Synthesis of derivatives of methyl rosmarinate and their inhibitory activities against matrix metalloproteinase-1 (MMP-1)

Article abstract of DOI:10.1016/j.ejmech.2012.09.047

A series of MMP-1 inhibitors have been identified based upon a methyl rosmarinate scaffold using structure-based drug design methods. The best compound in the series showed an IC₅₀ value of 0.4 μM. A docking study was conducted for compound (S)

Full text of DOI:10.1016/j.ejmech.2012.09.047

European Journal of Medicinal Chemistry 62 (2013) 148e157
Contents lists available at SciVerse ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis of derivatives of methyl rosmarinate and their inhibitory
activities against matrix metalloproteinase-1 (MMP-1)
,
d
,
,
,
Hu Yuan a 1, Weiqiang Lu b 1, Liyan Wang b, Lei Shan a, Honglin Li b, Jin Huang b
*
,
Qingyan Sun c , Weidong Zhang
,
a,d,
**
*
a Department of Phytochemistry, School of Pharmacy, Second Military Medical University, Shanghai 200433, China
b Shanghai Key Laboratory of Chemical Biology, State Key Laboratory of Bioreactor Engineering, School of Pharmacy,
East China University of Science and Technology, Shanghai 200237, China
c Department of Organic Chemistry, School of Pharmacy, Second Military Medical University, Shanghai 200433, China
d School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 9 June 2012
Received in revised form
27 September 2012
Accepted 28 September 2012
Available online 16 October 2012
A series of MMP-1 inhibitors have been identified based upon a methyl rosmarinate scaffold using
structure-based drug design methods. The best compound in the series showed an IC50 value of 0.4 M. A
docking study was conducted for compound (S)-10n in order to investigate its binding interactions with
MMP-1. The structureeactivity relationships (SAR) were also briefly discussed. Useful SAR was estab-
lished which provides important guidelines for the design of future generations of potent inhibitors
against MMP-1.
m
Ó 2012 Elsevier Masson SAS. All rights reserved.
Keywords:
MMP-1
Inhibitors
SAR
1. Introduction
Interstitial collagenase (MMP-1), discovered from a meta-
morphosing tadpole in 1962 by Gross and Lapiere [12], plays an
The matrix metalloproteinases (MMPs) are a family of zinc-
dependent endopeptidases that are involved in the degradation
of all components of the extracellular matrix [1]. The implication of
MMPs in a number of pathological processes has been reported,
thus, they are considered to be important therapeutic targets for
the treatment of a wide array of disease processes such as cancer,
tumor metastasis, arthritis, and cardiovascular diseases, as well as
wound healing [2e9]. MMPs have been classified on the basis of
their substrate specificity into the five following classes: gelatinases
(MMP-2 and MMP-9), collagenases (MMP-1, -8, -13), stromelysins
(MMP-3, -10), membrane types (MMP-14, -16, -17), and other
related enzymes such as matrilysin (MMP-7) [10,11].
important role in diverse physiologic processes such as growth,
tissue morphogenesis, and wound repair [13e15]. Likewise, it seems
to be implicated in a variety of human diseases including athero-
sclerosis, rheumatoid arthritis, pulmonary emphysema, and fibrotic
disorders, suggesting that its inhibition or stimulation may open
therapeutic avenues [16,17]. Last year, Paul Elkington’s group found
that MMP-1 may drive tissue destruction in immunopathology of
Tuberculosis (TB) and represents a therapeutic target to limit
immunopathology [18]. The major structural difference observed
between MMP-1 and other MMP enzymes is the relative size and
shape of the S1’ pocket. MMP-1 is characterized by a short and
narrow S1’ pocket. Currently, there are only two well-defined
structures of MMP-1 available in the PDB. These two forms mainly
differ in the S1’ pocket, which can be in a “closed” (low energy) or in
an “open” (inhibitor induced) conformation [19e21] Fig. 1.
During the past decades, a variety of different structural classes
of MMP-1 inhibitors have been discovered using structure-based
design and combinatorial chemistry [22,23]. Some of these inhib-
itors showed promising pre-clinical results in various cancer
models [24]. Broad spectrum MMP inhibitors I (marimastat) [25]
and II (prinomastat) [26] were tested against cancers; MMP
* Corresponding authors. Tel./fax: þ86 21 81871244.
** Corresponding author. Department of Phytochemistry, School of Pharmacy,
Second Military Medical University, Shanghai 200433, China. Tel./fax: þ86 21
81871244.
E-mail addresses: huangjin@ecust.edu.cn (J. Huang), sqy_2000@163.com
(Q. Sun), wdzhangy@hotmail.com (W. Zhang).
1
These authors contributed equally to this work.
0223-5234/$ e see front matter Ó 2012 Elsevier Masson SAS. All rights reserved.
http://dx.doi.org/10.1016/j.ejmech.2012.09.047

H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
149
Fig. 1. Molecularstructures offour broadspectrum MMPinhibitorstestedinclinicaltrials.
inhibitors III (cipemastat) [27] and IV (ilomastat) [28] were tried in
the clinics for inflammation. However, advanced clinical trials of
these compounds failed for poor oral bioavailability, decreased
potency in vivo and musculoskeletal side effects. Hence, developing
new types of MMP-1 inhibitors is especially essential.
Our previous screening disclosed natural product methyl ros-
marinate (1) as a MMP-1 inhibitor with an IC50 of 14.7 mM against
MMP-1 (unpublished data). Specific interactions devised by molec-
ular docking between 1 and MMP-1 are shown in Fig. 2A. The phenyl
ring of the caffeic acid group inserts into the enzymes’ hydrophobic
domains (S1’ pocket), which makes hydrophobic interaction with
His218 and Tyr240. In addition, several polar interactions occur in
the interactions between compound and the enzyme. The carbonyl
group has a chelate bond with the zinc atom of the enzyme. Another
carbonyl group in the middle of the compound makes ionic inter-
actions with the polar nitrogen atom of Ala182. And the hydroxyl
groups of the two terminal aryl rings which locate in compound
make hydrogen bonds with the polar atoms of Ala234, Thr241 in S1’
pocket and Asn180 in S3’ pocket, respectively. Hence, when
compound 1 is bound to MMP-1, the enzyme is inactivated resulting
from high affinity between compound 1 and MMP-1.
To probe the SAR of the derivatives of methyl rosmarinate as MMP-
1 inhibitors and exploit more potent MMP-1 inhibitors, we have
investigated various replacements for the R1, R2, and R3 groups
according to the results of computer-aided drug design (Fig. 2B), which
predicted that different substituent groups for R1, R2, and R3 may make
differences in activities of the compounds. Meanwhile, R2 and R3
groups seem to be particularly important to the potency because they
chelate with zinc ion and make hydrophobic interactions with S1’
pocket, while R1 group may play a less important role. Consequently,
we defined R1 as hydroxyl group or methoxyl group, R2 as ester group,
carboxyl group orhydroxamate group, and R3 asdifferenthydrophobic
groups to discuss the effects of different substituted groups for
compounds’ inhibitional activities against MMP-1 in this paper. We
now describe the structure-based design, synthesis of inhibitors of
MMP-1 that utilizes methyl rosmarinate as a scaffold.
Fig. 2. (A) Ligand interaction diagrams for 1, an inhibitor with a ZBG bound to MMP-1.
The compound is represented by the yellow sticks. The amino residues are represented
by the cyan lines. The zinc ion is represented by grey sphere. The MMP-1’s tertiary
structure is represented by the green cartoon. (B) Scaffold based on methyl rosmari-
nate. R1, R2, and R3 groups were supposed to be replaced by different groups. (For
interpretation of the references to colour in this figure legend, the reader is referred to
the web version of this article.)
the first step. Further treatment with 3 M hydrochloric acid con-
verted 4 into hydroxycinnamic acid 5 [29,30], and 5 was hydroge-
nated to the corresponding unstable lactic acid 6, which was
transformed to the allyl ester 7a and methyl ester 7b by reaction
with allyl alcohol and methanol, respectively, followed by esterifi-
cation (EDCI method) of allyl ester and methyl ester at the free
alcoholic function with cinnamic acid (Scheme 1).
Compound 9q was deprotected by TBAF in THF to afford 9q0 in
a excellent yield (See Supporting information). The allyl esters 9ae
k and 9meq0 were deprotected by catalytic amounts of Pd(PPh3)4
and morpholine following the KunzeWaldmann procedure [31] to
give substitutional rosmarinic acids 10aep, followed by conden-
sation with hydroxylamine hydrochloride which afforded
compounds 11f, 11i, 11j, and 11nep.
The derivatives of cinnamic acids 8j and 8neq were prepared
conveniently from 3,4-dihydroxy cinnamic acid, p-hydroxy cin-
namic acid by O-allylation and subsequent hydrolysis of the esters
or Knoevenagel condensation of aldehydes (12o, 12p) with malonic
acid (See Supporting information). Completion of the synthesis
required removal of four ether methyl groups to arrive at rosmar-
inic acid (2, See Supporting information). The deprotection of
pentamethyl rosmarinic acid was studied, and it was found that
2. Chemistry
All the target compounds were designed and synthesized via
the routes shown in Scheme 1. Compound
4 from 3,4-
dimethoxybenzaldehyde and N-acetyl glycine was employed as

150
H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
Reagents: a) NaOAc, Ac2O, AcHNCH2COOH; b) 3 M HCl; c) NaBH4; d) p-TsOH, allyl alcohol or
methanol, toluene; e) EDCI, DMAP, CH2Cl2; f) TBAF, THF; g) Pd(PPh3)4, morpholine, THF; h) DCC,
DMAP, CH2Cl2, NH2OH·HCl.
Scheme 1. Synthetic route of target compounds.
several conditions gave only decomposition products or selective
deprotection products (Table 1), which is difficult to separate by
crystallization or column chromatography. Using Brossi’s [32]
conditions, in which iodotrimethylsilane (TMSI) and quinoline are
precomplexed, pentamethyl rosmarinic acid was converted back to
rosmarinic acid in 56% yield.
2 and ester for its predecessor 1, respectively. Both of these two
groups could chelate with zinc ion at catalytic activity center of the
enzyme. However, the carboxyl group seemed to be a more potent
ZBG than ester (COOCH3) as shown in the activity order of 2 and its
predecessor 1, which was confirmed again by sharp decrease in
activities after conversion from carboxyl group (10c, 10e, 10f, 10h,
and 10j) to corresponding ester (9c, 9e, 9f, 9h, and 9r). Moreover,
considering the high affinity of the hydroxamate moiety for zinc ion
relative to other coordinating moieties [33], a series of hydrox-
amates (11f, 11i, 11j, and 11nep) were prepared to improve the
activities of these ligands by allowing for a good interaction with
the ZBGs in R2 position. The results showed that compounds 11f,
11i, 11j, and 11nep were more potent than their predecessors 10f,
10i, 10j, and 10nep. These activity differences were likely caused by
the ZBGs (R2), which were the only structural difference between
11f, 11i, 11j, and 11nep and their predecessors. The ZBG was
hydroxamate (CONHOH) for 11f, 11i, 11j, and 11nep and carboxyl
for their predecessors. Therefore, the hydroxamate group was
a more potent ZBG than carboxyl group as shown in the activity
order of 11f, 11i, 11j, and 11nep and their predecessors.
3. Results and discussion
All final compounds were tested in vitro, with a fluorometric
assay on purified enzymes, for their abilities to inhibit MMP-1. Data
obtained are shown in Table 2. Our approach focused on a series of
derivatives beginning with the lead compound methyl rosmarinate
(1), giving IC50 of 14.7 mM against MMP-1.
Firstly, our approach focused on a series of derivatives beginning
with the lead compound methyl rosmarinate (1) with changing the
R2 group. Compound 2 was more potent than its predecessor 1. As
can be seen from the docking result (Fig. 3A), this activity difference
was likely caused by the ZBG (R2), which was the only structural
difference between 2 and its predecessor 1. The ZBG is carboxyl for
Next, R1 group was altered by hydroxyl group and methoxyl
group. Among compounds 2 and 10l, R2 and R3 groups were fixed as
carboxyl and 3,4-dihydroxyphenyl, respectively. For compound 10l,
R1 group was methoxyl, provided a 1.5-fold decrease in the inhibitory
activity compared to compound 2, which indicated that methoxyl
substitution at R1 position was less favorable than the hydroxyl
substitution. This might be attributed to the hydroxyl group, which
has stronger hydrophilic interaction than the methoxyl group, was
more favorable for binding the site of a solvent exposed area (Fig. 3).
Finally, we turned our attention to understand the R3 group’s
effects on MMP-1. It was altered by various substituted phenyls.
Among compounds 10aec, 10h, 10k, 10m, 10o, and 10p, R1 and R2
groups were fixed as methoxyl and carboxyl, respectively, and R3
Table 1
Demethylation of pentamethyl rosmarinic acid (10m).
Entry
Reagents and conditions
Yield/%
1
2
3
4
5
6
7
8
9
BBr3, CH2Cl2, ꢀ50 ꢁC
Ester cleavage
Ester cleavage
Decomposition
Decomposition
Decomposition
Partial deprotection
<5
46% HBr, TBAB, reflux
AlCl3, SHCH2CH2SH, CH2Cl2, 25 ꢁC
BF3$Et2O, SHCH2CH2SH, 25 ꢁC
Pyridine hydrochloride, 180 ꢁC/N2
AlCl3, CH2Cl2, 25 ꢁC
Me3SiI, CHCl3, r.t./N2
Me3SiI, quinoline, 4 h, 100 ꢁC
Me3SiI, quinoline, 4 h, 180 ꢁC
<5
56

H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
Table 2 (continued )
151
Table 2
Evaluation of synthesized compounds for their inhibitory activity towards MMP-1.
Compound R1
R2
R3
Inhibitiona (%) IC50
(mM)
OCH3
OH
10k
10l
OMe COOH
OMe COOH
0
>100
Compound R1
R2
R3
Inhibitiona (%) IC50
(m
M)
43.2
13.7
OH
OH
1
OH COOMe
58.6
14.7
OCH3
OH
OH
10m
10n
OMe COOH
OMe COOH
21.3
86.6
>100
OCH3
OBn
2
OH COOH
68.6
5.6
OH
2.5
OBn
10a
10b
OMe COOH
OMe COOH
28
53.7
10o
10p
OMe COOH
OMe COOH
0.1
0.3
>100
>100
CH3
CF3
F
10.3
>100
38.9
41.7
42.6
10.7
O
10c
10d
10e
10f
OMe COOH
OMe COOH
OMe COOH
OMe COOH
25.8
22.9
40.6
73.1
Br
11f
11i
OMe CONHOH
OMe CONHOH
56.8
85.4
7.6
5.5
Cl
OBn
Br
11j
OMe CONHOH
OMe CONHOH
87.2
100
3.6
4.2
OBn
OBn
11n
10g
OMe COOH
33.2
34.7
F
11o
11p
OMe CONHOH
OMe CONHOH
65
6.8
NO2
10h
10i
OMe COOH
OMe COOH
29.8
55.7
38.5
8.6
47.9
10.6
O
CF3
9c
9e
OMe COOAllyl
OMe COOAllyl
1.8
0
>100
>100
Cl
OBn
10j
OMe COOH
87.9
8.9
(continued on next page)

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H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
Table 2 (continued )
Compound R1
R2
R3
Inhibitiona (%) IC50
(mM)
Br
9f
OMe COOAllyl
OMe COOAllyl
14.2
0
>100
>100
NO2
9h
OBn
9r
OMe COOMe
1.7
>100
OBn
(R)-10n
OMe COOH
OMe COOH
100
100
0.4
0.8
OBn
OBn
(S)-10n
OBn
a
Measured at 10 mM.
group was altered as various substituted phenyls. So the differences
in the inhibitory activities of these compounds were likely caused by
various R3 groups. For compound 10a, R3 group was phenyl,
provided a 3-fold decrease in the inhibitory activity compared to
compound 10l. For compounds 10b,10k,10m,10o, and 10p, R3 group
were 4-methylphenyl, 4-methoxyphenyl, 3,4-dimethoxyphenyl,
naphthyl, and 2,3-dihydrobenzofuran, respectively, showed no
inhibitory activities against MMP-1. For compound 10c and 10h, R3
group were 4-trifluoromethylpheny and 4-nitrophenyl, respectively,
each compound demonstrated a 1.8-fold decrease in the inhibitory
activity compared to compound 10l. These results suggested that
small hydrophobic substituent groups on aromatic ring impaired
affinity, which might be attributed to the small hydrophobic groups
were unfavorable to the accommodation with the enzymes’ hydro-
phobic domain (S1’ pocket). Comparing compounds with halogen-
substitution at the para-position or ortho-position in the aromatic
ring (10deg), it seemed that the increased bulk of halogen substit-
uents leads to improved activities, suggesting there is a space
requirement in the binding pocket to accommodate the suitable
substituents. Among compounds 10i, 10j, and 10n, R1 and R2 groups
were fixed as methoxyl and carboxyl, respectively, and R3 group was
altered as various substituted phenyls. So the differences in the
inhibitory activities of these compounds were likely caused by
various R3 groups. Compound 10n displayed the highest affinity
Fig. 3. Docking of compound 2 (A) and 10l (B) into MMP-1. The compound is repre-
sented by the yellow sticks. The amino residues are represented by the cyan lines. The
zinc ion is represented by grey sphere. The MMP-1’s tertiary structure is represented
by the green cartoon. (For interpretation of the references to colour in this figure
legend, the reader is referred to the web version of this article.)
(IC50 ¼ 2.5
mM), compound 10i and 10j presented similar activities,
suggesting long and bulky hydrophobic substituents on aromatic
ring improved affinities, which might be attributed to the long and
bulky hydrophobic groups were favorable to the accommodation
with S1’ pocket because they were able to induce the “open”
conformational change (long and bulky hydrophobic substituent
groups at R3 position required Arg 214 to adopt a new position
(Fig. 4), creating a larger, open S1’ pocket).
In order to rationalize the affinities observed for our inhibitors,
the binding modes of compound (S)-10n (the pure R-enantiomer
and S-enantiomer of 10n were accomplished using chiral chro-
matography) within the MMP-1 were studied by computational
docking method. Several important features of possible
interactions can be derived from the predicted binding mode of (S)-
10n. According to the Fig. 4, we can find that the compounds can
occupy three subpockets (S1, S1’ and S3’) of MMP-1, and form
chelate bonds through the carboxyl group and the zinc ion. More-
over, the compound (S)-10n is also stabilized by hydrophobic
interactions in the S1’and S3’ pocket. In the S1’ pocket, the 4-
(benzyloxyl)phenyl of the compound makes hydrophobic contacts
with residues Val 215, Arg 214 and His 218, while the 3-(benzyloxyl)
phenyl makes hydrophobic contacts with residues Tyr-240 and Tyr-
210 in the S3’ pocket. It is worth noticing that the group in para-
position of the benzene ring embedded in the S1’ pocket. When it

H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
153
Table 3
Evaluation of R(ꢀ)10n and S(ꢀ)10n for their inhibitory activities towards MMPs.
Compound
IC50
(mM)
MMP-1
MMP-2
MMP-3
MMP-9
MMP-12
MMP-13
(R)-10n
(S)-10n
0.4
0.8
3.2
3.0
4.0
3.4
6.7
6.0
2.1
2.3
4.5
5.4
was replaced with other small hydrophobic groups, such as 4-
methoxyphenyl (10k), 4-trifluoromethylphenyl (10c) and 4-
nitrophenyl (10h), the inhibitory activity would decrease. It indi-
cated that the hydrophobic contact in the S1’ pocket is important
for the inhibitory activity. Compared carboxylic acids (10f, 10i, 10j,
10n,10o and 10p) and hydroxamates (11f,11i,11j,11n,11o and 11p),
it was found that the exception is compound 10n that gives the best
results much better than the parent 11n. The docking study shows
that the compound (S)-11n has a similar binding pose with the
compound (S)-10n, but there is a difference at the chelated group:
the hydroxamate group of compound (S)-11n forms a monodentate
chelating replaced the bidentate chelating of compound (S)-10n,
which decrease the binding affinity of (S)-10n (Fig. 5). And this
phenomenon only appears for compound 11n, it is presumed that
the long and bulky R3 group pushes the chelate group hydroxamate
away from the zinc atom, which might cause the activity of the
compound (S)-11n poorer than compound (S)-10n. Further up
along the active pocket, the linker groups in the middle of the
inhibitor almost wrap around the zinc atom and the carbonyl group
of the linker groups forms hydrogen bonds with the nitrogen of
Asn-180. The other terminal extends toward the S1 pockets: the
3,4-dimethoxyphenyl makes an interaction with Phe-185 and Gln-
186 by hydrophobic contacts. The cupped inhibitor conformation
predicted fits the shape and size of the catalytic position of the
MMP-1 well, so it makes the compound combine with the enzyme
closely, which is consistent with the high potency against MMP-1.
(R)-10n and (S)-10n were also tested for their inhibitory activ-
ities towards MMP-1, -2, -3, -9, -12, and -13 (Table 3). The activity of
10n against MMP-1 is almost 5e10-fold better than for the other
MMPs. Although the selectivity toward MMP-1 versus other MMPs
was not satisfying, the result encourages us to further design
selective MMP-1 inhibitors using 10n as a lead compound which
would be reported later.
Fig. 4. The predicted binding mode of the compound (S)-10n against the MMP-1. The
compound is represented by the yellow sticks. The amino residues are represented by
the cyan lines. The zinc ion is represented by grey sphere. The MMP-1’s tertiary
structure is represented by the green cartoon. (For interpretation of the references to
colour in this figure legend, the reader is referred to the web version of this article.)
In a word, the binding mode of the most potent compound
with MMP-1 was proposed as follows: (1) the hydroxamate or
carboxyl group on the scaffold (R2) chelates the active site zinc
ion; (2) at least one functional group on the scaffold that provides
a hydrogen bond interaction with the enzyme sidechain; (3) bulky
hydrophobic substituents on aromatic ring (R3) accommodate
with the enzymes’ hydrophobic domains (S1’ pocket). The above
binding mode information encouraged us to further design ros-
marinic acid scaffold-based selective MMP-1 inhibitors, which will
be reported later.
4. Conclusions
In summary, we have developed a new series of rosmarinic acid
derivatives as MMP-1 inhibitors, in which the compound (R)-10n
was the most potent candidate. SAR studies indicated that hydro-
philic group R1, strong electronegative group R2, and bulky hydro-
phobic group R3 at scaffold favored the inhibitory activity against
MMP-1. A docking study of the most interesting compound allowed
the understanding of its binding interactions with MMP-1, thus
suggesting the basis of its activity profile. This feature may provide
us a critical point for further chemical modification on rosmarinic
acid derivatives so as to exploit more potent MMP-1 inhibitors.
Fig. 5. The predicted binding mode of (S)-11n aganst the MMP-1. The compound is
represented by the yellow sticks. The amino residues are represented by the cyan lines.
The zinc ion is represented by grey sphere. The MMP-1’s tertiary structure is repre-
sented by the green cartoon. (For interpretation of the references to colour in this
figure legend, the reader is referred to the web version of this article.)

154
H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
5. Experimental section
d
(ppm), 37.0, 55.8, 73.6, 111.2, 112.6, 119.7, 121.5, 125.9, 128.3, 128.7,
130.9, 132.1, 132.2, 137.5, 143.9, 148.0, 148.8, 165.7, 167.8; ESI-MS: m/
z 447.1 [M þ Na]þ, 423.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C21H19F3O6Na [M þ Na]þ: 447.1031, found 447.1053.
5.1. Chemistry
Nuclear magnetic resonance (NMR) spectra were recorded using
TMS as the internal standard in DMSO-d6, MeOD or CDCl3 with
a Bruker BioSpin GmbH spectrometer at 300 MHz. When peak
multiplicities are reported, the following abbreviations are used:
s ¼ singlet, d ¼ doublet, t ¼ triplet, m ¼ multiplet, br ¼ broadened,
dd ¼ doubletofdoublets,dt¼ doubletoftriplets;ESI-MSwasrecorded
onAgilent1100LC/MSD(70ev)spectrometers.HRMSwasrecordedon
a Waters Q-Tof micro. Melting points (m.p.) were determined by
microscope melting point apparatus with aromatic temperature
control system (XT4A). THF was distilled from sodium/benzophenone
ketyl. Dichloromethane was distilled over CaH2. All other reagents and
starting materials were purchased and used as received (Aldrich, TCI,
Adamas). Reactions were monitored by analytical TLC using silica gel
60 F254 plates and spots were visualized by UV light irradiation
(254 nm). Flash column chromatography was performed by using
silica gel (200e300 mesh). All test compounds showed ꢂ95%purityas
determined by combustion analysis or by high-performance liquid
chromatography (HPLC). HPLC conditions were asfollows: CHIRALPAK
ADH, 4.6 mm ꢃ 250 mm, 5% / 90% CH3CN/MeOH/0.1% acetic acid,
5.1.5. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(4-fluorophenyl)
acryloyloxy) propanoic acid (10d)
White amorphous solid (76% yield); 1H NMR (CDCl3, 300 MHz):
d
(ppm), 3.08e3.28 (m, 2H, CH2), 3.84 (s, 3H, OCH3), 3.85 (s, 3H,
OCH3), 5.34 (s, 1H, CH), 6.36 (d, J ¼ 15.9 Hz, 1H, CH), 6.78e7.57 (m,
7H, ArH), 7.65 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
d
(ppm), 37.1, 55.9, 73.5, 111.1, 112.5, 119.8, 121.9, 125.3, 128.2, 131.3,
132.8, 137.9, 144.3, 148.6, 148.9, 166.2, 167.9; ESI-MS: m/z 397.2
[M þ Na]þ, 372.9 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for C20H19FO6Na
[M þ Na]þ: 397.1063, found 397.1054.
5.1.6. (E)-2-(3-(4-chlorophenyl) acryloyloxy)-3-(3,4-
dimethoxyphenyl) propanoic acid (10e)
White amorphous solid (88% yield); 1H NMR (CDCl3, 300 MHz):
d
(ppm), 3.11e3.28 (m, 2H, CH2), 3.85 (s, 3H, OCH3), 3.86 (s, 3H,
OCH3), 5.36 (m, 1H, CH), 6.42 (d, J ¼ 15.9 Hz, 1H, CH), 6.78e6.85 (m,
3H, ArH), 7.39 (dd, J ¼ 24.9, 8.4 Hz, 4H, ArH), 7.64 (d, J ¼ 15.9 Hz, 1H,
CH); 13C NMR (CDCl3, 75 MHz):
d (ppm), 37.1, 55.9, 73.0, 111.2, 112.7,
118.7, 121.9, 128.3, 129.7, 132.4, 136.7, 144.4, 148.3, 148.9, 165.7,
167.4; ESI-MS: m/z 413.1 [M þ Na]þ, 388.9 [M ꢀ H]ꢀ; HRMS (ESI):
m/z calcd for C20H19ClO6Na [M þ Na]þ: 413.0768, found 413.0787.
15 min run, flow rate 0.7 mL/min, UV detection (
l
¼ 220 nm).
5.1.1. Typical reaction procedure for compounds (10aep)
A solution of the allyl esters (9aek or 9meq0, 0.03 mmol) in
tetrahydrofuran (10 mL) was stirred in an argon atmosphere at
ambient temperature, Pd(PPh3)4 (0.002 mmol) and morpholine
(0.6 mmol) were added subsequently. After 30 min the solvent was
evaporated, and the residue was taken up in CH2Cl2 (50 mL). The
resulting solution was extracted three times with 2 N HC1 (10 mL),
dried over MgSO4, and concentrated in vacuo. The desired acid was
obtained after column purification using petroleum ether, ethyl
acetate and acetic acid (33:66:1) as the mobile phase eluent.
5.1.7. (E)-2-(3-(4-bromophenyl) acryloyloxy)-3-(3,4-
dimethoxyphenyl) propanoic acid (10f)
White amorphous solid (82% yield); 1H NMR (CDCl3, 300 MHz):
d
(ppm), 3.07e3.26 (m, 2H, CH2), 3.84 (s, 3H, OCH3), 3.85 (s, 3H, OCH3),
5.53 (brs,1H, CH), 6.38 (d, J ¼ 15.9 Hz, 1H, CH), 6.71e6.83 (m, 3H, ArH),
7.35 (d, J ¼ 8.7 Hz, 2H, ArH), 7.53 (d, J ¼ 8.1 Hz, 2H, ArH), 7.61 (d,
J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75MHz):
d (ppm), 37.1, 55.9, 72.8,
111.2, 112.7, 117.7, 121.7, 125.4, 129.6, 132.2, 132.9, 144.5, 145.7, 148.2,
148.9,165.4,166.6;ESI-MS: m/z458.2[Mþ Na]þ,433.1 [Mꢀ H]ꢀ, 869.0
[2M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for C20H19BrO6Na [M þ Na]þ:
457.0263, found 457.0246.
5.1.2. (E)-2-(cinnamoyloxy)-3-(3,4-dimethoxyphenyl) propanoic
acid (10a)
Yellow amorphous solid (83% yield); 1H NMR (CDCl3, 300 MHz):
5.1.8. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(2-fluorophenyl)
acryloyloxy) propanoic acid (10g)
d
(ppm), 3.11e3.28 (m, 2H, CH2), 3.85 (s, 3H, OCH3), 3.86 (s, 3H,
White amorphous solid (81% yield); 1H NMR (CDCl3, 300 MHz):
OCH3), 5.32e5.39 (m,1H, CH), 6.46 (d, J ¼ 15.9 Hz,1H, CH), 6.79e6.86
(m, 3H, ArH), 7.38e7.52 (m, 5H, ArH), 7.71 (d, J ¼ 15.9 Hz,1H, CH); 13C
d
(ppm), 3.11e3.27 (m, 2H, CH2), 3.83 (s, 3H, OCH3), 3.85 (s, 3H,
NMR (CDCl3, 75 MHz):
d (ppm), 37.1, 55.9, 73.3, 111.2, 112.7, 119.5,
OCH3), 5.23 (brs,1H, CH), 6.55 (d, J ¼ 16.2 Hz,1H, CH), 6.84e7.50 (m,
7H, ArH), 7.80 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
121.5,125.9,128.8,130.9,132.2,137.7,143.7,148.1,148.7,165.9,167.7;
ESI-MS: m/z 379.1 [M þ Na]þ, 355.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd
for C20H20O6Na [M þ Na]þ: 379.1158, found 379.1139.
d
(ppm), 37.0, 55.9, 73.1, 111.2, 112.7, 116.4, 118.8, 119.5, 121.5, 124.5,
128.3, 129.5, 131.4, 132.0, 148.1, 148.9, 165.7, 168.0; ESI-MS: m/z
397.2 [M þ Na]þ, 372.9 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C20H19FO6Na [M þ Na]þ: 397.1063, found 397.1051.
5.1.3. (E)-3-(3,4-dimethoxyphenyl)-2-(3-p-tolylacryloyloxy)
propanoic acid (10b)
White amorphous solid (85% yield); 1H NMR (CDCl3, 300 MHz):
5.1.9. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(4-nitrophenyl)
acryloyloxy) propanoic acid (10h)
d
(ppm), 2.36 (s, 3H, CH3), 3.09e3.26 (m, 2H, CH2), 3.84 (s, 3H,
Yellow amorphous solid (83% yield); 1H NMR (CDCl3, 300 MHz):
OCH3), 3.85 (s, 3H, OCH3), 5.33 (m, 1H, CH), 6.40 (d, J ¼ 15.9 Hz, 1H,
CH), 6.77e6.85 (m, 3H, ArH), 7.17 (d, J ¼ 7.8 Hz, 2H, ArH), 7.39 (d,
J ¼ 8.1 Hz, 2H, ArH), 7.67 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3,
d
(ppm), 3.12e3.26 (m, 2H, CH2), 3.86 (s, 3H, OCH3), 3.87 (s, 3H,
OCH3), 5.35e5.43 (m, 1H, CH), 6.58 (d, J ¼ 16.2 Hz, 1H, CH), 6.77e
6.85 (m, 3H, ArH), 7.66 (d, J ¼ 8.7 Hz, 2H, ArH), 7.72 (d,
J ¼ 16.2 Hz, 1H, CH), 8.23e8.26 (d, J ¼ 8.7 Hz, 2H, ArH); 13C NMR
75 MHz):
d (ppm), 21.3, 37.2, 55.8, 73.0, 111.2, 112.7, 118.9, 121.7,
128.5, 128.8, 129.8, 131.6, 140.9, 145.6, 148.4, 148.9, 166.6, 168.3; ESI-
MS: m/z 393.2 [M þ Na]þ, 369.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C21H22O6Na [M þ Na]þ: 393.1314, found 393.1332.
(CDCl3, 75 MHz):
d (ppm), 37.1, 55.9, 73.2, 111.2, 112.6, 118.9, 121.3,
124.2, 128.8, 131.3, 140.3, 143.5, 148.3, 148.7, 148.9, 165.5, 168.9; ESI-
MS: m/z 424.1 [M þ Na]þ, 400.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C20H19NO8Na [M þ Na]þ: 424.1008, found 424.1023.
5.1.4. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(4-(trifluoromethyl)
phenyl) acryloyloxy) propanoic acid (10c)
White amorphous solid (78% yield); 1H NMR (CDCl3, 300 MHz):
5.1.10. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(4-phenylphenyl)
acryloyloxy) propanoic acid (10i)
d
(ppm), 3.08e3.29 (m, 2H, CH2), 3.83 (s, 3H, OCH3), 3.84 (s, 3H,
White amorphous solid (79% yield); 1H NMR (CDCl3, 300 MHz):
OCH3), 5.35 (s, 1H, CH), 6.52 (d, J ¼ 15.9 Hz, 1H, CH), 6.78e6.86 (m,
3H, ArH), 7.44e7.73 (m, 5H, CH and ArH); 13C NMR (CDCl3, 75 MHz):
d
(ppm), 3.08e3.20 (m, 2H, CH2), 3.85 (s, 3H, OCH3), 3.86 (s, 3H,

H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
155
OCH3), 5.53 (brs, 1H, CH), 6.46 (d, J ¼ 15.9 Hz,1H, CH), 6.75e7.62 (m,
5.1.16. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(naphthalen-2-yl)
12H, ArH), 7.73 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
acryloyloxy) propanoic acid (10o)
d
(ppm), 36.9, 55.9, 73.3, 111.3, 112.6, 116.6, 121.5, 127.0, 127.6, 127.9,
White amorphous solid (88% yield); 1H NMR (CDCl3, 300 MHz):
128.2, 128.7, 128.9, 133.0, 140.0, 143.4, 145.8, 148,2, 148.9, 166,2,
168.0; ESI-MS: m/z 455.2 [M þ Na]þ, 431.1 [M ꢀ H]ꢀ; HRMS (ESI):
m/z calcd for C26H24O6 Na [M þ Na]þ: 455.1471, found 455.1452.
d
(ppm), 3.05e3.19 (m, 2H, CH2), 3.79 (s, 3H, OCH3), 3.82 (s, 3H,
OCH3), 5.34 (d,1H, J ¼ 6.8 Hz, CH), 6.56 (d, J ¼ 15.6 Hz,1H, CH), 6.72 (d,
J ¼ 7.8 Hz, 1H, ArH), 6.84 (d, J ¼ 10.2 Hz, 2H, ArH), 7.47e7.51 (m, 2H,
ArH), 7.57 (d, J ¼ 8.7 Hz, 1H, CH), 7.74e7.82 (m, 5H, ArH and CH); 13C
5.1.11. (E)-2-(3-(4-(benzyloxy) phenyl) acryloyloxy)-3-(3,4-
dimethoxyphenyl) propanoic acid (10j)
NMR (CDCl3, 75 MHz): d (ppm), 37.1, 55.9, 73.1, 111.3, 112.7, 118.3,
121.6,123.5,126.8,127.4,127.8,128.5,128.8,130.2,131.7,133.5,146.3,
148.3, 148.9, 166.7, 168.1; ESI-MS: m/z 429.3 [M þ Na]þ, 405.0
[M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for C24H22O6Na [M þ Na]þ:
429.1314, found 429.1341.
White amorphous solid (80% yield); 1H NMR (CDCl3, 300 MHz):
d
(ppm), 3.09e3.22 (m, 2H, CH2), 3.84 (s, 3H, OCH3), 3.85 (s, 3H,
OCH3), 4.66 (s, 2H, CH2), 5.22e5.26 (m, 1H, CH), 6.26 (d, J ¼ 16.2 Hz,
1H, CH), 6.65e6.93 (m, 5H, ArH), 7.26e7.49 (m, 7H, ArH), 7.56 (d,
J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
d (ppm), 37.0, 55.9,
5.1.17. (E)-2-(3-(2,3-dihydrobenzofuran-6-yl) acryloyloxy)-3-(3,4-
dimethoxyphenyl) propanoic acid (10p)
71.0, 71.2, 73.0, 112.2, 113.3, 114.4, 115.6, 117.2, 121.5, 122.7, 127.9,
129.9, 144.3, 145.3, 146.0, 146.4, 148.7, 165.7, 168.1; ESI-MS: m/z
463.2 [M þ H]þ, 485.3 [M þ Na]þ, 461.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z
calcd for C27H26O7 Na [M þ Na]þ: 485.1576, found 485.1568.
White amorphous solid (83% yield); 1H NMR (CDCl3, 300 MHz):
(ppm), 3.08e3.24 (m, 4H, CH2), 3.85 (s, 3H, OCH3), 3.86 (s, 3H,
d
OCH3), 4.62 (t, J ¼ 8.7 Hz, 2H, CH2), 5.32e5.36 (m, 1H, CH), 6.29 (d,
J ¼ 15.9 Hz, 1H, CH), 6.76e6.83 (m, 4H, ArH), 7.37 (s, 1H, ArH), 7.63
(d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
d (ppm), 29.7,
5.1.12. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(4-methoxyphenyl)
acryloyloxy) propanoic acid (10k)
37.1, 55.8, 71.9, 72.7,109.7, 111.1, 112.7, 112.9,121.7, 124.7,126.7, 127.9,
128.2, 130.0, 146.9, 148.0, 148.7, 162.8, 165.9, 167.0; ESI-MS: m/z
421.3 [M þ Na]þ, 397.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C22H22O7Na [M þ Na]þ: 421,1263, found 421,1242.
Yellow white solid (80% yield); 1H NMR (CDCl3, 300 MHz):
d
(ppm), 3.04e3.22 (m, 2H, CH2), 3.77 (s, 3H, OCH3), 3.81 (s, 3H,
OCH3), 3.82 (s, 3H, OCH3), 5.28(brs, 1H, CH), 6.27 (d, J ¼ 15.9 Hz, 1H,
CH), 6.72e6.84 (m, 5H, ArH), 7.36 ( d, J ¼ 8.7 Hz, 2H, ArH), 7.58 (d,
5.1.18. Typical reaction procedure for compounds (11f, 11i, 11j, and
11nep)
J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
d (ppm), 37.0, 55.8,
55.9, 73.2, 111.2, 112.6, 118.8, 121.6, 128.3, 129.2, 130.9, 131.8, 134.7,
146.3, 148.4, 148.9, 166.7, 168.8; ESI-MS: m/z 409.3 [M þ Na]þ, 385.0
[M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for C21H22O7Na [M þ Na]þ:
409.1263, found 409.1285.
A solution of Dicyclohexylcarbodiimide (DCC) (0.12 mmol), 4-
dimethylaminopyridine (DMAP) (0.01 mmol), acid 10f, i, j, or nep
(0.1 mmol), and CH2Cl2 (10 mL) was stirred at 0 ꢁC for 15 min.
After addition of hydroxylamine hydrochloride (NH2OH$HCl)
(0.12 mmol), the mixture was stirred at room temperature for 24 h.
The organic layers were washed with water after filtration,
concentrated under reduced pressure. The crude material was
chromatographed on SiO2 (petroleum ether and ethyl acetate (6:4)
as eluent) to afford 11f, 11i, 11j, or 11nep.
5.1.13. (E)-2-(3-(3,4-dihydroxyphenyl) acryloyloxy)-3-(3,4-
dimethoxyphenyl) propanoic acid (10l)
White amorphous solid (77% yield); 1H NMR (CDCl3, 300 MHz):
d
(ppm), 3.11e3.28 (m, 2H, CH2), 3.70 (s, 3H, OCH3), 3.73 (s, 3H,
OCH3), 5.10e5.24 (m, 1H, CH), 6.25 (d, J ¼ 15.9 Hz, 1H, CH), 6.75e
7.05 (m, 6H, ArH), 7.47 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3,
5.1.19. (E)-3-(3,4-dimethoxyphenyl)-1-(hydroxyamino)-1-
oxopropan-2-yl 3-(4-bromophenyl) acrylate (11f)
75 MHz):
d (ppm), 37.1, 55.9, 73.3, 113.9, 114.7, 115.3, 115.9, 116.3,
121.1,122.0,127.1,128.9,143.0,144.1,145.2,145.9, 148.0,166.2,167.9;
ESI-MS: m/z 411.3 [M þ Na]þ, 387.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd
for C20H20O8Na [M þ Na]þ: 411.1056, found 411.1034.
White power (60% yield); 1H NMR (CDCl3, 300 MHz):
d (ppm),
3.14e3.28 (m, 2H, CH2), 3.84 (s, 3H, OCH3), 3.86 (s, 3H, OCH3), 5.52
(brs, 1H, CH), 6.38 (d, J ¼ 16.2 Hz, 1H, CH), 6.71e6.79 (m, 3H, ArH),
7.34 (d, J ¼ 8.1 Hz, 2H, ArH), 7.52 (d, J ¼ 8.1 Hz, 2H, ArH), 7.60 (d,
5.1.14. (E)-3-(3,4-dimethoxyphenyl)-2-(3-(3,4-dimethoxyphenyl)
acryloyloxy) propanoic acid (10m)
J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
d (ppm), 37.0, 55.9,
72.9, 111.2, 112.6, 117.0, 117.7, 121.7, 125.4, 129.6, 132.2, 144.7, 145.6,
White amorphous solid (85% yield); 1H NMR (CDCl3, 300 MHz):
148.2, 148.9, 165.2, 166.7; ESI-MS: m/z 474.1 [M þ Na]þ, 449.9
d
(ppm), 3.07e3.21 (m, 2H, CH2), 3.84 (s, 3H, OCH3), 3.86 (s, 3H,
[M
ꢀ
H]ꢀ, 898.9 [2M
ꢀ
H]ꢀ; HRMS (ESI): m/z calcd for
OCH3), 3.90 (s, 3H, OCH3), 3.91 (s, 3H, OCH3), 5.32e5.38 (m, 1H, CH),
6.34 (d, J ¼ 15.9 Hz, 1H, CH), 6.77e6.98 (m, 4H, ArH), 7.11e7.24 (m,
2H, Ar), 7.64 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
C20H20BrNO6Na [M þ Na]þ: 472.0372, found 472.0394.
5.1.20. (E)-3-(3,4-dimethoxyphenyl)-1-(hydroxyamino)-1-
oxopropan-2-yl 3-(4-phenylphenyl) acrylate (11i)
d
(ppm), 37.1, 55.8, 55.9, 73.0, 111.2, 111.5, 112.6, 114.6, 118.8, 121.5,
White power (66% yield); 1H NMR (CDCl3, 300 MHz):
d (ppm),
122.9, 128.4, 131.5, 146.0, 148.1, 148.8, 149.3, 151.4, 166.1, 167.6; ESI-
MS: m/z 439.1 [M þ Na]þ, 415.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C22H24O8Na [M þ Na]þ: 439.1369, found 439.1351.
3.08e3.22 (m, 2H, CH2), 3.84 (s, 3H, OCH3), 3.86 (s, 3H, OCH3), 5.57
(brs, 1H, CH),6.49 (d, J ¼ 15.6 Hz, 1H, CH), 6.67e7.86 (m, 3H, ArH),
7.35e7.70 (m, 9H, ArH), 7.76 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR
5.1.15. (E)-2-(3-(3,4-bis (benzyloxy) phenyl) acryloyloxy)-3-(3,4-
dimethoxyphenyl) propanoic acid (10n)
(CDCl3, 75 MHz):
d (ppm), 37.1, 55.9, 73.1, 111.3, 112.8, 116.9, 121.9,
127.5, 127.9, 128.2, 128.7, 128.9, 129.3, 132.9, 140.1, 143.6, 145.9,
148.5, 148.9, 166,4, 167.7; ESI-MS: m/z 470.3 [M þ Na]þ, 446.1
[M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for C26H25NO6Na [M þ Na]þ:
470.1580, found 470.1561.
White amorphous solid (81% yield); 1H NMR (CDCl3, 300 MHz):
d
(ppm), 3.04e3.33 (m, 2H, CH2), 3.82 (s, 3H, OCH3), 3.84 (s, 3H,
OCH3), 5.15 (s, 2H, CH2), 5.18 (s, 2H, CH2),5.35 (s, 1H, CH), 6.26 (d,
J ¼ 15.9 Hz, 1H, CH), 6.75e7.61 (m, 18H, ArH and CH); 13C NMR
5.1.21. (E)-3-(3,4-dimethoxyphenyl)-1-(hydroxyamino)-1-
(CDCl3, 75 MHz):
d (ppm), 36.9, 55.9, 71.1, 71.3, 72.9, 111.2, 112.7,
oxopropan-2-yl 3-(4-(benzyloxy) phenyl) acrylate (11j)
113.6, 114.4,114.9, 121.6, 122.0, 123.3, 123.8, 127.2, 127.5, 128.1, 128.8,
136.9, 148.3, 149.2, 165.7, 168.1; ESI-MS: m/z 569.2 [M þ H]þ, 591.3
[M þ Na]þ; HRMS (ESI): m/z calcd for C34H32O8Na [M þ Na]þ:
591.1995, found 591.1979.
White power (50% yield); 1H NMR (CDCl3, 300 MHz):
d (ppm),
3.15e3.29 (m, 2H, CH2), 3.83 (s, 3H, OCH3), 3.86 (s, 3H, OCH3), 5.13
(s, 2H, CH2), 5.57 (brs, 1H, CH), 6.28 (d, J ¼ 15.6 Hz, 1H, CH), 6.72e

156
H. Yuan et al. / European Journal of Medicinal Chemistry 62 (2013) 148e157
6.81 (m, 3H, ArH), 6.99 (d, J ¼ 8.4 Hz, 2H, ArH), 7.41e7.51 (m, 7H,
ArH), 7.65 (d, J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
removed from the complex structure. Hydrogen atoms and charges
were added during a brief relaxation performed using the “Protein
Preparation Wizard” workflow in Maestro 9.0. After optimizing the
hydrogen bond network, the crystal structure was minimized using
OPLS 2005 force field with the maximum RMSD value of 0.3 Å. The
grid-enclosing box was centered on the ligand in the refined crystal
structure as described above and defined so as to enclose residues
located within 14 Å from the ligand, and a scaling factor of 1.0 was
set to van der Waals (VDW) radii with the partial atomic charges of
0.25 to soften the nonpolar parts of the receptor. And the three-
dimensional structures of compounds were generated with Lig-
prep module. In the docking process, standard precision (SP) and
extra precision (XP) approaches were adopted successively, and the
top 10 conformations were retrieved and ranked by GlideScore
with the XP mode, while these conformations were visually
inspected for their binding modes. Finally, the most reasonable
conformation was selected for explaining the structure activity
relationship of inhibitor against MMP-1.
d
(ppm), 37.1, 55.9, 71.2, 71.3, 73.2, 112.3, 113.7, 114.5, 115.6, 117.5,
121.6, 122.7, 127.9, 129.6, 144.5, 145.3, 146.1, 146.7, 148.9, 166.1,
168.3; ESI-MS: m/z 500.2 [M þ Na]þ, 476.1 [M ꢀ H]ꢀ; HRMS (ESI):
m/z calcd for C27H27NO7Na [M þ Na]þ: 500.1685, found 500.1669.
5.1.22. (E)-3-(3,4-dimethoxyphenyl)-1-(hydroxyamino)-1-
oxopropan-2-yl 3-(3,4-bis (benzyloxy) phenyl) acrylate (11n)
White power (53% yield); 1H NMR (CDCl3, 300 MHz):
d (ppm),
3.09e3.31 (m, 2H, CH2), 3.81 (s, 3H, OCH3), 3.84 (s, 3H, OCH3), 5.18
(s, 2H, CH), 5.20 (s, 2H, CH), 5.54 (s, 1H, CH), 6.20 (d, J ¼ 15.9 Hz, 1H,
CH), 6.71e6.79 (m, 3H, ArH), 6.92 (d, J ¼ 8.1 Hz, 1H, ArH), 7.01e7.17
(m, 2H, ArH), 7.30e7.52 (m, 10H, ArH), 7.56 (d, J ¼ 15.9 Hz, 1H, CH);
13C NMR (CDCl3, 75 MHz):
d (ppm), 36.8, 55.9, 71.0, 71.4, 72.8, 107.6,
108.7, 111.2, 112.7, 113.9, 114.2, 114.7, 121.6, 121.8, 123.3, 123.5, 127.2,
127.3, 128.0, 128.6, 136.8, 148.2, 149.0, 165.6, 167.9; ESI-MS: m/z
606.3 [M þ Na]þ, 582.1 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C34H33NO8Na [M þ Na]þ: 606.2104, found 606.2095.
Additional experimental details and NMR (1H and 13C), ESI-MS
and HRMS spectra of compounds has been included in the
Supporting information.
5.1.23. (E)-3-(3,4-dimethoxyphenyl)-1-(hydroxyamino)-1-
oxopropan-2-yl 3-(naphthalene-2-yl) acrylate (11o)
White power (58% yield); 1H NMR (CDCl3, 300 MHz):
d (ppm),
Acknowledgment
3.09e3.24 (m, 2H, CH2), 3.84 (s, 3H, OCH3), 3.86 (s, 3H, OCH3), 5.58
(brs, 1H, CH), 6.50 (d, J ¼ 15.6 Hz, 1H, CH), 6.69e6.82 (m, 3H, ArH),
The work was supported by program NCET Foundation, NSFC
(30725045), partially supported by Global Research Network for
Medicinal Plants (GRNMP) and King Saud University, Shanghai
Leading Academic Discipline Project(B906), FP7- PEOPLE-IRSES-
2008 (TCMCANCER Project 230232), Key laboratory of drug
research for special environments, PLA, Shanghai Engineering
Research Center for the Preparation of Bioactive Natural Pro-
ducts(10DZ2251300) and the Scientific Foundation of Shanghai
China (09DZ1975700, 09DZ1971500,10DZ1971700). The MMP-1
expression plasmid was kindly provided by Prof. Zigang Dong,
University of Minnesota.
7.50e7.84 (m, 8H, ArH and CH); 13C NMR (CDCl3, 75 MHz):
d (ppm),
37.0, 55.9, 73.1, 111.2, 112.6, 118.5, 121.7, 123.9, 126.7, 127.7, 127.9,
128.3, 128.8, 130.3, 131.9, 133.7, 146.1, 148.2, 148.7, 165.8, 167.5; ESI-
MS: m/z 444.3 [M þ Na]þ, 420.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd
for C24H23NO6Na [M þ Na]þ: 444.1423, found 444.1409.
5.1.24. (E)-3-(3,4-dimethoxyphenyl)-1-(hydroxyamino)-1-
oxopropan-2-yl 3-(2,3-dihydrobenzofuran-6-yl) acrylate (11p)
White power (69% yield); 1H NMR (CDCl3, 300 MHz):
d (ppm),
3.09e3.27 (m, 4H, CH2), 3.82 (s, 3H, OCH3), 3.84 (s, 3H, OCH3), 4.62
(t, J ¼ 8.7 Hz, 2H, CH2), 5.53 (brs, 1H, CH), 6.24 (d, J ¼ 15.6 Hz, 1H,
CH), 6.73e6.80 (m, 4H, ArH), 7.30e7.37 (m, 2H, ArH), 7.63 (d,
Appendix A. Supporting information
J ¼ 15.9 Hz, 1H, CH); 13C NMR (CDCl3, 75 MHz):
d (ppm), 29.5, 37.0,
55.8, 71.8, 72.8, 109.9, 111.2, 112.7, 112.8, 121.6, 124.8, 126.5, 127.4,
128.7, 130.3, 146.7, 148.3, 148.9, 162.2, 165.6, 166.7; ESI-MS: m/z
436.2 [M þ Na]þ, 412.0 [M ꢀ H]ꢀ; HRMS (ESI): m/z calcd for
C22H23NO7Na [M þ Na]þ: 436.1372, found 436.1395.
Supporting information related to this article can be found at
http://dx.doi.org/10.1016/j.ejmech.2012.09.047.
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