Synthesis and biological evaluation of curcuminoid derivatives

Article abstract of DOI:10.1248/cpb.c15-00470

Many curcuminoid derivatives have been reported to have multiple biological activities. The aim of this study was to improve the biological activity of curcuminoids by synthesizing 16 new derivatives which combined cinnamic acids with curcuminoids, and we also analyzed the structure-activity relationship of the new compounds. Almost all the new compounds showed encouraging activity, especially compound 7g. It had much better antioxidant activity than curcuminoids and Vitamin C (VC), and also had the most significant antibacterial activity, which was 5-folder better than ampicillin (one of the best marketed antibiotics) with a minimum inhibitory concentration (MIC) of 0.5 μg/mL against Gram-positive cocci (Staphylococcus aureus and Streptococcus viridans) as well as Escherichia coli and 0.6 μg/mL against Enterobacter cloacae. Compound 7g also showed the greatest anticancer activity with a much lower IC50, which was 0.51 μM against MCF-7, 0.58 μM against HepG-2, 0.63 μM against LX-2, and 0.79 μM against 3T3. The results suggest that these compounds have promising potential as candidates for the treatment of cancer and thus further studies are warranted.

Full text of DOI:10.1248/cpb.c15-00470

Vol. 63, No. 11
Chem. Pharm. Bull. 63, 873–881 (2015)
873
Regular Article
Synthesis and Biological Evaluation of Curcuminoid Derivatives
,b
,a
Ling Feng,a Yang Li,a Zhi-fang Song,a Hui-jing Li,* and Qi-yong Huai*
b
a Marine College, Shandong University; Weihai 264209, China: and School of Marine Science and Technology,
Harbin Institute of Technology at Weihai; Weihai 264209, China.
Received June 5, 2015; accepted July 22, 2015
Many curcuminoid derivatives have been reported to have multiple biological activities. The aim of
this study was to improve the biological activity of curcuminoids by synthesizing 16 new derivatives which
combined cinnamic acids with curcuminoids, and we also analyzed the structure–activity relationship of the
new compounds. Almost all the new compounds showed encouraging activity, especially compound 7g. It had
much better antioxidant activity than curcuminoids and Vitamin C (VC), and also had the most significant
antibacterial activity, which was 5-folder better than ampicillin (one of the best marketed antibiotics) with a
minimum inhibitory concentration (MIC) of 0.5µg/mL against Gram-positive cocci (Staphylococcus aureus
and Streptococcus viridans) as well as Escherichia coli and 0.6µg/mL against Enterobacter cloacae. Com-
pound 7g also showed the greatest anticancer activity with a much lower IC50, which was 0.51µM against
MCF-7, 0.58µM against HepG-2, 0.63µM against LX-2, and 0.79µM against 3T3. The results suggest that
these compounds have promising potential as candidates for the treatment of cancer and thus further studies
are warranted.
Key words curcuminoid derivative; cinnamic acid; anticancer; antibacterial; antioxidant; structure–activity
relationship
Since thousands of years, natural products have been used
to treat human cancers because of its significant biological
Results and Discussion
Chemistry To analyze the impact on the biological ac-
properties and safeties. In the development of the new cancer tivities of hydroxyl and methoxy of curcuminoids, we took
drugs, the natural product-derived derivatives are of growing cinnamic acids as examples to react with CCM which have
concern.1–4) Among them, Curcuma longa L. has been used both hydroxyl and methoxy as well as react with BCM which
for hundreds of years as a flavor, color and preservative.5) Cur- has no methoxy. The curcuminoid derivatives of cinnamic
cuminoids viz. curcumin (CCM), demethoxycurcumin (DCM) acid (compounds 3a–d) were obtained as outlined in Chart
and bisdemethoxycurcumin (BCM) are the yellow pigments 1. We used acetic anhydride (Ac2O) to protect hydroxyl with
of turmeric.6) They are the major components of Curcuma the method described in Chart 2 to obtain compounds 5a–c.
longa L., which is used in the food industry, for cooking, and To decorate the parent curcuminoids, acetylated compounds
in folkloric remedies.7) Many recent studies have shown that were reacted with CCM or BCM to get new compounds 6a–l,
curcuminoids are nutriceutical compounds which possess a to get the final product (7a–l), CH3ONa/methanol (MeOH)
variety of biological activities, including antioxidant,8–11) anti- was used to hydrolyze the acetylated curcuminoid derivatives
inflammatory,12–14) anticancer,15–18) and anti-angiogensis.19,20) (compounds 6a–l). All the newly synthetic compounds were
Besides, they also have therapeutic properties against dis- purified by column chromatography and their structures were
eases such as cystic fibrosis, human immunodeficiency virus established by (1H-NMR, 13C-NMR and MS) analysis (shown
(HIV)21) and Alzheimer’s disease.22) What’s more, curcumin in Experimental).
is nontoxic to humans up to a dose of 10g/d with almost no
Antioxidant Activity As well-known mechanisms, the
adverse effects. It is considered to be a potential chemopre- hydrogen atom or electron donation abilities of some pure
ventive agent and has been used in clinical trials.23) However, compounds were measured by the bleaching of a purple
previous reports indicated that the utility of curcumin is lim- colored methanol solution of the stable 1,1-diphenyl-2-picryl-
ited by its color, lack of water solubility, and relatively low hydrazyl (DPPH) radical, this spectrophotometric assay uses
in vivo bioavailability. Hence, synthesis of “man-made” cur- the stable radical, DPPH, as a reagent.31) This method is quite
cumin analogues which have no these problems is becoming simple and rapid for screening specific compounds. Thus, the
challenging.24–26) In this study, we aimed to synthesize a novel antioxidant activity of all the test compounds (3a–d, 7a–l,
of curcumin derivatives to improve their biological activities.
CCM, BCM, VC) was evaluated for their radical scavenging
In addition to curcuminoids, many other natural products ability using the stable DPPH radical method. The assay was
such as isoferulic acid,27) trans-3-hydroxylcinnamic acid,28) conducted at six different concentrations of test compounds
trans-4-hydroxylcinnamic acid29) and coumaric acid30) also (2.5, 5, 10, 20, 40, 80µM) in a polar, homogenous medium.
have apparent biological activities. To improve the potency The antioxidant potency (DPPH FRSA %) was presented in
of the curcuminoids without losing their apoptotic effect, we µM concentrations as shown in Table 1.
selected these active ingredients as starting materials to de-
The radical-scavenging assay obviously showed that
sign and synthesize curcuminoid derivatives. Then we evalu- compounds 7a–l had much higher DPPH FRSA than cur-
ated their antioxidant abilities, antibacterial activities and anti- cuminoids. Besides, all of the test compounds, the best radical
cancer activities, respectively.
scavenger was compound 7g (98.3%), whose scavenging abil-
*To whom correspondence should be addressed. e-mail: lihuijing@iccas.ac.cn; huaiqy01@163.com
© 2015 The Pharmaceutical Society of Japan

874
Chem. Pharm. Bull.
Vol. 63, No. 11 (2015)
Reagents and conditions: a) EDCI, HOBT, DIEA, reflux, room temp.; b) SOCl2, TEA, reflux.
Chart 1. Synthesis of Target Compounds 3a–d
ity was about 1.65-folder higher than curcumin (59.1%) and
was 1.7-folder higher than VC (57.6%) which was the standard
compound. However, compounds 3a–d which their active in-
gredients had no hydroxyl or methoxy had lower antioxidant
activity with much lower DPPH FRSA. Besides, curcuminoid
derivatives with two active ingredients had better antioxidant
noid derivatives on the growth of three lines of cultured tumor
cells (LX-2, HepG-2 and MCF-7) and one line of normal cells
(3T3) were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-di-
phenyltetrazolium bromide (MTT) assay. In each experiment,
the drug doxorubicin (ADR) was used as positive control and
of curcuminoids (CCM and BCM) were also pre-
the IC50
activity than the derivatives with only one active ingredient. sented to compare the anticancer activities. The anticancer
Hence, the test compounds 7a–l had great potential to be used activity of curcuminoid derivatives were evaluated at varying
as antioxidants.
Antibacterial Activity The antibacterial activities of all the test compounds were presented in µM as shown in Table 3.
the target compounds were tested against Gram-positive cocci
Almost all the newly synthetic curcuminoid derivatives
concentrations which were from 1 to 50µM. IC50 values of all
(Staphylococcus (S.) aureus and Streptococcus viridans) and exhibited much stronger inhibitory activity against LX-2,
Gram-negative bacilli (Escherichia (E.) coli and Enterobacter HepG-2, MCF-7 and relatively lower inhibitory activity
cloacae). The lowest concentration of the tested compounds against normal cells (3T3). As shown in Table 3, compound
in µg/mL which prevented in vitro growth of microorganism 7g which had 2-hydroxyl and 4-methoxy exhibited an IC50 of
has been represented with minimum inhibitory concentration 0.61 µM in MCF-7, 0.68µM in HepG-2, 0.73µM in LX-2 and
(MIC) shown in Table 2.
0.89µM in 3T3, which was about thirteen three fold higher
All the compounds 7a–l showed better antibacterial ac- than curcuminoids (9.14–12.11µM). On the other hand, the IC50
tivities than curcuminoids. The most encouraging results were value of compound 7g was almost the same as the positive
obtained in the case of compound 7g having an MIC of 0.5µg/ control drug ADR.
mL against S. aureus, 0.5µg/mL against S. viridans, 0.5µg/
The results shown in Table 3 indicated that compounds
mL against E. coli and 0.6µg/mL against E. cloacae respec- 3a–d which their active ingredients had no hydroxyl or me-
tively, while ampicillin, the best marked antibiotic, shows an thoxy had no anticancer activity, while compounds 7a–l which
MIC of 2.5µg/mL. It is obviously that compound 7g which their active ingredients had hydroxyl and methoxy had much
had 2-hydroxyl and 4-methoxy was five times more effec- better anticancer activity than curcuminoids (CCM and BCM)
tive than the ampicillin at similar concentrations and nearly and they also had lower activity against normal cells (3T3).
twenty-one times more effective than CCM (10.3µg/mL). On What’s more, the antitumor activity of CCM derivatives was
the other hand, the antibacterial activities of curcumin de- much better than BCM derivatives. Curcuminoid derivatives
rivatives (3a, c, 7a, c, e, g, i, k) were better than those of de- with two active ingredients had much better activity than
methoxycurcumin derivatives (3b, d, 7b, d, f, h, j, l). Besides, curcuminoid derivatives with one active ingredient. Hence,
compounds 7g–l which had two active ingredients had much compounds having both hydroxyl and methoxy have great ad-
better effect than 7a–f which had only one active ingredient.
vantages and hold promise as prodrugs.
However the curcuminoid derivatives of cinnamic acid
Structure–Activity Relationship Curcumin has two
(3a–d) exhibited low antibacterial activities. In this group, phenyl rings and substitutions at the 3 and 4 positions with
compounds 3a and b which had hydroxyl had relative good methoxy and hydroxyl groups respectively. BCM has two
activity and the best activity was against E. cloacae with an phenyl rings and substitutions at the 4 position with hydroxyl.
MIC of 11µg/mL. However, all this group compounds showed Research has shown that the biological activities are affected
lower activity than curcuminoids (CCM and BCM). Besides, by 4-hydroxyl groups present on both phenyl rings of curcum-
compound 3d which had no hydroxyl or methoxy had the low- inoids and 3-methoxy on phenyl rings of CCM.
est activity with an MIC of 24µg/mL while the MIC of CCM
was only 10.3µg/mL.
In this study, cinnamic acids were used as the active ingre-
dients to prepare new compounds which may hold promise as
Anticancer Activity The inhibitory effects of curcumi- prodrugs with curcuminoids. Among them, the curcuminoid

Vol. 63, No. 11 (2015)
Chem. Pharm. Bull.
875
Reagents and conditions: a) Ac2O, DMAP, reflux, room temp.; b) EDCI, DMAP, reflux, room temp.; c) SOCl2, DIEA, reflux; d) CH3ONa, MeOH, reflux; e) CH3ONa,
MeOH, reflux.
Chart 2. Synthesis of Target Compounds 7a–l
derivatives of cinnamic acid had no hydroxyl, what’s more,
their biological activities were lower than curcuminoids. But
curcuminoid derivatives of isoferulic acid, trans-3-hydroxyl
cinnamic acid and trans-4-hydroxyl cinnamic acid had hy-
droxyl, their biological activities were much better than
curcuminoids. On the other hand, the derivatives (7b, d, f,
h, j, l) which had no methoxy had relatively lower biological
activities.
derivatives will have. In other words, the hydroxyl groups
incorporated are helpful for the improvement of biologi-
cal activity.
2) The absence of the methoxy group in curcuminoid de-
rivatives leads to a decrease in the biological activity.
3) Positions of hydroxyl can cause difference in the bio-
logical activity.
Hence, we attempt to summarize the structure–activity re-
lationships:
Experimental
Materials and Methods Used reagents were bought from
1) Hydroxyl group is the major active group in tested Aldrich Chemical Co. (Beijing, China) and used without
compounds. To some extent, the more hydroxyl groups further purification. The products were purified by column
the substituent contains, the better biological activity the chromatography using silica gel (200–300 mesh). 1H- and

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Chem. Pharm. Bull.
Vol. 63, No. 11 (2015)
Table 1. In Vitro DPPH Free Radical Scavenging Activity (FRSA) of Table 3. IC50 Values of Test Compounds against 3T3, LX-2, HepG-2
the Target Compounds; CCM, Curcumin; BCM, Bisdemethoxycurcumin and MCF-7
and VC
IC50 (µM)a)
Compound
DPPH FRSA%
3T3
40
LX-2
35
HepG-2
MCF-7
Compound
2.5µM
5µM
10µM
20µM
40µM
80µM
3a
3b
37
>40
>40
>40
1.61
4.72
2.55
5.51
2.19
5.33
0.58
3.39
1.59
4.59
1.38
4.27
9.44
11.63
0.49
29
>40
>40
>40
1.53
4.75
4.51
5.44
2.28
5.19
0.51
3.38
1.55
4.52
1.41
4.33
9.28
11.64
0.47
3a
3b
1.3
1.1
0.3
0.1
8.2
4.3
7.1
3.3
7.1
3.6
11.4
6.2
9.1
5.2
9.3
5.4
1.8
1.5
1.7
2.6
2.4
4.3
4
7.1
6.3
8.2
6.7
9.2
8.3
>40
>40
>40
>40
>40
>40
3c
3c
0.7
0.9
2.4
3.9
6.2
3d
3d
0.3
0.7
2.1
3.5
5.7
7a
1.92
1.58
7a
15.4
9.2
32.7
18.7
27.5
15.2
28.6
15.8
43.1
26.9
37.2
22.9
40.2
23.5
7.5
71.6
36.3
57.6
31.3
59.3
32.1
88.2
54.3
81.3
37.1
83.5
37.8
14.3
12.3
82.3
67.2
78.6
61.7
80.9
62.9
92.6
73.8
83.6
68.9
90.1
69.3
29.6
26.1
92.9
86.9
90.3
85.3
92.1
86.1
98.3
89.1
93.4
87.3
97.2
88.2
59.1
53.2
7b
5.88
2.83
5.75
2.51
5.31
0.79
3.61
1.87
4.84
1.71
4.35
9.51
12.11
0.53
4.86
2.62
5.46
2.31
5.21
0.63
3.32
1.62
4.61
1.42
4.12
9.14
11.93
0.51
7b
7c
7c
13.9
7.1
7d
7d
7e
7e
14.2
7.6
7f
7f
7g
7g
20.3
13.1
17.5
11.3
18.1
11.8
3.7
7h
7h
7i
7i
7j
7j
7k
7k
7l
7l
CCM
BCM
ADRb)
CCM
BCM
VCa)
3.3
6.7
3.5
6.5
13.1
28.4
57.6
a) IC50 is the drug concentration effective in inhibiting 50% of the cell growth
measured by MTT method. If the IC50 of test compound is over 40µM, it is regarded
as inactive. b) The drug doxorubicin (ADR) was used as positive control in this study.
a) Vitamin C (VC) was used in this study as reference.
Table 2. MIC Correlation Diagram of Curcuminoid Derivatives against
Bacterial Strains
reactions were monitored by analytical thin-layer chromatog-
raphy TLC and the TLC was carried out on silica gel GF254
.
MICa)
The anhydrous solvents were dried and purified according
to standard techniques before use. Gram-positive cocci (S.
aureus and S. viridans), Gram-negative bacilli (E. coli and E.
cloacae), cancer cells (LX-2, HepG-2 and MCF-7) and normal
cells (3T3) were obtained from Expression Systems (Beijing,
China).
Isolation and Purification of Curcuminoids As cur-
cuminoid powder contain three components named curcumin,
demethoxycurcumin and bisdemethoxycurcumin. We sepa-
rated them using silica gel (100 mesh). Briefly, putting dried
silica gel (100 mesh) weigh 50g dissolved in chloroform and
filling them in a glass column of 5cm internal diameter and
60cm height. Then curcuminoid powder weighing 0.5g was
dissolved in 3mL chloroform and was put on the silica gel
column. Lastly, it was successively eluted with 500mL of
eluent (methanol–carbon tetrachloride–acetic acid=1:10:1).
They were analyzed by TLC on silica gel plates and the pure
fractions combined and solvents were removed to give pure
components which were curcumin, demethoxycurcumin and
bisdemethoxycurcumin, respectively.
Compound
Gram-positive
S. aureus S. viridans
Gram-negative
E. coli E. cloacae
3a
13
17
20
24
12
17
18
21
14
15
18
21
11
15
18
23
3b
3c
3d
7a
0.9
0.9
0.8
0.9
7b
2.1
1.2
2.7
1.1
2.3
0.5
1.4
0.6
1.9
0.6
1.7
10.3
16.1
2.5
2.1
1.3
2.8
1.2
2.3
0.5
1.4
0.6
1.9
0.7
1.6
10.3
16.1
2.5
2.3
1.2
2.7
0.9
2.3
0.5
1.4
0.8
1.8
0.7
1.6
13.1
14.3
3.2
2.5
1.2
2.7
0.9
2.4
0.6
1.4
0.8
1.7
0.7
1.6
13.1
14.3
3.2
7c
7d
7e
7f
7g
7h
7i
7j
7k
7l
CCM
BCM
Amipicillin
General Procedure for the Synthesis of 3a and b To
a solution of cinnamic acid (5mmol) in chloroform (20mL),
HOBT (5mmol) and DIEA (2mL) were added and were
stirred for 0.5h at 0°C. Then, EDCI (5mmol) was added and
was still stirred at 0°C for 2h. Afterwards, a chloroform solu-
tion (15mL) of 1a or b (3.5mmol) was added to the mixture,
a) MIC values were method in µg/mL. If MIC value of the test compound is over
200µg/mL, it is regarded as inactive.
13C-NMR spectra were recorded on Bruker-400 at room tem- which was allowed to be stirred at 0°C for 1h, then was
perature with tetramethylsilane (TMS) as an internal standard stirred for another 18h at room temperature. The reaction was
and chloroform-d3 (CDCl3) or dimethyl sulfoxide (DMSO)-d6 indicated by TLC and after it completed, the organic layer was
as solvents. Mass spectra were recorded with a MAT95 mass washed by 1M HCl solution and concentrated in the vacuum.
spectrometer (Finnigan). Melting points were measured with The residue was purified by column chromatography on silica
a micro melting point apparatus and are uncorrected. The gel with methanol–carbon tetrachloride–acetic acid=1:10:1

Vol. 63, No. 11 (2015)
Chem. Pharm. Bull.
877
to yield pure product (compounds 3a, b).
Curcumin-Mono-cinnamic Acid (3a)
(100MHz, CDCl3) δ: 198.71, 164.27, 151.173, 147.93, 142.67,
135.15, 134.43, 130.8, 129.05, 128.52, 128.46, 127.91, 125.21,
Yield 80%, yellow solid, mp 160–163°C; 1H-NMR 121.16, 120.73, 115.47, 51.63; HR-ESI-MS m/z: 568.6247 [M
(400MHz, DMSO-d6) δ: 3.83 (3H, s, OCH3), 3.86 (3H, s, +H]+ (Calcd for C37H28O6 568.6250).
OCH3), 4.57 (2H, s), 6.29 (1H, d, J=14.0Hz), 6.81 (1H, d,
General Procedure for the Synthesis of 5a–c Three mil-
J=6.9Hz), 6.89 (2H, d, J=13.5Hz), 6.94 (1H, d, J=7.2Hz), liliter AC2O was added to a pyridine solution (5mL) of 4a,
7.11 (1H, d, J=7.2Hz), 7.13 (1H, s), 7.19 (1H, d, J=6.9Hz), 7.25 b or c (5mmol) and then the mixture was heated reflux for
(1H, s), 7.35 (1H, m), 7.42 (2H, m), 7.48 (1H, m, J=14.0Hz), 8h. Afterwards, the solution was washed with dilute aque-
7.54 (2H, ddd, J=7.1, 1.5, 0.9Hz), 7.60 (2H, d, J=13.5Hz), 9.21 ous sodium hydroxide and then extraction. The organic layer
(1H, s); 13C-NMR (100MHz, CDCl3) δ: 198.71, 164.24, 150.38, was dried with anhydrous magnesium sulfate (MgSO4) and
149.03, 147.52, 147.11, 142.46, 138.18, 135.17, 130.37, 128.49, evaporated to dryness under vacuum. Lastly, the product was
128.51, 127.06, 126.61, 123.43, 122.87, 115.51, 114.74, 112.16, recrystallized from ethanol and then dried in vacuum to get
111.07, 56.05, 55.73, 51.63; high resolution-electrospray ioniza- 5a–c which were white solids.
tion (HR-ESI)-MS m/z: 498.5301 [M+H]+ (Calcd for C30H26O7
498.5310).
Bisdesmethoxycurcumin-Monocinnamic Acid (3b)
Acetylated Isoferulic Acid (5a)
Yield 92%, white solid, mp 120–123°C; 1H-NMR
(400MHz, DMSO-d6) δ: 2.31 (3H, s), 3.83 (3H, s, OCH3),
Yield 83%, yellow solid, mp 173–176°C; 1H-NMR 6.27 (1H, d, J=13.4Hz), 6.93 (1H, d, J=7.2Hz), 7.03 (1H, s),
(400MHz, DMSO-d6) δ: 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz), 7.33 (1H, d, J=7.2Hz), 7.45 (1H, d, J=13.4Hz), 12.05 (1H, s,
6.70 (1H, s), 6.83 (1H, dd, J=7.2, 1.3Hz), 6.89 (2H, d, OH); 13C-NMR (100MHz, CDCl3) δ: 171.47, 169.06, 150.58,
J=13.5Hz), 7.03 (1H, s), 7.16 (1H, dd, J=7.2, 1.3Hz), 7.21 144.85, 141.43, 127.04, 126.68, 123.41, 116.49, 111.08, 55.78,
(1H, dd, J=6.9, 1.3Hz), 7.31 (1H, m), 7.33 (1H, m), 7.38 (2H, 20.22; HRESI-MS m/z: 236.2231 [M+H]+ (Calcd for C12H12O5
m), 7.41 (1H, dd, J=6.9, 1.3Hz), 7.45 (1H, m), 7.48 (1H, d, 236.2230).
J=14.0Hz), 7.54 (2H, ddd, J=7.1, 1.5, 0.9Hz), 7.60 (2H, d,
Acetylated trans-3-Hydroxylcinnamic Acid (5b)
J=13.5Hz), 9.21 (1H, s, OH); 13C-NMR (100MHz, CDCl3) δ:
Yield 87%, white solid, mp 122–125°C; 1H-NMR (400MHz,
198.71, 164.28, 156.43, 151.17, 147.83, 142.76, 135.42, 135.28, DMSO-d6) δ: 2.31 (3H, s), 6.27 (1H, d, J=13.4Hz), 7.03 (1H,
134.31, 130.38, 129.04, 128.61, 128.45, 127.85, 121.22, 121.05, s), 7.21 (1H, dd, J=6.8, 1.7Hz), 7.45 (1H, d, J=13.4Hz), 7.48
120.73, 117.59, 115.51, 51.63; HR-ESI-MS m/z: 438.4786 (1H, m), 7.55 (1H, dd, J=6.8, 1.7Hz), 12.05 (1H, s, OH);
[M+H]+ (Calcd for C28H22O5 438.4790).
13C-NMR (100MHz, CDCl3) δ: 171.5, 169.07, 151.13, 144.93,
General Procedure for the Synthesis of 3c and d Excess 134.45, 129.03, 125.26, 121.24, 120.75, 116.43, 20.22; HR-ESI-
thionyl chloride was added to a stirred, ice-cooled chloro- MS m/z: 206.1971 [M+H]+ (Calcd for C11H10O4 206.1970).
form solution (20mL) rapidly, which contains cinnamic acid
(5mmol). The resulting solution was stirred for 30min at 0°C.
Acetylated trans-4-Hydroxylcinnamic Acid (5c)
1
Yield 88%, white solid, mp 119–122°C; H-NMR (400MHz,
Then dried the solution and unreacted thionyl chloride to give DMSO-d6) δ: 2.31 (3H, s), 6.27 (1H, d, J=13.4Hz), 7.28 (2H,
wanted chloride product. Afterwards, a chloroform solution d, J=7.8Hz), 7.45 (1H, d, J=13.4Hz), 7.62 (2H, d, J=7.8Hz),
(20mL) of 1a or b (2.5mmol) was mixed with the product as 12.05 (1H, s, OH); 13C-NMR (100MHz, CDCl3) δ: 171.47,
well as Et3N at 0°C and then was stirred for 24h at room tem- 169.06, 150.58, 144.13, 132.02, 129.69, 121.47, 116.48, 20.22;
perature. The reaction was indicated by TLC. After comple- HR-ESI-MS m/z: 206.1971 [M+H]+ (Calcd for C11H10O4
tion of the reaction, the mixture was washed with aqueous 206.1970).
hydrochloric acid and then extraction. The organic layer was
General Procedure for the Synthesis of 6a–f To a so-
dried with anhydrous MgSO4 and evaporated to dryness under lution of 5a, b or c (5mmol) in chloroform (20mL), DMAP
vacuum. Purification by chromatography on silica gel (metha- (0.1mmol) was added and was stirred for 0.5h at 0°C. Then,
nol–carbon tetrachloride–acetic acid=1:10:1.5) to give 3c and 4.2mmol EDCI was added and was still stirred at 0°C for
d which are yellow solids.
2h. Afterwards, a chloroform solution (20mL) of 1a or b
Curcumin-Dicinnamic Acid (3c)
(3.5mmol) was added to the mixture, which was allowed to be
Yield 85%, yellow solid, mp 173–176°C; 1H-NMR stirred 0°C for 1h, then was stirred for another 18h at room
(400MHz, DMSO-d6) δ: 3.83 (6H, s, OCH3), 4.57 (2H, s), temperature. The reaction was indicated by TLC and after it
6.29 (2H, d, J=14.0Hz), 6.94 (2H, d, J=7.2Hz), 6.89 (2H, d, completed, the mixture was washed with aqueous hydrochlo-
J=13.5Hz), 7.03 (2H, s), 7.11 (2H, d, J=7.2Hz), 7.33(2H, m), ric acid and then extraction. The organic layer was dried with
7.38 (4H, m), 7.48 (2H, d, J=14.0Hz), 7.54 (4H, ddd, J=7.1, anhydrous Na2SO4 and evaporated to dryness under vacuum.
1.5, 0.9Hz), 7.60 (2H, d, J=13.5Hz); 13C-NMR (100MHz, Purification by chromatography on silica gel (methanol–car-
CDCl3) δ: 198.71, 164.27, 150.87, 147.93, 142.87, 138.24, bon tetrachloride–acetic acid=1:10:1) to give 6a–f which are
135.13, 130.43, 128.52, 128.43, 127.87, 127.05, 126.63, 123.42, yellow solids.
115.41, 111.18, 55.75, 51.63; HR-ESI-MS m/z: 628.6768
Curcumin-Monoacetylated Isoferulic Acid (6a)
[M+H]+ (Calcd for C39H32O8 628.6770).
Yield 69%, yellow solid, mp 163–166°C; 1H-NMR
(400MHz, DMSO-d6) δ: 2.31 (3H, s, COCH3), 3.75 (6H,
Bisdesmethoxycurcumin-Dicinnamic Acid (3d)
Yield 84%, yellow solid, mp 165–168°C; 1H-NMR s, OCH3), 3.86 (3H, s, OCH3), 4.57 (2H, s), 6.31 (1H, d,
(400MHz, DMSO-d6) δ: 4.57 (2H, s), 6.31 (2H, d, J=14.0Hz), J=14.0Hz), 6.90 (1H, d, J=7.3Hz), 6.89 (2H, d, J=13.5Hz),
6.89 (2H, d, J=13.5Hz), 7.03 (2H, s), 7.21 (2H, dd, J=6.9, 6.93 (1H, d, J=7.2Hz), 6.94 (1H, d, J=7.2Hz), 7.02 (1H, d,
1.3Hz), 7.33 (2H, m), 7.38 (4H, m), 7.41 (2H, dd, J=6.9, J=7.2Hz), 7.03 (1H, s), 7.19 (1H, d, J=7.3Hz), 7.23 (1H, s),
1.3Hz), 7.45 (2H, m), 7.48 (2H, d, J=14.0Hz), 7.54 (4H, 7.33 (1H, d, J=7.2Hz), 7.48 (1H, d, J=14.0Hz),7.60 (2H, d,
ddd, J=7.1, 1.5, 0.9Hz), 7.60 (2H, d, J=13.5Hz); 13C-NMR J=13.5Hz); 13C-NMR (100MHz, CDCl3) δ: 198.71, 169.05,

878
Chem. Pharm. Bull.
Vol. 63, No. 11 (2015)
164.28, 150.92, 149.33, 147.85, 147.07, 142.72, 141.48, 138.27, [M+H]+ (Calcd for C32H28O9 556.5670).
130.38, 127.69, 127.05, 126.63, 123.48, 122.72, 115.43, 114.75, Bisdesmethoxycurcumin-Monoacetylated trans-4-Hydroxyl-
112.20, 111.05, 56.15, 55.73, 51.70, 20.22; HR-ESI-MS m/z: cinnamic Acid (6f)
586.5929 [M+H]+ (Calcd for C33H30O10 586.5930).
Yield 58%, yellow solid, mp 152–155°C; 1H-NMR
Bisdesmethoxycurcumin-Monoacetylated Isoferulic Acid (400MHz, DMSO-d6) δ: 2.31 (3H, s), 4.57 (2H, s), 6.31 (1H,
(6b)
d, J=14.0Hz), 6.83 (1H, dd, J=7.2, 1.3Hz), 6.89 (2H, d,
Yield 62%, yellow solid, mp 158–161°C; 1H-NMR J=13.5Hz), 7.03 (2H, s), 7.16 (2H, dd, J=7.2, 1.3Hz), 7.21
(400MHz, DMSO-d6) δ: 2.31 (3H, s, COCH3), 3.83 (3H, s, (1H, dd, J=7.5, 2.3Hz), 7.28 (2H, d, J=7.8Hz), 7.45 (2H, m),
OCH3), 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz), 6.70 (1H, s), 6.83 7.48 (1H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz), 7.62 (2H, d,
(1H, dd, J=7.2, 1.3Hz), 6.89 (2H, d, J=13.5Hz), 6.93 (1H, d, J=7.8Hz), 9.45 (1H, s, OH); 13C-NMR (100MHz, CDCl3) δ:
J=7.2Hz), 7.03 (1H, s), 7.16 (1H, dd, J=7.2, 1.3Hz), 7.21 (1H, 198.71, 169.07, 164.28, 158.46, 151.17, 150.58, 147.92, 142.72,
dd, J=6.9, 1.3Hz), 7.31 (1H, m), 7.33 (1H, d, J=7.2Hz), 7.41 135.34, 134.46, 132.02, 130.38, 130.08, 129.69, 129.05, 125.28,
(1H, dd, J=6.9, 1.3Hz), 7.45 (1H, m), 7.48 (1H, d, J=14.0Hz), 121.47, 121.18, 121.01, 120.73, 115.43, 115.13, 51.63, 20.22; HR-
7.60 (2H, d, J=13.5Hz); 13C-NMR (100MHz, CDCl3) δ: ESI-MS m/z: 496.5151 [M+H]+ (Calcd for C30H24O7 496.5150).
198.71, 169.05, 164.88, 158.32, 151.17, 150.92, 147.85, 142.72,
General Procedure for the Synthesis of 6g–l Ten mil-
141.48, 135.34, 134.46, 130.38, 129.05, 127.07, 126.63, 125.28, liliter thionyl chloride was added to a stirred, ice-cooled
121.18, 120.73, 117.55, 115.43, 115.13, 111.05, 55.73, 51.63, chloroform solution (20mL) rapidly, which contains 5.3mmol
20.22; HR-ESI-MS m/z: 526.5412 [M+H]+ (Calcd for C31H26O8 5a, b or c respectively. Then the resulting solution was stirred
526.5410).
for 30min at 0°C. Then dried the solution and unreacted thio-
Curcumin-Monoacetylated trans-3-Hydroxylcinnamic Acid nyl chloride to give wanted chloride product. Afterwards, a
(6c)
chloroform solution (20mL) of 1a or b (2.5mmol) was mixed
Yield 61%, yellow solid, mp 162–165°C; 1H-NMR with the product as well as Et3N at 0°C and then was stirred
(400MHz, DMSO-d6) δ: 2.31 (3H, s, COCH3), 3.83 (3H, for 24h at room temperature. The reaction was indicated
s, OCH3), 3.86 (3H, s, OCH3), 4.57 (2H, s), 6.31 (1H, d, by TLC. After completion of the reaction, the mixture was
J=14.0Hz), 6.89 (2H, d, J=13.5Hz), 6.90 (1H, d, J=7.3Hz), washed with aqueous hydrochloric acid and then extraction.
6.94 (1H, d, J=7.2Hz), 7.02 (1H, d, J=7.2Hz), 7.03 (2H, s), The organic layer was dried with anhydrous MgSO4 and
7.19 (1H, d, J=7.3Hz), 7.21 (1H, dd, J=7.5, 2.3Hz), 7.23 (1H, evaporated to dryness under vacuum. Purification by chroma-
s), 7.48 (1H, d, J=14.0Hz), 7.51 (1H, m), 7.55 (1H, dd, J=7.5, tography on silica gel (methanol–carbon tetrachloride–acetic
2.3Hz), 7.60 (2H, d, J=13.5Hz), 9.21 (1H, s, OH); 13C-NMR acid=1:10:1.5) to give 6g–l which are yellow solids.
(100MHz, CDCl3) δ: 198.71, 169.07, 164.28, 151.17, 150.92,
149.33, 147.92, 147.07, 142.72, 138.27, 134.46, 130.38, 129.05,
Curcumin-Diacetylated Isoferulic Acid (6g)
Yield 56%, yellow solid, mp 157–160°C; 1H-NMR
127.69, 127.07, 126.63, 125.28, 123.48, 122.83, 120.72, 115.43, (400MHz, DMSO-d6) δ: 2.31 (6H, s, COCH3), 3.75 (6H, s,
114.75, 112.16, 111.05, 56.15, 55.73, 51.63, 20.22; HR-ESI-MS OCH3), 4.57 (2H, s), 6.31 (2H, d, J=14.0Hz), 6.90 (2H, d,
m/z: 556.5671 [M+H]+ (Calcd for C32H28O9 556.5670).
J=7.3Hz), 6.89 (2H, d, J=13.5Hz), 6.93 (2H, d, J=7.2Hz),
Bisdesmethoxycurcumin-Monoacetylated trans-3-Hydroxyl- 7.03 (4H, s), 7.19 (2H, d, J=7.3Hz), 7.33 (2H, d, J=7.2Hz),
cinnamic Acid (6d)
7.48 (2H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz); 13C-NMR
Yield 69%, yellow solid, mp 157–160°C; 1H-NMR (100MHz, CDCl3) δ: 198.71, 169.05, 164.28, 150.92, 147.85,
(400MHz, DMSO-d6) δ: 2.31 (3H, s, COCH3), 4.57 (2H, s), 142.72, 141.48, 138.27, 130.38, 127.05, 126.63, 123.48, 115.43,
6.31 (1H, d, J=14.0Hz), 6.70 (1H, s), 6.83 (1H, dd, J=7.2, 111.05, 55.73, 51.63, 20.22; HR-ESI-MS m/z: 804.7998 [M+H]+
1.3Hz), 6.89 (2H, d, J=13.5Hz), 7.03 (2H, s), 7.16 (1H, dd, (Calcd for C45H40O14 804.8010).
J=7.2, 1.3Hz), 7.21 (1H, dd, J=7.5, 2.3Hz), 7.31 (1H, m), 7.41
(1H, dd, J=6.9, 1.3Hz), 7.45 (1H, m), 7.48 (1H, d, J=14.0Hz),
Bisdesmethoxycurcumin-Diacetylated Isoferulic Acid (6h)
Yield 53%, yellow solid, mp 156–159°C; 1H-NMR
7.55 (1H, dd, J=7.5, 2.3Hz), 7.60 (2H, d, J=13.5Hz), 9.45 (400MHz, DMSO-d6) δ: 2.31 (3H, s, OCH3), 3.75 (6H, s,
(1H, s, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71, 169.07, OCH3), 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz), 6.89 (2H, d,
164.28, 158.32, 151.17, 147.85, 142.72, 135.34, 134.46, 130.38, J=13.5Hz), 6.93 (1H, d, J=7.2Hz), 7.03 (1H, s), 7.21 (2H, dd,
130.05, 129.05, 125.28, 121.18, 120.73, 117.55, 115.43, 115.13, J=6.9, 1.3Hz), 7.33 (1H, d, J=7.2Hz), 7.41 (2H, dd, J=6.9,
51.63, 20.22; HR-ESI-MS m/z: 496.5151 [M+H]+ (Calcd for 1.3Hz), 7.45 (2H, m), 7.48 (1H, d, J=14.0Hz), 7.60 (2H, d,
C30H24O7 496.5150).
Curcumin-Monoacetylated trans-4-Hydroxylcinnamic Acid 164.28, 151.17, 150.92, 147.85, 142.72, 141.48, 134.38, 130.38,
J=13.5Hz); 13C-NMR (100MHz, CDCl3) δ: 198.71, 169.05,
(6e)
129.05, 127.07, 126.63, 125.28, 123.54, 121.18, 120.73, 115.43,
Yield 64%, yellow solid, mp 150–153°C; 1H-NMR 111.05, 55.73, 51.63, 20.22; HR-ESI-MS m/z: 744.7485 [M+H]+
(400MHz, DMSO-d6) δ: 2.31 (3H, s, COCH3), 3.83 (3H, (Calcd for C43H36O12 744.7490).
s, OCH3), 3.86 (3H, s, OCH3), 4.57 (2H, s), 6.31 (1H, d,
J=14.0Hz), 6.90 (2H, d, J=7.3Hz), 6.89 (2H, d, J=13.5Hz),
Curcumin-Diacetylated trans-3-Hydroxylcinnamic Acid (6i)
Yield 56%, yellow solid, mp 157–160°C; 1H-NMR
7.03 (2H, s), 7.19 (2H, d, J=7.3Hz), 7.23 (1H, s), 7.28 (2H, d, (400MHz, DMSO-d6) δ: 2.31 (6H, s, COCH3), 3.83 (6H, s,
J=7.8Hz), 7.48 (1H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz), OCH3), 4.57 (2H, s), 6.31 (2H, d, J=14.0Hz), 6.89 (2H, d,
7.62 (2H, d, J=7.8Hz), 9.21 (1H, s, OH); 13C-NMR (100MHz, J=13.5Hz), 6.90 (2H, d, J=7.3Hz), 7.03 (4H, s), 7.19 (2H,
CDCl3) δ: 198.71, 169.07, 164.28, 150.92, 150.58, 149.33, d, J=7.3Hz), 7.21 (2H, dd, J=7.5, 2.3Hz), 7.48 (2H, d,
147.92, 147.07, 142.72, 138.27, 132.02, 130.38, 129.63, 127.69, J=14.0Hz), 7.50 (2H, m), 7.55 (2H, dd, J=7.5, 2.3Hz), 7.60
127.07, 126.63, 123.48, 122.33, 121.47, 115.43, 114.75, 112.16, (2H, d, J=13.5Hz); 13C-NMR (100MHz, CDCl3) δ: 198.71,
111.05, 56.15, 55.73, 51.63, 20.22; HR-ESI-MS m/z: 556.5671 169.07, 164.28, 151.17, 150.92, 147.92, 142.72, 138.27, 134.46,

Vol. 63, No. 11 (2015)
Chem. Pharm. Bull.
879
130.38, 129.05, 127.07, 126.63, 125.28, 121.24, 120.72, 115.43, (1H, d, J=14.0Hz), 6.83 (1H, dd, J=7.2, 1.3Hz), 6.89 (2H, d,
111.05, 55.73, 51.63, 20.22; HR-ESI-MS m/z: 744.7483 [M+H]+ J=13.5Hz), 6.94 (1H, d, J=7.2Hz), 7.02 (1H, d, J=7.2Hz),
(Calcd for C43H36O12 744.7490).
Bisdesmethoxycurcumin-Diacetylated trans-3-Hydroxylcin- 1.3Hz), 7.23 (1H, s), 7.31 (1H, m), 7.41 (1H, dd, J=6.9, 1.3Hz),
namic Acid (6j)
7.03 (2H, s), 7.16 (1H, dd, J=7.2, 1.3Hz), 7.21 (1H, dd, J=6.9,
7.45 (1H, m), 7.48 (1H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz),
Yield 58%, yellow solid, mp 162–165°C; 1H-NMR 9.21 (1H, s, OH), 9.45 (1H, s, OH); 13C-NMR (100MHz,
(400MHz, DMSO-d6) δ: 2.31 (6H, s, COCH3), 4.57 (2H, s), CDCl3) δ: 198.71, 164.28, 158.32, 151.17, 149.33, 147.85, 147.07,
6.31 (2H, d, J=14.0Hz), 6.89 (2H, d, J=13.5Hz), 7.03 (4H, 142.72, 135.34, 134.38, 130.38, 130.04, 129.05, 127.69, 125.28,
s), 7.21 (4H, dd, J=7.5, 2.3Hz), 7.41 (2H, dd, J=6.9, 1.3Hz), 122.72, 121.18, 120.73, 117.55, 115.43, 115.13, 114.75, 112.18,
7.45 (2H, m), 7.48 (2H, d, J=14.0Hz), 7.50 (2H, m), 7.55 56.15, 51.63; HR-ESI-MS m/z: 484.5040 [M+H]+ (Calcd for
(2H, dd, J=7.5, 2.3Hz), 7.60 (2H, d, J=13.5Hz); 13C-NMR C29H24O7 484.5040).
(100MHz, CDCl3) δ: 198.71, 169.07, 164.28, 151.17, 147.92,
Curcumin-Mono-trans-3-hydroxylcinnamic Acid (7c)
142.72, 134.46, 130.38, 129.05, 125.28, 121.24, 120.72, 115.43,
Yield 94%, yellow solid, mp 186–189°C; 1H-NMR
51.83, 20.22; HR-ESI-MS m/z: 684.6964 [M+H]+ (Calcd for (400MHz, DMSO-d6) δ: 3.83 (3H, s, OCH3), 3.86 (3H, s,
C41H32O10 684.6970).
OCH3), 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz), 6.83 (1H, dd,
Curcumin-Diacetylated trans-4-Hydroxylcinnamic Acid J=7.5, 2.3Hz), 6.89 (2H, d, J=13.5Hz), 6.94 (2H, d, J=7.2Hz),
(6k)
7.02 (2H, d, J=7.2Hz), 7.03 (2H, s), 7.16 (1H, dd, J=7.5,
Yield 55%, yellow solid, mp 158–161°C; 1H-NMR 2.3Hz), 7.23 (1H, s), 7.31 (1H, m), 7.48 (1H, d, J=14.0Hz),
(400MHz, DMSO-d6) δ: 2.31 (6H, s, COCH3), 3.83 (6H, s, 7.60 (2H, d, J=13.5Hz), 9.21 (1H, s, OH), 9.45 (1H, s, OH);
OCH3), 4.57 (2H, s), 6.31 (2H, d, J=14.0Hz), 6.90 (2H, d, 13C-NMR (100MHz, CDCl3) δ: 198.71, 164.28, 158.32, 150.92,
J=7.3Hz), 6.89 (2H, d, J=13.5Hz), 7.03 (2H, s), 7.19 (2H, d, 149.33, 147.92, 147.07, 142.72, 138.27, 135.34, 130.38, 130.05,
J=7.3Hz), 7.28 (4H, d, J=7.8Hz), 7.48 (2H, d, J=14.0Hz), 127.63, 127.07, 126.63, 123.48, 122.83, 121.18, 117.55, 115.43,
7.60 (2H, d, J=13.5Hz), 7.62 (4H, d, J=7.8Hz); 13C-NMR 115.13, 114.75, 112.16, 111.05, 56.15, 55.73, 51.63; HR-ESI-MS
(100MHz, CDCl3) δ: 198.71, 169.07, 164.28, 150.88, 150.58, m/z: 514.5297 [M+H]+ (Calcd for C30H26O8 514.5300).
147.92, 142.72, 138.27, 132.02, 130.38, 129.69, 127.07, 126.63,
Bisdesmethoxycurcumin-Mono-trans-3-hydroxylcinnamic
123.48, 121.47, 115.43, 111.05, 55.73, 51.63, 20.22; HR-ESI-MS Acid (7d)
m/z: 744.7483 [M+H]+ (Calcd for C43H36O12 744.7490).
Yield 96%, yellow solid, mp 179–182°C; 1H-NMR
Bisdesmethoxycurcumin-Diacetylated trans-4-Hydroxylcin- (400MHz, DMSO-d6) δ: 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz),
namic Acid (6l)
6.70 (2H, s), 6.83 (1H, dd, J=7.5, 2.3Hz), 6.89 (2H, d,
Yield 57%, yellow solid, mp 163–166°C; 1H-NMR J=13.5Hz), 7.03 (1H, s), 7.16 (1H, dd, J=7.5, 2.3Hz), 7.21
(400MHz, DMSO-d6) δ: 2.31 (6H, s, COCH3), 4.57 (2H, s), (2H, dd, J=7.5, 2.3Hz), 7.31 (1H, m), 7.41 (2H, dd, J=6.9,
6.31 (2H, d, J=14.0Hz), 6.89 (2H, d, J=13.5Hz), 7.03 (2H, 1.3Hz), 7.45 (1H, m), 7.48 (1H, d, J=14.0Hz), 7.60 (2H, d,
s), 7.21 (2H, dd, J=7.5, 2.3Hz), 7.28 (4H, d, J=7.8Hz), 7.41 J=3.5Hz), 9.45 (2H, s, OH); 13C-NMR (100MHz, CDCl3) δ:
(2H, dd, J=6.9, 1.3Hz), 7.45 (2H, m), 7.48 (2H, d, J=14.0Hz), 198.71, 164.28, 158.32, 151.17, 147.92, 142.72, 135.34, 134.46,
7.60 (2H, d, J=13.5Hz), 7.62 (4H, d, J=7.8Hz); 13C-NMR 130.38, 129.05, 125.28, 121.18, 120.72, 117.55, 115.43, 115.13,
(100MHz, CDCl3) δ: 198.71, 169.07, 164.28, 151.17, 150.58, 51.63; HR-ESI-MS m/z: 454.4773 [M+H]+ (Calcd for C28H22O6
147.92, 142.72, 134.46, 132.02, 130.38, 129.69, 129.05, 125.28, 454.4780).
121.47, 121.18, 120.73, 115.43, 51.63, 20.22; HR-ESI-MS m/z:
Curcumin-Mono-trans-4-hydroxylcinnamic Acid (7e)
684.6964 [M+H]+ (Calcd for C41H32O10 684.6970).
Yield 94%, yellow solid, mp 174–177°C; 1H-NMR
General Procedure for the Synthesis of 7a–l A solution (400MHz, DMSO-d6) δ: 3.83 (3H, s, OCH3), 3.86 (3H, s,
of 6a–l (2mmol) in MeOH (10mL) and sodium hydroxide OCH3), 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz), 6.59 (2H, d,
solution (10mL, 1M) was stirred at room temperature over- J=6.3Hz), 6.90 (1H, d, 7.3Hz), 6.89 (2H, d, J=13.5Hz), 6.94
night. The solvent was washed with aqueous hydrochloric and (1H, d, J=7.2Hz), 7.02 (1H, d, J=7.2Hz), 7.03 (2H, s), 7.19
then was extracted with ethyl acetate. Lastly, the ethyl acetate (1H, d, J=7.3Hz), 7.23 (1H, s), 7.45 (2H, d, J=6.3Hz), 7.48
was dried with anhydrous Na2SO4 and evaporated to dryness (1H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz), 9.21 (1H, s, OH),
under vacuum to give 7a–l which were yellow solids.
Curcumin-Monoisoferulic Acid (7a)
9.68 (1H, s, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71,
164.28, 157.65, 149.33, 147.92, 147.01, 142.72, 138.27, 130.62,
Yield 95%, yellow solid, mp 178–181°C; 1H-NMR 130.38, 127.75, 127.07, 126.63, 123.48, 122.83, 115.72, 115.43,
(400MHz, DMSO-d6) δ: 3.75 (3H, s, OCH3), 3.86 (6H, s, 114.75, 112.12, 111.05, 56.15, 55.73, 51.63; HR-ESI-MS m/z:
OCH3), 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz), 6.90 (1H, d, 514.5297 [M+H]+ (Calcd for C30H26O8 514.5300).
J=7.3Hz), 6.89 (2H, d, J=13.5Hz), 6.94 (2H, d, J=7.2Hz),
Bisdesmethoxycurcumin-Mono-trans-4-hydroxylcinnamic
7.02 (2H, d, J=7.2Hz), 7.03 (1H, s), 7.19 (1H, d, J=7.3Hz), Acid (7f)
7.23 (2H, s), 7.48 (1H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz),
Yield 97%, yellow solid, mp 166–169°C; 1H-NMR
9.21 (2H, s, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71, (400MHz, DMSO-d6) δ: 4.57 (2H, s), 6.31 (1H, d, J=14.0Hz),
164.28, 150.92, 149.33, 147.85, 147.07, 142.72, 138.27, 130.38, 6.59 (2H, d, J=6.3Hz), 6.83 (1H, dd, J=7.2, 1.3Hz), 6.89 (2H,
127.69, 127.07, 126.63, 123.48, 122.72, 115.43, 114.75, 112.18, d, J=13.5Hz), 7.03 (2H, s), 7.16 (1H, dd, J=7.2, 1.3Hz), 7.21
111.05, 56.15, 55.73, 51.63; HR-ESI-MS m/z: 544.5562 [M+H]+ (1H, dd, J=7.5, 2.3Hz), 7.31 (2H, m), 7.41 (1H, dd, J=6.9,
(Calcd for C31H28O9 544.5560).
Bisdesmethoxycurcumin-Monoisoferulic Acid (7b)
1.3Hz), 7.45 (2H, d, J=6.3Hz), 7.47 (1H, dd, J=6.9, 1.3Hz),
7.60 (2H, d, J=13.5Hz), 7.48 (1H, d, J=14.0Hz), 9.45 (1H, s,
Yield 97%, yellow solid, mp 173–176°C; 1H-NMR OH), 9.68 (1H, s, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71,
(400MHz, DMSO-d6) δ: 3.86 (3H, s, OCH3), 4.57 (2H, s), 6.31 164.28, 158.46, 157.65, 151.17, 147.92, 142.72, 135.34, 134.46,

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Vol. 63, No. 11 (2015)
130.62, 130.38, 130.08, 129.05, 127.75, 125.83, 121.01, 120.73, 115.72, 115.43, 111.05, 55.73, 51.63; HR-ESI-MS m/z: 660.6750
117.64, 115.72, 115.43, 51.63; HR-ESI-MS m/z: 454.4773 [M+H]+ (Calcd for C39H32O10 660.6750).
[M+H]+ (Calcd for C28H22O6 454.4780).
Bisdesmethoxycurcumin-Di-trans-4-hydroxylcinnamic Acid
(7l)
Yield 92%, yellow solid, mp 180–183°C; 1H-NMR
Curcumin-Diisoferulic Acid (7g)
Yield 95%, yellow solid, mp 192–195°C; 1H-NMR
(400MHz, DMSO-d6) δ: 3.75 (6H, s, OCH3), 3.86 (6H, s, (400MHz, DMSO-d6) δ: 4.57 (2H, s), 6.31 (2H, d, J=14.0Hz),
OCH3), 4.57 (2H, s), 6.31 (2H, d, J=14.0Hz), 6.90 (2H, d, 6.59 (4H, d, J=6.3Hz), 6.89 (2H, d, J=13.5Hz), 7.03 (2H, s),
J=7.3Hz), 6.89 (2H, d, J=13.5Hz), 6.94 (2H, d, J=7.2Hz), 7.21 (2H, dd, J=7.5, 2.3Hz), 7.41 (2H, dd, J=6.9, 1.3Hz), 7.45
7.02 (2H, d, J=7.2Hz), 7.19 (2H, d, J=7.3Hz), 7.23 (2H, s), (2H, d, J=6.3Hz), 7.47 (1H, dd, J=6.9, 1.3Hz), 7.48 (2H, d,
7.48 (2H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz), 9.21 (2H, s, J=14.0Hz), 7.50 (2H, m), 7.60 (2H, d, J=13.5Hz), 9.68 (1H, s,
OH); 13C-NMR (100MHz, CDCl3) δ: 198.71, 164.28, 150.92, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71, 164.28, 157.65,
149.33, 147.85, 147.07, 142.72, 138.27, 130.38, 127.69, 127.07, 151.17, 147.92, 142.72, 134.46, 130.62, 130.38, 129.05, 127.75,
126.63, 123.48, 122.72, 115.43, 114.75, 112.18, 111.05, 56.15, 125.28, 121.18, 120.73, 115.72, 115.43, 51.63; HR-ESI-MS m/z:
55.73, 51.63; HR-ESI-MS m/z: 720.7271 [M+H]+ (Calcd for 600.6228 [M+H]+ (Calcd for C37H28O8 600.6230).
C41H36O12 720.7270).
Bisdesmethoxycurcumin-Diisoferulic Acid (7h)
Antioxidant Method The antioxidant activity was deter-
mined by DPPH method. To be brief, 100µL ethanol solu-
Yield 93%, yellow solid, mp 194–197°C; 1H-NMR tions of the test compound and VC (2.5, 5, 10, 20, 40, 80µM)
(400MHz, DMSO-d6) δ: 3.86 (6H, s, OCH3), 4.57 (2H, s), were added to 100µL of ethanol solution of DPPH radicals
6.31 (2H, d, J=14.0Hz), 6.89 (2H, d, J=13.5Hz), 6.94 (2H, (100 µM). Then the mixture was incubated at 25°C for 30min.
d, J=7.2Hz), 7.02 (2H, d, J=7.2Hz), 7.03 (2H, s), 7.21 (2H, Lastly, the absorbance was recorded at 570nm, using ethanol
dd, J=6.9, 1.3Hz), 7.23 (2H, s), 7.41 (2H, dd, J=6.9, 1.3Hz), as a blank for correction. VC was used as references, and its
7.45 (2H, m), 7.48 (2H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz), concentration was maintained to that of the synthesized com-
9.21 (2H, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71, 164.28, pounds. The experiment was carried out in triplicate, and the
151.17, 149.33, 147.85, 147.07, 142.72, 134.38, 130.38, 129.05, resulting values were averaged. The radical-scavenging activ-
127.69, 125.28, 122.72, 121.18, 120.73, 115.43, 114.75, 112.18, ity (%) was calculated using the following formula:
56.15, 51.63; HR-ESI-MS m/z: 660.6746 [M+H]+ (Calcd for
Radical-scavenging activity (%)=[(AC − A ) / AC ]×100%
S
C39H32O10 660.6750).
Curcumin-Di-trans-3-hydroxylcinnamic Acid (7i)
where AC is the absorbance of the control and AS is the absor-
Yield 97%, yellow solid, mp 196–199°C; 1H-NMR bance of the tested sample after 30min.
(400MHz, DMSO-d6) δ: 3.83 (6H, s, OCH3), 4.57 (2H, s), 6.31
Antibacterial Method The antibacterial activity was
(2H, d, J=14.0Hz), 6.70 (2H, s), 6.83 (2H, dd, J=7.5, 2.3Hz), tested by the drilling method. The S. aureus, Bacilllus subtilis,
6.89 (2H, d, J=13.5Hz), 6.90 (2H, d, J=7.3Hz), 7.03 (2H, s), E. coli and Pseudomonas aeruginosa were activated for 2h at
7.16 (2H, dd, J=7.5, 2.3Hz), 7.19 (2H, d, J=7.3Hz), 7.31 (2H, optimum temperature. The resulting broth was diluted to 108
m), 7.48 (2H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz), 9.45 Colony Forming Unit (CFU)/mL. The stock solutions of the
(1H, s, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71, 164.28, unJugates along with curcuminoids were prepared in DMSO
158.32, 150.92, 147.92, 142.72, 138.27, 135.34, 130.38, 130.05, and they were in different concenirations (1, 1.25, 2.5, 5, 10,
127.07, 126.63, 123.48, 121.18, 117.55, 115.43, 115.13, 111.05, 20, 40, 50µg/mL). Then in each dish access 108 CFU/mL ex-
55.73, 51.63; HR-ESI-MS m/z: 660.6750 [M+H]+ (Calcd for perimental strains for 100mL and polee holes for 6mm. Then
C39H32O10 660.6750).
add 10µL the compounds, chloromycethin and sterile saline
Bisdesmethoxycurcumin-Di-trans-3-hydroxylcinnamic Acid solution into the well, respecticely. Each solution was three
(7j)
parallel experinents alone. They were developed at an optimun
Yield 91%, yellow solid, mp 190–193°C; 1H-NMR incubation temperature for a growth cycle and then the diam-
(400MHz, DMSO-d6) δ: 4.57 (2H, s), 6.31 (2H, d, J=14.0Hz), eter of each zone of inhibition was measured. The concentra-
6.70 (2H, s), 6.83 (2H, dd, J=7.5, 2.3Hz), 6.89 (2H, d, tion in the hole showing the diameter within 6.2mm has been
J=13.5Hz), 7.03 (2H, s), 7.16 (2H, dd, J=7.5, 2.3Hz), 7.21 (2H, reported as the MIC. As each test was performed in triplicate,
dd, J=7.5, 2.3Hz), 7.31 (2H, m), 7.41 (2H, dd, J=6.9, 1.3Hz), the MIC reported represents the result of three repetitions.
7.45 (2H, m), 7.48 (2H, d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz),
Cytotoxicity Assay in Vitro The four lines of cells (3T3,
9.45 (2H, s, OH); 13C-NMR (100MHz, CDCl3) δ: 198.71, LX-2, HepG-2 and MCF-7) were incubated at 37°C under a
164.28, 158.32, 151.17, 147.92, 142.72, 135.34, 134.46, 130.38, humidified atmosphere containing 5% CO2 for 24h with a
130.05, 129.05, 125.28, 121.18, 121.14, 120.72, 117.55, 115.43, density of 0.2×104 cells/well. Then the cells were cultured for
115.13, 51.63; HR-ESI-MS m/z: 600.6228 [M+H]+ (Calcd for another 48h with various concentrations (1, 5, 10, 15, 20, 40,
C37H28O8 600.6230).
50µM) of the test compounds and ADR. After that, add 20µL
Curcumin-Di-trans-4-hydroxylcinnamic Acid (7k)
of 5mg/mL MTT to the wells and go on culturing for 3h in
Yield 98%, yellow solid, mp 186–189°C; 1H-NMR the same condition. Then 200µL DMSO was added and the
(400MHz, DMSO-d6) δ: 3.83 (6H, s, OCH3), 4.57 (2H, absorbance was measured at 570nm with a microplate reader.
s), 6.31 (2H, d, J=14.0Hz), 6.59 (4H, d, J=6.3Hz), 6.90 And the cell viability (%) was calculated as the ratio of the
(2H, d, J=7.3Hz), 6.89 (2H, d, J=13.5Hz), 7.03 (2H, s), number of surviving cells upon treatment with the test com-
7.19 (2H, d, J=7.3Hz), 7.45 (2H, d, J=6.3Hz), 7.48 (2H, pounds compared to the blank.
d, J=14.0Hz), 7.60 (2H, d, J=13.5Hz), 9.68 (1H, s, OH);
13C-NMR (100MHz, CDCl3) δ: 198.71, 164.28, 157.65, 150.88,
Acknowledgments This study was supported by the Na-
147.92, 142.72, 138.27, 130.62, 130.38, 127.75, 126.63, 123.48, tional Natural Science Foundation of China (No. 21372054,

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Chem. Pharm. Bull.
881
16) Ohtsu H., Xiao Z. Y., Ishida J., Nagai M., Wang H., Itokawa K.
H., Su C. Y., Shih C., Chiang T. Y., Chang E., Lee Y., Tsai M. Y.,
Chang C., Lee K. H., J. Med. Chem., 45, 5037–5042 (2002).
17) Gafner S., Lee S. K., Cuendet M., Barthelemy S., Vergnes L., Labi-
dalle S., Phytochem., 65, 2849–2859 (2004).
No. 21202028).
Conflict of Interest The authors declare no conflict of
interest.
18) Basile V., Ferrari E., Lazzari S., Belluti S., Pignedoli F., Imbriano
C., Biochem. Pharmacol., 78, 1305–1315 (2009).
19) Fan X., Zhang C., Liu D. B., Yan J., Liang H. P., Curr. Pharm. Des.,
19, 2011–2031 (2013).
20) Adams B. K., Ferstl E. M., Davis M. C., Herold M., Kurtkaya S.,
Camalier R. F., Kaur G., Sausville E. A., Rickles F. R., Snyder J. P.,
Liotta D. C., Shoji M., Bioorg. Med. Chem., 12, 3871–3883 (2004).
21) Conteas C. N., Panossian A. M., Tran T. T., Singh H. M., Dig. Dis.
Sci., 54, 2188–2191 (2009).
22) Mourtas S., Lazar A. N., Markoutsa E., Duyckaerts C., Antimisiaris
S. G., Eur. J. Med. Chem., 80, 175–183 (2014).
23) Aggarwal B. B., Kumar A., Bharti A. C., Anticancer Res., 23 (1A),
363–398 (2003).
24) Mishra S., Kapoor N., Ali A. M., Pardhasaradhi B. V. V., Kumari
A., Khar A., Misra K., Free Radic. Biol. Med., 38, 1353–1360
(2005).
25) Mishra S., Narain U., Mishra R., Misra K., Bioorg. Med. Chem., 13,
1477–1486 (2005).
26) Cao Y. K., Li H. J., Song Z. F., Li Y., Huai Q. Y., Molecules, 19,
16349–16372 (2014).
27) Nawwar M. A. M., Hussein S. A. M., Ayoub N. A., Hofmann K.,
Linsheio M., Harms M., Wende K., Lindequist U., Org. Artif., 64,
342–347 (2009).
28) Sardo M., Ruano C., Castro J. L., López-Tocón I., Riberio C., Otero
J. C., Chem. Phys. Lett., 467, 101–104 (2008).
29) Adisakwattana S., Sookkongwaree K., Roengsumran S., Petsom A.,
Ngamrojnavanich N., Chavasiri W., Deesamer S., Yibchok-anun S.,
Bioorg. Med. Chem. Lett., 14, 2893–2896 (2004).
References
1) Lee C. S., Kim Y. J., Lee M. S., Han E. S., Lee S. J., Life Sci., 83,
481–489 (2008).
2) Jutooru I., Chadalapaka G., Chintharlapalli S., Papineni S., Safe S.,
Mol. Carcinog., 48, 692–702 (2009).
3) Hibasami H., Iwase H., Yoshioka K., Takahashi H., Int. J. Mol.
Med., 17, 215–219 (2006).
4) Satomi Y., Nishino H., Shibata S., Anticancer Res., 25 (6B), 4043–
4047 (2005).
5) Cousins M., Adelberg J., Chen F., Rieck J., Ind. Crops Prod., 25,
129–135 (2007).
6) Chattopadhyay I., Biswas K., Bandyopadhyay U. BanerJee R. K.,
Curr. Sci., 87, 44–53 (2004).
7) Goel A., Kunnumakkara A. B., Aggarwal B. B., Biochem. Pharma-
col., 75, 787–809 (2008).
8) Motterlini R., Foresti R., Bassi R., Green C. J., Free Radic. Biol.
Med., 28, 1303–1312 (2000).
9) Menon V. P., Sudheer A. R., Adv. Exp. Med. Biol., 595, 105–125
(2007).
10) Tuba A. K., İlhami G., Chem. Biol. Interact., 174, 27–37 (2008).
11) Jayaprakasha G. K., Jaganmohan Rao L., Sakariash K. K., Food
Chem., 98, 720–724 (2006).
12) Yang Z., Zhao T., Zou Y., Zhang J. H., Feng H., Immunol. Lett.,
160, 89–95 (2014).
13) Wang Y. F., Zu J. N., Li J., Chen C., Xi C. Y., Yan J. L., Neurosci.
Lett., 7, 51–56 (2014).
14) Preetha A., Sherin G. T., Ajaikumar B. K., Chitra S., Kuzhuvelil B.
H., Bokyung S., SheeJa T. T., Krishna M., Indira K. P., Kallikat N.
R., Bharat B. A., Bio. Pharm., 76, 1590–1611 (2008).
15) Oelkrug C., Lange C. M., Wenzel E., Fricke S., Hartke M., Simasi
J., Schubert A., Anticancer Res., 34, 4781–4788 (2014).
30) Luceri C., Giannini L., Lodovici M., Antonucci E., Abbate R., Ma-
sini E., Dolara P., Br. J. Nutr., 97, 458–463 (2007).
31) Burits M., Bucar F., Phytother. Res., 14, 323–328 (2000).