Synthesis and antiproliferative evaluation of amide-containing flavone and isoflavone derivatives

Article abstract of DOI:10.1016/j.bmc.2008.07.013

Certain amide-containing flavone and isoflavone derivatives were synthesized and evaluated for their antiproliferative activities. These compounds were synthesized via alkylation of hydroxyl precursors followed by the reaction with H₂SO₄ and NaN₃ (Schmidt reaction). The preliminary assays indicated that the inhibitory activity against the growth of NCI-H661 decreased in an order of linked chromophore flavone-6-yl 16a-d > flavone-7-yl 17a-d > flavone-3-yl 15a-d and isoflavone-7-yl 18a-d. Among these flavone-6-yl derivatives, N-(4-methoxyphenyl)-2-(4-oxo-2-phenyl-4H-chromen-6-yloxy)acetamide (16c) was the most potent with a GI₅₀ value of 0.84 μM. The inhibitory activity against the growth of NPC-TW01 decreased in an order of linked chromophore flavone-6-yl 16a-d > isoflavone-7-yl 18a-d > flavone-7-yl 17a-d > flavone-3-yl 15a-d. Flavone-6-yl derivatives 16a-d demonstrated significant inhibitory activities against the growth of NPC-TW01 cell with an average GI₅₀ value of 0.84 μM. The oxime derivatives 1 and 2 caused accumulation of NPC-TW01 cell in G₂/M phase which were distinct from that of their amide isomers 16b and 16c, respectively, which induced cell-cycle arrest in G₀/G₁ phase followed by apoptosis. Therefore, the antiproliferative mechanism of flavone derivatives was affected not only by the phenyl benzopyran-4-one pharmacophore but also by the peripheral substituents.

Full text of DOI:10.1016/j.bmc.2008.07.013

Bioorganic & Medicinal Chemistry 16 (2008) 7639–7645
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Synthesis and antiproliferative evaluation of amide-containing flavone
and isoflavone derivatives
I-Li Chen a, Jhy-Yih Chen a, Po-Chuen Shieh a, Jih-Jung Chen a, Choa-Hsun Lee b,
a,
Shin-Hun Juang b,c, , Tai-Chi Wang
*
*
a Department of Pharmacy, Tajen University, Pingtung 907, Taiwan
b School of Pharmacy, China Medical University, Taichung 404, Taiwan
c Department of Medical Research, China Medical University Hospital, Taichung 404, Taiwan
a r t i c l e i n f o
a b s t r a c t
Article history:
Certain amide-containing flavone and isoflavone derivatives were synthesized and evaluated for their
antiproliferative activities. These compounds were synthesized via alkylation of hydroxyl precursors fol-
lowed by the reaction with H2SO4 and NaN3 (Schmidt reaction).
The preliminary assays indicated that the inhibitory activity against the growth of NCI-H661 decreased
in an order of linked chromophore flavone-6-yl 16a–d > flavone-7-yl 17a–d > flavone-3-yl 15a–d and iso-
flavone-7-yl 18a–d. Among these flavone-6-yl derivatives, N-(4-methoxyphenyl)-2-(4-oxo-2-phenyl-4H-
Received 4 June 2008
Revised 3 July 2008
Accepted 4 July 2008
Available online 10 July 2008
Keywords:
chromen-6-yloxy)acetamide (16c) was the most potent with a GI50 value of 0.84 lM. The inhibitory activity
Antiproliferative activity
Cytotoxicity
Apoptosis
against the growth of NPC-TW01 decreased in an order of linked chromophore flavone-6-yl 16a–d > isoflav-
one-7-yl 18a–d > flavone-7-yl 17a–d > flavone-3-yl 15a–d. Flavone-6-yl derivatives 16a–d demonstrated
significant inhibitory activities against the growth of NPC-TW01 cell with an average GI50 value of
Flavone
0.84 lM. The oxime derivatives 1 and 2 caused accumulation of NPC-TW01 cell in G2/M phase which were
Isoflavone
distinct from that of their amide isomers 16b and 16c, respectively, which induced cell-cycle arrest in G0/G1
phase followed by apoptosis. Therefore, the antiproliferative mechanism of flavone derivatives was affected
not only by the phenyl benzopyran-4-one pharmacophore but also by the peripheral substituents.
Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction
ethoxy]-2-phenyl-4H-1-benzopyran-4-one (2) exhibited signifi-
cant antiproliferative activities.24 To further explore and optimize
Flavonoidsand isoflavonoids are polyphenolic compoundswhich
have been found in plants and dietary components such as fruits, soy
beans, vegetables, and red wine. Their extensive biological activities
including anticancer,1–8 antifungal,9 antiviral,10 anti-inflamma-
tory,11 antioxidant,12,13 cardiovascular,14–18 and anti-osteoporotic
effects19,20 have attracted substantial attentions. Although the skel-
eton of phenyl benzopyran-4-one pharmacophore plays an impor-
tant role in biological effects of flavonoid and isoflavonoid
derivatives, the type of peripheral substituents is also crucial. For
example, isoflavones containing a sulfur or oxygen hinge with an
amine-bearing side chain are potential selective estrogen receptor
modulators,6 while substitution of 2-pyridylmethylthio or 2-thioaz-
ole group on isoflavone pharmacophore enhanced aromatase inhib-
itory activity.7,8 Recently, we have reported preparation of certain
oxime-bearing flavone and isoflavone derivatives and investigated
for their antiproliferative activities.21–24 Among them, (Z)-6-[2-
hydroxyimino-2-(4-fluorophenyl)ethoxy]-2-phenyl-4H-1-benzo-
pyran-4-one (1) and (Z)-6-[2-hydroxyimino-2-(4-methoxyphenyl)-
antiproliferative effects, the present report describes the prepara-
tion of isomeric amide derivatives of 1 and 2 on the ground that a
number of biologically active compounds possess the amide func-
tional moiety.25–27 To establish a detailed structure–activity rela-
tionship (SAR), other amide-containing flavone and isoflavone
derivatives have also been synthesized for evaluation.
OH
N
O
O
R
Ο
1
2
: R = F
: R = OMe
R
O
O
O
N
H
Ο
* Corresponding authors. Tel.: +886 8 7624002x315; fax: +886 8 7625308.
E-mail address: tcwang@mail.tajen.edu.tw (T.-C. Wang).
Amide isomers
0968-0896/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2008.07.013

7640
I-Li Chen et al. / Bioorg. Med. Chem. 16 (2008) 7639–7645
exception of N-(biphenyl-4-yl)-2-(4-oxo-2-phenyl-4H-chromen-7-
yloxy)acetamide (17d), which was more active than that of 16d
(GI50 values of 1.28 and 9.71 M, respectively). Among these fla-
vone-6-yl derivatives, N-(4-methoxyphenyl)-2-(4-oxo-2-phenyl-
4H-chromen-6-yloxy)acetamide (16c) was the most potent with a
2. Chemistry
l
The preparation of amide-containing flavone and isoflavone
derivatives is illustrated in Scheme 1. Alkylation of 3-hydroxyflav-
one with 2-bromo-1-(naphthalen-2-yl)ethanone gave 3-(2-(naph-
thalen-2-yl)-2-oxoethoxy)-2-phenyl-4H-chromen-4-one (3), which
was then treated with H2SO4 and NaN3 to afford N-(naphthalen-2-
GI50 value of 0.84
NPC-TW01 decreased in an order of linked chromophore flavone-
6-yl 16a–d (GI50 values of 1.26, 0.74, 0.71, and 0.64 M, respec-
lM. The inhibitory activity against the growth of
l
yl)-2-(4-oxo-2-phenyl-4H-chromen-3-yloxy)acetamide (11) in
a
tively) > isoflavone-7-yl 18a–d > flavone-7-yl 17a–d > flavone-3-yl
15a–d with an exception of N-(4-fluorophenyl)-2-(4-oxo-3-phe-
nyl-4H-chromen-7-yloxy)acetamide (18b), which was more active
than that of 16b (GI50 values of 0.55 and 0.74 lM, respectively).
All the four flavone-6-yl derivatives demonstrated significant inhib-
good overall yield. The same synthetic procedures were applied
for the synthesis of 12–14 from their respective ketone precursor
4, 5, and 6, respectively. Accordingly, 15a–d, 16a–d, 17a–d, and
18a–d were prepared from 7a–d, 8a–d, 9a–d, and 10a–d,
respectively.24
itory activities against the growth of NPC-TW01 cell with an average
GI50 value of 0.84 lM. Our data have shown that derivatives of fla-
3. Pharmacological results and discussion
vone-3-yl were inactive against the growth of three cells tested
probably due to the steric effect between C-2 phenyl and C-3 substi-
tuent, which hindered the coplanar formation of the molecule. In
addition, the peripheral substituent of naphthalen-2-yl is not favor-
able for both flavone and isoflavone chromophores in which com-
pounds 11–14 were inactive. Results from this study have shown
that the most preferred pharmacophore is flavone-6-yl and two of
the most active substituents (R group) are 4-F-Ph and 4-MeO-Ph.
Although a slightly different antiproliferative efficacy of 16b and
16c against the growth of NCI-H661 and MT-2 was observed, similar
GI50 values were identified for both compounds against the growth
of NPC-TW01. Thus, 16b and 16c along with their respective oxime
isomers 1 and 2 were further evaluated on their effects of cell-cycle
distribution and the results are summarized in Table 2. The oxime
derivatives 1 and 2 caused accumulation of NPC-TW01 cell in G2/
M phase which were similar to that of genistein (an isoflavone deriv-
ative)29 and certain flavonoids such as casticin30 and apigenin.31
However, the amide isomers 16b and 16c induced cell-cycle arrest
in G0/G1 phase which were similar to that of quercetin and luteolin
Flavonoids are emerging as prospective anticancer drug candi-
dates and some of them have already entered in clinical trials.28 In
view of the therapeutic potential of flavonoids, our laboratories have
tried to elucidate possible structure–activity relationships that
might lead to new drug discovery. Our current work continues ef-
forts to design and synthesize a series of amide containing flavone
and isoflavone derivatives and to evaluate their biological activities.
Initially, the growth inhibitory activity of all compounds is evalu-
ated in vitro against a panel of human cancer cell lines, including
lung carcinoma (NCI-H661), nasopharyngeal (NPC-TW01), and T-
cell leukemia (MT-2) cells. Results from Table 1 indicated that MT-
2 is relatively insensitive to the treatment of these amide derivatives
with exception of N-(4-fluorophenyl)-2-(4-oxo-2-phenyl-4H-chro-
men-6-yloxy)acetamide (16b) which exhibited a GI50 value of
0.47
creased in an order of linked chromophore flavone-6-yl 16a–d (GI50
values of 5.60, 1.47, 0.84, and 9.71 M, respectively) > flavone-7-yl
lM. The inhibitory activity against the growth of NCI-H661 de-
l
17a–d > flavone-3-yl 15a–d and isoflavone-7-yl 18a–d with an
O
Br
R
H
N
Aryl
O
NaN3
R
Aryl
O
Aryl OH
O
K2CO3
R
O
a: R = H
b: R = F
15 - 18
7 - 10
O
c: R = OMe
d: R = Ph
Br
O
3; 7; 11; 15 Aryl =
K2CO3
Ο
O
Aryl
Aryl
O
O
O
4;8;12;16 Aryl =
3 - 6
Ο
NaN3
O
H
N
5; 9; 13; 17 Aryl =
O
Ο
11 - 14
O
6; 10; 14; 18 Aryl =
Ο
Scheme 1.

I-Li Chen et al. / Bioorg. Med. Chem. 16 (2008) 7639–7645
7641
Table 1
Antiproliferative activity of flavone and isoflavone derivatives
NHR
Aryl
O
O
Compound
Substituents
GI50 (l
M)a,b
Aryl
R
NCI-H661
NPC-TW01
MT-2
11
12
13
14
Flavone-3-yl
Flavone-6-yl
Flavone-7-yl
Isoflavone-7-yl
Flavone-3-yl
Flavone-3-yl
Flavone-3-yl
Flavone-3-yl
Flavone-6-yl
Flavone-6-yl
Flavone-6-yl
Flavone-6-yl
Flavone-7-yl
Flavone-7-yl
Flavone-7-yl
Flavone-7-yl
Isoflavone-7-yl
Isoflavone-7-yl
Isoflavone-7-yl
Isoflavone-7-yl
Naph
Naph
Naph
Naph
Ph
6.50 0.52
6.71 0.61
>10
>10
>10
>10
6.74 0.72
>10
5.60 0.52
1.47 0.15
0.84 0.25
9.71 1.52
>10
5.77 0.82
5.50 0.52
1.28 0.58
>10
6.52 0.61
6.75 0.42
>10
1.37 0.22
>10
9.50 0.82
5.48 0.62
>10
1.26 0.32
0.74 0.20
0.71 0.15
0.64 0.23
>10
>10
>10
>10
7.68 0.92
6.72 0.52
>10
>10
>10
1.43 0.33
0.47 0.32
3.01 0.52
>10
15a
15b
15c
15d
16a
16b
16c
16d
17a
17b
17c
17d
18a
18b
18c
18d
4-F–Ph
4-MeO–Ph
4-Ph–Ph
Ph
4-F–Ph
4-MeO–Ph
4-Ph–Ph
Ph
4-F–Ph
4-MeO–Ph
4-Ph–Ph
Ph
4-F–Ph
4-MeO–Ph
4-Ph–Ph
>10
>10
6.41 1.21
6.70 1.03
2.48 0.72
>10
2.50 0.72
4.55 0.82
>10
5.97 0.92
1.61 0.42
>10
0.55 0.20
6.70 1.14
1.75 0.42
>10
9.53 1.13
>10
a
All tested compounds were dissolved in 100% DMSO at a concentration of 20 mM as the stock solution. Cells were cultured without or in the presence of flavone or
isoflavone derivatives at different concentrations for 72 h. Cell survival was determined by MTT assay. Drug molar concentration causing 50% cell growth inhibition (GI50) was
calculated. Each value represents the mean SD of three independent experiments.
b
NCI-H661: human lung carcinoma; NPC-TW01: human nasopharyngeal carcinoma; MT-2: human T-cell leukemia.
Table 2
activities. The results indicated that the most preferred pharmaco-
phore is flavone-6-yl and two of the most active peripheral substit-
Effect of flavone derivatives on cell-cycle progression of NPC-TW01a
uents are 4-F-Ph and 4-MeO-Ph. All the four flavone-6-yl
derivatives demonstrated significant inhibitory activity against
the growth of NPC-TW01 cell with an average GI50 value of
Compound
G0/G1 (%)
S (%)
G2/M (%)
Sub-G1 (%)
Control
1
2
16b
16c
48.7 6.4
22.3 2.7
0.5 0.2
77.2 9.5
77.8 8.2
36.5 3.7
33.2 3.1
27.5 2.3
13.6 3.0
13.6 1.5
14.2 2.2
42.8 4.4
70.8 5.7
5.2 0.6
5.3 0.7
0.6 0.2
1.7 0.6
1.2 0.8
4.0 1.5
3.3 2.0
0.84
active against the growth of MT-2 with a GI50 value of 0.47
while 16c was the most active against the growth of NCI-H661
with a GI50 value of 0.84 M. Compounds 16b and 16c induced
lM. Among these flavone-6-yl derivatives, 16b was the most
lM,
a
The human nasopharyngeal carcinoma cells (NPC-TW01) were co-cultured with
M, 48.0 M, 10.5 M, and 10.5 M for com-
l
flavone derivatives at 15 ꢀ GI50 (6.0
l
l
l
l
cell-cycle arrest in G0/G1 phase followed by apoptosis which was
distinct from that of their isomeric oxime derivatives 1 and 2
which induced cell-cycle arrest in G2/M phase. Further evaluation
of 16b and 16c as potential anticancer drugs is on-going.
pound 1, 2, 16b, and 16c, respectively) for 72 h. Control cells were cultivated with
complete medium in the present of 0.5% DMSO for 72 h. The DNA content was
evaluated on a Becton Dickinson FACScan flow cytometer and the percentage of
cells in various cell-cycle phases was determined by using the ModFit LT software.
Data are mean SD of three independent experiments.
5. Experimental
5.1. General
(flavone derivatives).32,33 Therefore, the antiproliferative mecha-
nism of flavone derivatives was affected not only by the phenyl
benzopyran-4-one pharmacophore but also by the peripheral sub-
stituents in which oxime derivatives 1 and 2 were distinct from that
of their amide isomers 16b and 16c. Figure 1 shows the effect of 16b
on cell-cycle progression in NPC-TW01 cell. The proportion of cells
was slightly increased in the sub-G1 and accumulated in G0/G1
phase after 24 h treatment. After 96 h, the accumulation of the cells
in G0/G1 DNA content was decreased, while the hypodiploid (sub-G1
phase) cells increased. Compound 16b inhibited proliferation of
NPC-TW01 by the alteration of cell division, accumulation of cells
in G0/G1 phase at early 72 h which was then decreased followed
by the increase of apoptotic cells (sub-G1 phase) after 96 h treat-
ment. Thus, compound 16b induces cell-cycle arrest followed by
apoptosis.
TLC. Precoated (0.2 mm) silica gel 60 F254 plates from EM Labo-
ratories, Inc.; detection by UV light (254 nm). Mp: Electrothermal
IA9100 digital melting-point apparatus; uncorrected. 1H NMR
spectra: Varian-Unity-400 spectrometer at 400, chemical shifts d
in ppm with SiMe4 as an internal standard (=0 ppm), coupling con-
stants J in Hz. Elemental analyses were carried out on a Heraeus
CHN-O-Rapid elemental analyzer, and results were within 0.4%
of calculated values.
5.1.1. 3-(2-(Naphthalen-2-yl)-2-oxoethoxy)-2-phenyl-4H-
chromen-4-one (3)
A solution of 3-hydroxyflavone (0.24 g, 1 mmol) in DMF (20 mL)
was added a solution of 2-bromo-1-(naphthalen-2-yl)ethanone
(0.25 g, 1 mmol) in DMF (2 mL). The mixture was stirred at room
temperature for 48 h (TLC monitoring) and evaporated to give a
residual solid. The white solid thus obtained was collected
and purified by flash column chromatography (FC; silica gel;
4. Conclusion
A number of amide containing flavone and isoflavone deriva-
tives were synthesized and evaluated for their antiproliferative

7642
I-Li Chen et al. / Bioorg. Med. Chem. 16 (2008) 7639–7645
5.1.2. 6-(2-(Naphthalen-2-yl)-2-oxoethoxy)-2-phenyl-4H-
chromen-4-one (4)
Yield: 81%. Mp 178–179 °C. 1H NMR (400 MHz, DMSO-d6): 5.87
(s, OCH2), 6.98 (s, 1H–C(3)), 7.47 (d, J = 3.2, 1H–C(5)), 7.53 (dd,
J = 9.2, 3.2, 1H–C(7)), 7.55–7.59 (m, 3H, arom. H), 7.62–7.71 (m,
2H, arom. H), 7.77 (d, J = 9.2, 1H–C(8)), 8.00 (s, 1H, arom. H), 8.02
(d, J = 1.6, 1H–C(10)), 8.05–8.08 (m, 3H, arom. H), 8.14 (d, J = 7.6,
1H, arom. H), 8.80 (s, 1H, arom. H). 13C NMR (100 MHz, DMSO-
d6): 71.37 (CH2O), 106.84, 120.88, 123.95, 124.38, 124.67, 127.00,
127.84, 128.49, 129.21, 129.67, 129.82, 130.31, 130.71, 131.89,
132.22, 132.46, 132.81, 136.05, 151.28, 156.09, 163.07, 177.54
(C(4)), 194.76 (C@O). Anal. Calcd for C27H18O4: C 79.79, H 4.46.
Found: C 79.41, H 4.45.
5.1.3. 7-(2-(Naphthalen-2-yl)-2-oxoethoxy)-2-phenyl-4H-
chromen-4-one (5)
Yield: 86%. Mp 201–202 °C. 1H NMR (400 MHz, DMSO-d6): 5.98
(s, OCH2), 6.99 (s, 1H–C(3)), 7.21 (dd, J = 8.8, 2.4, 1H–C(6)), 7.48 (d,
J = 2.4, 1H–C(8)), 7.54–7.60 (m, 3H, arom. H), 7.66–7.75 (m, 2H,
arom. H), 7.99 (d, J = 8.8, 1H–C(5)), 8.05–8.12 (m, 5H, arom. H),
8.17 (d, J = 8.0, 1H, arom. H), 8.82 (s, 1H, arom. H). 13C NMR
(100 MHz, DMSO-d6): 71.50 (CH2O), 102.66, 107.50, 115.82,
118.13, 123.98, 126.89, 126.92, 127.88, 128.51, 129.18, 129.68,
129.77, 130.28, 130.69, 131.85, 132.15, 132.38, 132.79, 136.07,
158.10, 162.91, 163.43, 177.13 (C(4)), 194.09 (C@O). Anal. Calcd
for C27H18O4: C 79.79, H 4.46. Found: C 79.69, H 4.43.
5.1.4. 7-(2-(Naphthalen-2-yl)-2-oxoethoxy)-3-phenyl-4H-
chromen-4-one (6)
Yield: 66%. Mp 192–193 °C. 1H NMR (400 MHz, DMSO-d6): 5.91
(s, OCH2), 7.19 (dd, J = 8.8, 2.4, 1H–C(6)), 7.27 (d, J = 2.4, 1H–C(8)),
7.33–7.43 (m, 3H, arom. H), 7.53–7.56 (m, 2H, arom. H), 7.62–7.71
(m, 2H, arom. H), 7.99–8.06 (m, 4H, arom. H), 8.12 (d, J = 8.0, 1H–
C(5)), 8.40 (s, 1H, arom. H), 8.77 (s, 1H, arom. H). 13C NMR
(100 MHz, DMSO-d6): 71.43 (CH2O), 102.41, 115.83, 118.61,
123.90, 124.50, 127.72, 127.84, 128.47, 128.51, 128.83, 129.19,
129.59, 129.68, 130.26, 130.70, 132.10, 132.57, 132.75, 136.06,
154.85, 158.02, 163.24, 175.20 (C(4)), 194.15 (C@O). Anal. Calcd
for C27H18O4: C 79.79, H 4.46. Found: C 79.91, H 4.85.
5.1.5. N-(Naphthalen-2-yl)-2-(4-oxo-2-phenyl-4H-chromen-
3-yloxy)acetamide (11)
A solution of 3 (0.41 g, 1 mmol) in H2SO4 (3 mL) was stirred at rt
for 10 min. To this solution, sodium azide (0.13 g, 2 mmol) was
added in one portion. The mixture was stirred at rt for 1 h (TLC mon-
itoring) and then poured into ice-water (100 mL). The white solid
thus obtained was collected and purified by flash column chroma-
tography (FC; silica gel; MeOH/EtOAc 1:1) and recrystallized from
CH2Cl2 to give 11 (0.30 g, 71%). Mp 190–191 °C. 1H NMR (400 MHz,
DMSO-d6): 4.73 (s, OCH2), 7.38–7.49 (m, 2H, arom. H), 7.51–7.55
(m, 1H, arom. H), 7.58–7.60 (m, 3H, arom. H), 7.66 (dd, J = 8.8, 2.4,
1H, arom. H), 7.79–7.89 (m, 5H, arom. H), 8.14–8.19 (m, 3H, arom.
H), 8.30 (d, J = 1.6, 1H–C(10)), 10.53 (s, NH). 13C NMR (100 MHz,
DMSO-d6): 71.91 (CH2O), 116.27, 119.25, 120.78, 123.92, 125.48,
125.75, 126.05, 127.19, 128.04, 128.17, 129.15, 129.37, 129.44,
130.62, 130.94, 131.86, 134.02, 135.14, 136.59, 140.59, 155.53,
155.93, 167.71 (CONH), 174.99 (C(4)). Anal. Calcd for C27H19NO4: C
76.95, H 4.54, N 3.32. Found: C 76.99, H 4.55, N 3.26.
Figure 1. The time- and dose-effect of 16b on cell-cycle distribution in NPC-TW01.
Cells were treated with 30 lM (top panel) or 60 lM (lower panel) of compound 16b
for the time indicated. Control cells were cultivated with complete medium in the
presence of 0.3% DMSO without 16b for the time period indicated. The DNA content
of treated cells was analyzed by flow cytometry.
n-hexane/EtOAc 1:1) and recrystallized from CH2Cl2 to give 3
(0.38 g, 93%). Mp 170–171 °C. 1H NMR (400 MHz, DMSO-d6): 5.80
(s, OCH2), 7.47–7.54 (m, 4H, arom. H), 7.58–7.68 (m, 2H, arom.
H), 7.77–7.86 (m, 2H, arom. H), 7.92–8.02 (m, 3H, arom. H),
8.06–8.09 (m, 2H, arom. H), 8.17–8.20 (m, 2H, arom. H), 8.64 (s,
1H, arom. H). 13C NMR (100 MHz, DMSO-d6): 74.23 (CH2O),
119.16, 123.89, 123.99, 125.62, 125.88, 127.73, 128.41, 129.15,
129.22, 129.34, 129.53, 130.26, 130.45, 131.18, 131.59, 132.22,
132.77, 134.91, 135.92, 140.08, 154.97, 155.37, 174.54 (C(4)),
194.90 (C@O). Anal. Calcd for C27H18O4: C 79.79, H 4.46. Found:
C 79.43, H 4.42.
The same procedure was applied to convert 4 to 12; 5 to 13; 6 to
14; 7a–d to 15a–d; 8a–d to 16a–d; 9a–d to 17a–d; and 10a–d to
18a–d, respectively.
5.1.6. N-(Naphthalen-2-yl)-2-(4-oxo-2-phenyl-4H-chromen-
6-yloxy)acetamide (12)
The same procedure was applied to convert 6-hydroxyflavone
to 4; 7-hydroxyflavone to 5; and 7-hydroxyisoflavone to 6,
respectively.
Yield: 89%. Mp 253–254 °C. 1H NMR (400 MHz, DMSO-d6): 4.91
(s, OCH2), 7.02 (s, 1H–C(3)), 7.38–7.48 (m, 2H, arom. H), 7.51 (d,

I-Li Chen et al. / Bioorg. Med. Chem. 16 (2008) 7639–7645
7643
J = 3.2, 1H–C(5)), 7.56–7.59 (m, 4H, arom. H), 7.65 (dd, J = 8.8, 2.0,
1H, arom. H), 7.80–7.89 (m, 4H, arom. H), 8.08–8.11 (m, 2H, arom.
H), 8.31 (d, J = 1.6, 1H–C(10)), 10.39 (s, NH). 13C NMR (100 MHz,
DMSO-d6): 68.16 (CH2O), 106.87, 116.57, 120.88, 120.97, 124.41,
124.66, 125.55, 127.03, 127.21, 128.04, 128.17, 129.15, 129.85,
130.65, 131.86, 132.52, 133.99, 136.61, 151.41, 155.93, 163.16,
167.14 (CONH), 177.55 (C(4)). Anal. Calcd for C27H19NO4ꢁ0.1H2O:
C 76.62, H 4.57, N 3.30. Found: C 76.39, H 4.56, N 3.29.
129.34, 129.43, 130.91, 131.86, 132.08, 135.13, 140.55, 155.52,
156.02, 156.19, 166.85 (CONH), 174.94 (C(4)). Anal. Calcd for
C
24H19NO5ꢁ0.2H2O: C 71.17, H 4.82, N 3.46. Found: C 71.00, H
4.75, N 3.31.
5.1.12. N-(Biphenyl-4-yl)-2-(4-oxo-2-phenyl-4H-chromen-
3-yloxy)acetamide (15d)
Yield: 65%. Mp 171–172 °C. 1H NMR (400 MHz, DMSO-d6): 4.67
(s, OCH2), 7.30–7.34 (m, 1H, arom. H), 7.41–7.45 (m, 2H, arom. H),
7.51–7.65 (m, 8H, arom. H), 7.73–7.88 (m, 4H, arom. H), 8.14–8.18
(m, 3H, arom. H); 10.43 (s, NH). 13C NMR (100 MHz, DMSO-d6):
71.93 (CH2O), 119.25, 120.53, 123.92, 125.75, 126.05, 126.99,
127.68, 127.79, 129.35, 129.44, 129.61, 130.91, 131.87, 135.15,
136.01, 138.49, 140.32, 140.59, 155.53, 155.99, 167.47 (CONH),
174.99 (C(4)). Anal. Calcd for C29H21NO4: C 77.84, H 4.73, N 3.13.
Found: C 77.52, H 4.77, N 3.17.
5.1.7. N-(Naphthalen-2-yl)-2-(4-oxo-2-phenyl-4H-chromen-
7-yloxy)acetamide (13)
Yield: 77%. Mp 202–203 °C. 1H NMR (400 MHz, DMSO-d6): 4.98
(s, OCH2), 6.97 (s, 1H–C(3)), 7.21 (dd, J = 8.8, 2.4, 1H–C(6)), 7.38–
7.48 (m, 3H, arom. H), 7.54–7.58 (m, 3H, arom. H), 7.65 (dd,
J = 8.8, 2.0, 1H, arom. H), 7.80–7.89 (m, 3H, arom, H), 7.99 (d,
J = 8.8, 1H–C(5)), 8.06–8.08 (m, 2H, arom. H), 8.31 (s, 1H, arom.
H), 10.40 (s, NH). 13C NMR (100 MHz, DMSO-d6): 68.03 (CH2O),
102.79, 107.53, 115.73, 116.61, 118.29, 120.88, 125.55, 126.92,
127.01, 127.21, 128.04, 128.17, 129.15, 129.81, 130.65, 131.82,
132.42, 133.99, 136.60, 157.98, 162.99, 163.19, 166.72 (CONH),
177.15 (C(4)). Anal. Calcd for C27H19NO4: C 76.95, H 4.54, N 3.32.
Found: C 76.67, H 4.55, N 3.30.
5.1.13. 2-(4-Oxo-2-phenyl-4H-chromen-6-yloxy)-N-phenyl-
acetamide (16a)
Yield: 91%. Mp 224–225 °C. 1H NMR (400 MHz, DMSO-d6): 4.84
(s, OCH2), 7.01 (s, 1H–C(3)), 7.05–7.08 (m, 1H, arom. H), 7.29–7.33
(m, 2H, arom. H), 7.47 (d, J = 3.2, 1H–C(5)), 7.53 (dd, J = 9.2, 3.2, 1H–
C(7)), 7.55–7.63 (m, 5H, arom. H), 7.79 (d, J = 9.2, 1H–C(8)), 8.07–
8.10 (m, 2H, arom. H), 10.18 (s, NH). 13C NMR (100 MHz, DMSO-
d6): 68.08 (CH2O), 106.78, 106.85, 120.35, 120.94, 124.38, 124.45,
124.64, 127.02, 129.48, 129.83, 131.85, 132.50, 139.01, 151.38,
155.89, 163.13, 166.83 (CONH), 177.53 (C(4)). Anal. Calcd for
5.1.8. N-(Naphthalen-2-yl)-2-(4-oxo-3-phenyl-4H-chromen-
7-yloxy)acetamide (14)
Yield: 88%. Mp 239–240 °C. 1H NMR (400 MHz, DMSO-d6): 4.97
(s, OCH2), 7.22–7.24 (m, 2H, arom. H), 7.36–7.48 (m, 5H, arom. H),
7.55–7.57 (m, 2H, arom. H), 7.65 (dd, J = 8.8, 2.0, 1H–C(6)), 7.80–
7.85 (m, 2H, arom. H), 7.88 (d, J = 8.8, 1H–(C5)), 8.09 (dd, J = 8.4,
1.2, 1H, arom. H), 8.31 (d, J = 1.2, 1H, arom. H), 8.46 (s, 1H–C(2)),
10.41 (s, NH). 13C NMR (100 MHz, DMSO-d6): 68.12 (CH2O),
102.38, 115.88, 116.63, 118.76, 120.88, 124.47, 125.56, 127.22,
127.80, 128.06, 128.17, 128.54, 128.85, 129.15, 129.63, 130.67,
132.59, 133.99, 136.56, 154.98, 157.91, 163.00, 166.68 (CONH),
175.13 (C(4)). Anal. Calcd for C27H19NO4: C 76.95, H 4.54, N 3.32.
Found: C 76.68, H 4.55, N 3.30.
C23H17NO4: C 74.38, H 4.61, N 3.77. Found: C 74.28, H 4.65, N 3.76.
5.1.14. N-(4-Fluorophenyl)-2-(4-oxo-2-phenyl-4H-chromen-
6-yloxy)acetamide (16b)
Yield: 96%. Mp 241–242 °C. 1H NMR (400 MHz, DMSO-d6): 4.83
(s, OCH2), 7.01 (s, 1H–C(3)), 7.13–7.18 (m, 2H, arom. H), 7.47 (d,
J = 3.2, 1H–C(5)), 7.53 (dd, J = 9.2, 3.2, 1H–C(7)), 7.56–7.59 (m,
3H, arom. H), 7.62–7.66 (m, 2H, arom. H), 7.79 (d, J = 9.2, 1H–
C(8)), 8.07–8.10 (m, 2H, arom. H), 10.23 (s, NH). 13C NMR
(100 MHz, DMSO-d6): 68.07 (CH2O), 106.86, 115.95, 116.17,
120.94, 122.20, 122.28, 124.35, 124.64, 127.02, 129.83, 131.85,
132.51, 135.36, 135.38, 151.39, 155.84, 157.78, 160.16, 163.15,
166.81 (CONH), 177.52 (C(4)). Anal. Calcd for C23H16FNO4: C
70.95, H 4.14, N 3.60. Found: C 70.88, H 4.23, N 3.57.
5.1.9. 2-(4-Oxo-2-phenyl-4H-chromen-3-yloxy)-N-phenylacet-
amide (15a)
Yield: 78%. Mp 156–157 °C. 1H NMR (400 MHz, DMSO-d6): 4.64
(s, OCH2), 7.05–7.08 (m, 1H, arom. H), 7.29–7.33 (m, 2H, arom. H),
7.50–7.64 (m, 6H, arom. H), 7.78–7.88 (m, 2H, arom. H), 8.13–8.17
(m, 3H, arom. H), 10.31 (s, NH). 13C NMR (100 MHz, DMSO-d6):
71.89 (CH2O), 119.24, 120.16, 123.92, 124.37, 125.74, 126.05,
129.34, 129.43, 129.47, 130.91, 131.86, 135.14, 138.99, 140.57,
155.52, 155.97, 167.39 (CONH), 174.96 (C(4)). Anal. Calcd for
5.1.15. N-(4-Methoxyphenyl)-2-(4-oxo-2-phenyl-4H-chromen-
6-yloxy)acetamide (16c)
Yield: 94%. Mp 194–195 °C. 1H NMR (400 MHz, DMSO-d6): 3.70
(s, OCH3), 4.79 (s, OCH2), 6.87–6.90 (m, 2H, arom. H), 7.01 (s, 1H–
C(3)), 7.47 (d, J = 3.2, 1H–C(5)), 7.52 (dd, J = 9.2, 3.2, 1H–C(7)),
7.53–7.59 (m, 5H, arom. H), 7.79 (d, J = 9.2, 1H–C(8)), 8.07–8.10
(m, 2H, arom. H), 10.04 (s, NH). 13C NMR (100 MHz, DMSO-d6):
55.84 (MeO), 68.11 (CH2O), 106.85, 114.56, 120.92, 122.02,
124.37, 124.64, 127.02, 129.83, 131.85, 132.06, 132.50, 151.37,
155.90, 156.25, 163.12, 166.35 (CONH), 177.53 (C(4)). Anal. Calcd
for C24H19NO5: C 71.81, H 4.77, N 3.49. Found: C 71.49, H 4.79, N
3.51.
C23H17NO4: C 74.38, H 4.61, N 3.77. Found: C 74.33, H 4.63, N 3.71.
5.1.10. N-(4-Fluorophenyl)-2-(4-oxo-2-phenyl-4H-chromen-
3-yloxy)acetamide (15b)
Yield: 85%. Mp 191–192 °C. 1H NMR (400 MHz, DMSO-d6): 4.60
(s, OCH2), 7.12–7.16 (m, 2H, arom. H), 7.52–7.63 (m, 6H, arom. H),
7.76–7.84 (m, 2H, arom. H), 8.11–8.13 (m, 3H, arom. H), 10.35 (s,
NH). 13C NMR (100 MHz, DMSO-d6): 71.79 (CH2O), 115.94,
116.16, 119.22, 122.10, 122.18, 123.84, 125.71, 126.11, 129.31,
129.44, 130.80, 131.91, 135.21, 140.43, 155.50, 156.16, 157.78,
160.17, 167.44 (CONH), 174.98 (C(4)). Anal. Calcd for C23H16FNO4:
C 70.95, H 4.14, N 3.60. Found: C 70.99, H 4.27, N 3.66.
5.1.16. N-(Biphenyl-4-yl)-2-(4-oxo-2-phenyl-4H-chromen-
6-yloxy)acetamide (16d)
Yield: 61%. Mp 254–255 °C. 1H NMR (400 MHz, DMSO-d6): 4.89
(s, 2H, OCH2), 7.05 (s, 1H–C(3)), 7.32–7.38 (m, 1H, arom. H), 7.43–
7.47 (m, 2H, arom. H), 7.52 (d, J = 3.2, 1H–C(5)), 7.58 (dd, J = 9.2,
3.2, 1H–C(7)), 7.59–7.63 (m, 3H, arom. H), 7.65–7.67 (m, 4H, arom.
H), 7.75–7.77 (m, 2H, arom. H), 7.83 (d, J = 9.2, 1H–C(8)), 8.11–8.13
(m, 2H, arom. H), 10.30 (s, NH), 13C NMR (100 MHz, DMSO-d6):
68.17 (CH2O), 106.88, 120.69, 120.96, 124.38, 124.67, 126.99,
127.03, 127.68, 127.80, 129.60, 129.80, 129.84, 131.88, 132.50,
136.09, 138.50, 140.30, 151.40, 155.91, 163.13, 166.90 (CONH),
5.1.11. N-(4-Methoxyphenyl)-2-(4-oxo-2-phenyl-4H-chromen-
3-yloxy)acetamide (15c)
Yield: 72%. Mp 212–213 °C. 1H NMR (400 MHz, DMSO-d6): 3.71
(s, OCH3), 4.60 (s, OCH2), 6.87–6.89 (m, 2H, arom. H), 7.50–7.59 (m,
6H, arom. H), 7.78–7.88 (m, 2H, arom. H), 8.13–8.16 (m, 3H, arom.
H), 10.17 (s, NH). 13C NMR (100 MHz, DMSO-d6): 55.85 (MeO),
71.88 (CH2O), 114.56, 119.24, 121.75, 123.92, 125.74, 126.04,

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I-Li Chen et al. / Bioorg. Med. Chem. 16 (2008) 7639–7645
177.51 (C(4)). Anal. Calcd for C29H21NO4: C 77.84, H 4.73, N 3.13.
Found: C 77.56, H 4.75, N 3.05.
5.1.22. N-(4-Fluorophenyl)-2-(4-oxo-3-phenyl-4H-chromen-
7-yloxy)acetamide (18b)
Yield: 93%. Mp 269–270 °C. 1H NMR (400 MHz, DMSO-d6): 4.89
(s, OCH2), 7.14–7.21 (m, 4H, arom. H), 7.35–7.44 (m, 3H, arom. H),
7.55–7.57 (m, 2H, arom. H), 7.62–7.66 (m, 2H, arom. H), 8.07 (d,
J = 8.8, 1H–C(5)), 8.46 (s, 1H–C(2)), 10.25 (s, NH). 13C NMR
(100 MHz, DMSO-d6): 68.03 (CH2O), 102.36, 115.86, 115.97,
116.19, 118.78, 122.25, 122.34, 124.49, 127.80, 128.55, 128.85,
129.63, 132.58, 135.30, 135.33, 154.98, 157.89, 162.91, 166.36
(CONH), 175.13 (C(4)). Anal. Calcd for C23H16FNO4: C 70.95, H
4.14, N 3.60. Found: C 70.92, H 4.16, N 3.59.
5.1.17. 2-(4-Oxo-2-phenyl-4H-chromen-7-yloxy)-N-phenylacet-
amide (17a)
Yield: 87%. Mp 207–208 °C. 1H NMR (400 MHz, DMSO-d6): 4.92
(s, OCH2), 6.98 (s, 1H–C(3)), 7.07–7.11 (m, 1H, arom. H), 7.19 (dd,
J = 8.8, 2.4, 1H–C(6)), 7.31–7.35 (m, 2H, arom. H), 7.37 (d, J = 2.4,
1H–C(8)), 7.57–7.66 (m, 5H, arom. H), 7.99 (d, J = 8.8, 1H–C(5)),
8.07–8.09 (m, 2H, arom. H), 10.20 (s, NH). 13C NMR (100 MHz,
DMSO-d6): 67.98 (CH2O), 102.73, 107.52, 115.68, 118.26, 120.37,
124.49, 126.91, 126.99, 129.49, 129.81, 131.81, 132.41, 138.99,
157.96, 162.98, 163.14, 166.42 (CONH), 177.13 (C(4)). Anal. Calcd
for C23H17NO4: C 74.38, H 4.61, N 3.77. Found: C 74.00, H 4.60, N
3.75.
5.1.23. N-(4-Methoxyphenyl)-2-(4-oxo-3-phenyl-4H-chromen-
7-yloxy)acetamide (18c)
Yield: 91%. Mp 228–229 °C. 1H NMR (400 MHz, DMSO-d6): 3.70
(s, OCH3), 4.85 (s, OCH2), 6.87–6.91 (m, 2H, arom. H), 7.18–7.21 (m,
2H, arom. H), 7.34–7.44 (m, 3H, arom. H), 7.50–7.55 (m, 3H, arom.
H), 7.56 (d, J = 1.6, 1H, arom. H), 8.06 (d, J = 9.2, 1H–C(5)), 8.44 (s,
1H–C(2)), 10.06 (s, NH). 13C NMR (100 MHz, DMSO-d6): 55.85
(MeO), 68.11 (CH2O), 102.33, 114.56, 115.89, 118.74, 122.06,
124.48, 127.77, 128.54, 128.85, 129.63, 131.99, 132.58, 154.97,
156.29, 157.89, 162.96, 165.89 (CONH), 175.13 (C(4)). Anal. Calcd
for C24H19NO5: C 71.81, H 4.77, N 3.49. Found: C 71.79, H 4.78, N
3.47.
5.1.18. N-(4-Fluorophenyl)-2-(4-oxo-2-phenyl-4H-chromen-
7-yloxy)acetamide (17b)
Yield: 85%. Mp 207–208 °C. 1H-NMR (400 MHz, DMSO-d6): 4.90
(s, OCH2), 6.96 (s, 1H–C(3)), 7.15 (dd, J = 9.2, 2.4, 1H–C(6)), 7.16–
7.19 (m, 2H, arom. H), 7.36 (d, J = 2.4, 1H–C(8)), 7.55–7.67 (m,
5H, arom. H), 7.97 (d, J = 9.2, 1H–C(5)), 8.05–8.08 (m, 2H, arom.
H), 10.24 (s, NH). 13C NMR (100 MHz, DMSO-d6): 67.95 (CH2O),
102.75, 107.52, 115.70, 115.96, 116.17, 118.30, 122.23, 122.31,
126.91, 126.99, 129.81, 131.81, 132.41, 135.36, 157.79, 157.95,
160.18, 162.97, 163.08, 166.40 (CONH), 177.13 (C(4)). Anal. Calcd
for C23H16FNO4ꢁ0.1H2O: C 70.62, H 4.17, N 3.58. Found: C 70.48,
H 4.18, N 3.59.
5.1.24. N-(Biphenyl-4-yl)-2-(4-oxo-3-phenyl-4H-chromen-
7-yloxy)acetamide (18d)
Yield: 90%. Mp 285–286 °C. 1H NMR (400 MHz, DMSO-d6): 4.92
(s, OCH2), 7.20–7.22 (m, 2H, arom. H), 7.30–7.44 (m, 6H, arom. H),
7.55–7.57 (m, 2H, arom. H), 7.62–7.65 (m, 4H, arom. H), 7.72–7.74
(m, 2H, arom. H), 8.08 (d, J = 9.6, 1H–C(5)), 8.46 (s, 1H–C(2)), 10.31
(s, NH). 13C NMR (100 MHz, DMSO-d6): 68.10 (CH2O), 102.35,
115.87, 118.76, 120.73, 124.48, 126.98, 127.68, 127.81, 128.55,
128.85, 129.63, 132.58, 136.14, 138.43, 140.26, 154.98, 157.90,
162.96, 166.45 (CONH), 175.13 (C(4)). Anal. Calcd for C29H21NO4:
C 77.84, H 4.73, N 3.13. Found: C 77.81, H 4.75, N 3.08.
5.1.19. N-(4-Methoxyphenyl)-2-(4-oxo-2-phenyl-4H-chromen-
7-yloxy)acetamide (17c)
Yield: 67%. Mp 188–189 °C. 1H NMR (400 MHz, DMSO-d6): 3.70
(s, OCH3), 4.86 (s, OCH2), 6.87–6.90 (m, 2H, arom. H), 6.96 (s, 1H–
C(3)), 7.17 (dd, J = 8.8, 2.4, 1H–C(6)), 7.35 (d, J = 2.4, 1H–C(8)),
7.52–7.58 (m, 5H, arom. H), 7.97 (d, J = 8.8, 1H–C(5)), 8.05–8.08
(m, 2H, arom. H), 10.04 (s, NH). 13C NMR (100 MHz, DMSO-d6):
55.84 (MeO), 68.03 (CH2O), 102.73, 107.52, 114.56, 115.72,
118.26, 122.04, 126.91, 126.98, 129.81, 131.81, 132.03, 132.41,
156.27, 157.95, 162.97, 163.12, 165.93 (CONH), 177.13 (C(4)). Anal.
Calcd for C24H19NO5: C 71.81, H 4.77, N 3.49. Found: C 71.42, H
4.88, N 3.41.
5.2. Antiproliferative activity
5.2.1. Cell lines
Human non-small cell lung carcinoma (NCI-H661) was pur-
chased from American Type Culture Collection (ATCC; Rockville,
MD). T-cell leukemia (MT-2) was obtained from Japanese Collec-
tion of Research Bioresources (JCRB) and nasopharyngeal carci-
noma (NPC-TW01) was purchased from Bioresource Collection
and Research Center (BCRC, Taiwan). All the tumor cell lines were
maintained in either RPMI-1640 or Modified essential medium
(MEM) supplied with 10% fetal bovine serum at 37 °C in a humid-
ified atmosphere of 5% CO2/95% air in the absence of antibiotics.
5.1.20. N-(Biphenyl-4-yl)-2-(4-oxo-2-phenyl-4H-chromen-
7-yloxy)acetamide (17d)
Yield: 85%. Mp 216–217 °C. 1H NMR (400 MHz, DMSO-d6): 4.94
(s, OCH2), 6.97 (s, 1H–C(3)), 7.19 (dd, J = 8.8, 2.4, 1H–C(6)), 7.30–
7.33 (m, 1H, arom. H)), 7.38 (d, J = 2.4, 1H–C(8)), 7.40–7.44 (m,
2H, arom. H), 7.56–7.65 (m, 7H, arom. H), 7.72–7.75 (m, 2H, arom.
H), 7.99 (d, J = 8.8, 1H–C(5)), 8.06–8.09 (m, 2H, arom. H), 10.30 (s,
NH). 13C NMR (100 MHz, DMSO-d6): 68.03 (CH2O), 102.76, 107.53,
115.71, 118.30, 120.72, 126.92, 126.98, 127.02, 127.68, 127.81,
129.61, 129.82, 131.82, 132.42, 136.11, 138.47, 140.26, 157.97,
162.99, 163.15, 166.49 (CONH), 177.14 (C(4)). Anal. Calcd for
5.2.2. Growth inhibition assay
Logarithmic phase cells were seeded in a 96-well plate and
incubated overnight prior to addition of the designated com-
pounds. After incubation with different concentrations of the
tested compounds for 72 h, cells were incubated with MEM con-
taining 0.4 mg/mL MTT for 2 h. The conversion of MTT to formazan
by metabolically viable cells was measured by the absorbance at
570 nm in a 96-well microtiter plate reader. The percentage con-
version by mock-treated control cells was used to evaluate the ef-
fect of the chemicals on cell growth and to determine the
concentration that inhibited 50% of growth (GI50).
C29H21NO4: C 77.84, H 4.73, N 3.13. Found: C 77.89, H 4.74, N 3.07.
5.1.21. 2-(4-Oxo-3-phenyl-4H-chromen-7-yloxy)-N-
phenylacetamide (18a)
Yield: 89%. Mp 233–234 °C. 1H NMR (400 MHz, DMSO-d6): 4.90
(s, OCH2), 7.05–7.09 (m, 1H, arom. H), 7.19–7.21 (m, 2H, arom. H),
7.30–7.42 (m, 5H, arom. H), 7.55–7.57 (m, 2H, arom. H), 7.61–7.63
(m, 2H, arom. H), 8.07 (d, J = 9.2, 1H–C(5)), 8.45 (s, 1H–C(2)), 10.20
(s, NH). 13C NMR (100 MHz, DMSO-d6): 68.07 (CH2O), 102.32,
115.85, 118.75, 120.38, 124.48, 124.51, 127.79, 128.54, 128.85,
129.49, 129.63, 132.58, 138.96, 154.96, 157.89, 162.96, 166.38
(CONH), 175.13 (C(4)). Anal. Calcd for C23H17NO4: C 74.38, H
4.61, N 3.77. Found: C 74.28, H 4.60, N 3.70.
5.2.3. Cell-cycle analysis
Exponentially growing cells were incubated with various con-
centrations of the tested compounds for the indicated times. The
cells were then fixed, incubated with RNase, and stained with

I-Li Chen et al. / Bioorg. Med. Chem. 16 (2008) 7639–7645
13. Manthey, J. A.; Grohmann, K.; Guthrie, N. Curr. Med. Chem. 2001, 8, 135.
7645
50 lg/mL of propidium iodide. DNA content was evaluated on a
14. Qin, C. X.; Chen, X.; Hughes, R. A.; Williams, S. J.; Woodman, O. L. J. Med. Chem.
2008, 51, 1874.
15. Wang, T. C.; Chen, Y. L.; Tzeng, C. C.; Liou, S. S.; Chang, Y. L.; Teng, C. M. Helv.
Chim. Acta 1996, 79, 1620.
16. Tzeng, C. C.; Zhao, Y. L.; Chen, Y. L.; Liou, S. S.; Wang, T. C.; Chang, Y. L.; Teng, C.
M. Helv. Chim. Acta 1997, 80, 2337.
Becton Dickinson FACScan flow cytometer and the percentage of
cells in various cell-cycle phases was determined by using the
ModFit LT software (Verity Software House, Inc.). For each analysis,
10,000 events were recorded.
17. Liou, S. S.; Teng, C. M.; Ko, F. N.; Lin, C. N. J. Pharm. Sci. 1994, 83, 391.
18. Zhao, Y. L.; Wang, T. C.; Chen, Y. L.; Chang, Y. L.; Teng, C. M.; Tzeng, C. C. Chin.
Pharm. J. 1999, 51, 49.
Acknowledgments
19. Delcanale, M.; Amari, G.; Armani, E.; Lipreri, M.; Civelli, M.; Galbiati, E.; Glossi,
M.; Caruso, P. L.; Crivori, P.; Corrupt, P. A.; Testa, B. Helv. Chim. Acta 2001, 84,
2417.
20. Wang, S. F.; Jiang, Q.; Ye, Y. H.; Li, Y.; Tan, R. X. Bioorg. Med. Chem. 2005, 13,
4880.
This study was supported by the National Science Council of the
Republic of China (NSC-95-2320-B-039-034-MY2, NSC-95-2320-B-
039-026-MY2) and China Medical University (CMU96-194).
21. Wang, T. C.; Zhao, Y. L.; Liou, S. S. Helv. Chim. Acta 2002, 85, 1382.
22. Chen, Y. L.; Chen, I. L.; Tzeng, C. C.; Wang, T. C. Helv. Chim. Acta 2000, 83, 989.
23. Wang, T. C.; Chen, I. L.; Lu, C. M.; Kuo, D. H.; Liao, C. H. Chem. Biodiver. 2005, 2,
253.
24. Wang, T. C.; Chen, I. L.; Lu, P. J.; Wong, C. H.; Liao, C. H.; Tsiao, K. C.; Chang, K.
M.; Chen, Y. L.; Tzeng, C. C. Bioorg. Med. Chem. 2005, 13, 6045.
25. Chen, J. J.; Huang, S. U.; Duh, C. Y.; Chen, I. S.; Wang, T. C.; Fang, H. Y. Planta
Med. 2006, 72, 935.
26. Harmange, J. C.; Weiss, M. M.; Germain, J.; Polverino, A. J.; Borg, G.;
Bready, J.; Chen, D.; Choquette, D.; Coxon, A.; DeMelh, T.; DiPietro, L.;
Doerr, N.; Estrada, J.; Flynn, J.; Graceffa, R. F.; Harriman, S. P.; Kaufman,
S.; La, D. S.; Long, A.; Martin, M. W.; Neervannan, S.; Patel, V. F.;
Potashman, M.; Regal, K.; Roveto, P. M.; Schrag, M. L.; Starnes, C.; Tasker,
A.; Teffera, Y.; Wang, L.; White, R. D.; Whittington, D. A.; Zanon, R. J. Med.
Chem. 2008, 51, 1649.
27. Chen, I. L.; Chang, K. M.; Miaw, C. L.; Liao, C. H.; Chen, J. J.; Wang, T. C. Bioorg.
Med. Chem. 2007, 15, 6527.
28. Ren, W.; Qiao, Z.; Wang, H.; Zhu, L.; Zhang, L. Med. Res. Rev. 2003, 23, 519.
29. Matsukawa, Y.; Marui, N.; Sakai, T.; Satomi, Y.; Yoshida, M.; Matsumoto, K.;
Nishino, H.; Aoike, A. Cancer Res. 1993, 53, 1328.
30. Junko, K.; Fumiko, S. N.; Masataka, M.; Yoshizumi, M. Cancer Lett. 2004, 208, 59.
31. Sato, F.; Matsukawa, Y.; Matsumoto, K.; Nishino, H.; Sakai, T. Biochem. Biophys.
Res. Commun. 1994, 204, 578.
32. Yoshida, M.; Sakai, T.; Hosokawa, N.; Marui, N.; Matsumoto, K.; Fujioka, A.;
Nishino, H.; Aoike, A. FEBS Lett. 1990, 260, 10.
References
1. The Flavonoids. Advances in Research since 1986; Harborne, J. B., Ed.; Chapman
and Hall: London, 1999.
2. Kohen, F.; Gayer, B.; Kulik, T.; Frydman, V.; Nevo, N.; Katzburg, S.; Limor, R.;
Sharon, O.; Stern, N.; Somjen, D. J. Med. Chem. 2007, 50, 6405.
3. Blank, V. C.; Poli, C.; Marder, M.; Roguin, L. P. Bioorg. Med. Chem. Lett. 2004, 14,
133.
4. Li, S.; Pan, M. H.; Lai, C. S.; Lo, C. Y.; Dushenkov, S.; Ho, C. T. Bioorg. Med. Chem.
2007, 15, 3381.
5. Cabrera, M.; Simoens, M.; Falchi, G.; Lavaggi, M. L.; Piro, O. E.; Castellano, E. E.;
Vidal, A.; Azqueta, A.; Monge, A.; de Cerain, A. L.; Sagrera, G.; Seoane, G.;
Cerecetto, H.; Gonzalez, M. Bioorg. Med. Chem. 2007, 15, 3356.
6. Kim, Y. W.; Mobley, J. A.; Brueggemeier, R. W. Bioorg. Med. Chem. Lett. 2003, 13,
1475.
7. Kim, Y. W.; Hackett, J. C.; Brueggemeier, R. W. J. Med. Chem. 2004, 47, 4032.
8. Hackett, J. C.; Kim, Y. W.; Su, B.; Brueggemeier, R. W. Bioorg. Med. Chem. 2005,
13, 4063.
9. Li, X. C.; Joshi, A. S.; ElSohly, H. N.; Khan, S. I.; Jacob, M. R.; Zhang, Z.; Khan, I. A.;
Ferreira, D.; Walker, L. A.; Broedel, S. E., Jr.; Raulli, R. E.; Cihlar, R. L. J. Nat. Prod.
2002, 65, 1909.
10. Arthan, D.; Svasti, J.; Kittakoop, P.; Pittayakhachonwut, D.; Tanticharoen, M.;
Thebtaranonth, Y. Phytochemistry 2002, 59, 459.
11. Laupattarakasem, P.; Houghton, P. J.; Hoult, J. R. S. Planta Med. 2004, 70, 496.
12. Kang, K. A.; Zhang, R.; Piao, M. J.; Ko, D. O.; Wang, Z. H.; Kim, B. J.; Park, J. W.;
Kim, H. S.; Kim, D. H.; Hyun, J. W. Bioorg. Med. Chem. 2008, 16, 1133.
33. Hosokawa, N.; Hosokawa, Y.; Sakai, T.; Yoshida, M.; Marui, N.; Nishino, H.;
Kawai, K.; Aoike, A. Int. J. Cancer 1990, 45, 1119.