Synthesis, Antiproliferative, and Multidrug Resistance Reversal Activities of Heterocyclic α,β-Unsaturated Carbonyl Compounds

Article abstract of DOI:10.1111/cbdd.12777

A series of heterocyclic α,β-unsaturated carbonyl compounds (1a-1d, 2a-2d, 3a-3d, 4a-3d, and 5a-5d) with 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore were synthesized for the development of anticancer and multidrug resistance reverting agents. The antiproliferative activities were tested against nine human cancer cell lines. Approximately 73% of the IC₅₀ values were below 5 μm, while 35% of these figures were submicromolar, and compounds 3a-3d with 4-trifluoro methyl in the arylidene benzene rings were the most potent, since their IC₅₀ values are between 0.06 and 3.09 μm against all cancer cell lines employed. Meanwhile, their multidrug resistance reversal properties and cellular uptake were further examined. The data displayed that all of these compounds could reverse multidrug resistance, particularly, compounds 3a and 4a demonstrated both potent multidrug resistance reverting properties and strong antiproliferative activities, which can be taken as leading molecules for further research of dual effect agents in tumor chemotherapy.

Full text of DOI:10.1111/cbdd.12777

Chem Biol Drug Des 2016
Research Article
Synthesis, Antiproliferative, and Multidrug Resistance
Reversal Activities of Heterocyclic a,b-Unsaturated
Carbonyl Compounds
Ju-feng Sun*, Gui-ge Hou, Feng Zhao, Wei Cong,
Hong-juan Li, Wen-shuai Liu and Chunhua
Wang*
carbonyl units with thiols existing in cellular ingredients such
as glutathione, while a number of currently available antitu-
mor agents can produce mutagenic and carcinogenic toxi-
city since they alkylate cellular nucleophile by interaction
with nucleic acid (8,9). In contrast with amino or hydroxyl
groups of nucleic acids, a,b-unsaturated carbonyl com-
pounds react preferentially or exclusively with thiols which
are not components of the nucleic acid. Thus, these
compounds may eliminate the problems of mutagenicity or
carcinogenicity associated with the alkylating agents used
in chemotherapy (10,11).
School of Pharmacy, Binzhou Medical University, Yantai,
Shandong 264003, China
*Corresponding authors: Ju-feng Sun, sjf.xzy@163.com;
Chunhua Wang, chunhuawang508@126.com
A series of heterocyclic a,b-unsaturated carbonyl com-
pounds (1a-1d, 2a-2d, 3a-3d, 4a-3d, and 5a-5d) with
1
,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore were
synthesized for the development of anticancer and
multidrug resistance reverting agents. The antiprolifer-
ative activities were tested against nine human cancer
cell lines. Approximately 73% of the IC50 values were
below 5 lM, while 35% of these figures were submicro-
molar, and compounds 3a-3d with 4-trifluoro methyl in
the arylidene benzene rings were the most potent,
since their IC50 values are between 0.06 and 3.09 lM
against all cancer cell lines employed. Meanwhile, their
multidrug resistance reversal properties and cellular
uptake were further examined. The data displayed that
all of these compounds could reverse multidrug resis-
tance, particularly, compounds 3a and 4a demon-
strated both potent multidrug resistance reverting
properties and strong antiproliferative activities, which
can be taken as leading molecules for further research
of dual effect agents in tumor chemotherapy.
The pharmacophores concerned with a,b-unsaturated
carbonyl compounds mainly include 1,3-diphenylpropen-
1
-one, 1,5-diphenyl-pent-1-en-3-one, 1,7-diphenyl-hept-3-
en-5-one 1,5-diaryl-3-oxo-1,4-pentadiene (Figure 1). In
particular, recently 1,5-diaryl-3-oxo-1,4-pentadienyl phar-
macophore with two conjugated arylidenes keto group has
been incorporated into various cyclic systems, which can
alkylate with thiols two times successively (12). Dimmock
et al. found that a,b-unsaturated carbonyl compounds dis-
play remarkable cytotoxic activity and MDR reversal activity
if heterocyclic scaffold (piperidone) is introduced into
(13,14).
Now MDR is a major cause of chemotherapeutic treatment
failure in cancer therapy. The overexpression of P-glycopro-
tein (P-gp) is considered as mostly involved in MDR through
the studied mechanisms about MDR. The pharmaceutical
strategy used to overcome MDR has been to improve the
bioavailability of chemotherapeutic agents by co-administra-
tion of P-gp inhibitors and these agents (15). The first gen-
eration P-gp inhibitors include the calcium channel blocker
verapamil and the immunosuppressant cyclosporin A. They
caused severe side-effects through associated toxicity
when administered at high doses (16). The second genera-
tion include more specific with less side-effect inhibitors,
such as dexverapamil or Dexniguldipine, which interfered
with the metabolism and excretion of cytotoxic agents by
inhibiting cytochrome P450, and then caused unpredictable
pharmacokinetic interactions (17). A third generation of
P-gp modulators comprised compounds to overcome the
limitation of the second generation, like tariquidar (18) and
zosuquidar (19), but they showed unexpected toxic effects
in clinical studies and did not display an improvement in
Key words: 4-Piperidones, antiproliferative activity, hetero-
cyclic, multidrug resistance reversal activity, a,b-Unsaturated
carbonyl compounds
Received 13 January 2016, revised 11 April 2016 and
accepted for publication 13 April 2016
Though a,b-unsaturated carbonyl compounds is always a
type of controversial substances as their Michael acceptor
activity may result in cell damage (1), many natural products
with diverse biological activities (antitumor, antioxidant, anti-
tubercular, anti-inflammatory, and multidrug resistance
(
MDR) reversal property etc.) possess a,b-unsaturated car-
bonyl units such as chalcone, curcumin, coumarin (2–7).
These compounds demonstrate cytotoxicity and novel
mechanism through the alkylation of a,b-unsaturated
ª 2016 John Wiley & Sons A/S. doi: 10.1111/cbdd.12777
1

Sun et al.
O
and different N-substituents in the heterocycle are shown
O
as Scheme 1.
A
B
A
B
B
1
,7-diphenyl-hept-3-en-5-one
1
,3-diphenylpropen-1-one
Experimental Section
O
O
Materials and methods
A
Samples for ultraviolet (UV) studies were prepared as
A
B
À5
1
0
M in methanol, and spectra were obtained with a
R
R
Beckman Du-70 ultraviolet spectrophotometer (Beckman
coulter Inc., Pasadena, CA, USA). Elemental analyses
were performed on a Perkin-Elmer Model 240c analyzer
1
,5-diphenyl-pent-1-en-3-one
1,5-diaryl-3-oxo-1,4-pentadiene
Figure 1: The main pharmacophores concerned with a,b-
unsaturated carbonyl compounds.
1
13
(
Perkin-Elmer Inc., Fremont, CA, USA). H NMR and
NMR spectra were recorded with a Bruker Avance-
00 MHz spectrometer. Chemical shifts are reported in d
C
4
therapeutic efficacy (20). Hence, new and innovative meth-
ods should be employed to revert MDR, such as the
research of molecules having a double efficacy, potent
tumor antiproliferative activity and P-gp expression inhibitory
action, and the investigation of natural products and their
analogs etc. (21,22).
relative to TMS. Antiproliferative activity was performed
using a Microplate Reader 450 (Bio-Rad Inc., Hercules,
CA, USA) enzyme-labeled instrument.
Synthesis of 1a, 2a, 3a, 4a, 5a
N-methyl-4-piperidone (0.01 mol) and the appropriate aryl
aldehyde (0.02 mol) were mixed into glacial acetic acid
(50 mL). Dry hydrogen chloride gas was added to the mix-
ture for 1 h until a clear solution was obtained. After stirred
for about 24 h at room temperature, the precipitate was
collected and washed with 40% sodium hydroxide in
water. The free base was collected and washed with water
until pH 7, then dried under the vacuum at 50–65 °C for
2 h. The compounds were recrystallized from methanol
(1a); ethanol (2a); methanol (3a); methanol-chloroform (4a);
chloroform (5a). The melting points (°C) and yields (%) of
1a-5a were as follows: 1a: 140–146, 81%; 2a: 178–180,
76%; 3a: 122–126, 80%, 4a: 121–124, 78%; 5a: 202–
204, 75%.
Flavonoids and coumarins (Figure 2) with a,b-unsaturated
carbonyl units from food and plant extracts were focused
on as the poor success of the three generations of P-gp
inhibitors (23,24). Therefore, a series of new heterocyclic
a,b-unsaturated carbonyl compounds bearing 1,5-diaryl-
3
-oxo-1,4-pentadienyl pharmacophore were designed
and synthesized to assess the antiproliferative activity and
MDR reversal effect. The structures are in accord with
the characteristics such as lipophilicity, nitrogen atom,
cation charge at neutral pH and with aromatic rings men-
tioned by Zamora et al. (25). The exploration of agents
with a dual effect, potent tumor cell-killing activity and P-
gp activity/expression inhibiting property for cancer treat-
ment remains a major goal in this study. As we found, in
our previous report (26,27), the properties of different
groups in the arylidene aryl rings can influence the
antiproliferative activity, especially the electron-withdraw-
ing groups are helpful to the potency, while the nature of
the N-substituents in the heterocycle may also have great
impact on the bioactivity. In order to further optimize the
structures on the original basis and obtain greater potent
derivatives, herein, the compounds which mainly possess
electron-withdrawing groups in the arylidene aryl rings
General synthesis of 1b-1d, 2b-2d, 3b-3d, 4b-4d,
5b-5d
1a, 2a, 3a, 4a or 5a (1 mmol) was put into N,N-dimethyl
formamide (2 mL), and heated at 80–90 °C until the solid
was dissolved. Then the mixture was added alternatively
4-fluorobenzyl bromide, benzyl bromide, or 4-methoxy
benzyl chloride (1.5 mmol). The resulting solution was stir-
red for approximately 0.5–1.5 h at 80–90 °C and detected
Figure 2: Examples of P-glycoprotein modulators: flavonoid A and coumarin B.
2
Chem Biol Drug Des 2016

Antiproliferative and MDR reversal property
Br
O
Br
Br
O
Br
VI
I
1b-1d
3
H CO
N
O
OCH
3
3
H CO
N
O
OCH
3
R
1a
X
OCH
3
OCH
3
OCH
3
OCH
3
II
VI
VI
2b-2d
F
N
O
F
F
N
O
F
R
R
2
a
X
O
N
III
3b-3d
F
3
C
N
O
CF
3
F
3
C
N
O
CF
3
3a
X
Scheme 1: Synthesis of heterocyclic a,b-
unsaturated carbonyl compounds. Reagents
and conditions: (I) 2-bromo-4,5-dimethoxy-
Br
Br
Br
Br
IV
V
VI
VI
4b-4d
N
O
N
O
benzaldehyde/CH
fluorobenzaldehyde/CH
-trifluoromethyl-benzaldehyde/CH
dry HCl; (IV) 3-bromobenzaldehyde/
CH COOH/dry HCl; (V) 4-
methoxybenzaldehyde/CH
3
COOH/dry HCl; (II) 4-
4a
R
R
X
3
COOH/dry HCl; (III)
4
3
COOH/
5b-5d
H
3
CO
N
OCH
3
H
3
CO
N
OCH
3
5a
b
c
d
X
3
3
COOH/dry HCl;
(VI) 4-fluorobenzyl bromide, benzyl bromide
R
X=Br or Cl
or 4-methoxy benzyl chloride/N,N-dimethyl
formamide.
F
OCH
3
by TLC (chloroform:methanol = 10:1 or 15:1). After the
reaction was complete, appropriate diethyl ether was
added to the mixture, then the precipitate was collected,
and dried in vacuo. The compounds were recrystallized
from methanol or methanol-chloroform (1b-1d and 2b-2d),
or 95% ethanol or chloroform (3b-3d), or acetone or
methanol (4b-4d), or methanol-chloroform (5b-5d). The
melting points (°C) and yields (%) of 1b-1d, 2b-2d, 3b-3d,
aryl rings of parent 3,5-bis(arylidene)-4-piperidones and
the proximal olefinic linkages for most of compounds
except 1a, 2a, 3a, 4a, 5a (14,26), while the corresponding
carbon signals in the C NMR spectra were not influ-
enced.
13
In vitro antiproliferative activity and antitumor
activity
Nine human tumor cell lines, including A549, Hela, HT-
29, K562, MCF-7, U937, U87, U251, and HepG2 which
come from respiratory system, reproductive system,
digestive system, circulatory system, immune system
4b-4d, 5b-5d were as follows: 1b: 170–173, 45%; 1c:
156–159, 49%; 1d: 152–155, 51%; 2b: 226–229, 43%;
2c: 137–142, 48%; 2d: 206–207, 68%; 3b: 186–189,
52%; 3c: 194–196, 65%; 3d: 185–188, 61%, 4b: 156–
159, 50%; 4c: 148–151, 55%; 4d: 125–128, 59%, 5b:
158–160, 52%; 5c: 147–149, 52%; 5d: 143–144, 67%.
and nervous system and
a
human umbilical vein
endothelial cell line (HUVEC) were used to evaluate com-
pounds 1a-1d, 2a-2d, 3a-3d, 4a-4d, and 5a-5d in order
to confirm whether their antiproliferative activities toward
variety of neoplasms can be displayed. The results are
tabulated in Table 1, summarizing the corresponding
IC50 values (The concentration of the drug that inhibits
cells growth by 50%).
Results and Discussion
Synthesis and structures
The compounds 1a-1d (series 1), 2a-2d (series 2), 3a-3d
(series 3), 4a-4d (series 4), and 5a-5d (series 5) were syn-
thesized by the synthetic routes as shown in Scheme 1.
Dry hydrogen chloride was used as the catalyst to make
various aryl aldehydes react with N-methyl-4-piperidone
via a Claisen-Schmidt condensation, resulting in the target
intermediates of 1a, 2a, 3a, 4a, and 5a. After treatment of
these compounds using 4-fluorobenzyl bromide, benzyl
bromide, or 4-methoxy benzyl chloride, respectively, the
corresponding heterocyclic a,b-unsaturated carbonyl com-
pounds 1a-1d, 2a-2d, 3a-3d, 4a-4d, and 5a-5d were
obtained. The yields of the compounds were between
The biological evaluation revealed that the compounds
synthesized demonstrate potent antiproliferative activity
toward Hela, HT-29, K562, U937, U87, U251 and HepG2
cell lines, and Hela, K562 and U87 are the most sensitive
to these compounds, while A549 and MCF-7 are particu-
larly refractory to them. The data in Table 1 showed that
73% of the IC50 values of the compounds in series 1–5
toward nine human tumor cells are less than 5 lM, while
35% of these figures are submicromolar. Overall these
compounds are substantially more potent than a reference
anticancer drug Cisplatin (CDDP) against almost all tumor
cells used. In particular, compounds 3a-3d bearing large
and strong electron-withdrawing group 4-trifluoromethyl in
4
3% and 81%. Their structures were completely charac-
1
13
terized by H NMR, C NMR and elemental analysis. The
NMR signals of CH2 groups in the central piperidone ring
split because of the effect of non-coplanarity between two
Chem Biol Drug Des 2016
3

Sun et al.
the arylidene benzene rings displayed the greatest antipro-
liferative activity, and 64% of the IC50 values of them are
submicromolar. The possible reason is that electron-with-
drawing groups are helpful to diminish the electron density
on the adjacent olefinic carbon atoms, which may result in
the nucleophilic attack more easily by cellular components,
for instance thiols (28).
with antitumor activity which can revert MDR may be
found to be useful as dual agents. It can be seen from
Figure 3 that all of the compounds synthesized possess
MDR reverting properties compared with the positive con-
trol, and 80% of the compounds made the expression
level of resistance gene MDR1 decrease to <65%, in con-
trast with the positive control. In general, the potency of
QAS derivatives 1b-1d, 2b-2d, 3b-3d, 4b-4d, and 5b-5d
is lower than or almost the same as that of the corre-
sponding tertiary amines 1a, 2a, 3a, 4a, and 5a with the
exception of 2b. The expression level of compounds 3a-
3d with 4-trifluoro methyl and 4a-4d with 3-bromo in the
arylidene aryl rings drops to 11–38% and 31–46% sepa-
rately, which shows these derivatives are greater potent
than the other corresponding analogs with the same N-
substituted groups whose expression level declines to 42–
88%. In particular, compounds 3a and 4a displayed both
potent MDR reverting properties and strong antiprolifera-
tive activities, which is clearly a prospective prototype
molecule for the development of dual effect agents.
Since it has been reported that a number of quaternary
ammonium salts (QAS) have displayed significant antiprolif-
erative ability (29–32), here the compounds synthesized
were designed to form N-methyl-N-substituted benzyl
QAS on the piperidone nitrogen, however, there was no
remarkable changes of the activity against all tumor cell
lines used except for HT-29. The antiproliferative activities
of compounds 1a, 2a, 3a, 4a, 5a with N-methyl was less
potent than those of their corresponding QAS 1b-1d, 2b-
2
d, 3b-3d, 4b-4d, and 5b-5d against HT-29, while for the
other tumor cell lines, the antitumor activities of most of
QAS were not as the same as those of their non-QAS
derivatives. The positive charge of nitrogen atom in QAS
derivatives might exert a negative influence on the penetra-
tion of the molecules to the action sites through cell mem-
branes. Another purpose of preparing these QAS
derivatives is to improve their solubility, as it has been
found that the solubility of this type of non-quaternary
derivatives is poor in our previous studies (31,32), thus
resulting in certain difficulty during the biological evalua-
tion.
The evaluation of the expression level of P-gp
through western blot
The investigation was performed to further confirm the
effect of the compounds synthesized on the expression
level of resistance protein P-gp by western blot. The repre-
sentative compounds 1a, 2a, 3a, 4a, and 5a were chosen
to make the assay. The results are presented in Figure 4
and Table 3, taking the ratio of P-gp/b-actin as the relative
expression level of protein. Obviously, compounds 1a, 2a,
3a, 4a, and 5a all can make the expression level of P-gp
reduce. The ratios of P-gp/b-actin in the K562/DOX trea-
ted with compounds 1a, 2a, 3a, 4a, and 5a are less than
that of the control, especially, the ratios handled with com-
pounds 3a and 4a are just around one-third of that of the
control. The important molecular features of promising
MDR reversal agents are conjugated and coplanar aro-
matic rings, nitrogen atoms with basicity and good
lipophilicity, particularly piperidine and piperazine rings
existing in the molecules are more potent (14,27). There-
fore, compounds 3a and 4a were introduced hydrophobic
4-trifluoromethyl and 3-bromo in the arylidene aryl rings
respectively. Meanwhile, the piperidine rings and basic
nitrogen atoms which can provide hydrogen bond are all
helpful to the activity, resulting in the enhancement of
MDR reversal property.
In addition, in order to discern that these compounds
demonstrated selective antiproliferative activity to tumor
cells compared with normal cells, all the compounds were
examined with normal human cell line (Human umbilical
vein endothelial cells, HUVEC), which is widely used to
investigate the pathogenetic mechanism of tumors. All
these compounds showed certain selectivity toward most
of the tumor cells used. The selectivity index (SI) figures for
compounds 3a-3d with remarkable activity were com-
puted, which are the ratios of the IC50 value of each com-
pound toward HUVEC cell and the IC50 figure against a
certain malignant cell line. The SI figures are summarized
in Table 2. All SI figures for compounds 3a-3d are over 1,
and 94% of them are >5 which can be regarded as the
evidence of significant preferential toxicity for malignant
cells. The results indicated the importance of compounds
3
a-3d as promising antitumor lead molecules.
Multidrug resistance reversal activities
The investigation of cellular uptake in vitro
Quantitative real time polymerase chain reaction
Cellular uptake of compounds synthesized was detected
qualitatively by confocal laser scanning microscopy
(CLSM), as the fluorescence of these compounds can
allow the visualization inside the cells. The effect of repre-
sentative compounds 3b, 3d, 1d, and 5b on the cellular
uptake of HepG2 cells is shown in Figure 5. By analyzing
the data obtained from treating the cells for 1 h, it could
be found that most of these compounds mainly
(qPCR)
As multidrug-resistant property has become one of the
major reasons which cause the failure of cancer
chemotherapy, and the co-administration between anti-
cancer drugs and MDR reversal agents often cannot
obtain the desirable effect due to the pharmacokinetics
conflicts of two types of drugs. Thus these compounds
4
Chem Biol Drug Des 2016

Antiproliferative and MDR reversal property
Chem Biol Drug Des 2016
5

Sun et al.
Table 2: Antiproliferative activity of compounds 3a-3d and selectivity index (SI) values versus HUVEC
a
IC50 (lM)/SI
Comp. A549
Hela
0.09 (163)
1.39 (7.1)
0.28 (140)
1.22 (19)
HT-29
K562
MCF-7
U937
U87
U251
HepG2
HUVEC
3
3
3
3
a
b
c
d
0.98 (15)
0.97 (10)
1.45 (27)
0.3 (83)
1.71 (8.6)
0.68 (14)
0.41 (95)
0.39 (64)
0.23 (64)
3.09 (3.2)
2.13 (18)
1.53 (16)
0.54 (27)
1.09 (9.0)
1.23 (32)
0.91 (28)
0.24 (61)
2.39 (4.1)
0.4 (98)
0.67 (22)
1.92 (5.1)
0.37 (105)
0.23 (109)
>100
0.64 (23)
1.01 (9.7)
3.09 (13)
0.75 (34)
>100
0.53 (28) 14.7
0.41 (24)
0.57 (69) 39.05
0.88 (29) 25.13
57.67
9.82
0.06 (419)
CDDP 46.8 (0.7)
18.48 (1.7)
11.93 (2.7) >100
20.89 (1.5) 16.76 (1.9)
32.27
a
The digits in the brackets represent SI.
Control
1
0
0
0
0
0
.0
.8
.6
.4
.2
.0
*p<0.05
*
*
*
*
*
*
Figure 4: The effect of compounds 1a, 2a, 3a, 4a, and 5a on
the expression level of resistance protein P-glycoprotein detected
by western blot.
*
*
*
*
*
*
*
*
*
*
*
*
*
3b
3d
1d
5b
*
1
a 2a 3a 4a 5a 1b 2b 3b 4b 5b 1c 2c 3c 4c 5c 1d 2d 3d 4d 5d
Groups
Figure 3: The effect of compounds 1a-1d, 2a-2d, 3a-3d, 4a-4d,
and 5a-5d on the expression level of resistance gene MDR1
detected by qPCR; The control is K562/DOX without treated with
any compounds. The bars are the average tests and the standard
deviations (n = 3) are presented.
accumulate into the nuclei (such as 3b and 3d) except for
compounds 1d, 2a, 2b, 3c, 5b, 5c, and 5d which a little
amount can be observed in the cytoplasma. This may be
caused by different transport procedures of different com-
pounds, and the mechanism of action should be further
studied in the future.
Figure 5: The cellular uptake of HepG2 cells observed by CLSM.
Scale bar: 50 lM.
these compounds displayed preferential toxicity toward
cancer cells. Moreover, the study of multidrug resistance
reversal property confirmed that all the compounds syn-
thesized can reverse MDR, particularly, compounds 1a,
Conclusion
2
a, 3a, 4a, and 5a as the tertiary amines are more
A number of heterocyclic a,b-unsaturated carbonyl com-
pounds with 1,5-diaryl-3-oxo-1,4-pentadienyl pharma-
cophore were shown to possess remarkable activity
against various human cancer cell lines, and most of
potent. The data presented in this work can be the
guideline for the molecular modification of dual effect
compounds with both MDR reversal property and antipro-
liferative activity in the future.
Table 3: The evaluation of P-glycoprotein expression level in K562/DOX treated with 0.5 lM compounds 1a, 2a, 3a, 4a, and 5a respec-
tively
Control
1a
2a
3a
444
4a
584
5a
893
P-gp
1701
1402
1524
b-actin
Ratio
2394
71.05%
2361
59.38%
2730
45.93%
2199
20.19%
2221
26.29%
2034
43.97%
6
Chem Biol Drug Des 2016

Antiproliferative and MDR reversal property
Acknowledgments
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9
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We are acknowledged with gratitude for financial support
from National Natural Science Foundation of China (No.
9. Silverman R.B. (1992) The Organic Chemistry of Drug
Design and Drug Action. San Diego: Academic Press
Inc.; p. 220–222.
21402010), the Natural Science Foundation of Shandong
Province (Nos. ZR2014BL008, ZR2013BM022), the
Youth Science Foundation of Shandong Province
10. Chien C.I., Kirollos K.S., Linderman R.J., Dauterman
W.C. (1994) Alpha, beta -unsaturated carbonyl com-
pounds: inhibition of rat liver glutathione S-transferase
isozymes and chemical reaction with reduced glu-
tathione. Biochim Biophys Acta;1204:175–180.
(2015GGX102013), the Foundation of higher institution of
Shandong Province (J11LF27), and the Foundation of
Yantai (Nos. 2013ZH095, 2011076, 2015WS010).
1
1. Dimmock J.R., Elias D.W., Beazely M.A., Kandepu
N.M. (1999) Bioactivities of chalcones. Curr Med
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Conflict of Interest
1
2. Das U., Gul H.I., Alcorn J., Shrivastav A., George T.,
Sharma R.K., Nienaber K.H. et al. (2006) Cytotoxic 5-
aryl-1-(4-nitrophenyl)-3-oxo-1,4-pentadienes mounted
on alicyclic scaffolds. Eur J Med Chem;41:577–585.
All authors declare no conflict of interest.
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dones with fluorescence.
J
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Appendix S1. H NMR, C NMR, elemental analysis and
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evaluations.
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