Synthesis and anti-inflammatory activity of paeonol analogues in the murine model of complete Freund's adjuvant induced arthritis

Article abstract of DOI:10.1016/j.bmcl.2016.09.060

A new series of paeonol alkyl ether analogues were synthesized and confirmed with IR,¹H NMR,¹³C NMR and HRMS spectra. They have shown anti-inflammatory activities by scavenging mediator of free radicals and inhibiting lipid mediator

Full text of DOI:10.1016/j.bmcl.2016.09.060

Accepted Manuscript
Synthesis and anti-inflammatory activity of paeonol analogues in the murine
model of complete freund’s adjuvant induced arthritis
Ligua Huang, Baoshun Zhang, You Yang, Xiaobao Gong, Zhu Chen, Zhenxu
Wang, Peng Zhang, Qingyan Zhang
PII:
S0960-894X(16)31009-5
DOI:
http://dx.doi.org/10.1016/j.bmcl.2016.09.060
BMCL 24284
Reference:
To appear in:
Bioorganic & Medicinal Chemistry Letters
Received Date:
Revised Date:
Accepted Date:
9 April 2016
1 September 2016
24 September 2016
Please cite this article as: Huang, L., Zhang, B., Yang, Y., Gong, X., Chen, Z., Wang, Z., Zhang, P., Zhang, Q.,
Synthesis and anti-inflammatory activity of paeonol analogues in the murine model of complete freund’s adjuvant
induced arthritis, Bioorganic & Medicinal Chemistry Letters (2016), doi: http://dx.doi.org/10.1016/j.bmcl.
2
016.09.060
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Synthesis and anti-inflammatory activity of paeonol analogues in the
murine model of complete freund’s adjuvant induced arthritis
a,
a,
b
a
c
Ligua Huang *, Baoshun Zhang *, You Yang , Xiaobao Gong , Zhu Chen ,
c
d
d 
Zhenxu Wang , Peng Zhang , Qingyan Zhang
a
College of Pharmaceutical Sciences, Southwest University, Chongqing 400716, P.R.China
College of Animal Science and Technology, Southwest University, Chongqing 400716, P.R.China
Chongqing Institute for Food and Drug Control, Chongqing 401211, P.R.China
The Ninth People’s Hospital of Chongqing, Chongqing 400700, P.R.China
b
c
d
Abstract:
A new series of paeonol alkyl ether analogues were synthesized and confirmed with
1
13
IR, H NMR, C NMR and HRMS spectra. They have shown anti-inflammatory
activities by scavenging mediator of free radicals and inhibiting lipid mediator of
inflammation on complete Freund’s adjuvant (CFA) induced arthritis in mice. The in
vitro and in vivo scavenging ability of free radicals was determined by using chemical
analysis and commercial assay kits, respectively. The in vivo inhibiting lipid mediator
of inflammation was examined by ELISA. Our results indicated that the substitution
of the hydrogen in hydroxyl group at C
in the presence or absence of bromo atom at C
ability on radicals (3a or 4a vs 1), while the long alkyl substitution (C
2
position of paeonol 1 by short carbon chain,
5
position, decreased its scavenging
n
>14) increased
the activity. Compared with 3a or 4a, scavenging abilities of 3a-h or 4a-h gradually
increased following the length elongation of alkyl carbon chain. Compounds 3h and
-
+
4
h showed great scavenging ability on ·OH, O · , DPPH, ATBS and MDA, and good
2

*
These authors contributed equally to this work.
Correspondence to: Baoshun Zhang; tel: +86 23 68251225; fax: +86 23 68251046.
E-mail: zbs360@swu.edu.cn (B.S. Zhang)

promotion on T-AOC and SOD. The results of the in vivo inhibiting lipid mediator of
inflammation also demonstrated that 3h, 4h exhibited substantial inhibition on
enzyme activity of COX-2, PGE2. Therefore, 3h and 4h have great potential to be the
novel anti-inflammatory drug candidates for the therapy of arthritis.
Keywords: Paeonol analogues; Free radicals; Anti-inflammatory; Cyclooxygenase-2
Rheumatoid arthritis (RA), which affects nearly 1% of the world’s population and
1
places a significant burden upon society and patients, is a serious, chronic and
debilitating autoimmune disease characterized by inflammation and progressive joint
destruction. Disease progression leads to bone, cartilage, and ligament destruction
resulting in pain, stiffness, and deformity.
The drug treatment focuses on the use of nonsteroidal antiinflammatory drugs
2
(
NSAIDs) and disease-modifying anti-rheumatic drugs (DMARDs). The main target
for NSAID is to inhibit cyclooxygenase (COX). COX is one of the key enzymes
3
involved in the degradation of arachidonic acid to prostaglandins (PG
S
). COX-2 is
inducible and expressed mainly in inflammatory cells and COX-1 is cytoprotective
and constitutively expressed in many tissues such as stomach, kidney, and platelets.
Although NSAIDs are widely used to treat pain, fever, and inflammatory conditions,
4
they can offer only palliative relief and do not halt disease progression. Disease-
modifying antirheumatic drugs (DMARDs) remain the first line of treatment for the
5
majority of patients due to low cost and ability to retard disease at early onset.
However, there are still more drawbacks related to production efficiency and
administration by injection. Furthermore, side effects tend to be serious and
opportunistic infections may arise with fatal consequences.
Now treatment for RA has made significant advances over the last several
decades, particularly since the introduction of biological therapies. Despite the
discovery of many biological agents, there is still significant unmet medical need for
safe and efficacious treatments for inflammatory, autoimmune diseases, and with
6
different mechanism of action for patients unresponsive to current therapies.
Moutan cortex radicis (MC), the roots of Paeonia suffruticosa Andrews
(
Ranunculaceae), are traditionally used in Chinese herbal medicine as an anti-

inflammatory, antibacterial, antioxidant, antipyretic and analgesic agents for more
7
than a thousand years. The chemical constituents of MC include paeonolide,
paeonifolorin, polysaccharides, steroids, and gallic acid. Paeonol (2-hydroxy-4-
methoxyacetophenone) , the major phenolic component of MC, has been reported to
8
9
10
possess anti-inflammatory, anti-hepatitis B virus, reducing myocardial damage,
11
12
13
antibacterial, antidiabetic and antioxidant properties. In the regard of anti-
inflammation, paeonol can inhibit the expression of cell surface adhesion molecules,
reactive oxygen species production, proinflammatory cytokines such as TNF-α and
1
4
IL-1β. Nowadays in Chinese medical market, paeonol has been prepared as different
drug formations (tablets, ointments, injections) to treat skin pruritus, pain and
rheumatoid arthritis. In addition, a large number of studies have also demonstrated
1
5
that paeonol derivatives are associated with several biological activities. Qin
reported that paeonol Schiff-base derivatives could form complexes with copper ions
and showed high antioxidant activity, moderate DNA-binding activity, and excellent
1
6
tumor cell cytotoxicity. Zhu presented that paeonol thiosemicarbazone derivatives
are potential mushroom tyrosinase inhibitors. However, there is little literature to
study the relationship between paeonol derivatives and their anti-inflammatory
activities.
Therefore, we aim at synthesizing these compounds and evaluating their abilities of
scavenging free radicals and inhibiting inflammatory factors in the murine model of
complete freund’s adjuvant induced arthritis.
As illustrated in Figure 1, the bromination of paeonol 1 to important intermediate
2
followed by the etherification with different substituted alkyl halides in the presence
of K CO and acetone, afforded paenol ether analogues 3a-h. Direct etherification of
2
3
paeonol 1 obtained paenol ether analogues 4a-h. Characterizations of these
synthesized compounds were performed by infrared spectroscopies (IR), high
resonance mass spectrometry (HRMS) and nuclear magnetic resonance (NMR). Their
physical properties were summarized in Figure S1.
The in vitro scavenging abilities of synthetic compounds on superoxide radical
-
(
O
2
· ), hydroxyl radical (·OH), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2´-
+
azino-bis-3-ethylbenzthi-azoline-6-sulphonic acid (ABTS ) radical were measured by

Figure 1 Protocol for synthesis of paeonol analogues
(
2 3 2 3
a) Br , anhydrous AlCl3, CHCl , ice-water bath; (b) Bromoalkanes, K CO , DMF, acetone, 60℃
1
7
18
19
20
the modified method of Pyrogallol autotrophic , Yu , Sachindra and Feng ,
respectively. Trolox was used as a positive control. The data were depicted in Table 1.
Compared to the lead compound 1, the scavenging ability of 3a-3h and 4a-h on
free radicals firstly decreased and then increased with the carbon chain extension. 3h
exhibited extremely significant difference (3h vs 1, P < 0.01); 4h had no difference
(
4h vs 1). When 3a-h and 4a-h compared with 3a and 4a respectively, the scavenging
ability on free radicals increased with the length elongation of carbon chain. The
scavenging effects of 3a-h showed better than its corresponding compounds 4a-h.
-
+
The IC50 values of 3h on O
2
· , DPPH, ·OH and ABTS were 1.8, 6.5, 0.1, 4.6 mM,
-
+
respectively; the IC50 values of 4h on O
2
· , DPPH, ·OH and ABTS were 39.4, 39.4,
6
1.5 and 36.3 mM, respectively. Based on the above findings, the introduction of long
alkyl group (C >14) and bromine moiety into the lead compound could increase the
n
in vitro scavenging abilities on free radicals. The influences of the title compounds on
paw swelling degrees were observed in the murine model of complete Freund's
adjuvant (CFA)-induced arthritis (Figure S ).
2

Table 1 The half maximal inhibitory concentrations (IC50) of scavenging activity of title
x  s
compounds and positive control (mM) (
, n =6)
-
+
Compd.
O
2
· (mM)
DPPH (mM)
·OH (mM)
ABTS (mM)
Trolox
0.6 ± 0.1
5.8 ± 0.0
0.2 ± 0.1
0.2 ± 0.1
0.2 ± 0.1
0.3 ± 0.0
1
42.8 ± 2.6
16.0 ± 1.0
2
15.6 ± 0.5
37.9 ± 0.2
38.2 ± 0.5
34.0 ± 1.0
30.9± 1.0
15.0 ± 0.3
10.6 ± 0.4
6.8 ± 0.4
41.8 ± 8.4
46.8 ± 3.0
42.3 ± 8.1
42.4 ± 9.9
39.0 ± 2.0
35.1 ± 5.6
29.5 ± 1.7**
16.1 ± 0.6**
6.5 ± 0.4**
39.6 ± 5.1
43.3 ± 2.3
42.6 ± 3.6
40.0 ± 9.5
40.1 ± 7.7
37.4± 5.6
3.0 ± 0.1
31.4 ± 2.2
36.0 ± 0.4
34.1 ± 0.8
35.7 ± 4.0
32.0 ± 2.7
34.7 ± 5.8
32.7 ± 4.2
8.7 ± 1.2**
4.6 ± 0.9**
37.7 ± 2.5
36.3 ± 1.5
42.1 ± 0.9
38.3 ± 1.0
41.7 ± 3.2
40.7 ± 2.5
38.0 ± 1.7
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
a
b
c
d
e
f
57.7 ± 1.6
56.9 ± 1.9
53.1 ± 2.5
38.1 ± 15.0
29.7 ± 13.2
23.1 ± 10.8
13.2 ± 5.3
0.1 ± 0.0**
35.3 ± 8.4
57.2 ± 2.0
84.4 ± 5.6
69.4 ± 3.1
57.4 ± 4.0
65.6± 10.8
57.0 ± 7.2
g
h
a
b
c
d
e
f
1.8 ± 0.1**
6.6 ± 0.5
15.6 ± 0.5
18.0 ± 0.3
21.2 ± 0.9
26.6 ± 0.5
28.5 ± 0.5
35.9 ± 1.1
g
43.6 ± 4.1
4h
39.4 ± 0.5
39.4 ± 0.9
61.5± 6.7
36.3 ± 4.9
*P < 0.05, **P < 0.01 vs compd. 1. All experiments were run in triplicat.

After the administration of the CFA, paw swelling degrees in arthritis mice
gradually increased till the maximum degree at the thirteenth day. Therefore, the
administrations of these compounds were performed seven days after the model was
established successfully, to evaluate the effects of synthetic compounds on paw edema
in mice.
1
3
Day
Day
&&
5 Day
70
60
50
40
30
20
10
0
#
*
# &&
Mod Cel 1-H 1-L 2-H 2-L 3h-H 3h-L 4h-H 4h-L
Compounds
Figure 2 Effects of different compounds on paw swelling inhibition in the murine model of
complete Freund's adjuvant (CFA) induced paw edema. Results are expressed as mean±SD and
#
&
analyzed by two-way ANOVA followed by multiple comparison tests. *, , P < 0.05 considered
#
#
&&
to be significant difference compared to Celecoxib group. **,
extremely significant difference compared to Celecoxib group.
,
P < 0.01 considered to be
In order to study the effects of different compounds on paw swelling inhibition, we
employed the mice model of CFA-induced paw edema with Celecoxib as positive
control. As shown in Figure 2, compounds 1, 2, 3h, 4h had good inhibitory activity on
-1
-1
mice paw edema. The high dose (100 mg·kg ·d ) of these compounds were better
-1
-1
than the low dose (25 mg·kg ·d ). The paw swelling inhibitions were up to 45% and
5% at the high dose of 3h, 4h, respectively. Compared to Celecoxib (Cel) group, the
inhibition of paw swelling with the high dose of 3h exhibited significant difference (P
0.05) and the high dose of 4h had shown extremely significant difference (P < 0.01)
6
<

after the third day. Compounds 3h and 4h had excellent inhibition on mice paw
edema.
The effects of these synthetic compounds on the in vivo activity of COX-2,
prostaglandin E2 (PGE2), malondialdehyde (MDA) and superoxide dismutase (SOD),
and total anti-oxidation capacity (T-AOC) in the mice serum were evaluated with
chemical assay kit using Cel as a positive control, shown in Table 2.
Table 2 Influence of different compounds on the in vivo concentrations of COX-2, PGE2, MDA,
x  s
T-AOC and SOD in the serum of mice (
, n =6 )
Compd.
COX-2
ng/L)
PGE2
(ng/L)
MDA
(nmol/ml)
6.1 ± 0.3
15.5 ± 1.1
T-AOC
(U/ml)
SOD
(
(U/ml)
Control
60.4 ± 1.4
112.4 ± 1.6
6.9 ± 1.1
2.9 ± 0.5
90.8 ± 1.3
66.7 ± 0.9
78.0 ± 2.1*
68.1 ± 3.7
62.5 ± 2.4
78.1 ± 1.3*
76.3 ± 2.0*
Model
Cel
85.3 ± 0.1
207.0 ± 2.1
61.6 ± 0.4**
61.1 ± 2.4**
66.2 ± 0.5*
57.6 ± 4.8**
65.4 ± 2.2**
64.7 ± 2.3**
63.9 ± 0.2**
64.4 ± 2.4**
65.2 ± 0.8**
135.3 ± 1.2**
137.1 ± 5.0**
155.5 ± 4.1**
142.3 ± 7.3**
179.5 ± 3.5*
150.1 ± 3.1**
189.3 ± 6.4*
159.4 ± 2.3**
182.2 ± 4.3*
7.3 ± 0.7** 6.3 ± 0.3**
7.9 ± 0.3** 4.1 ± 0.7
8.9 ± 0.1** 4.6 ± 0.2*
6.4 ± 0.2** 6.0 ± 0.1**
9.9 ± 0.2** 3.8 ± 0.7
1
1
2
2
3
3
4
4
-H
-L
-H
-L
h-H
h-L
h- H
h-L
5.8 ± 0.3** 11.6 ± 0.5** 76.2 ± 3.1*
7.5 ± 0.1** 6.5 ± 0.3** 73.9 ± 4.3
8.8 ± 0.4** 16.9 ± 0.4** 80.7 ± 1.1*
9.7 ± 0.5* 11.1 ± 0.3** 72.1 ± 3.2
-
1
-1
The dose of Celecoxib group was 30 mg·kg ·d ; The high dose of compounds group were 100
-1
-1
-1 -1
mg·kg ·d ; The low dose of compounds group were 25 mg·kg ·d ; *P < 0.05, **P < 0. 01 vs
Model group.
Compounds 1，2，3h, 4h could inhibit the in vivo levels of COX-2, PGE2 and MDA
activities, and increase their T-AOC and SOD activities, and especially the high dose
-
1
-1
-1 -1
(
100 mg·kg ·d ) of these compounds were better than the lowers (25 mg·kg ·d ). The
biological effects of those high dose of compounds 2，3h, 4h showed either significant
differences (P < 0.05) or extremely significant differences (P < 0. 01) compared to the
lead compound 1.
Compared to 1, the scavenging ability of 3h exhibited extremely significant
difference (P < 0.01); 4h had no difference. The introduction of bromine on paeonol
might be responsible for the promotion of pharmacological activity. Furthermore,
when compared with 1, the scavenging ability of 3a-h and 4a-h on free radicals firstly
decreased and then increased with the carbon chain extension. Our results indicated

that the substitution of the hydrogen in hydroxyl group at C
short carbon chain, in the presence or absence of the bromine atom at C
decreased its scavenging ability on radicals (3a or 4a vs 1), while the long alkyl
substitution (C >14) increased the activity, which might result from the change of
2
position of paeonol 1 by
5
position,
n
lipophilic/hydrophobic property and stereoscopic size. As known that, homologous
effect in those analogues resulted in physical and chemical properties changing in
2
1
sequence. If the biological activity of those analogues was related to water solubility,
in other words, those compounds only in a water soluble state displayed their
biological activities, the higher water solubility attributed to the stronger biological
activity. Because the hydroxyl group possessed a hydrophilic property and the short
alkoxyl group had a lipophilic property, paeonol 1 had higher water solubility than its
derivatives 3a and 4a, resulting in the stronger scavenging ability of paeonol 1 than
them.
The scavenging abilities of 3a-h or 4a-h gradually increased following the length
elongation of alkyl carbon chain, compared with 3a or 4a. When the number of
carbon exceeded fourteen (C >14), the biological activity of 3h and 4h became good.
n
The in vivo experimental data had also demonstrated 3h and 4h exhibited the best
biological activities. Taking the data of COX-2 as an example, there was
supplementary effect between the ligand homologue and the receptor COX-2 enzyme
2
2
according to induced-fit theory in vivo . If the active site of COX-2 enzyme receptor
had enough space, when the volume of alkyl partition in homologue increased and
was fitted to the supplement with the stereoscopy of COX-2 enzyme receptor, the
biological activity promoted with the increase of carbon number. That was the most
likely explanation for 3a-h or 4a-h, which scavenging abilities gradually increased
with the extension of alkyl carbon chain.
As we known, inflammatory disease was resulted from the stimulation of
2
3
inflammatory mediators such as free radicals and lipid mediators. From the
preliminary results of scavenging abilities of those analogues on free radicals in vitro,
3
h and 4h had good ability, however, 3h exhibited better ability among them.
According to the screening result, the in vivo inhibition of 3h, 4h on CFA-induced

paw swelling in mice had been observed. They also showed good inhibition, and
especially 4h had stronger inhibition. Thus, 3h and 4h should be considered as the
lead compounds for further investigation on anti-inflammatory drug candidates.
Although the anti-inflammatory activities of those new synthetic compounds with
the introduction of alkyl side chains into the paeonol scaffold were not as good as Cel
with the same dosage, their biological activities have increased a lot compared to the
lead compound 1. In other words, the etherification of paeonol with the long alkyl
chain could promote the anti-inflammatory activity of paeonol. In order to further
study the relationship between the structures and the anti-inflammatory activity, more
paeonol derivatives needed to be synthesized.
In conclusion, inspired by the functional scaffold of paeonol, we have demonstrated
that some alkyl ether analogues of bromo-paeonol exhibited anti-inflammatory
activities. The introduction of bromine and the long alkyl chain group on paeonol
might be the major factor contributing to their pharmacological properties. Therefore,
3
h and 4h have great potential to be the novel anti-inflammatory drug candidates for
the therapy of arthritis.
Acknowledgements
We would like to thank Prof. Erkang Fan (University of Washington, USA) for
helpful discussions and technical assistance. This work was supported by grants from
National Natural Science Foundation of China (21402160), Chongqing Foundation
and Cutting-edge Research Plan Project (cstc2013jcyjA10070), Chongqing Science
and Technology Project (2013GS500102-D2014-5), Chongqing Social Undertaking
and Livelihood Security Project (cstc2016shmszx130063)，Fundamental Research
Funds for the Central Universities (XDJK2013B040) and Medical & Scientific
Research projects of Chongqing Municipal Health Bureau (2011-1-114).
Supplementary data
Supplementary data (General procedures and spectral data) associated with this
article can be found on the attachment.

References and notes
1
2
. Isaacs, J.D. Nature Rev. Immunol. 2010, 10, 605.
. Miwatashi, S.; Arikawa, Y.; Kotani, E.; Miyamoto, M.; Naruo, K.; Kimura, H.; Tanaka, T.;
Asahi, S.; Ohkawa, S. J. Med. Chem. 2005, 48, 5966.
3
4
5
. (a) Chowdhury, M.A.; Abdellatif, K.R.A.; Dong, Y.; Das, D.; Suresh, M.R.; Knaus, E.E. J.
Med. Chem. 2009, 52,1525. (b)Almansa, C.; Bartrolí, J.; Belloc, J.; Cavalcanti, F.L.; Ferrando,
R.; Gómez, L.A.; Ramis, I.; Carceller, E.; Merlos, M.; García-Rafanell, J. J. Med. Chem. 2004,
4
7, 5579.
. (a) Portevin, B.; Tordjman, C.; Pastoureau, P.; Bonnet, J.; Nanteril, G.D. J. Med. Chem. 2000,
3, 4582. (b)Koch, K.; Melvin, L.S.; Reiter, L.A.; Biggers, M.S.; Showell H.J.; Griffiths, R.J.;
4
Pettipher, E.R.; Cheng J.B.; Milici, A.J.; Breslow, R.; Conklyn, M.J.; Smith, M.A.; Hackman,
B.C.; Doherty, N.S.; Salter, E.; Farrell, C.A.; Schulte, G. J. Med. Chem. 1994, 37, 3197.
. Safina, B.S.; Baker, S.; Baumgardner, M.; Blaney, P.M.; Chan, B.K.; Chen, Y.H.; Cartwright,
M.W.; Castanedo, G.; Chabot, C.; Cheguillaume, A.J.; Goldsmith, P.; Goyal, B.; Hancox, T.;
Handa, R.K.; Iyer, P.S.; Kaur, J. Kondru, R.; Kenny, J.R.; Krintel, S,L.; Li, J.; Sohal, S.
Sweeney, Z.K.; Tay, S.; Tivitmahaisoon, P.; Waszkowycz, B.; Wei, B.Q.; Yue, Q.; Zhang,C.H.;
Sutherlin, D.P. J. Med. Chem. 2012, 55, 5887.
6
7
. Lou, Y.; Han, X.; Kuglstatter, A.; Kondru, R.K.; Sweeney, Z.K.; Soth, M.; McIntosh, J.;
Litman, R.; Suh, J.; Kocer, B.; Davis, D.; Park, J.; Frauchiger, S.; Dewdney, N.; Zecic, H.;
Taygerly, J.P.; Sarma, K.; Hill, R.J. Gabri, T.; Goldstein, D.M.; Owens, T.D. J. Med. Chem.
2015, 58, 512.
. (a) Baumgartner, R.R.; Steinmann, D.; Heiss, E.H.; Atanasov, A.G.; Ganzera, M.; Stuppner, H.;
Dirsch, V.M. J. Nat. Prod. 2010, 73, 1578. (b)Ha, D.T.; Ngoc, T.M.; Lee, I.S.; Lee, Y.M.; Kim,
J.S.; Jung, H.J.; Lee, S.M.; Na, M.K.; Bae, K.H. J. Nat. Prod. 2009, 72, 1465.
. Chou, T.C. Brit. J. Pharmacol. 2003, 139, 1146.
8
9
. Huang, T.J.; Chuang, H.; Liang, Y.C.; Lin, H.H.; Horng, J.C.; Kuo, Y.C.; Chen, C.W.; Tsai,
F.Y.; Yen, S.C.; Chou, S.C.; Hsu, M.H. Eur. J. Med. Chem. 2015, 90, 428.
0. Nizamutdinova, I.T.; Jin, Y.C.; Kim, J.S.; Yean, M.H.; Kang, S.S.; Kim, Y.S.; Lee, J.H.; Seo,
H.G.; Kim, H.J.; Chang, K.C. Planta Med. 2008, 74, 8.
1
1
1. Kim, H.K.; Tak, J.H.; Ahn, Y.J. J. Agric. Food Chem. 2004, 52, 7857.

12. Lau, C.H.; Chan, C.M.; Chan, Y.W.; Lau, K.M.; Lau, T.W.; Lam, F.C.; Law, W.T.; Che, C.T.;
Leung, P.C.; Fung, K.P.; Ho, Y.Y.; Lau, C.B.S. Phytomed. 2007, 14, 778.
1
1
3. Chen, B.; Ning, M.; Yang, G. Molecules. 2012, 17, 4672.
4. (a) Pan, L.L.; Dai, M. Phytomed. 2009, 16, 1027. (b) Hsieh, C.L.; Cheng, C.Y.; Tsai, T.H.;Lin,
I.H.; Liu, C.H.; Chiang, S.Y.; Lin, J.G.; Lao, C.J.; Tang, N.Y. J. Ethnopharmacol, 2006, 106,
2
08.
5. Qin, D.D.; Yang, Z.Y.; Zhang, F.H.; Du, B.; Wang, P.; Li, T.R. Inorg. Chem. Commun. 2010,
3, 727.
1
1
1
1
1
1
6. Zhu, T.H.; Cao, S.W.; Yu, Y.Y. Int. J. Biol. Macromolec. 2013, 62, 589.
7. Li, X.; Lin, J.; Gao, Y.; Han, W.; Chen, D. Chem. Cent. J. 2012, 6,140.
8. Yu, F.; Xu, D.; Lei, R.; Li, N.; Li, K. J. Agric. Food. Chem. 2008, 56, 730.
9. Sachindra, N.M.; Sato, E.; Maeda, H.; Hosokawa, M. Niwano, Y.; Kohno, M.; Miyashita, K.
J. Agric. Food. Chem. 2007, 55, 8516.
2
2
2
2
0. Feng, J.Y.; Liu, Z.Q. J. Agric. Food. Chem. 2009, 57, 11041.
1. Zhang B.S.; Ye X.L.; Chen Z.; Yao B.; Tan P.; Li X.G. Acta Pharm. Sin. 2011, 46, 811.
2. Koshland Jr D.E.; Neet K.E. Annu Rev Biochem. 1968, 37(1), 359-411.
3. Wang D.X.; Jin H.M. Human Pathophysiology. 3rd ed. Beijing: People’s Medical Publishing
House, 2008: 386.

Synthesis and anti-inflammatory activity of Paeonol analogues in the
murine model of complete freund’s adjuvant induced arthritis
a,
a,
b
a
c
Ligua Huang *, Baoshun Zhang *, You Yang , Xiaobao Gong , Zhu Chen ,
c
d
d
Zhenxu Wang , Peng Zhang , Qingyan Zhang