA, CH Cl , rt; ii. 10% TFA(aq)
MeOH, rt, 42-62%.
2
3 4
)
K
2
3
,
H
2
(
2
2
1
4, which all possess 4-methoxyphenyl group at C6 position of
2
2
2
2
,
quinoline revealed that the sulfonamide linkage of 13 led to a
2
2
slight loss of activity. The discovery of ACY1215 and
2
3
tubastatin A as HDAC6 inhibitors, specifically ACY1215 is
undergoing clinical trials, has drawn numerous scientific efforts
to seek HDAC isoform inhibitors. Considering cellular activity
and the structural features, compounds 9, 10, 12, and 14 were
subject to an examination of HDAC selectivity using HDAC1, 2,
The preparation of compounds 14 and 15 is shown in Scheme
Compound 17 was oxidized by SeO to yield the
corresponding aldehyde (29). The subsequent Suzuki reaction of
9 with (4-methoxyphenyl)boronic acid and furan-3-ylboronic
acid in the presence of Pd(PPh with the assistance of
microwave radiation yielded compounds 30a and 30b. The
resulting compounds underwent Wittig olefination with methyl
triphenylphosphoranylidene)acetate to give the acrylates which
4
.
2
2
3 4
)
6
, and 8 (Table 2). In the classification of HDAC isoforms,
HDAC1, 2, and 8 belong to class I HDAC, while HDAC6 is a
2
4
class IIb HDAC. The results showed that 9, 10, 12, and 14
(
possess distinct inhibitory activity against HDAC6 over the other

three isoforms. Compound 9 showed remarkable HDAC6
selectivity, and is more than 483-fold and 374-fold selective over
HDAC1 or HDAC8, respectively. Compound 10, with a 3,4,5-
trimethoxyphenoxy moiety also showed marked HDAC2
inhibitory activity with an IC50 value of 18.7 nM, but it lacks
selectivity toward specific HDAC isoforms. Comparison of 9 and
hydroxamic acid motif also forms a hydrogen bond with His573
and Gly582 (green dashed lines). The quinoline moiety has three
π-π interactions (magenta dashed lines) with adjacent amino
acids (phe583, His 614, and Phe643). Notably, the hydroxamic
acid has no interaction with the zinc ion of HDAC1 and HDAC2
(see supporting information Figure S1), which explains HDAC6
selectivity of compounds 9 and 10.
1
4 revealed that the removal of the ether linkage led to a decrease
of selectivity. H3 and tubulin have been identified as substrates
2
5
3. Conclusion
of HDAC , for instance, class I HDACs and HDAC6 are
respresponsible for deacetylation of Ac-H3 and Ac-tubulin in
cells, respectively. Therefore, compounds 9, 10, 12, and 14 were
tested for their influence on the expression of acetylated H3 and
acetylated tubulin, in an effort to understand their HDAC
inhibitory activity (Figure 3). As shown in Figure 3, treatment
with 9, 10, 12, and 14 led to the increase of acetylation status of
H3 and tubulin in a dose-dependent manner, which indicates that
This study is a continuation of our previous studies on
development of quinoline-containing HDAC inhibitors to design
a series of N-hydroxy-2-quinolineacrylamides (3-15) and to
investigate the influence of linkages such as sulfonamide,
carbonyl and ether on biological activity. Some copper- and
palladium-mediated reactions were utilized to construct the
corresponding bridging groups. Notably, the presence of N,N-
dimethylglycine improved the Ullmann reaction, which helps to
produce ether-containing compounds 8-12 in satisfactory yields.
The results of biological assays revealed that compound 10
exhibited the most potent antiproliferative activity against
HCT116 cell lines with a GI50 value of 0.74 μM. The mechanism
of action was shown to involve inhibition of HDAC. Detailed
examination of the enzymatic activity of ether-containing
compounds 9, 10, 12, and 14 revealed that compound 9 has
remarkable HDAC6 selectivity over other HDAC isoforms.
These findings assist the development of 6-aryloxy-N-hydroxy-2-
quinolineacrylamides as potential HDAC6 inhibitors that may be
used for the corresponding indications.
9
, 10, 12, and 14 are able to inhibit HDAC. Upregulated
acetylated tubulin was also observed after treatment with
compounds 9, 10, 12, and 14. The extent of the compound 9 is
most pronounced, and this is consistent with the data shown in
Table 2. In addition, despite the HDAC6 selectivity of 9 is
weaker than that of tubastatin A, 9 exhibited distinct cellular
activity (Table 1).
Figure 3. Effect of α-tubulin acetylation and histone H3 acetylation in
cultured human colorectal cancer HCT116 cells by compounds 9, 10, 12,
and 14 using Western blot analysis.
a
Table 2. Inhibitory activity (IC50, nM ) of compounds 9, 10,
b
1
2, and 14 against HDAC1, 2, 6, and 8 (selectivity ratio is
shown in brackets).
HDAC isoform
Compound
HDAC1
HDAC2
HDAC6
20.7
HDAC8
>
10000
7750
(374)
NCc
9
(> 438)
1
770
67)
18.7
(0.7)
2820
(106)
1
0
2
4
26.5
51.4
49.0
13.7
(
6
050
2320
(45)
1
1
NC
(118)
Figure 4. Docking pose of compound 9 (yellow) and 10 (blue) in the
1
310
27)
4770
(97)
binding site of HDAC6 (green, PDB ID: 6CGP).
NC
(
Tubastatin
> 10000
> 10000
(> 729)
NTe
4. Experimental section
d
A
(
> 729)
4
.1. Chemistry
Nuclear magnetic resonance ( H NMR and 13C NMR) spectra
Trichostatin
A
17.9
18.7
(5)
650
3
600
1
(5)
(181)
aIC50 values displayed the result of a single experiment. Selectivity ratio:
selectivity ratio of HDAC subtypes over HDAC6. NC: no curve, which
b
were obtained with a Bruker DRX-300 spectrometer operating at
300 MHz and at 75 MHz, respectively. Chemical shifts are
reported in parts per million (ppm, δ) downfield from TMS as an
internal standard. High-resolution mass spectra (HRMS) were
recorded with a JEOL (JMS-700) mass spectrometer. The
purities of the final compounds were determined using an Agilent
c
indicates no inhibition or compound activity that could not be fit to an IC50
d
e
curve. data from reference 21. NT: not tested.
To understand the interaction of compounds 9 and 10 with
HDAC6, we docked 9 and 10 into the available crystal structures
of HDAC6 (PDB ID: 6CGP, Figure 4), using Discovery
Studio2017 R2. The result shows that the N-hydroxycinnamate
moiety of 9 and 10 is able to insert into a narrow cavity of
HDAC6. In addition to interaction with the zinc ion, the
1
100 series HPLC system with a C-18 column (Agilent
ZORBAX Eclipse XDB-C18 5 μm, 4.6 mm × 150 mm). Flash
column chromatography was conducted using silica gel (Merck
Kieselgel 60, No. 9385, 230−400 mesh ASTM). All reactions
2
were conducted under an atmosphere of dry N .

4
.1.1. (E)-3-(6-(4-Fluorobenzoyl)quinolin-2-yl)-N-
4.1.5. (E)-N-hydroxy-3-(6-(3,4,5-
trimethoxybenzoyl)quinolin-2-yl)acrylamide (7)
hydroxyacrylamide (3)
The title compound was obtained in 9.6% overall yield from
The title compound was obtained in 17.5% overall yield from
compound 20a in a manner similar to that described for the
compound 20e in a manner similar to that described for the
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 7.16 (d, J
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 3.79 (s,
=
15.6 Hz, 1H), 7.40-7.47 (m, 2H), 7.67 (d, J = 15.3 Hz, 1H),
3
7
8
1
H), 3.81 (s, 6H), 7.12-7.19 (m, 3H), 7.67 (d, J = 15.6 Hz, 1H),
.88 (d, J = 8.7 Hz, 1H), 8.12 (s, 2H), 8.46 (s, 1H), 8.65 (d, J =
7
9
1
1
1
.87-7.96 (m, 3H), 8.00-8.16 (m, 2H), 8.39 (s, 1H), 8.60 (d, J =
.0 Hz, 1H). C NMR (75 MHz, DMSO-d ): δ = 115.67, 115.96,
6
1
3
1
3
.7 Hz, 1H). C NMR (75 MHz, DMSO-d
6
): δ = 56.09, 60.21,
22.38, 125.95, 126.76, 129.31, 129.64, 131.36, 132.73, 132.85,
33.57, 133.61, 134.76, 137.35, 139.00, 148.84, 155.61, 161.68,
07.57, 122.32, 125.87, 126.82, 129.19, 129.81, 131.35, 131.99,
o
134.97, 137.38, 139.06, 141.63, 148.77, 152.72, 155.50, 194.12.
66.52, 193.91. mp: 186.2-186.6 C. HRMS (ESI) for
o
mp: 140.2-140.7 C. HRMS (ESI) for C22
H
19
N
2
O
6
(M-H) calcd
C
19
H
12FN
2
O
3
(M-H) calcd 335.0832, found 335.0830.
4
07.1243, found 407.1240.
4
.1.2. (E)-N-hydroxy-3-(6-(4-methylbenzoyl)quinolin-2-
yl)acrylamide (4)
4
.1.6. (E)-N-hydroxy-3-(6-(3-
methoxyphenoxy)quinolin-2-yl)acrylamide (8)
The title compound was obtained in 14.4% overall yield from
compound 20b in a manner similar to that described for the
The title compound was obtained in 32.5% overall yield from
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 2.43 (s,
compound 23a in a manner similar to that described for the
3
H), 7.16 (d, J = 15.6 Hz, 1H), 7.41 (d, J = 7.8 Hz, 2H), 7.67 (d,
J = 15.6 Hz, 1H), 7.74 (d, J = 8.4 Hz, 2H), 7.88 (d, J = 8.4 Hz,
H), 8.00-8.15 (m, 2H), 8.36 (d, J = 1.2 Hz, 1H), 8.60 (d, J = 8.4
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 3.76 (s,
3
=
7
H), 6.67-6.75 (m, 2H), 6.81 (dd, J = 2.4, 8.4 Hz, 1H), 7.05 (d, J
15.6 Hz, 1H), 7.35 (t, J = 8.1 Hz, 1H), 7.42 (d, J = 2.7 Hz, 1H),
.56 (dd, J = 2.4, 8.4 Hz, 1H), 7.61 (d, J = 15.6 Hz, 1H), 7.76 (d,
1
1
3
Hz, 1H). C NMR (75 MHz, DMSO-d
1
1
6
): δ = 21.20, 30.68,
22.33, 125.82, 126.73, 129.26, 129.66, 130.01, 131.11, 134.28,
35.13, 137.37, 138.90, 143.38, 148.76, 155.47, 194.88, 206.47.
J = 8.4 Hz, 1H), 8.03 (d, J = 9.3 Hz, 1H), 8.34 (d, J = 8.4 Hz,
1
3
o
1H). C NMR (75 MHz, DMSO-d
6
): δ = 55.36, 105.57, 110.17,
15 2 3
mp: 176.9-177.5 C. HRMS (ESI) for C20H N O (M-H) calcd
1
1
11.44, 112.73, 121.66, 123.98, 124.84, 128.70, 130.40, 130.80,
3
31.1083, found 331.1082.
36.98, 137.14, 143.37, 151.91, 155.48, 156.90, 160.90, 161.80.
4
.1.3. (E)-N-Hydroxy-3-(6-(4-
o
mp: 159.8-160.5 C. HRMS (ESI) for C19
H
15
N
2
O
4
(M-H) calcd
methoxybenzoyl)quinolin-2-yl)acrylamide (5)
3
35.1032, found 335.1032.
A mixture of compound 20c (0.1 g, 0.3 mmol), NH
2
OTHP
4
.1.7. (E)-N-hydroxy-3-(6-(4-
(
0.04 g, 0.34 mmol), EDC·HCl (0.12 g, 0.63 mmol),
triethylamine (0.06 g, 0.59 mmol), and DCM (10 mL) was stirred
at rt for 3 h. The reaction was quenched with H O and extracted
methoxyphenoxy)quinolin-2-yl)acrylamide (9)
2
The title compound was obtained in 14.0% overall yield from
with DCM. The organic layer was collected and dried to afford a
crude product. The resulting residue was dissolved in MeOH (5
mL), and then 10% TFA (2 mL) was added. The resulting
mixture was stirred at rt for 1 day. The organic solvent was
removed under reduced pressure followed by addition of DCM.
The precipitate was collected by filtration and washed with DCM
compound 23b in a manner similar to that described for the
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 3.78 (s,
3
9
8
H), 7.00-7.16 (m, 5H), 7.24 (d, J = 2.7 Hz, 1H), 7.56 (dd, J = 2.7,
.3 Hz, 1H), 7.61 (d, J = 15.6 Hz, 1H), 7.75 (d, J = 8.7 Hz, 1H),
13
.01 (d, J = 9.0 Hz, 1H), 8.32 (d, J = 8.4 Hz, 1H). C NMR (75
MHz, DMSO-d
6
): δ = 55.54, 110.85, 115.42, 121.55, 121.61,
1
to afford compound 5 (0.02 g, 19.1%). H NMR (300 MHz,
1
1
23.49, 128.78, 130.37, 137.06, 148.56, 151.58, 151.60, 156.34,
DMSO-d
6
): δ = 3.88 (s, 3H), 7.11-7.19 (m, 3H), 7.67 (d, J = 15.3
o
57.05, 158.19, 158.68, 161.93. mp: 136.1-136.7 C. HRMS
(M-H) calcd 335.1032, found 335.1031.
Hz, 1H), 7.83-7.90 (m, 3H), 8.00-8.15 (m, 2H), 8.35 (s, 1H), 8.60
(ESI) for C19
H
15
N
2
O
4
1
3
(
d, J = 8.7 Hz, 1H). C NMR (75 MHz, DMSO-d
6
): δ = 55.66,
1
1
1
14.07, 122.28, 125.86, 126.77, 129.10, 129.36, 129.82, 130.61,
4
.1.8. (E)-N-hydroxy-3-(6-(3,4,5-
32.39, 135.64, 137.34, 138.90, 148.53, 155.31, 161.70, 163.19,
trimethoxyphenoxy)quinolin-2-yl)acryl-amide (10)
o
93.86. mp: 171.8-172.5 C. HRMS (ESI) for C20
H
15
N
2
O
4
(M-H)
The title compound was obtained in 19.2% overall yield from
calcd 347.1032, found 347.1033.
compound 23c in a manner similar to that described for the
preparation of 5: H NMR (300 MHz, CD
3.79 (s, 6H), 6.49 (s, 2H), 7.06 (d, J = 15.6 Hz, 1H), 7.38 (d, J =
1
3
OD): δ = 3.78 (s, 3H),
4
.1.4. (E)-3-(6-(3,4-dimethoxybenzoyl)quinolin-2-
yl)-N-hydroxyacrylamide (6)
2
1
=
9
1
.4 Hz, 1H), 7.66 (d, J = 2.4, 9.3 Hz, 1H), 7.77 (d, J = 15.6 Hz,
The title compound was obtained in 14.9% overall yield from
H), 7.90 (d, J = 8.7 Hz, 1H), 8.08 (d, J = 9.3 Hz, 1H), 8.45 (d, J
compound 20d in a manner similar to that described for the
13
8.7 Hz, 1H). C NMR (75 MHz, DMSO-d
6
): δ = 56.14, 60.25,
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 3.83 (s,
8.02, 111.70, 121.64, 123.47, 124.41, 128.79, 130.73, 134.51,
36.86, 137.59, 143.71, 151.54, 151.94, 153.93, 156.17, 162.07.
3
H), 3.88 (s, 3H), 7.12-7.19 (m, 2H), 7.40-7.46 (m, 2H), 7.67 (d,
J = 15.3 Hz, 1H), 7.88 (d, J = 8.4 Hz, 1H), 8.00-8.15 (m, 2H),
.37 (d, J = 1.8 Hz, 1H), 8.60 (d, J = 8.4 Hz, 1H). 13C NMR (75
MHz, DMSO-d ): δ = 55.57, 55.84, 110.83, 111.98, 122.27,
25.20, 125.74, 126.74, 129.10, 129.26, 129.81, 130.60, 135.64,
38.80, 148.59, 148.76, 153.12, 155.30, 193.85. mp: 141.8-142.4
19 2 6
HRMS (ESI) for C21H N O (M-H) calcd 395.1243, found
3
8
95.1240.
6
1
1
o
4
.1.9. (E)-N-hydroxy-3-(6-(4-
isopropylphenoxy)quinolin-2-yl)acrylamide (11)
C. HRMS (ESI) for C21
77.1136.
17 2 5
H N O (M-H) calcd 377.1137, found
The title compound was obtained in 8.2% overall yield from
3
compound 23d in a manner similar to that described for the

1
preparation of 5: H NMR (300 MHz, DMSO-d
6.9 Hz, 6H), 2.80-2.97 (m, 1H), 7.00-7.10 (m, 3H), 7.30-7.37
m, 3H), 7.54 (dd, J = 2.7, 9.0 Hz, 1H), 7.60 (d, J = 15.6 Hz, 1H),
.74 (d, J = 8.7 Hz, 1H), 8.01 (d, J = 9.6 Hz, 1H), 8.32 (d, J = 8.4
6
): δ = 1.22 (d, J
128.07, 128.27, 129.45, 131.16, 136.43, 138.43, 140.79, 144.93,
145.09, 152.47, 161.74. mp: 172.0-172.7 C. HRMS (ESI) for
C H N O (M-H) calcd 279.0770, found 279.0769.
16 11 2 3
o
=
(
7
1
3
Hz, 1H). C NMR (75 MHz, DMSO-d
12.12, 119.47, 121.69, 123.67, 124.43, 128.02, 128.67, 130.68,
6
): δ = 23.97, 32.81,
4.1.14. 6-Bromo-2-methylquinoline (17)
mixture of 4-bromoaniline (3.0 g, 17.5 mmol),
1
1
A
36.73, 144.47, 151.89, 153.62, 155.86, 158.04, 158.54, 161.90.
crotonaldehyde (1.3 g, 18.6 mmol), 6 N HCl (60 mL, 360 mmol),
and toluene (3 mL) was heated to reflux for 2 h. The reaction
mixture was cooled and neutralized with aqueous NaOH. The
resulting mixture was extracted with EtOAc, and then the organic
o
mp: 136.9-138.5 C. HRMS (ESI) for C21
H
19
N
2
O
3
(M-H) calcd
3
47.1396, found 347.1395.
4
.1.10. (E)-N-hydroxy-3-(6-(4-
nitrophenoxy)quinolin-2-yl)acrylamide (12)
layer was purified by column chromatography to afford
1
compound 17 (0.6 g, 15.5%). H NMR (300 MHz, DMSO-d
6
): δ
The title compound was obtained in 28.7% overall yield from
= 3.33 (s, 3H), 7.44 (d, J = 8.4 Hz, 1H), 7.76-7.90 (m, 2H), 8.10-
compound 23e in a manner similar to that described for the
8.22 (m, 2H).
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 7.08 (d, J
=
(
1
(
15.6 Hz, 1H), 7.29 (d, J = 9.3 Hz, 2H), 7.61-7.67 (m, 2H), 7.74
d, J = 2.7 Hz, 1H), 7.81 (d, J = 8.4 Hz, 1H), 8.11(d, J = 9.0 Hz,
H), 8.29 (d, J = 9.3 Hz, 2H), 8.39 (d, J = 8.7 Hz, 1H). 13C NMR
75 MHz, DMSO-d ): δ = 116.21, 118.44, 121.87, 124.69, 125.24,
4.1.15. (4-Fluorophenyl)(2-methylquinolin-6-
yl)methanone (18a)
The title compound was obtained in 48.6% overall yield from
6
compound 17 in a manner similar to that described for the
1
1
26.33, 128.71, 131.17, 137.19, 137.38, 142.93, 144.45, 153.00,
53.05, 161.88, 162.20. mp: 139.9-140.4 C. HRMS (ESI) for
1
preparation of 18c: H NMR (300 MHz, CDCl
3
): δ = 2.82 (s, 3H),
o
7
7
.16-7.23 (m, 2H), 7.39 (d, J = 8.4 Hz, 1H), 7.85-7.91 (m, 2H),
.80-8.20 (m, 4H).
C
18
H
12
N
3
O
5
(M-H) calcd 350.0777, found 350.0779.
4
.1.11. (E)-N-Hydroxy-3-(6-((4-
4
.1.16. (2-Methylquinolin-6-yl)(p-tolyl)methanone
methoxyphenyl)sulfonamido)quinolin-2-
yl)acrylamide (13)
(
18b)
The title compound was obtained in 84.6% overall yield from
The title compound was obtained in 20.5% overall yield from
compound 17 in a manner similar to that described for the
compound 28 in a manner similar to that described for the
1
1
preparation of 18c: H NMR (300 MHz, CDCl
3
): δ = 2.46 (s, 3H),
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 3.75 (s,
2
7
.87 (s, 3H), 7.32 (d, J = 8.1 Hz, 2H), 7.42 (d, J = 8.4 Hz, 1H),
.75 (d, J = 8.1 Hz, 2H), 8.14 (dd, J = 1.8, 8.7 Hz, 1H), 8.20-8.30
(m, 3H).
3
1
=
H), 6.90-7.10 (m, 3H), 7.50-7.64 (m, 3H), 7.71 (d, J = 8.4 Hz,
H), 7.77 (d, J = 8.7 Hz, 2H), 7.87 (d, J = 9.3 Hz, 1H), 8.31 (d, J
1
3
6
8.7 Hz, 1H), 10.65 (s, 1H). C NMR (75 MHz, DMSO-d ): δ =
5
1
2
3
5.72, 114.60, 121.70, 124.52, 125.09, 128.25, 129.14, 129.39,
4
.1.17. (4-Methoxyphenyl)(2-methylquinolin-6-
30.85, 136.89, 137.51, 143.33, 151.94, 161.87, 162.74. mp:
yl)methanone (18c)
o
02.7-203.4 C. HRMS (ESI) for C19
98.0811, found 398.0812.
16 3 5
H N O S (M-H) calcd
o
n-BuLi (2.5 M in hexane, 3.78 mL) was added dropwise at -78 C
to a solution of compound 17 (2.1 g, 9.5 mmol) in THF (80 mL)
then stirred at the same temperature for 1 h. The resulting
solution was added slowly to a prepared solution of 4-
methoxybenzaldehyde (1.3 g, 9.6 mmol) in THF (80 mL) at 0 C.
The solution was stirred at the same temperature for 1 h and then
4
.1.12. (E)-N-Hydroxy-3-(6-(4-
methoxyphenyl)quinolin-2-yl)acrylamide (14)
o
The title compound was obtained in 42.4% overall yield from
compound 31a in a manner similar to that described for the
preparation of 5: H NMR (300 MHz, DMSO-d
1
2
quenched with H O. The resulting mixture was extracted with
6
): δ = 3.88 (s,
EtOAc and the organic layer was collected and dried. The
resulting residue was dissolved in DCM (50 mL) and then
pyridinium dichromate (PDC, 4.69 g, 12.5 mmol) and 4 Å
molecular sieves (equal quantity to PDC) were added at rt. After
stirring at rt for 6 h, the reaction mixture was filtered through a
pad of Celite and the filtrate was purified by flash
3
7
2
=
1
1
H), 7.11 (d, J = 9.0 Hz, 2H), 7.22 (d, J = 15.6 Hz, 1H), 7.77-
.88 (m, 3H), 8.20 (d, J = 8.4 Hz, 2H), 8.37 (dd, J = 1.8, 7.8 Hz,
H), 8.92 (d, J = 8.7 Hz, 1H). 1 C NMR (75 MHz, DMSO-d
3
6
): δ
55.31, 114.69, 121.37, 124.29, 126.10, 127.85, 128.21, 128.34,
30.03, 131.10, 138.66, 138.93, 152.44, 158.26, 158.75, 159.59,
o
61.62. mp: 181.3-182.8 C. HRMS (ESI) for C19
H
17
N
2
O
3
1
+
chromatography to afford 18c (1.23 g, 46.7%). H NMR (300
(M+H ) calcd 321.1239, found 321.1238.
MHz, CDCl
H), 7.33 (d, J = 8.7 Hz, 1H), 7.84 (d, J = 8.7 Hz, 2H), 8.00-8.16
(m, 4H).
3
): δ = 2.76 (s, 3H), 3.87 (s, 3H), 6.96 (d, J = 9.0 Hz,
2
4
.1.13. (E)-3-(6-(Furan-3-yl)quinolin-2-yl)-N-
hydroxyacrylamide (15)
The title compound was obtained in 61.5% overall yield from
4
.1.18. (3,4-Dimethoxyphenyl)(2-methylquinolin-6-
compound 31b in a manner similar to that described for the
yl)methanone (18d)
1
preparation of 5: H NMR (300 MHz, DMSO-d
6
): δ = 7.08 (d, J
The title compound was obtained in 43.4% overall yield from
=
15.6 Hz, 1H), 7.13 (d, J = 0.9 Hz, 1H), 7.64 (d, J = 15.3 Hz,
compound 17 in a manner similar to that described for the
1
1
H), 7.79-7.83 (m, 2H), 8.00 (d, J = 9.0 Hz, 1H), 8.09 (dd, J =
.8, 9.0 Hz, 1H), 8.21 (s, 1H), 8.38-8.42 (m, 2H). 13C NMR (75
1
preparation of 18c: H NMR (300 MHz, CDCl
3
): δ = 2.83 (s, 3H),
3
.95 (s, 3H), 3.97 (s, 3H), 6.92 (d, J = 8.4 Hz, 1H), 7.38-7.43 (m,
6
MHz, DMSO-d ): δ = 108.77, 121.55, 123.48, 125.23, 125.90,

2
8
H), 7.52 (d, J = 1.8 Hz, 1H), 8.08 (dd, J = 1.8, 8.7 Hz, 1H),
.16-8.21 (m, 3H).
4.1.25. (E)-3-(6-(4-Fluorobenzoyl)quinolin-2-
yl)acrylic acid (20a)
4
.1.19. (2-Methylquinolin-6-yl)(3,4,5-
The title compound was obtained in 100% overall yield from
trimethoxyphenyl)methanone (18e)
compound 19a in a manner similar to that described for the
1
The title compound was obtained in 42.6% overall yield from
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 7.08 (d,
compound 17 in a manner similar to that described for the
J = 15.9 Hz, 1H), 7.40-7.50 (m, 2H), 7.74 (d, J = 15.9 Hz, 1H),
7.90-7.96 (m, 2H), 8.00-8.19 (m, 3H), 8.39 (d, J = 1.5 Hz, 1H),
8.61 (d, J = 8.4 Hz, 1H).
1
preparation of 18c: H NMR (300 MHz, CDCl
3
): δ = 3.87 (s, 6H),
3
1
.96 (s, 3H), 7.09 (s, 2H), 7.44 (d, J = 8.4 Hz, 1H), 8.14 (dd, J =
.8, 8.7 Hz, 1H), 8.20-8.28 (m, 3H). H NMR (75 MHz, CDCl ):
3
1
3
δ = 25.55, 56.30, 60.94, 107.75, 122.99, 125.49, 128.83, 129.52,
4.1.26. (E)-3-(6-(4-Methylbenzoyl)quinolin-2-
yl)acrylic acid (20b)
1
1
30.75, 132.56, 134.84, 137.22, 142.17, 149.37, 152.92, 161.54,
95.10.
The title compound was obtained in 97.8% overall yield from
compound 19b in a manner similar to that described for the
4
.1.20. 6-(4-Fluorobenzoyl)quinoline-2-
1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.33 (s,
carbaldehyde (19a)
3
H), 7.07 (d, J = 15.9 Hz, 1H), 7.40 (d, J = 9.3 Hz, 2H), 7.71-
The title compound was obtained in 55.9% overall yield from
7.78 (m, 3H),8.00-8.18 (m, 3H), 8.36 (d, J = 1.8 Hz, 1H), 8.60 (d,
J = 8.4 Hz, 1H).
compound 18a in a manner similar to that described for the
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 7.19-7.26 (m,
2
1
1
H), 7.89-7.95 (m, 2H), 8.12 (d, J = 8.4 Hz, 1H), 8.21 (dd, J =
.8, 8.7 Hz, 1H), 8.29 (d, J = 1.8 Hz, 1H), 8.37-8.45 (m, 2H),
0.28 (s, 1H).
4.1.27. (E)-3-(6-(4-Methoxybenzoyl)quinolin-2-
yl)acrylic acid (20c)
A
mixture of 19c (0.33 g, 1.1 mmol), methyl
triphenylphosphor-anylidene)acetate (0.38 g, 1.1 mmol), and
DCM was heated under reflux for 1 h. The reaction was
quenched with H O and extracted with DCM. The organic layer
(
4
.1.21. 6-(4-Methylbenzoyl)quinoline-2-
carbaldehyde (19b)
2
The title compound was obtained in 94.9% overall yield from
was collected and dried under reduced pressure. The resulting
residue was dissolved in MeOH (15 mL) and 1 N KOH (2.5 mL)
was added. The reaction mixture was heated to reflux for 1 h,
then cooled to rt, and neutralized by HCl followed by extraction
with EtOAc. The organic layer was collected and dried under
compound 18b in a manner similar to that described for the
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 2.48 (s, 3H),
7
.34 (d, J = 8.1 Hz, 2H), 7.78 (d, J = 8.1 Hz, 2H), 8.11 (d, J =8.4
Hz, 1H), 8.23 (dd, J = 1.8, 8.7 Hz, 1H), 8.30 (d, J = 1.5 Hz, 1H),
.38-8.45 (m, 2H), 10.30 (s, 1H).
1
8
reduced pressure to obtain compound 20c (0.3 g, 79.0%). H
NMR (300 MHz, DMSO-d
Hz, 1H), 7.13 (d, J = 8.7 Hz, 2H), 7.75 (d, J = 15.9 Hz, 1H), 7.84
d, J = 8.7 Hz, 2H), 8.00-8.10 (m, 2H), 8.16 (d, J = 9.0 Hz, 1H),
6
): δ = 3.88 (s, 3H), 7.07 (d, J = 15.9
4
.1.22. 6-(4-Methoxybenzoyl)quinoline-2-
carbaldehyde (19c)
(
8
.36 (d, J = 1.5 Hz, 1H), 8.60 (d, J = 8.4 Hz, 1H).
The title compound was obtained in 77.4% overall yield from
compound 18c in a manner similar to that described for the
4
.1.28. (E)-3-(6-(3,4-Dimethoxybenzoyl)quinolin-2-
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 3.91 (s, 3H),
yl)acrylic acid (20d)
7
.01 (d, J = 8.7 Hz, 2H), 7.88 (d, J = 8.7 Hz, 2H), 8.09 (d, J = 8.4
Hz, 1H), 8.18 (dd, J = 1.8, 8.7 Hz, 1H), 8.34 (d, J = 9.0 Hz, 1H),
The title compound was obtained in 84.9% overall yield from
8
.40 (d, J = 8.4 Hz, 1H), 10.25 (s, 1H).
compound 19d in a manner similar to that described for the
1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.83 (s,
4
.1.23. 6-(3,4-Dimethoxybenzoyl)quinoline-2-
3H), 3.87 (s, 3H), 7.00-7.15 (m,2H), 7.39-7.45 (m, 2H), 7.76 (d,
J = 15.9 Hz, 1H), 8.05-8.19 (m, 3H), 8.38 (s, 1H), 8.63 (d, J = 8.4
Hz, 1H).
carbaldehyde (19d)
The title compound was obtained in 94.3% overall yield from
compound 18d in a manner similar to that described for the
4
2
.1.29. (E)-3-(6-(3,4,5-Trimethoxybenzoyl)quinolin-
-yl)acrylic acid (20e)
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 3.97 (s, 3H),
3
1
.99 (s, 3H), 6.93 (d, J = 8.4 Hz, 1H), 7.41 (dd, J = 1.5, 8.4 Hz,
H), 7.56 (d, J = 1.5 Hz, 1H), 8.12 (d, J = 8.4 Hz, 1H), 8.20 (dd,
The title compound was obtained in 90.9% overall yield from
J = 1.8, 8.7 Hz, 1H), 8.29 (d, J = 1.8 Hz, 1H), 8.39-8.47 (m,2H),
compound 19e in a manner similar to that described for the
1
1
0.31 (s, 1H).
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.79 (s,
3
H), 3.81 (s, 6H), 7.02 (d, J = 15.3 Hz, 1H), 7.10-7.13 (m, 2H),
7.75 (d, J = 15.9 Hz, 1H), 8.05 (d, J = 8.7 Hz, 1H), 8.13-8.16
m,2H), 8.47 (s, 1H), 8.66 (d, J = 8.7 Hz, 1H).
4
.1.24. 6-(3,4,5-Trimethoxybenzoyl)quinoline-2-
carbaldehyde (19e)
(
The title compound was obtained in 92.8% overall yield from
4
.1.30. 6-(3-Methoxyphenoxy)-2-methylquinoline
compound 18e in a manner similar to that described for the
(
21a)
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 3.87 (s, 6H),
3
1
.97 (s, 3H), 7.11 (s, 2H), 8.11 (d, J = 8.4 Hz, 1H), 8.20 (dd, J =
.8, 8.7 Hz, 1H), 8.31-8.44 (m, 3H), 10.26 (d, J = 0.6 Hz, 1H).
The title compound was obtained in 78.0% overall yield from
compound 17 in a manner similar to that described for the

1
preparation of 21b: H NMR (300 MHz, MeOD): δ = 2.69 (s,
H), 3.77 (s, 3H), 6.61-6.66 (s, 2H), 6.73-6.78 (m, 1H), 7.26-7.32
m, 2H), 7.39 (d, J = 8.4 Hz, 1H), 7.48 (dd, J = 2.7, 9.3 Hz, 1H),
The title compound was obtained in 91.7% overall yield from
3
(
compound 21b in a manner similar to that described for the
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 3.85 (s, 3H),
7
.95 (d, J = 9.3 Hz, 1H), 8.10 (d, J = 8.4 Hz, 1H).
6.97 (d, J = 9.3 Hz, 2H), 7.00-7.12 (m, 3H), 7.23 (d, J = 8.4 Hz,
H), 7.57 (dd, J = 2.7, 9.3 Hz, 1H), 7.96 (d, J = 8.7 Hz, 1H), 8.07
(d, J = 8.4 Hz, 1H), 8.19 (d, J = 9.3 Hz, 1H), 10.18 (s, 1H).
1
4
.1.31. 6-(4-Methoxyphenoxy)-2-methylquinoline
(
21b)
4
.1.37. 6-(3,4,5-Trimethoxyphenoxy)quinoline-2-
A
mixture of compound 17 (0.6 g, 2.7 mmol), 4-
CO (2.4 g, 7.4 mmol),
carbaldehyde (22c)
methoxyphenol (0.36 g, 2.9 mmol), Cs
2
3
CuI (0.06 g, 0.3 mmol), N,N-dimethylglycine (0.3 g, 1.0 mmol),
and DMF (6.0 mL) was heated to 100 C under microwave
The title compound was obtained in 83.0% overall yield from
o
compound 21c in a manner similar to that described for the
1
radiation for 10 min. The reaction was quenched with H
2
O (15
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 3.80 (s, 6H),
mL) and extracted with EtOAc (3 x 15 mL). The organic layer
3.86 (s, 3H), 6.37 (s, 2H), 7.19 (d, J = 2.7 Hz, 1H), 7.56 (dd, J =
2.7, 9.3 Hz, 1H), 7.95 (d, J = 8.7 Hz, 1H), 8.11 (d, J = 8.4 Hz,
1H), 8.19 (d, J = 9.3 Hz, 1H), 10.15 (s, 1H).
was collected and purified by column chromatography to afford
1
compound 21b (0.65 g, 90.0%). H NMR (300 MHz, CDCl
3
): δ =
2
3
.71 (s, 3H), 3.83 (s, 3H), 6.92 (d, J = 9.3 Hz, 2H), 7.00-7.10 (m,
H), 7.23 (d, J = 8.4 Hz, 1H), 7.42 (dd, J = 2.7, 8.7 Hz, 1H), 7.86
4.1.38. 6-(4-Isopropylphenoxy)quinoline-2-
carbaldehyde (22d)
(d, J = 8.4 Hz, 1H), 7.97 (d, J = 8.7 Hz, 1H).
The title compound was obtained in 65.8% overall yield from
4
.1.32. 2-Methyl-6-(3,4,5-
compound 21d in a manner similar to that described for the
trimethoxyphenoxy)quinoline (21c)
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 1.28 (s, 3H),
The title compound was obtained in 64.3% overall yield from
1.30 (s, 3H), 2.89-3.10 (m, 1H), 7.06 (d, J = 8.7 Hz, 2H), 7.18 (d,
J = 2.7 Hz, 1H), 7.29 (d, J = 8.7 Hz, 2H), 7.59 (dd, J = 2.7, 9.3
Hz, 1H), 7.97 (d, J = 8.4 Hz, 1H), 8.11 (d, J =8.7 Hz, 1H), 8.22
(d, J = 9.0 Hz, 1H), 10.20 (s, 1H).
compound 17 in a manner similar to that described for the
1
preparation of 21b: H NMR (300 MHz, CDCl
3
): δ = 2.85 (s, 3H),
3
7
.80 (s, 6H), 3.86 (s, 3H), 6.33 (s, 2H), 7.21 (d, J = 2.4 Hz, 1H),
.34 (d, J = 8.4 Hz, 1H), 7.53 (dd, J = 2.4, 9.0 Hz, 1H), 8.07 (d, J
=
8.4 Hz, 1H), 8.29 (d, J = 6.9 Hz, 1H).
4.1.39. 6-(4-Nitrophenoxy)quinoline-2-
carbaldehyde (22e)
4
.1.33. 6-(4-Isopropylphenoxy)-2-methylquinoline
The title compound was obtained in 88.6% overall yield from
(
21d)
compound 21e in a manner similar to that described for the
1
The title compound was obtained in 95.0% overall yield from
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 7.17 (d, J =
compound 17 in a manner similar to that described for the
9.0 Hz, 2H), 7.47 (d, J = 2.7 Hz, 1H), 7.61 (dd, J = 2.7, 9.3 Hz,
1H), 8.06 (d, J = 8.4 Hz, 1H), 8.24 (d, J = 8.7 Hz, 1H), 8.29 (d, J
= 9.3 Hz, 2H), 8.34 (d, J = 9.3 Hz, 1H), 10.24 (s, 1H).
1
preparation of 21b: H NMR (300 MHz, CDCl
3
): δ = 1.25 (s, 3H),
1
2
2
1
.28 (s, 3H), 2.74 (s, 3H), 2.85-3.00 (m, 1H), 7.00 (d, J = 8.4 Hz,
H), 7.18 (d, J = 2.7 Hz, 1H), 7.20-7.30 (m, 3H), 7.45 (dd, J =
.7, 9.0 Hz, 1H), 7.91 (d, J = 8.4 Hz, 1H), 8.04 (d, J = 9.3 Hz,
H).
4.1.40. (E)-3-(6-(3-Methoxyphenoxy)quinolin-2-
yl)acrylic acid (23a)
The title compound was obtained in 99.1% overall yield from
4
.1.34. 2-Methyl-6-(4-nitrophenoxy)quinoline (21e)
compound 22a in a manner similar to that described for the
1
The title compound was obtained in 64.9% overall yield from
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.74 (s,
compound 17 in a manner similar to that described for the
3H), 6.67-6.75 (m, 2H), 6.78-6.83 (m, 1H), 6.95 (d, J = 15.9 Hz,
1H), 7.32-7.42 (m, 2H), 7.55 (dd, J = 2.7, 9.3 Hz, 1H), 7.69 (d, J
= 15.9 Hz, 1H), 7.90 (d, J = 8.7 Hz, 1H), 8.05 (d, J = 9.0 Hz, 1H),
8.32 (d, J = 8.7 Hz, 1H).
1
preparation of 21b: H NMR (300 MHz, CDCl
3
): δ = 2.79 (s, 3H),
.08 (d, J = 9.3 Hz, 2H), 7.34 (d, J = 8.4 Hz, 1H), 7.40-7.49 (m,
H), 8.02 (d, J = 8.7 Hz, 1H), 8.16 (d, J = 9.0 Hz, 1H), 8.23 (d, J
7
2
=
9.3 Hz, 2H).
4
.1.41. (E)-3-(6-(4-Methoxyphenoxy)quinolin-2-
yl)acrylic acid (23b)
4
.1.35. 6-(3-Methoxyphenoxy)quinoline-2-
carbaldehyde (22a)
The title compound was obtained in 99.3% overall yield from
The title compound was obtained in 90.0% overall yield from
compound 21a in a manner similar to that described for the
compound 22b in a manner similar to that described for the
1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.78 (s,
1
3H), 7.00-7.24 (m, 6H), 7.53 (dd, J = 2.7, 9.0 Hz, 1H), 7.69 (d, J
= 15.9 Hz, 1H), 7.87 (d, J = 8.7 Hz, 1H), 8.03 (d, J = 9.0 Hz, 1H),
8.27 (d, J = 8.4 Hz, 1H).
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 3.81 (s, 3H),
.69-6.82 (m, 3H), 7.24 (d, J = 2.7 Hz, 1H), 7.32 (t, J = 8.1 Hz,
H), 7.59 (dd, J = 2.7, 9.0 Hz, 1H), 7.98 (d, J = 8.7 Hz, 1H), 8.12
6
1
(
1
d, J = 8.4 Hz, 1H), 8.21 (d, J = 9.0 Hz, 1H), 10.18 (d, J = 0.9 Hz,
H).
4
.1.42. (E)-3-(6-(3,4,5-
Trimethoxyphenoxy)quinolin-2-yl)acrylic acid (23c)
4
.1.36. 6-(4-Methoxyphenoxy)quinoline-2-
The title compound was obtained in 99.1% overall yield from
compound 22c in a manner similar to that described for the
carbaldehyde (22b)

1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.66 (s,
4.1.48. (E)-3-(6-((4-
methoxyphenyl)sulfonamido)quinolin-2-yl)acrylic
acid (28)
3
H), 3.72 (s, 6H), 6.51 (s, 2H), 6.94 (d, J = 15.9 Hz, 1H), 7.37 (d,
J = 3.0 Hz, 1H), 7.54 (dd, J = 3.0, 9.0 Hz, 1H), 7.69 (d, J = 15.9
Hz, 1H), 7.89 (d, J = 8.7 Hz, 1H), 8.04 (d, J = 9.0 Hz, 1H), 8.33
The title compound was obtained in 28.3% overall yield from
(d, J = 8.7 Hz, 1H).
compound 27 in a manner similar to that described for the
1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.75 (s,
4
.1.43. (E)-3-(6-(4-Isopropylphenoxy)quinolin-2-
3
H), 6.92 (d, J = 15.9 Hz, 1H), 7.03 (d, J = 8.7 Hz, 2H), 7.53 (dd,
yl)acrylic acid (23d)
J = 2.4, 9.0 Hz, 1H), 7.60-7.70 (m, 2H), 7.78 (d, J = 8.7 Hz, 2H),
7.80-7.93 (m, 2H), 8.30 (d, J = 8.7 Hz, 1H).
The title compound was obtained in 70.9% overall yield from
compound 22d in a manner similar to that described for the
preparation of 20c: H NMR (300 MHz, MeOD): δ = 1.26 (d, J =
1
4.1.49. 6-Bromoquinoline-2-carbaldehyde (29)
6
(
2
=
.6 Hz, 6H), 2.85-3.00 (m, 1H), 6.90 (d, J = 16.2 Hz, 1H), 7.02
d, J = 8.4 Hz, 2H), 7.18 (d, J = 2.7 Hz, 1H), 7.28 (d, J = 8.7 Hz,
H), 7.49 (dd, J = 2.7, 9.0 Hz, 1H), 7.72-7.52 (m, 2H), 8.00 (d, J
A mixture of compound 17 (1.28 g, 5.8 mmol), SeO
.7 mmol), and xylene (13 mL) was heated to reflux for 4 h. The
reaction mixture was filtered to remove SeO and the resulting
2
(0.96 g,
8
2
9.0 Hz, 1H), 8.11 (d, J = 8.7 Hz, 1H).
filtrate was purified by column chromatography to afford
1
compound 29 (0.82 g, 60.3%). H NMR (300 MHz, CDCl
3
): δ =
4
.1.44. (E)-3-(6-(4-Nitrophenoxy)quinolin-2-
7
.89 (dd, J = 2.1, 9.0 Hz, 1H), 8.00-8.13 (m, 3H), 8.22 (d, J = 8.4
yl)acrylic acid (23e)
Hz, 1H), 10. 20 (s, 1H).
The title compound was obtained in 85.0% overall yield from
compound 22e in a manner similar to that described for the
4.1.50. 6-(4-Methoxyphenyl)quinoline-2-
carbaldehyde (30a)
1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 6.99 (d,
J = 16.2 Hz, 1H), 7.28 (d, J = 9.3 Hz, 2H), 7.65 (dd, J = 2.7, 9.3
Hz, 1H), 7.68-7.75 (m, 2H), 7.98 (d, J = 8.7 Hz, 1H), 8.14 (d, J =
The title compound was obtained in 79.3% overall yield from
compound 29 in a manner similar to that described for the
9
.3 Hz, 1H), 8.28 (d, J = 9.3 Hz, 2H), 8.39 (d, J = 8.4 Hz, 1H).
1
preparation of 30b: H NMR (300 MHz, CDCl
3
): δ = 3.88 (s, 3H),
7
3
.05 (d, J = 8.7 Hz, 2H), 7.69 (d, J = 8.7 Hz, 2H), 8.01-8.10 (m,
H), 8.26-8.35 (m, 2H), 10.23 (d, J = 0.9 Hz, 1H).
4
.1.45. 2-Methyl-6-nitroquinoline (25)
The title compound was obtained in 55.8% overall yield from
4
.1.51. 6-(Furan-3-yl)quinoline-2-carbaldehyde
compound 24 in a manner similar to that described for the
1
(30b)
preparation of 17: H NMR (300 MHz, CDCl
3
): δ = 2.80 (s, 3H),
7
.44 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 9.3 Hz, 1H), 8.21 (d, J = 8.4
A mixture of 29 (0.7 g, mmol), furan-3-ylboronic acid (0.35 g,
mmol), Pd(PPh (0.21 g, mmol), TBAB (0.13 g, mmol), K CO
1.2 g, mmol), H O (5.25 mL), and dioxane (10.5 mL) was
placed in a sealed tube and irradiated by microwaves at 120 C
for 20 min. The reaction mixture was filtered and the filtrate was
Hz, 1H), 8.43 (dd, J = 2.7, 9.3 Hz, 1H), 8.73 (d, J = 2.4 Hz, 1H).
3
)
4
2
3
(
2
4
.1.46. 4-Methoxy-N-(2-methylquinolin-6-
o
yl)benzenesulfonamide (26)
A mixture of compound 25 (0.4 g, 2.1 mmol), a catalytic
amount of Pd/C, and MeOH (10 mL) was stirred under hydrogen
at rt for 2 h. The reaction was filtered to remove the Pd/C, and
then the resulting filtrate was dried under reduced pressure to
afford a gray solid. The resulting solid was dissolved in DCM (10
mL), and then 4-methoxybenzenesulfonyl chloride (0.48 g, 2.3
mmol) and pyridine (0.18 mL, 2.2 mmol) were added and the
mixture was stirred for 1 h. The reaction mixture was filtered and
purified by column chromatography to obtain compound 30b
1
(0.44 g, 66.0%). H NMR (300 MHz, CDCl
3
): δ = 6.86 (dd, J =
0.9, 2.1 Hz, 1H), 7.56 (t, J = 1.5 Hz, 1H), 7.93-8.00 (m, 3H), 8.04
(d, J = 8.4 Hz, 1H), 8.25 (d, J = 8.4 Hz, 1H), 8.29 (d, J = 8.4 Hz,
1H), 10.23 (s, 1H).
4
.1.52. (E)-3-(6-(4-Methoxyphenyl)quinolin-2-
yl)acrylic acid (31a)
the filtrate was purified by column chromatography to afford
The title compound was obtained in 43.1% overall yield from
1
compound 26 (0.39 g, 55.9%). H NMR (300 MHz, CDCl
3
): δ =
compound 30a in a manner similar to that described for the
2
8
1
.71 (s,3H), 3.75 (s, 3H), 6.83 (d, J = 8.7 Hz, 2H), 7.24 (d, J =
.4 Hz, 1H), 7.43 (d, J = 2.4, 9.0 Hz, 1H), 7.57 (d, J = 2.1 Hz,
H), 7.75 (d, J = 9.0 Hz, 2H), 7.88-7.96 (m, 2H).
1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 3.81 (s,
3
8
H), 7.00-7.12 (m, 3H), 7.64 (d, J = 15.6 Hz, 1H), 7.79 (d, J =
.7 Hz, 2H), 7.84 (d, J = 8.7 Hz, 1H), 8.00-8.15 (m, 2H), 8.25 (d,
J = 1.8 Hz, 1H), 8.49 (d, J = 8.4 Hz, 1H).
4
.1.47. N-(2-Formylquinolin-6-yl)-4-
methoxybenzenesulfonamide (27)
4
.1.53. (E)-3-(6-(Furan-3-yl)quinolin-2-yl)acrylic
acid (31b)
The title compound was obtained in 67.1% overall yield from
compound 26 in a manner similar to that described for the
The title compound was obtained in 29.5% overall yield from
1
preparation of 29: H NMR (300 MHz, CDCl
3
): δ = 3.78 (s, 3H),
compound 30b in a manner similar to that described for the
6
.89 (d, J = 9.0 Hz, 2H), 7.56 (dd, J = 2.4, 9.0 Hz, 1H), 7.63 (d, J
1
preparation of 20c: H NMR (300 MHz, DMSO-d
6
): δ = 7.04 (d,
=
2.4 Hz, 1H), 7.85 (d, J = 9.0 Hz, 2H), 7.96 (d, J = 8.4 Hz, 1H),
J = 15.9 Hz, 1H), 7.13 (dd, J = 0.9, 1.8 Hz, 1H), 7.75 (d, J = 16.2
Hz, 1H), 7.82 (t, J = 1.8 Hz, 1H), 8.00-8.16 (m, 3H), 8.24 (d, J =
8
.08-8.18 (m, 2H), 10.14 (s, 1H).
1
.8 Hz, 1H), 8.40-8.46 (m, 2H).

4
4
.2. Biology
cells. Thus, the Western blot results leaded to strong elevation of
both Ac-histone H3 and Ac-tubulin and easily to underestimate
the selectivity toward HDAC6 of compound 9. A similar effect
can be observed in the increased-levels of Ac-histone H3 and Ac-
tubulin between compound 9 and compound 10. The different
exposure times of compound 9 and 10 caused more significant
expression level of Ac-tubulin in compound 10 (0.6 μM)-treated
group than compound 9 (0.6 μM)-treated one. However, the
relative fold increase of compound 10 (0.6 μM)/control was not
higher than compound 9 (0.6 μM)/control. The level of Ac-
tubulin was much higher in control/compound 10 than
control/compound 9 since the exposure time is shorter in
DMSO/compound 9-treated cells.
.2.1. Cell culture
The colon cancer cell line HCT116 and non-small cell lung
cancer cell line A549 were maintained in RPMI 1640 medium
containing 10% fetal bovine serum, 100 units/mL penicillin, 100
μg/mL streptomycin and 2.5 μg/mL amphotericin B. Cells were
cultured in tissue culture flasks in a humidified incubator at 37 C,
in an atmosphere of 5% CO
o
2
and 95% air.
4
.2.2. Sulforhodamine B (SRB) Assays
Counted cells were seeded in 96-well plates in medium with
% FBS. After 24 h, cells were fixed with 10% trichloroacetic
5
acid (TCA) to represent the cell population at the time of
compound addition (T ). After additional incubation of DMSO or
4.2.4. HDAC enzyme inhibition assays
0
Enzyme inhibition assays were conducted by the Reaction
Biology Corporation, Malvern, PA. Compounds were dissolved
in DMSO and tested in at least 10-dose IC50 mode with 3-fold
serial dilution starting at 10 μM. HDAC Control Compound
trichostatin A was tested in a 10-dose IC50 with 3-fold serial
dilution starting at 10 μM.
test compound for 48 h, cells were fixed with 10% TCA and then
stained with SRB at 0.4 % (w/v) in 1% AcOH. Unbound SRB
was washed out by 1% AcOH and SRB-containing cells were
solubilized with 10 mM Trizma base. The absorbance was
measured at a wavelength of 515 nm. Using the following
absorbance measurements, such as time zero (T
0
), control growth
), the
(C), and cell growth in the presence of the compound (T
x
Acknowledgments
percentage of growth was calculated at each of the compound
concentration levels. Growth inhibition of 50% (GI50) was
calculated from the equation [(T -T )/(C-T )] x 100 = 50, which
i z z
provides the compound concentration resulting in a 50%
reduction in the net protein increase (as measured by SRB
staining) in control cells during the incubation with the
compound.
This research were supported by the Ministry of Science and
Technology, Taiwan (grant no. MOST 105-2320-B-038-010) and
Taipei Medical University grant (TMU104-AE1-B17)
References and notes
4
.2.3. Western blot analysis
1
.
Luger, K.; Mäder, A. W.; Richmond, R. K.; Sargent, D. F.;
Richmond, T. J. Nature 1997, 389, 251-260.
Chen, H. P.; Zhao, Y. T.; Zhao, T. C. Crit. Rev. Oncog. 2015, 20,
35-47
Kuo, M. H.; Allis, C. D. BioEssays 1998, 20, 615-626.
Lakshmaiah, K. C.; Jacob, L. A.; Aparna, S.; Lokanatha, D.;
Saldanha, S. C. J. Cancer Res. Ther. 2014, 10, 469-478.
Blanchard, F.; Chipoy, C. Drug Discov. Today. 2005, 10, 197-204.
Zhang, L.; Sheng, S.; Qin, C. J. Alzheimers Dis. 2013, 33, 283-
295.
HCT116 cells were treated with 0.1% DMSO or indicated test
2.
compound at 0.6, 1.25, 2.5, 5, 10, 20 μM in RPMI 1640
supplemented with 10% FBS for 48 h. The cells were then
collected in ice-cold lysis buffer [10 mmol/L Tris-HCl (pH 7.4),
3
4
.
.
1
50 mmol/L NaCl,
1
mmol/L EGTA,
1
mmol/L
5
6
.
.
phenylmethylsulfonyl fluoride, 10 mg/mL aprotinin, 10 mg/mL
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Supplementary Material
Supplementary material that may be helpful in the review
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Conflicts of interest
There are no conflicts to declare.