Synthesis and evaluation of a novel series of heterocyclic oleanolic acid derivatives with anti-osteoclast formation activity

Article abstract of DOI:10.1016/j.ejmech.2008.12.024

Oleanolic acid with anti-bone resorption effect was an active component discovered in a medicinal plant of Achyranthes bidentata. A series of heterocyclic derivatives of oleanolic acid including indole, pyrazine, quinoxaline, quinoline moieties and their natural amino acid amides were synthesized. Their inhibitory activity on the formation of osteoclast-like multinucleated cells (OCLs) and cytotoxicity of the selected derivatives were evaluated. Among the derivatives, compounds 2a and 8a displayed quite a potent activity even at 200 nM. The structure-activity relationships of the derivatives were also discussed.

Full text of DOI:10.1016/j.ejmech.2008.12.024

European Journal of Medicinal Chemistry 44 (2009) 2796–2806
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and evaluation of a novel series of heterocyclic oleanolic acid
derivatives with anti-osteoclast formation activity
*
Jun-Feng Li, Yu Zhao, Min-Min Cai, Xiao-Fei Li, Jian-Xin Li
Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Oleanolic acid with anti-bone resorption effect was an active component discovered in a medicinal plant
of Achyranthes bidentata. A series of heterocyclic derivatives of oleanolic acid including indole, pyrazine,
quinoxaline, quinoline moieties and their natural amino acid amides were synthesized. Their inhibitory
activity on the formation of osteoclast-like multinucleated cells (OCLs) and cytotoxicity of the selected
derivatives were evaluated. Among the derivatives, compounds 2a and 8a displayed quite a potent
activity even at 200 nM. The structure–activity relationships of the derivatives were also discussed.
Ó 2008 Elsevier Masson SAS. All rights reserved.
Received 30 September 2008
Received in revised form
16 December 2008
Accepted 23 December 2008
Available online 31 December 2008
Keywords:
Oleanolic acid
Heterocyclic derivatives
Osteoclast formation
Inhibitory activity
SAR
1. Introduction
In a research project aiming at new anti-osteoporosis agents, we
discovered that the n-butanol extract from the root of a medicinal
Osteoporosis, widely recognized as a major public health
problem, particularly among postmenopausal women, is a disease
characterized by low bone mass and structural deterioration of
bone tissue, leading to bone fragility and an increased susceptibility
to fractures [1]. Currently, it is estimated that over 200 million
people worldwide have osteoporosis [2] and osteoporosis related
fractures accounted for more disability-adjusted life years (DALYs)
lost than common cancers except for lung cancer in Europe [3].
Bone is a mechanically optimized connective tissue that is main-
tained in dynamic equilibrium via bone resorption by osteoclasts
and bone formation by osteoblasts. A shift or uncoupling of this
dynamic process favoring resorption results in osteoporosis.
Increased osteoclastic bone resorption plays a key role in the
pathogenesis of osteoporosis. Osteoclast, the only known cell
responsible for the bone resorption, is one of the key therapeutical
targets for osteoporosis. Inhibitors of the osteoclast may therefore
present a potential to prevent the excessive bone resorption asso-
ciated with osteoporosis [4].
plant, Achyranthes bidentata Blume (Amaranthaceae) possesses the
anti-osteoporosis activity in vitro and in vivo, further research
revealed that oleanolic acid (OA,1, Fig.1) and its glycosides were the
active components of the extract responsible for the activity [5,6]. It
has been reported that OA possesses a variety of biological activi-
ties, such as anti-inflammatory [7], anti-cancer [8] and hep-
atoprotective effects [9]. Cognizing oleanolic acid to be a potential
anti-osteoporosis lead compound and commercially available, tar-
geting to discover novel structures with a better biological profile,
we therefore started a structure modification of OA (1). Heterocy-
clic system has been known to be a very important recognition
segment in biologically active molecules and also could produce
effective anti-osteoporosis activity [10–12]. It has been reported
that conjugates of amino acids and natural product could provide
effective bioactivity [13], and our previous results also implied that
amino acids might be effective moieties to improve the potency of
anti-osteoclast formation of OA [6]. The above information inspired
us to incorporate heterocyclic and amino acid segments in the
synthesis of oleanolic acid derivatives to improve the inhibitory
effect on osteoclast formation. In the present study, we report here
the synthesis, activity evaluation of several heterocyclic derivatives
in A-ring of oleanolic acid and C17-amides using several natural
* Corresponding author. Tel./fax: þ86 25 83686419.
E-mail address: lijxnju@nju.edu.cn (J.-X. Li).
0223-5234/$ – see front matter Ó 2008 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2008.12.024

J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
2797
with 2 by refluxing in absolute EtOH in the presence of saturated
ethanolic KOH to afford target compound 9.
Scheme 2 characterizes the synthesis of pyrazine and quinoxa-
line derivatives (11, 12). At first, the same synthetic protocol as that
of 7 and 8 was used for the preparation of 11 and 12, unfortunately
no target compounds could be obtained. Thus, an attempt was
made to synthesize 11 and 12 via diketone intermediate, 2,3-diketo
OA (10) obtained by oxidation with SeO2 in acetic acid reacted with
corresponding 1,2-diamine compounds (1.5 mol equiv) in refluxing
acetic acid to yield compounds 11 (yield, 53%) and 12 (yield, 44%),
respectively. However, the yields were relatively lower compared
with those of 7 and 8 (about 70% yield). It should be noted that SeO2
oxidized the methylene next to the ketone but did not oxidize the
allylic methylene next to the olefin, which might be due to the
Fig. 1. Chemical structure of oleanolic acid.
amino acids. The structure–activity relationships of these deriva-
tives are also discussed.
Pummerer-like rearrangement of b-ketoseleninic acids [18].
Scheme 3 depicts the synthesis of amino acid derivatives 2a–l,
3a–l, 4a–l, 7a–l and 8a–l from compounds 2–4 and 7, 8. A general
procedure to introduce amino acid moieties was conducted
according to the following steps. 17-Acyl chlorides of OA derivatives
were prepared by stirring OA derivatives with oxalyl chloride in
anhydrous CH2Cl2. Treatment with corresponding amino acid
methyl esters [19] in the presence of triethylamine afforded amides
2a–f, 3a–f, 4a–f, 7a–f and 8a–f. Hydrolysis of the methyl esters in
aqueous sodium hydroxide yielded corresponding compounds 2g–
l, 3g–l, 4g–l, 7g–l and 8g–l.
2. Results and discussion
2.1. Chemistry
The target molecules are divided into five categories: 3-keto
oleanolic acid 2; indole derivatives 3–6; pyrazine derivatives 7, 11;
quinoxaline derivatives 8, 12 and quinoline derivative 9. Their
syntheses are shown in Schemes 1–3.
Scheme 1 describes the synthesis of target compounds 3–9.
Compound 2, 3-keto OA, a key intermediate was prepared by Jones
oxidation of 1 in 92% yield [14]. Indole compound 3 was prepared
by Fischer indolization of 2 with the phenylhydrazine in the pres-
ence of acetic acid [15]. In order to understand the influences on
activity of substitution group at phenyl ring, compounds 4–6 were
synthesized with the same protocol as 3. It is noteworthy that
unprotection of the C-17 carboxyl group of 2 did not impact the
Fischer indolization yield.
2.2. Biological activity and SAR
Bone resorption is accomplished by the osteoclasts. The most
successfully established therapies of osteoporosis with agents such
as bisphosphonates are based on osteoclast inhibition [20,21]. Thus,
all of the derivatives together with OA (1) were tested for their
The synthesis of target compounds pyrazine 7 and quinoxaline 8
was undertaken as depicted in Scheme 1. The reaction of ketone
with available 1,2-diamine and sulfur in refluxing morpholine has
been applied for the preparation of pyrazine and quinoxaline
derivatives [16]. 3-Keto OA (2) reacted with ethylenediamine and o-
phenylenediamine followed by silica gel column chromatography
to provide 7 and 8, respectively.
inhibitory activity on 1a,25-dihydroxy vitamin D3 [1a,25(OH)2D3]
induced TRAP-positive osteoclast-like multinucleated cell (OCL)
formation using a co-culture assay system with mouse bone
marrow cells and osteoblast-like cells reported by Takahashi [22].
Alendronate sodium, a clinically available bisphosphonate type
anti-osteoporosis drug was used as a positive control [23]. In
a preliminary screening (see Table 1), out of the 70 compounds at
To introduce quinoline moiety, Friedla¨nder reaction was
employed. 2-Aminobenzaldehyde obtained by reduction of 2-
nitrobenzaldehyde with iron powder in acidic medium [17], reacted
20 mM, 26 exhibited a better inhibitory activity than OA did.
Compound 2, in which 3-OH of OA was converted to 3-keto showed
a much stronger activity compared with OA, the OCL formation was
Scheme 1. (i) Jones oxidation; (ii) phenylhydrazine derivatives, AcOH, reflux; (iii) ethylenediamine, morpholine, S, reflux; (iv) o-phenylenediamine, morpholine, S, reflux; (v)
o-aminobenzaldehyde, saturated ethanolic KOH, absolute EtOH, reflux.

2798
J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
Scheme 2. (i) SeO2, H2O, AcOH, reflux; (ii) 1,2-diphenyl-1,2-ethanediamine, AcOH, reflux; (iii) 4-nitro-o-phenylenediamine, AcOH, reflux.
only 1.4% compared with control group (100.0%). Compounds 7
(1.8%) and 8 (0%) which contained pyrazine and quinoxaline
moieties with two nitrogen atoms displayed a comparable activity
with 2. On the other hand, indole and quinoline moieties (3 and 9)
containing only one nitrogen atom, negatively impacted the
activity. However, substitutions of –Cl, –NO2 and –COOH at phenyl
ring of indole moiety (4, 5 and 6) resulted in a much more potent
inhibitory effect compared with compound 3, while substituents of
phenyl group at pyrazine ring (11) or –NO2 at quinoxaline ring (12)
lowered the activity.
cytotoxicity which will be discussed later. Most of the derivatives
with glycine and alanine displayed a better activity than those with
other amino acids.
Further evaluation of the compounds with potent activity (OCL%
less than 75% was defined as potent activity) was conducted at
2
mM and 200 nM. As shown in Table 2, most of the compounds
displayed weak activity at M. However, encouragingly,
a
2 m
compounds 2a, 7k, 8a and 8i displayed quite a potent activity even
at 200 nM.
It is reasonable to consider that the inhibitory activity of the
compounds in this in vitro assay is sometimes a result of their
cytotoxic effect, and an erroneous conclusion might occur. Thus, to
avoid such confusion, a recovery test [24] was conducted (Table 3).
The inhibitory activity of compound 4 series was clearly due to their
In addition, all of the derivatives with amino acid methyl ester
showed a stronger activity compared with those of amino acid ones
except for certain compounds (3c–e and 3i–k) in compound 3
series, and compound 4 series which was clearly due to their
Scheme 3. (i) ClCOCOCl, CH2Cl2, r.t; (ii) SOCl2, MeOH; (iii) Et3N, CH2Cl2; (iv) 4 M NaOH, MeOH, THF.

J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
2799
Table 1
Table 3
Effects of target compounds on 1
a
,25(OH)2D3 induced TRAP(þ)-OCL formation.
Recovery of TRAP(þ)-OCLs from inhibition by selected compounds.
Compd
OCLs (%)
Compd
OCLs (%)
Compd
OCLs (%)
Compd
OCLs (%)
20
Compd
OCLs (%)
20
Control
AS
OA (1)
2
3
4
5
6
7
8
100.0 ꢀ 9.7#
Normal
3a
3b
3c
3d
3e
3f
3g
3h
3i
20.0 ꢀ 10.0
0**
0**
m
M
2
m
M
m
M
2 mM
0**
7a
7b
7c
7d
7e
7f
7g
7h
7i
41.1 ꢀ 7.1**
3.4 ꢀ 4.0**
Control
OA (1)
4
7
8
100.0 ꢀ 13.5
98.0 ꢀ 5.6
0**
100.0 ꢀ 8.5
73.3 ꢀ 6.8**
7c
7d
7e
7f
73.1 ꢀ 8.0**
77.6 ꢀ 8.2**
95.7 ꢀ 4.3**
96.2 ꢀ 2.9**
95.6 ꢀ 3.9**
93.9 ꢀ 3.0**
81.3 ꢀ 3.5**
19.4 ꢀ 4.8**
1.4 ꢀ 3.4**
51.1 ꢀ 6.2**
0**
0**
0**
99.0 ꢀ 7.6
96.8 ꢀ 8.5**
98.4 ꢀ 10.0
0**
9.0 ꢀ 8.3**
21.0 ꢀ 12.4**
6.1 ꢀ 7.2**
0**
84.4 ꢀ 10.3**
58.0 ꢀ 26.1**
0**
10.1 ꢀ 3.8**
21.1 ꢀ 6.0**
86.0 ꢀ 8.7**
82.4 ꢀ 18.6**
77.4 ꢀ 11.7**
0**
27.8 ꢀ 8.3**
2.8 ꢀ 1.7**
93.2 ꢀ 9.6**
92.6 ꢀ 5.3**
18.9 ꢀ 9.0**
94.5 ꢀ 2.2*
41.3 ꢀ 12.7**
100.2 ꢀ 3.2
99.1 ꢀ 7.2
89.5 ꢀ 5.3**
0.7 ꢀ 1.1**
7j
29.6 ꢀ 4.3**
85.1 ꢀ 5.4**
76.5 ꢀ 13**
83.5 ꢀ 10.9**
44.8 ꢀ 14.4**
73.7 ꢀ 9.1**
89.4 ꢀ 4.6**
20.7 ꢀ 8.7**
31.2 ꢀ 4.2**
36.3 ꢀ 14.2**
14.0 ꢀ 6.1**
78.5 ꢀ 1.7**
34.2 ꢀ 10.5**
91.9 ꢀ 6.3*
9
73.0 ꢀ 8.9**
73.9 ꢀ 8.5**
7k
8a
8b
8c
8d
8f
8i
8j
8k
11
2a
2d
2f
3a
4f
94.3 ꢀ 2.5*
97.7 ꢀ 5.4
94.6 ꢀ 3.8*
97.3 ꢀ 2.9
93.5 ꢀ 2.5**
1.8 ꢀ 0.9**
0**
9
33.2 ꢀ 23.1**
28.1 ꢀ 8.8**
24.1 ꢀ 5.3**
0**
3j
3k
3l
7j
7k
7l
11
12
2a
2b
2c
2d
2e
2f
2g
2h
2i
2j
2k
2l
82.9 ꢀ 9.0**
70.7 ꢀ 8.5**
96.1 ꢀ 3.2**
95.2 ꢀ 3.2**
93.4 ꢀ 3.6**
96.1 ꢀ 5.4**
70.6 ꢀ 8.9**
4a
4b
4c
4d
4e
4f
4g
4h
4i
8a
8b
8c
8d
8e
8f
8g
8h
8i
4h
7b
92.3 ꢀ 5.0**
94.7 ꢀ 4.8*
29.3 ꢀ 8.0**
100.6 ꢀ 0.7
92.9 ꢀ 6.0**
1.4 ꢀ 9.4**
82.3 ꢀ 8.5**
103.0 ꢀ 12.8
100.0 ꢀ 13.6
99.8 ꢀ 9.2
100.6 ꢀ 16.8
100.3 ꢀ 9.6
80.7 ꢀ 13.1**
Control: cultured with
1a
,25(OH)2D3 (10ꢁ8 M). Samples: cultured with
M or 2 M). Each value was
1
a
,25(OH)2D3 (10ꢁ8 M) and each compound (20
m
m
expressed as mean ꢀ SD, n ¼ 4. The data of control group were pegged as 100%,
while other data were calculated relative to it. Data were analyzed by student’s t test.
0**
0**
0**
0**
96.5 ꢀ 8.9*
42.8 ꢀ 6.0**
45.9 ꢀ 10.6**
30.6 ꢀ 7.5**
75.4 ꢀ 10.2**
Significantly different from 1a,25(OH)2D3 alone, * p < 0.05, ** p < 0.01.
4j
4k
4l
8j
8k
8l
toxicity at 20 mM (see Supplementary data, Table 2). Most of the
tested compounds with strong activity were reversed after removal
of the compounds, suggesting that the compounds did not possess
0**
Control: cultured with 1
with 1
,25(OH)2D3 (10ꢁ8 M) and AS (20
tions. Samples: cultured with 1
,25(OH)2D3 (10ꢁ8 M) and each compound (20
a
,25(OH)2D3 (10ꢁ8 M). AS (alendronate sodium): cultured
M). Normal: cultured without any addi-
M).
a
m
irreversible toxicity at 20
recovery was observed by removing 2
7k, 8i and 9. Because osteoblastic cells are essential for OCL
formation [22], the toxic effect of those compounds (2 M) on
osteoblastic-like cells was examined using MTT assay. As shown in
Table 4, no cytotoxicity on osteoblastic-like cells was confirmed, on
the contrary, all of the compounds except for 7k enhanced the
differentiation of osteoblastic-like cells. These results suggested
that those compounds might affect the differentiation of the bone
marrow cells rather than impacting the collaboration of osteo-
blastic cells in OCL differentiation.
m
M or 2
mM. However, only partial
a
m
mM of compounds 2a, 4, 7c,
Each value was expressed as mean ꢀ SD, n ¼ 4. The data of control group were
pegged as 100%, while other data were calculated relative to it. Data were analyzed
by student’s t test. Significant differences in TRAP(þ)-OCLs compared with control
group, * p < 0.05, ** p < 0.01, # p < 0.01 versus normal group.
m
Table 2
Effects of selected compounds on 1
a
,25(OH)2D3 induced TRAP(þ)-OCL formation.
Compd OCLs (%)
Compd OCLs (%)
Taking the above results together, a preliminary SAR for OA
derivatives could be outlined as follows: (1) A carbonyl group at C-3
of OA could enhance the activity. (2) It seems that a six-membered
heterocyclic ring with two nitrogen atoms at C-2 and 3 positions of
OA is relevant to the strong activity, while if the heterocyclic ring
possessing one nitrogen atom, the compounds become less active.
(3) Substituted groups at phenyl ring of indole moiety could
promote the activity, while any substituents such as phenyl or NO2
groups at six-membered heterocyclic moieties with two nitrogen
atoms, should be detrimental to the activity. (4) A hydrophobic
group (methyl ester) at the amino acid could elevate the activity,
compared with those of the derivatives with amino acid. (5) The
short chain length of amino acid, such as glycine and alanine seems
2
m
M
200 nM
2
m
M
200 nM
Control 100.0 ꢀ 6.2#
100.0 ꢀ 8.2#
47.5 ꢀ 6.3**
97.5 ꢀ 4.6*
Normal 20.0 ꢀ 7.4
20.0 ꢀ 8.6
AS
OA (1)
2
3
4
5
6
7
8
3.5 ꢀ 2.9**
89.5 ꢀ 10.2**
79.2 ꢀ 12.0**
94.6 ꢀ 9.6**
13.0 ꢀ 3.7**
77.2 ꢀ 13.4**
83.0 ꢀ 10.6**
16.4 ꢀ 5.7**
72.7 ꢀ 8.0**
39.2 ꢀ 5.2**
76.2 ꢀ 6.1**
88.7 ꢀ 12.0**
27.2 ꢀ 10.9**
68.7 ꢀ 7.2**
94.0 ꢀ 8.3**
32.3 ꢀ 2.3**
99.4 ꢀ 2.7
4c
4g
4h
4i
4j
4k
4l
7a
7b
7c
7d
90.8 ꢀ 14.2**
74.2 ꢀ 4.9**
1.4 ꢀ 1.9**
98.3 ꢀ 13.8
99.5 ꢀ 8.3
80.0 ꢀ 3.2**
71.6 ꢀ 3.7**
86.9 ꢀ 12.6**
77.8 ꢀ 3.3**
93.5 ꢀ 11.2**
3.8 ꢀ 6.9**
97.6 ꢀ 15.5
97.2 ꢀ 15.5
9
93.7 ꢀ 12.2*
78.4 ꢀ 12.5**
96.4 ꢀ 10.7
101.0 ꢀ 5.9
11
12
2a
2b
2e
3a
3b
3f
3g
3h
3i
59.8 ꢀ 10.8**
1.7 ꢀ 2.2**
31.7 ꢀ 9.1** 7e
0.7 ꢀ 1.6**
7f
7j
82.8 ꢀ 7.9**
21.2 ꢀ 8.6**
16.2 ꢀ 5.9**
31.9 ꢀ 6.1**
25.7 ꢀ 6.1**
37.1 ꢀ 8.9**
55.1 ꢀ 7.6**
53.6 ꢀ 6.0**
47.3 ꢀ 5.6**
58.3 ꢀ 7.2**
58.7 ꢀ 8.7**
100.2 ꢀ 5.8
52.6 ꢀ 17.9**
34.1 ꢀ 2.8**
77.0 ꢀ 12.3**
93.0 ꢀ 8.0**
91.2 ꢀ 14.5*
93.0 ꢀ 7.8**
57.5 ꢀ 4.8**
86.3 ꢀ 7.3**
95.0 ꢀ 8.0*
86.3 ꢀ 6.3** 7k
Table 4
8a
8b
8c
8d
8f
8i
8j
8k
Effects of compounds on viability of osteoblast-like cell.
69.2 ꢀ 4.9**
95.2 ꢀ 7.5*
Compd
Osteoblasts (%)
90.2 ꢀ 4.6**
70.8 ꢀ 6.1**
98.2 ꢀ 4.0
Control
4
9
2a
7c
7k
8i
100.0 ꢀ 13.1
132.1 ꢀ 7.4**
134.0 ꢀ 13.3**
141.1 ꢀ 6.7**
141.6 ꢀ 6.7**
109.4 ꢀ 7.7
3j
4a
4b
66.6 ꢀ 2.6**
79.9 ꢀ 12.0**
Control: cultured with 1
with 1
,25(OH)2D3 (10ꢁ8 M) and AS. Normal: cultured without any additions.
Samples: cultured with 1
,25(OH)2D3 (10ꢁ8 M) and each compound. Each value was
a
,25(OH)2D3 (10ꢁ8 M). AS (alendronate sodium): cultured
128.5 ꢀ 6.5*
a
a
Control: cultured without compounds. Samples: cultured with each compound
(2
expressed as mean ꢀ SD, n ¼ 4. The data of control group were pegged as 100%,
while other data were calculated relative to it. Data were analyzed by student’s t
test. Significant differences in TRAP(þ)-OCLs compared with control group,
m
M). Each value was expressed as mean ꢀ SD, n ¼ 4. The data of control group
were pegged as 100%, while other data were calculated relative to it. Data were
analyzed by student’s t test. Significant differences compared to control group,
* p < 0.05, ** p < 0.01.
#
* p < 0.05, ** p < 0.01, p < 0.01 versus normal group.

2800
J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
to relate to a stronger activity, in other words, the amino acid with
big molecular weights will render the derivative less active or
inactive.
provide indole derivative 3. Compounds 4–6 were prepared
following the same protocol.
Compound 3: Yield 69%; mp 229–230 ꢃC; 1H NMR (CDCl3)
d 7.70
(1H, s, N-H), 7.42 (1H, d, J ¼ 6.0 Hz, Ar-H), 7.31–7.26 (1H, m, Ar-H),
7.13–7.03 (2H, m, Ar-H), 5.40 (1H, s, H-12), 2.87 (1H, dd, J ¼ 3 Hz,
J0 ¼ 15.0 Hz, H-18), 2.75 (1H, d, J ¼ 15.3 Hz, H-1), 2.18 (1H, d,
J ¼ 15.3 Hz, H-1), 1.26 (s, CH3), 1.19 (s, CH3), 1.17 (s, CH3), 0.95 (s,
CH3), 0.94 (s, CH3), 0.92 (s, CH3), 0.83 (s, CH3); 13C NMR (CDCl3)
3. Conclusion
We have synthesized a novel series of heterocyclic oleanolic acid
derivatives with inhibitory effect on OCL formation. Compounds 2a
and 8a exhibited quite a potent activity even at 200 nM. Carbonyl
group at C-3 and introducing heterocyclic ring with two nitrogen
atoms enhanced the activity, and glycine and alanine substituents
of the derivatives show benefits on improvement of the activity.
The in vivo tests including PK profiles of 2a and 8a are in progress.
We deem the oleanolic acid and its derivatives as a promising new
class of anti-osteoporosis leads deserving of further studies.
d
184.5 (C-28), 143.3 (C-13), 140.8 (Ar-C), 136.0 (Ar-C), 128.2 (Ar-C),
122.8 (C-12), 120.9 (Ar-C), 118.8 (Ar-C), 117.9 (Ar-C), 110.3 (Ar-C),
106.8 (Ar-C), 53.1, 46.6, 46.3, 45.8, 41.7, 41.0, 39.4, 38.0, 36.7, 33.9,
33.0, 32.4, 32.1, 30.9, 30.6, 25.8, 23.5, 23.3, 22.9, 19.2, 16.9, 15.5; ESI-
MS (negative) m/z: 526 [M ꢁ H]ꢁ. This compound was already
reported by Finlay et al. [15].
Compound 4: Yield 60%; mp 173 ꢃC; 1H NMR (CDCl3)
d 7.73 (1H, s,
N-H), 7.37 (1H, d, J ¼ 3.0 Hz, Ar-H), 7.19 (1H, d, J ¼ 6.0 Hz, Ar-H),
7.07–7.04 (1H, m, Ar-H), 5.40 (1H, s, H-12), 2.88 (1H, dd, J ¼ 3.0 Hz,
J0 ¼ 16.5 Hz, H-18), 2.70 (1H, d, J ¼ 15.0 Hz, H-1), 1.28 (s, CH3), 1.18 (s,
CH3), 1.15 (s, CH3), 0.96 (s, CH3), 0.93 (s, CH3), 0.92 (s, CH3), 0.85 (s,
4. Experimental
1H and 13C NMR spectra were taken on a Bruker Avance II 300
spectrometer with tetramethylsilane (TMS) as an internal standard
and chemical shifts were recorded in d values. The splitting pattern
CH3); 13C NMR (CDCl3)
d 184.3 (C-28), 143.3 (C-13), 142.5 (Ar-C),
134.4 (Ar-C), 129.4 (Ar-C), 124.6 (Ar-C), 122.8 (C-12), 121.0 (Ar-C),
117.6 (Ar-C), 111.2 (Ar-C), 106.8 (Ar-C), 53.0, 46.6, 45.8, 41.8, 41.1,
39.4, 38.1, 36.5, 35.7, 34.0, 33.0, 32.5, 32.1, 30.9, 27.7, 25.8, 23.5, 23.3,
22.9, 19.2, 16.9, 15.5; ESI-MS (negative) m/z: 560 [M ꢁ H]ꢁ.
abbreviations are as follows: s ¼ singlet, d ¼ doublet, t ¼ triplet and
m ¼ multiplet. Melting points were determined using X4 apparatus
and uncorrected. ESI-MS spectra were obtained on a Finnigan TSQ-
7000 mass spectrometer. All of the materials and reagents were
obtained from commercial suppliers and were used without further
purifications. Thin layer chromatography (TLC) was carried out on
precoated Kieselgel F254 plates (0.25 mm), and spots were visual-
ized under a UV lamp or by iodine spray to monitor all of the
described reactions. The purities of all of the compounds were
analyzed by HPLC methods (see Supplementary data).
ICR mice were used for activity evaluations. All procedures
involving animals were approved by the Jiangsu Animal Care and
Use Committee, China and followed the national and institutional
rules considering animal experiments. Mice were housed in
a climate-controlled room, 12 h light/dark photoperiod, water and
food ad libitium.
Compound 5: Yield 60%; mp 251 ꢃC; 1H NMR (CDCl3)
d 8.27 (1H,
s, Ar-H), 7.95 (1H, s, N-H), 7.85 (1H, d, J ¼ 9.0 Hz, Ar-H), 7.29–7.26
(1H, m, Ar-H), 5.41 (1H, s, H-12), 2.95 (1H, d, J ¼ 12.0 Hz, H-18), 2.70
(1H, d, J ¼ 15.2 Hz, H-1), 2.18 (1H, d, J ¼ 15.2 Hz, H-1), 1.27 (s, CH3),
1.20 (s, CH3), 1.15 (s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.85 (s, CH3),
0.82 (s, CH3); 13C NMR (CDCl3)
d 184.6 (C-28), 173.3 (Ar-COOH),
143.0 (C-13), 142.3 (Ar-C), 139.3 (Ar-C), 127.9 (Ar-C), 122.8 (C-12),
121.8 (Ar-C), 119.6 (Ar-C), 109.8 (Ar-C), 108.4 (Ar-C), 53.0, 46.6, 41.7,
39.4, 37.9, 33.9, 33.0, 30.6, 27.6, 25.7, 23.5, 19.2, 15.4; ESI-MS
(negative) m/z: 570 [M ꢁ H]ꢁ.
Compound 6: Yield 61%; mp 200 ꢃC; 1H NMR (CDCl3)
d 8.39 (1H,
d, J ¼ 2.5 Hz, Ar-H), 8.18 (1H, s, N-H), 8.06–8.02 (1H, m, Ar-H), 7.31–
7.26 (1H, m, Ar-H), 5.41 (1H, t, J ¼ 3.0 Hz, H-12), 2.90 (1H, dd,
J ¼ 3.0 Hz, J0 ¼ 15.0 Hz, H-18), 2.71 (1H, d, J ¼ 15.2 Hz, H-1), 2.18 (1H,
d, J ¼ 15.2 Hz, H-1), 1.28 (s, CH3), 1.19 (s, CH3), 1.15 (s, CH3), 0.96 (s,
CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.83 (s, CH3); 13C NMR (CDCl3)
4.1. Synthesis of compounds
d
183.8 (C-28), 144.2 (Ar-C), 143.3 (C-13), 141.2 (Ar-C), 139.3 (Ar-C),
4.1.1. Preparation of 3-keto OA (2)
127.8 (Ar-C), 122.7 (C-12), 116.9 (Ar-C), 115.3 (Ar-C), 110.0 (Ar-C),
109.5 (Ar-C), 53.0, 46.6, 46.3, 45.7, 41.7, 41.1, 39.4, 38.0, 36.3, 33.8,
32.4, 30.7, 27.7, 25.7, 23.5, 23.3, 22.9, 19.2, 16.8, 15.5; ESI-MS
(negative) m/z: 571 [M ꢁ H]ꢁ.
To a solution of OA (1) (456 mg, 1 mmol) in CHCl3/CH3COCH3
(2:1, 45 mL) in an ice bath was added Jones reagent dropwise until
the color of the solution changed from orange to green, then stirred
at room temperature for 10 min. After removal of the solvent, water
was added to the resultant mixture. The aqueous mixture was
extracted with a mixture of CH2Cl2/Et2O (1:2) (3 ꢂ 40 mL). After
removal of CH2Cl2/Et2O, the residue was purified by column chro-
matography (silica gel; EtOAc/petroleum ether) to give 2 (417 mg,
4.1.3. General procedure for pyrazine and quinoxaline derivatives
(7, 8, 11–12)
To a solution of 3-keto OA (2, 2.27 g, 5 mmol) in morpholine
(20 mL) were added sulfur (1.50 g, 47 mmol) and each 1,2-diamine
compound (25 mmol), and the reaction mixture was refluxed for 2–
4 h. The mixture was poured into distilled water and then extracted
with CH2Cl2 (3 ꢂ 80 mL). Organic layer was washed with H2O,
diluted aqueous HCl, H2O, saturated aqueous NaHCO3, H2O, dried
with anhydrous Na2SO4, successively, and then evaporated under
reduced pressure. The crude product was purified by column
chromatography (silica gel; EtOAc/petroleum ether) to yield the
expected products 7 and 8, respectively.
92%). mp 187 ꢃC; 1H NMR (CDCl3)
d 5.32 (1H, s, H-12), 2.85 (1H, dd,
J ¼ 3.0 Hz, J0 ¼ 15.0 Hz, H-18), 2.62–2.51 (1H, m, H-2), 2.45–2.33
(1H, m, H-2), 1.15 (s, CH3), 1.10 (s, CH3), 1.05 (s, CH3), 1.03 (s, CH3),
0.95 (s, CH3), 0.94 (s, CH3), 0.82 (s, CH3); 13C NMR (CDCl3)
d 217.7 (C-
3),184.2 (C-28),143.6 (C-13),122.3 (C-12), 55.3, 47.4, 46.6, 45.6, 41.7,
41.0, 39.2, 34.1, 30.7, 27.6, 26.4, 25.8, 23.5, 22.9, 21.4, 19.5, 17.0, 15.0;
ESI-MS (negative) m/z: 453 [M ꢁ H]ꢁ.
4.1.2. General method for Fischer indolization of OA (3–6)
A mixture of 3-keto OA (2, 4.54 g, 10 mmol) and selenium
dioxide (1.34 g, 1.2 mmol) in acetic acid (30 mL) was refluxed for
24 h. After cooling to room temperature, the reaction mixture was
filtered and evaporated to dryness. The residue was dissolved in
Et2O and washed with brine. The organic layer was dried (anhy-
drous Na2SO4), and the solvent was evaporated under reduced
pressure. The crude product was purified by column
A
mixture of 3-keto OA (2, 0.19 mmol), phenylhydrazine
(1.05 equiv, prepared from aniline [25]) in acetic acid (10 mL) was
refluxed for 1 h under nitrogen atmosphere. The reaction mixture
was pipetted into distilled water (50 mL) and then extracted with
Et2O (4 ꢂ 20 mL). After removing Et2O, the residue was purified by
column chromatography (silica gel; EtOAc/petroleum ether) to

J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
2801
chromatography (silica gel; Et2OAc/petroleum ether) to get 2,3-
diketo OA (10).
7.61–7.56 (1H, m, Ar-H), 7.44–7.39 (1H, m, Ar-H), 5.38 (1H, t,
J ¼ 3.0 Hz, H-12), 2.96–2.85 (2H, m, H-1 and H-18), 2.54 (1H, d,
J ¼ 15.0 Hz, H-1), 1.38 (s, CH3), 1.28 (s, CH3), 1.20 (s, CH3), 0.96 (s,
CH3), 0.95 (s, CH3), 0.92 (s, CH3), 0.88 (s, CH3); 13C NMR (CDCl3)
A mixture of 10 (468 mg, 1 mmol), each 1,2-diamine compound
(1.50 mmol) and acetic acid (10 mL) was refluxed under nitrogen
atmosphere for 2 h. The reaction solution was evaporated under
reduced pressure and the residue was purified by column chro-
matography (silica gel; Et2OAc/petroleum ether) to obtain the
expected products 11, 12, respectively.
d
184.1 (C-28), 166.0 (Ar-C), 147.3 (Ar-C), 143.7 (C-13), 135.3 (Ar-C),
128.8 (Ar-C), 128.6 (Ar-C), 128.0 (Ar-C), 126.9 (Ar-C), 126.5 (Ar-C),
125.4 (Ar-C), 122.5 (C-12), 53.9, 46.7, 45.6, 41.9, 41.1, 40.2, 39.2, 36.3,
33.8, 33.1, 30.7, 27.7, 25.8, 23.6, 20.4, 16.7, 15.0; ESI-MS (negative)
m/z: 538 [M ꢁ H]ꢁ.
Compound 7: Yield 70%; mp 267 ꢃC; 1H NMR (CDCl3)
d 8.44 (1H,
s, Ar-H), 8.28 (1H, s, Ar-H), 5.37 (1H, s, H-12), 3.0 (1H, d, J ¼ 15.0 Hz,
H-1), 2.87 (1H, dd, J ¼ 3.0 Hz, J0 ¼ 15.0 Hz, H-18), 2.52 (1H, d,
J ¼ 15.0 Hz, H-1), 1.31 (s, CH3), 1.28 (s, CH3), 1.19 (s, CH3), 0.94 (s,
CH3), 0.93 (s, CH3), 0.92 (s, CH3), 0.86 (s, CH3); 13C NMR (CDCl3)
4.1.5. General synthetic procedure for compounds 2a–l, 3a–l, 4a–l,
7a–l and 8a–l
The target compounds were synthesized with the route outlined
in Scheme 3. To a solution of 2 (2.72 g, 6 mmol) in anhydrous
CH2Cl2 (40 mL) was added oxalyl chloride (2.2 mL) and stirred at
room temperature for 24 h. The mixture was concentrated to
dryness under reduced pressure. Hexane (3 ꢂ 50 mL) was added to
the residue, then the solution was concentrated to dryness (this
procedure was repeated three times) to give acid chloride. To an
anhydrous CH2Cl2 (200 mL) solution of each corresponding amino
acid methyl ester (6.60 mmol) and triethylamine (3.4 mL) was
added the above acid chloride. The reaction mixture was stirred at
room temperature for 2 h, and then concentrated and chromato-
graphed to yield compounds 2a–f.
The above compounds 2a–f (3 mmol) were treated with 4 M
NaOH (16 mL) in CH3OH–THF (1:1.5, 75 mL) at room temperature
overnight. The solutions were neutralized with 2 M HCl, then
extracted with CH2Cl2 to provide compounds 2g–l, respectively.
Compounds 3a–l, 4a–l, 7a–l, 8a–l were synthesized with the same
protocol as 2a–l from 3, 4, 7 and 8, respectively. Data of compounds
2a–l, 3a–l, 4a–l, 7a–l and 8a–l are summarized in Table 5.
d
183.7 (C-28), 159.8 (Ar-C), 150.4 (Ar-C), 143.5 (C-13), 142.4 (Ar-C),
141.2 (Ar-C), 122.4 (H-12), 53.1, 48.1, 46.7, 45.9, 41.9, 41.3, 39.3, 36.7,
33.2, 31.7, 30.8, 27.8, 25.9, 24.3, 23.7, 20.2, 16.9, 15.6; ESI-MS m/z:
490 [M þ H]þ.
Compound 8: Yield 67%; mp 152 ꢃC; 1H NMR (CDCl3)
d 8.03–7.96
(2H, m, Ar-H), 7.68–7.64 (2H, m, Ar-H), 5.39 (1H, t, J ¼ 3.0 Hz, H-12),
3.26 (1H, d, J ¼ 15.0 Hz, H-1), 2.88 (1H, dd, J ¼ 3.0 Hz, J0 ¼ 15.0 Hz, H-
18), 2.66 (1H, d, J ¼ 15.0 Hz, H-1), 1.39 (s, CH3), 1.38 (s, CH3), 1.19 (s,
CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.92 (s, CH3), 0.84 (s, CH3); 13C NMR
(CDCl3) d 184.0 (C-28), 161.2 (Ar-C), 152.0 (Ar-C), 143.6 (C-13), 142.3
(Ar-C), 140.7 (Ar-C), 129.0 (Ar-C), 128.9 (Ar-C), 128.7 (Ar-C), 128.0
(Ar-C), 122.7 (C-12), 53.6, 49.3, 46.7, 45.7, 42.0, 41.2, 40.5, 39.4, 37.0,
34.0, 33.2, 32.4, 30.8, 27.8, 25.9, 25.5, 23.7, 20.5, 16.9, 15.7; ESI-MS
(negative) m/z: 539 [M ꢁ H]ꢁ.
Compound 11: Yield 53%; mp 238 ꢃC; 1H NMR (CDCl3)
d 7.43–
7.26 (10H, m, Ar-H), 5.39 (1H, s, H-12), 3.02–2.83 (2H, m, H-1 and H-
18), 1.39 (s, CH3), 1.28 (s, CH3), 1.19 (s, CH3), 1.18 (s, CH3), 0.97 (s,
CH3), 0.93 (s, CH3), 0.89 (s, CH3); 13C NMR (CDCl3)
d 184.3 (C-28),
164.9 (Ar-C), 161.8 (Ar-C), 149.7 (Ar-C), 148.7 (Ar-C), 143.2 (C-13),
139.8 (Ar-C), 139.6 (Ar-C), 130.0 (Ar-C), 129.9 (Ar-C), 128.0 (Ar-C),
127.9 (Ar-C), 123.2 (C-12), 46.6, 45.7, 45.5, 43.1, 41.3, 40.8, 33.8, 33.0,
32.4, 30.6, 28.4, 27.8, 26.4, 25.5, 23.5, 22.6, 22.0, 18.4, 18.2, 17.2; ESI-
MS (negative) m/z: 641 [M ꢁ H]ꢁ.
4.2. Formation of OCLs
A co-culture assay using mouse bone marrow cells and osteo-
blast-like cells was used for the evaluation of the effects of the
compounds on OCL formation (Takahashi et al. [22]). Briefly, oste-
oblast-like cells were prepared from calvaria of 2-day-old ICR mice.
Mouse bone marrow cells were obtained from tibiae of 6-week-old
male ICR mouse. Osteoblast-like cells (1 ꢂ104/well) and bone
marrow cells (1 ꢂ105/well) were co-cultured for 6 days with
Compound 12: Yield 44%; mp 176 ꢃC; 1H NMR (CDCl3)
d 8.96 (1H,
s, Ar-H), 8.47–8.41 (2H, m, Ar-H), 5.40 (1H, s, H-12), 3.28 (1H, d,
J ¼ 15.0 Hz, H-1), 2.90 (1H, dd, J ¼ 3.0 Hz, J0 ¼ 15.0 Hz, H-18), 2.64
(1H, d, J ¼ 15.0 Hz, H-1), 1.38 (s, CH3), 1.28 (s, CH3), 1.19 (s, CH3), 1.15
(s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.83 (s, CH3); 13C NMR (CDCl3)
d
184.2 (C-28), 164.0 (Ar-C), 155.8 (Ar-C), 147.0 (Ar-C), 143.6 (Ar-C),
1a
,25(OH)2D3 (10ꢁ8 M) and each compound. The medium was
143.3 (C-13), 140.8 (Ar-C), 129.6 (Ar-C), 125.4 (Ar-C), 122.4 (C-12),
53.2, 49.5, 46.6, 45.7, 41.8, 40.7, 39.2, 36.9, 33.8, 30.7, 27.6, 25.8, 23.5,
20.3, 16.7, 15.8; ESI-MS (negative) m/z: 584 [M ꢁ H]ꢁ.
replaced every 2 days. After 6 days, adherent cells on the well
surface were fixed with 10% formalin-phosphate buffered saline
(PBS, pH ¼ 7.2) for 10 min and dehydrated with ethanol–acetone
(1:1, v/v) for 1 min. The cells were stained by tartrate-resistant acid
phosphatase (TRAP) for 12 min at room temperature and TRAP-
positive cells containing three or more nuclei were counted. The
percentages of TRAP(þ)-OCLs cultured with compounds were
4.1.4. Preparation of 2,3-quinoline OA (9)
To a solution of o-nitrobenzaldehyde (588 mg, 3.89 mmol) in
EtOH/AcOH/H2O (2:2:1, 25 mL) were added iron powder (650 mg,
11.61 mmol) and concentrated hydrochloric acid (0.2 mL). The
reaction mixture was refluxed for 15 min and then stirred at room
temperature for 40 min, filtered, and extracted with EtOAc
(3 ꢂ 50 mL). The organic layer was washed with saturated NaHCO3
(3 ꢂ 30 mL) and brine (40 mL), dried over Na2SO4, and then puri-
fied by chromatography to produce o-aminobenzaldehyde. To
a mixture of o-aminobenzaldehyde (250 mg, 1.45 mmol) and 2
(658 mg, 1.45 mmol) in absolute EtOH (15 mL) under nitrogen
atmosphere was added saturated ethanolic KOH (0.5 mL) drop-
wise, and the mixture was refluxed for 24 h. After cooling to room
temperature, the solution was extracted with CH2Cl2 (3 ꢂ 30 mL).
The organic layer was washed with water and dried over MgSO4,
removal of the solvent gave the crude product, further purification
of the product by silica gel chromatography with EtOAc/petroleum
ether provided compound 9 (72% yield). mp 294 ꢃC; 1H NMR
compared to that only with 1a,25(OH)2D3 group.
4.3. Recovery assay
Recovery experiment was performed as described above. The
cells were treated with 1
,25(OH)2D3 (10ꢁ8 M) and each compound
for the first 2 days. Thereafter each compound was removed from
a
the medium and the cells were cultured with 1
a,25(OH)2D3
(10ꢁ8 M) only.
4.4. Osteoblast viability
The cell viability of osteoblasts was determined by means of MTT
[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]
assay. Osteoblast-like cells (5 ꢂ103/well) were cultured with each
compound in 96-well. The control group was cultured without
(CDCl3)
d
8.00 (1H, d, J ¼ 3.0 Hz, Ar-H), 7.71–7.67 (2H, m, Ar-H),

2802
J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
Table 5
Data of compounds 2a–l, 3a–l, 4a–l, 7a–l and 8a–l.
No. Yield Mp ESI-MS m/z
1H NMR (CDCl3)
13C NMR (CDCl3)
(%)
(ꢃC)
(
d
ppm) J ¼ Hz
(d ppm)
2a 89
101 526
6.52 (1H, t, J ¼ 6.0, N-H), 5.47 (1H, s, H-12), 4.16–4.09 (1H, m, H-20), 3.86– 217.6 (C-3), 178.2 (COO), 170.5 (CON), 144.3 (C-13), 123.0 (C-12),
3.80 (1H, m, H-20), 3.76 (3H, s, CH3), 2.66–2.53 (2H, m, H-2 and H-18), 2.40– 55.3, 52.3, 47.4, 42.4, 42.0, 39.3, 37.5, 34.1, 34.0, 32.9, 32.3, 31.9,
2.34 (1H, m, H-2), 1.17 (s, CH3), 1.08 (s, CH3), 1.04 (s, CH3), 1.03 (s, CH3), 0.95 27.2, 26.5, 25.6, 24.6, 23.8, 23.6, 21.4, 19.5, 18.1, 16.3
(s, CH3), 0.94 (s, CH3), 0.76 (s, CH3)
6.53 (1H, d, J ¼ 6.0, N-H), 5.36 (1H, s, H-12), 4.39–4.35 (1H, m, H-20), 3.64 217.3 (C-3), 177.2 (COO), 173.4 (CON), 143.6 (C-13), 122.8 (C-12),
(3H, s, CH3), 2.62 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.54–2.47 (1H, m, H-2), 55.1, 52.2, 47.4, 47.2, 46.6, 46.2, 42.5, 39.7, 36.5, 33.9, 32.8, 32.6,
2.30–2.24 (1H, m, H-2), 1.15 (s, CH3), 1.10 (s, CH3), 1.05 (s, CH3), 1.04 (s, CH3), 30.5, 26.8, 25.9, 23.8, 21.5, 19.8, 17.6, 16.3, 15.4
0.95 (s, CH3), 0.94 (s, CH3), 0.82 (s, CH3)
6.42 (1H, d, J ¼ 6.0, N-H), 5.46 (1H, s, H-12), 4.46 (1H, s, H-20), 3.72 (3H, s, 218.0 (C-3), 178.0 (COO), 172.8 (CON), 144.1 (C-13), 123.4 (C-12),
CH3), 2.67 (1H, dd, J ¼ 3.0, J0 ¼ 13.8, H-18), 2.57–2.49 (1H, m, H-2), 2.40–2.35 57.6, 55.6, 52.1, 47.2, 46.8, 42.6, 39.5, 34.5, 33.6, 33.3, 32.5, 32.1, 27.7,
(1H, m, H-2), 1.15 (s, CH3), 1.09 (s, CH3), 1.05 (s, CH3), 1.04 (s, CH3), 0.95 (s, 26.8, 24.0, 23.9, 21.8, 19.9, 19.1, 18.6, 17.0, 15.4
CH3), 0.94 (s, CH3), 0.78 (s, CH3)
6.33 (1H, d, J ¼ 6.0, N-H), 5.44 (1H, t, J ¼ 3.0, H-12), 4.55–4.53 (1H, m, H-20), 217.6 (C-3), 177.5 (COO), 173.5 (CON), 143.9 (C-13), 122.9 (C-12),
3.71 (3H, s, CH3), 2.65 (1H, dd, J ¼ 3.0, J0 ¼ 13.8, H-18), 2.58–2.50 (1H, m, H- 55.2, 52.1, 50.9, 47.4, 46.8, 46.5, 46.3, 42.1, 42.0, 39.3, 39.2, 36.7,
2), 2.39–2.30 (1H, m, H-2), 1.16 (s, CH3), 1.09 (s, CH3), 1.05 (s, CH3), 1.04 (s, 34.1, 32.9, 32.1, 30.7, 27.3, 26.4, 25.5, 25.0, 23.8, 23.6
CH3), 0.95 (s, CH3), 0.93 (s, CH3), 0.82 (s, CH3).
[M þ H]þ;
548
[M þ Na]þ
2b 90
2c 86
2d 85
2e 89
2f 90
103 540
[M þ H]þ;
562
[M þ Na]þ
215 568
[M þ H]þ;
590
[M þ Na]þ
146 582
[M þ H]þ;
604
[M þ Na]þ
98 582
6.46 (1H, d, J ¼ 6.0, N-H), 5.45 (1H, s, H-12), 4.52 (1H, t, J ¼ 3.0, H-20), 3.71 217.7 (C-3), 177.4 (COO), 172.3 (CON), 143.8 (C-13), 123.0 (C-12),
(3H, s, CH3), 2.66 (1H, dd, J ¼ 3.0, J0 ¼ 13.8, H-18), 2.58–2.50 (1H, m, H-2), 56.2, 55.2, 52.0, 51.9, 48.9, 47.6, 47.4, 46.8, 46.5, 46.1, 42.7, 42.2, 41.4,
2.39–2.31 (1H, m, H-2), 1.15 (s, CH3), 1.08 (s, CH3), 1.05 (s, CH3), 1.04 (s, CH3), 39.8, 39.4, 39.2, 38.2, 37.5, 36.7, 34.1, 33.1, 32.6, 30.7, 26.6, 25.8,
[M þ H]þ;
604
[M þ Na]þ
0.94 (s, CH3), 0.93 (s, CH3), 0.79 (s, CH3)
23.5, 21.5, 19.8, 16.9, 15.3, 11.7
82 616
7.28–7.23 (3H, m, Ar-H), 7.11–7.08 (2H, m, Ar-H), 6.38 (1H, d, J ¼ 6.0, N-H), 217.6 (C-3), 177.5 (COO), 172.0 (CON), 143.7 (C-13), 136.1 (Ar-C),
5.30 (1H, s, H-12), 4.77–4.75 (1H, m, H-20), 3.70 (3H, s, CH3), 3.17–3.01 (2H, 129.3 (Ar-C),128.4 (Ar-C),127.0 (Ar-C),123.0 (C-12), 55.2, 53.3, 52.1,
m, H-30), 2.59–2.49 (2H, m, H-2 and H-18), 2.39–2.31 (1H, m, H-2), 1.16 (s, 47.4, 46.8, 46.4, 42.0, 41.9, 39.3, 36.6, 34.1, 32.9, 32.6, 32.0, 27.2,
CH3), 1.08 (s, CH3), 1.05 (s, CH3), 1.03 (s, CH3), 0.94 (s, CH3), 0.89 (s, CH3), 0.79 26.4, 25.5, 23.7, 23.5, 19.2, 16.8, 15.4
(s, CH3)
[M þ H]þ;
638
[M þ Na]þ
2g 90
2h 89
2i 91
140 511 [M þ H]þ 6.70 (1H, s, N-H), 5.48 (1H, s, H-12), 4.14–3.86 (2H, m, H-20), 2.62–2.53 (2H, 218.1 (C-3), 179.8 (COO), 172.0 (CON), 144.2 (C-13), 123.5 (C-12),
m, H-2 and H-18), 2.41–2.35 (1H, m, H-2), 1.15 (s, CH3), 1.07 (s, CH3), 1.04 (s, 57.2, 55.3, 49.7, 47.6, 46.5, 42.3, 41.3, 39.5, 36.8, 34.2, 33.1, 32.3,
CH3), 1.03 (s, CH3), 0.95 (s, CH3), 0.91 (s, CH3), 0.77 (s, CH3).
30.8, 26.6, 25.8, 23.7, 21.6, 19.7, 18.8, 16.5, 15.2
134 526 [M þ H]þ 6.68 (1H, d, J ¼ 6.0, N-H), 5.46 (1H, s, H-12), 4.47–4.43 (1H, m, H-20), 2.62– 218.1 (C-3), 179.4 (COO), 175.3 (CON), 144.0 (C-13), 123.5 (C-12),
2.52 (2H, m, H-2 and H-18), 2.39–2.30 (1H, m, H-2), 1.16 (s, CH3), 1.09 (s, 55.3, 48.9, 47.5, 46.9, 46.4, 42.2, 39.5, 36.8, 34.2, 33.1, 32.1, 30.8,
CH3), 1.05 (s, CH3), 1.04 (s, CH3), 0.95 (s, CH3), 0.91 (s, CH3), 0.82 (s, CH3)
26.6, 25.7, 23.7, 21.5, 19.6, 17.9, 16.6, 15.2
232 554
6.53 (1H, d, J ¼ 6.0, N-H), 5.46 (1H, t, J ¼ 3.0, H-12), 4.47 (1H, t, J ¼ 3.0, H-20), 217.9 (C-3), 179.1 (COO), 175.4 (CON), 143.9 (C-13), 123.4 (C-12),
2.62–2.52 (2H, m, H-2 and H-18), 2.39–2.30 (1H, m, H-2), 1.16 (s, CH3), 1.09 57.4, 55.3, 47.6, 46.9, 42.3, 39.5, 36.8, 34.2, 33.0, 30.8, 26.6, 25.7,
(s, CH3), 1.05 (s, CH3), 1.04 (s, CH3), 0.98 (s, CH3), 0.97 (s, CH3), 0.78 (s, CH3) 23.6, 21.6, 19.1, 18.1, 16.8, 15.2
[M þ H]þ;
576
[M þ Na]þ
2j 86
2k 88
2l 90
3a 84
142 568 [M þ H]þ 6.33 (1H, d, J ¼ 6.0, N-H), 5.44 (1H, t, J ¼ 3.0, H-12), 4.55–4.53 (1H, m, H-20), 218.4 (C-3), 179.3 (COO), 175.4 (CON), 143.8 (C-13), 123.4 (C-12),
2.65 (1H, dd, J ¼ 3.0, J0 ¼ 13.8, H-18), 2.58–2.50 (1H, m, H-2), 2.39–2.30 (1H, 56.6, 55.3, 42.3, 39.5, 37.6, 36.8, 33.1, 30.8, 26.6, 23.6, 16.8, 15.3, 11.8
m, H-2), 1.15 (s, CH3), 1.09 (s, CH3), 1.05 (s, CH3), 1.04 (s, CH3), 0.94 (s, CH3),
0.93 (s, CH3), 0.82 (s, CH3)
142 568 [M þ H]þ 6.55 (1H, d, J ¼ 6.0, N-H), 5.45 (1H, s, H-12), 4.53–4.50 (1H, m, H-20), 2.67 218.1 (C-3), 178.3 (COO), 175.4 (CON), 143.9 (C-13), 123.4 (C-12),
(1H, dd, J ¼ 3.0, J0 ¼ 13.8, H-18), 2.58–2.50 (1H, m, H-2), 2.39–2.31 (1H, m, H- 56.6, 55.3, 47.6, 46.9, 42.9, 39.5, 37.6, 36.8, 34.2, 33.1, 30.8, 26.6,
2), 1.16 (s, CH3), 1.09 (s, CH3), 1.05 (s, CH3), 1.04 (s, CH3), 0.94 (s, CH3), 0.93 (s, 25.7, 23.6, 21.6, 19.7, 16.8, 15.3, 11.8
CH3), 0.79 (s, CH3)
128 602 [M þ H]þ 7.31–7.17 (5H, m, Ar-H), 6.44 (1H, d, J ¼ 6.0, N-H), 5.23 (1H, s, H-12), 4.71– 218.2 (C-3), 179.8 (COO), 173.7 (CON), 143.6 (C-13), 135.8 (Ar-C),
4.69 (1H, m, H-20), 3.30–3.06 (2H, m, H-30), 2.59–2.50 (2H, m, H-2 and H-18), 129.5 (Ar-C), 128.8 (Ar-C), 127.4 (Ar-C), 123.5 (C-12), 55.2, 53.8,
2.39–2.30 (1H, m, H-2), 1.15 (s, CH3), 1.08 (s, CH3), 1.05 (s, CH3), 1.03 (s, CH3), 47.6, 46.5, 42.3, 40.3, 39.4, 36.7, 34.3, 33.0, 30.8, 27.3, 26.5, 25.6,
0.94 (s, CH3), 0.92 (s, CH3), 0.79 (s, CH3)
7.81 (1H, s, N-H), 7.46–7.43 (1H, m, Ar-H), 7.34–7.28 (1H, m, Ar-H), 7.16–7.08 178.4 (COO), 170.5 (CON), 144.0 (C-13), 140.8 (Ar-C), 136.1 (Ar-C),
128.1 (Ar-C), 123.6 (C-12), 120.9 (Ar-C), 118.8 (Ar-C), 117.9 (Ar-C),
25.1, 23.5, 23.1, 22.3, 21.6, 16.7, 15.3
140 621
[M þ Na]þ
(2H, m, Ar-H), 6.61 (1H, s, N-H), 5.60 (1H, s, H-12), 4.18 (1H, dd, J ¼ 3.0,
J0 ¼ 15.0, H-20), 3.90–3.78 (4H, m, CH3 and H-20), 2.80 (1H, d, J ¼ 15.0, H-1), 110.4 (Ar-C),106.7 (Ar-C), 52.4, 47.5, 46.4, 42.1, 41.5, 39.5, 38.0, 36.7,
2.72 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.18 (1H, d, J ¼ 15.0, H-1), 1.26 (s, CH3), 34.0, 32.3, 31.8, 30.8, 27.3, 25.6, 23.3, 21.5, 16.2, 15.7
1.20 (s, CH3), 1.19 (s, CH3), 1.17 (s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.83 (s,
CH3)
3b 87
3c 89
3d 82
3e 88
129 635
7.84 (1H, s, N-H), 7.42 (1H, d, J ¼ 6.0, Ar-H), 7.30–7.25 (1H, m, Ar-H), 7.11–7.05 177.6 (COO), 173.6 (CON), 143.6 (C-13), 140.9 (Ar-C), 136.1 (Ar-C),
[M þ Na]þ
(2H, m, Ar-H), 6.64 (1H, d, J ¼ 6.0, N-H), 5.55 (1H, s, H-12), 4.50–4.46 (1H, m, 128.1 (Ar-C), 123.6 (C-12), 120.9 (Ar-C), 118.8 (Ar-C), 117.9 (Ar-C),
H-20), 3.74 (3H, s, CH3), 2.82 (1H, d, J ¼ 15.0, H-1), 2.74 (1H, dd, J ¼ 3.0,
110.4 (Ar-C), 106.7 (Ar-C), 52.4, 48.4, 46.3, 42.2, 39.5, 36.0, 34.0,
J0 ¼ 15.0, H-18), 2.18 (1H, d, J ¼ 15.0, H-1), 1.28 (s, CH3), 1.18 (s, CH3), 1.16 (s, 30.8, 27.4, 25.6, 23.6, 18.7, 16.4, 15.5
CH3), 0.97 (s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.84 (s, CH3)
122 663
7.86 (1H, s, N-H), 7.45 (1H, d, J ¼ 6.0, Ar-H), 7.33–7.25 (1H, m, Ar-H), 7.16–7.08 178.2 (COO), 172.7 (CON), 143.9 (C-13), 141.2 (Ar-C), 136.5 (Ar-C),
(2H, m, Ar-H), 6.50 (1H, d, J ¼ 6.0, N-H), 5.58 (1H, s, H-12), 4.50 (1H, t, J ¼ 6.0, 128.6 (Ar-C), 123.9 (C-12), 121.3 (Ar-C), 119.2 (Ar-C), 118.3 (Ar-C),
[M þ Na]þ
H-20), 3.73 (3H, s, CH3), 2.82 (1H, d, J ¼ 15.0, H-1), 2.74 (1H, dd, J ¼ 3.0,
110.7 (Ar-C), 107.1 (Ar-C), 57.7, 53.5, 52.3, 47.1, 46.9, 46.7, 42.8, 37.2,
J0 ¼ 15.0, H-18), 2.18 (1H, d, J ¼ 15.0, H-1), 1.27 (s, CH3), 1.19 (s, CH3), 1.16 (s, 34.5, 33.6, 33.4, 32.6, 32.1, 31.3, 27.8, 25.9, 24.1, 23.9, 23.6, 19.1, 18.7,
CH3), 0.97 (s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.83 (s, CH3)
16.9, 16.0
145 655
7.82 (1H, s, N-H), 7.42 (1H, d, J ¼ 6.0, Ar-H), 7.30–7.25 (1H, m, Ar-H), 7.11–7.05 177.6 (COO), 173.4 (CON), 143.6 (C-13), 140.8 (Ar-C), 136.1 (Ar-C),
[M þ H]þ;
(2H, m, Ar-H), 6.40 (1H, d, J ¼ 6.0, N-H), 5.54 (1H, s, H-12), 4.56 (1H, d, J ¼ 6.0, 128.2 (Ar-C), 123.5 (C-12), 120.9 (Ar-C), 118.8 (Ar-C), 117.9 (Ar-C),
677
H-20), 3.70 (3H, s, CH3), 2.85 (1H, d, J ¼ 15.2, H-1), 2.74 (1H, dd, J ¼ 3.0,
110.3 (Ar-C), 106.7 (Ar-C), 55.2, 53.1, 52.1, 51.0, 46.8, 46.6, 46.3, 42.2,
[M þ Na]þ
J0 ¼ 15.0, H-18), 2.18 (1H, d, J ¼ 15.2, H-1), 1.26 (s, CH3), 1.18 (s, CH3), 1.17 (s, 41.9, 39.5, 39.2, 36.8, 34.1, 33.9, 33.0, 32.9, 30.9, 27.4, 26.4, 25.5,
CH3), 0.97 (s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.85 (s, CH3)
23.9, 23.6, 22.7, 22.4, 21.4, 19.3, 16.6, 15.6
148 655
7.80 (1H, s, N-H), 7.42 (1H, d, J ¼ 6.0, Ar-H), 7.30–7.25 (1H, m, Ar-H), 7.13– 177.7 (COO), 172.3 (CON), 143.5 (C-13), 140.9 (Ar-C), 136.1 (Ar-C),
7.03 (2H, m, Ar-H), 6.52 (1H, d, J ¼ 6.0, N-H), 5.55 (1H, t, J ¼ 3.0, H-12), 4.53 128.1 (Ar-C), 123.6 (C-12), 120.9 (Ar-C), 118.8 (Ar-C), 117.9 (Ar-C),
(1H, t, J ¼ 6.0, H-20), 3.70 (3H, s, CH3), 2.82 (1H, d, J ¼ 15.0, H-1), 2.72 (1H, dd, 110.4 (Ar-C), 106.7 (Ar-C), 56.3, 53.1, 52.0, 46.7, 42.2, 39.5, 38.2,
J ¼ 3.0, J0 ¼ 15.0, H-18), 2.16 (1H, d, J ¼ 15.0, H-1), 1.23 (s, CH3), 1.18 (s, CH3), 36.8, 34.0, 33.1, 32.2, 30.8, 27.5, 25.5, 19.3, 16.5, 15.2, 11.6
1.16 (s, CH3), 0.95 (s, CH3), 0.94 (s, CH3), 0.84 (s, CH3)
[M þ H]þ;
677
[M þ Na]þ

J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
2803
Table 5 (continued )
No. Yield Mp ESI-MS m/z
1H NMR (CDCl3)
ppm) J ¼ Hz
13C NMR (CDCl3)
(%)
(ꢃC)
(
d
(d ppm)
3f 89
158 689 [M þ H]þ 7.79 (1H, s, N-H), 7.41 (1H, d, J ¼ 6.0, Ar-H), 7.30–7.02 (8H, m, Ar-H), 6.44 (1H, 177.7 (COO), 171.9 (CON), 143.4 (C-13), 140.8 (Ar-C), 136.1 (Ar-C),
d, J ¼ 6.0, N-H), 5.40 (1H, s, H-12), 4.78–4.75 (1H, m, H-20), 3.70 (3H, s, CH3), 129.4 (Ar-C), 128.5 (Ar-C), 127.1 (Ar-C), 123.6 (C-12), 120.9 (Ar-C),
3.23–3.06 (2H, m, H-30), 2.75 (1H, d, J ¼ 15.2, H-1), 2.52 (1H, dd, J ¼ 3.0,
118.8 (Ar-C), 117.9 (Ar-C), 110.4 (Ar-C), 106.7 (Ar-C), 53.5, 53.1, 52.2,
J0 ¼ 15.0, H-18), 2.14 (1H, d, J ¼ 15.2, H-1), 1.26 (s, CH3), 1.19 (s, CH3), 1.15 (s, 47.4, 46.6, 46.3, 42.1, 39.5, 38.0, 36.8, 34.0, 33.0, 32.6, 32.0, 30.7,
CH3), 0.97 (s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.83 (s, CH3)
27.3, 25.5, 23.4, 16.2, 15.6, 15.1
3g 86
226 585
7.76 (1H, s, N-H), 7.42 (1H, d, J ¼ 6.0, Ar-H), 7.31–7.26 (1H, m, Ar-H), 7.14–7.05 180.0 (COO), 172.1 (CON), 144.0 (C-13), 140.9 (Ar-C), 136.2 (Ar-C),
[M þ H]þ;
(2H, m, Ar-H), 6.76 (1H, s, N-H), 5.57 (1H, t, J ¼ 3.0, H-12), 4.11 (1H, dd,
J ¼ 3.0, J0 ¼ 15.0, H-20), 3.92 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-20), 2.77 (1H, d,
128.3 (Ar-C), 124.0 (C-12), 121.1 (Ar-C), 119.0 (Ar-C), 118.0 (Ar-C),
110.5 (Ar-C),106.8 (Ar-C), 53.2, 46.6, 42.3, 39.6, 38.1, 34.1, 33.1, 30.8,
607
[M þ Na]þ
J ¼ 15.0, H-1), 2.65 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.20 (1H, d, J ¼ 15.0, H-1), 27.4, 25.7, 23.7, 23.4, 19.4, 16.3, 15.8
1.26 (s, CH3), 1.20 (s, CH3), 1.19 (s, CH3), 1.17 (s, CH3), 0.93 (s, CH3), 0.92 (s,
CH3), 0.82 (s, CH3)
3h 89
3i 90
3j 88
3k 90
3l 91
4a 85
4b 83
4c 87
4d 89
4e 88
4f 85
4g 88
220 599
7.84 (1H, s, N-H), 7.42 (1H, d, J ¼ 6.0, Ar-H), 7.31–7.26 (1H, m, Ar-H), 7.13–7.06 180.0 (COO), 175.0 (CON), 143.8 (C-13), 140.9 (Ar-C), 136.3 (Ar-C),
(2H, m, Ar-H), 6.70 (1H, d, J ¼ 6.0, N-H), 5.56 (1H, t, J ¼ 3.0, H-12), 4.47–4.43 128.3 (Ar-C), 124.1 (C-12), 121.1 (Ar-C), 119.0 (Ar-C), 118.0 (Ar-C),
(1H, m, H-20), 2.78 (1H, d, J ¼ 15.0, H-1), 2.62 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 110.5 (Ar-C), 106.8 (Ar-C), 53.2, 49.0, 47.6, 46.5, 42.4, 39.7, 38.1,
2.20 (1H, d, J ¼ 15.0, H-1), 1.28 (s, CH3), 1.22 (s, CH3), 1.18 (s, CH3), 1.16 (s, 36.8, 34.1, 33.1, 30.8, 27.4, 25.7, 23.6, 21.6, 19.4, 17.7, 16.5, 15.8
CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.81 (s, CH3)
7.83 (1H, s, N-H), 7.43 (1H, d, J ¼ 6.0, Ar-H), 7.31–7.29 (1H, m, Ar-H), 7.12–7.03 179.6 (COO), 174.9 (CON), 143.7 (C-13), 140.9 (Ar-C), 136.3 (Ar-C),
(2H, m, Ar-H), 6.54 (1H, d, J ¼ 6.0, N-H), 5.56 (1H, s, H-12), 4.45 (1H, t, J ¼ 6.0, 128.3 (Ar-C), 124.0 (C-12), 121.1 (Ar-C), 119.0 (Ar-C), 118.0 (Ar-C),
H-20), 2.80 (1H, d, J ¼ 15.0, H-1), 2.62 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.18 110.5 (Ar-C), 106.8 (Ar-C), 57.5, 53.3, 47.1, 46.4, 42.5, 39.7, 38.1, 34.1,
(1H, d, J ¼ 15.0, H-1), 1.28 (s, CH3), 1.18 (s, CH3), 1.17 (s, CH3), 0.98 (s, CH3), 33.0, 31.1, 30.8, 27.5, 25.6, 23.4, 19.2, 18.0, 16.8, 15.8
0.96 (s, CH3), 0.94 (s, CH3), 0.81 (s, CH3)
7.80 (1H, s, N-H), 7.42 (1H, d, J ¼ 6.0, Ar-H), 7.31–7.26 (1H, m, Ar-H), 7.14–7.03 180.3 (COO), 174.7 (CON), 144.0 (C-13), 140.9 (Ar-C), 136.3 (Ar-C),
(2H, m, Ar-H), 6.49 (1H, d, J ¼ 6.0, N-H), 5.54 (1H, t, J ¼ 3.0, H-12), 4.49–4.42 128.3 (Ar-C), 124.1 (C-12), 121.1 (Ar-C), 119.0 (Ar-C), 118.0 (Ar-C),
(1H, m, H-20), 2.80 (1H, d, J ¼ 15.0, H-1), 2.60 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 110.5 (Ar-C),106.8 (Ar-C), 53.2, 51.8, 46.7, 42.5, 40.4, 39.6, 38.1, 36.8,
2.17 (1H, d, J ¼ 15.0, H-1), 1.30 (s, CH3), 1.21 (s, CH3), 1.17 (s, CH3), 0.96 (s, 34.1, 33.0, 30.8, 27.4, 25.6, 25.2, 23.1, 22.3, 19.4, 16.7, 15.8
CH3), 0.95 (s, CH3), 0.94 (s, CH3), 0.82 (s, CH3)
7.85 (1H, s, N-H), 7.43 (1H, d, J ¼ 6.0, Ar-H), 7.31–7.26 (1H, m, Ar-H), 7.11–7.05 178.9 (COO), 175.6 (CON), 143.6 (C-13), 140.8 (Ar-C), 136.3 (Ar-C),
(2H, m, Ar-H), 6.58 (1H, d, J ¼ 6.0, N-H), 5.56 (1H, s, H-12), 4.53 (1H, t, J ¼ 3.0, 128.3 (Ar-C), 123.9 (C-12), 121.1 (Ar-C), 119.0 (Ar-C), 118.0 (Ar-C),
H-20), 2.80 (1H, d, J ¼ 15.0, H-1), 2.62 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.16 110.5 (Ar-C), 106.8 (Ar-C), 56.5, 53.3, 47.0, 46.4, 42.4, 39.7, 38.1, 34.1,
(1H, d, J ¼ 15.0, H-1), 1.28 (s, CH3), 1.18 (s, CH3), 1.16 (s, CH3), 0.97 (s, CH3), 33.0, 30.8, 27.5, 25.6, 23.4, 19.4, 16.8, 15.8, 15.5, 11.7
0.96 (s, CH3), 0.94 (s, CH3), 0.84 (s, CH3)
[M þ H]þ;
621
[M þ Na]þ
223 627
[M þ H]þ;
649
[M þ Na]þ
208 641
[M þ H]þ;
663
[M þ Na]þ
206 641
[M þ H]þ;
663
[M þ Na]þ
205 675
7.77 (1H, s, N-H), 7.41–7.06 (9H, m, Ar-H), 6.40 (1H, d, J ¼ 6.0, N-H), 5.29 (1H, 181.0 (COO), 172.8 (CON), 143.6 (C-13), 140.9 (Ar-C), 136.3 (Ar-C),
t, J ¼ 3.0, H-12), 4.70–4.64 (1H, m, H-20), 3.23–3.06 (2H, m, H-30), 2.76 (1H, d, 135.8 (Ar-C), 129.5 (Ar-C), 129.0 (Ar-C), 128.3 (Ar-C), 127.5 (Ar-C),
J ¼ 15.1, H-1), 2.52 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.12 (1H, d, J ¼ 15.1, H-1), 124.1 (C-12), 121.1 (Ar-C), 119.0 (Ar-C), 118.0 (Ar-C), 110.5 (Ar-C),
1.28 (s, CH3), 1.19 (s, CH3), 1.15 (s, CH3), 0.89 (s, CH3), 0.88 (s, CH3), 0.74 (s, 106.8 (Ar-C), 54.1, 53.2, 46.7, 42.0, 39.6, 38.1, 36.3, 34.1, 32.9, 31.1,
[M þ H]þ;
697
[M þ Na]þ
CH3), 0.73 (s, CH3)
30.7, 27.3, 25.6, 23.4, 19.3, 16.4, 15.8
162 633
7.91 (1H, s, N-H), 7.37 (1H, d, J ¼ 3.0, Ar-H), 7.20 (1H, d, J ¼ 6.0, Ar-H), 7.07– 178.5 (COO), 170.6 (CON), 144.2 (C-13), 142.6 (Ar-C), 134.5 (Ar-C),
7.04 (1H, m, Ar-H), 6.59 (1H, s, N-H), 5.58 (1H, s, H-12), 4.17 (1H, dd, J ¼ 3.0, 129.4 (Ar-C), 124.6 (Ar-C), 123.6 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
J0 ¼ 15.0, H-20), 3.84 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-20), 3.76 (3H, s, CH3), 2.75– 111.4 (Ar-C),106.8 (Ar-C), 53.0, 52.5, 46.5, 42.4, 42.2, 41.6, 39.6, 38.1,
2.60 (2H, m, H-1 and H-18), 2.16 (1H, d, J ¼ 15.3, H-1), 1.30 (s, CH3), 1.22 (s, 36.7, 34.2, 33.1, 32.5, 30.9, 27.4, 25.7, 23.7, 19.4, 16.3, 15.7
CH3), 1.21 (s, CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.85 (s, CH3)
[M þ H]þ;
678
[M þ 2Na]þ
118 669
7.83 (1H, s, N-H), 7.37 (1H, s, Ar-H), 7.21 (1H, d, J ¼ 6.0, Ar-H), 7.06–7.04 (1H, 177.7 (COO), 173.7 (CON), 143.7 (C-13), 142.6 (Ar-C), 134.6 (Ar-C),
[M þ Na]þ
m, Ar-H), 6.64 (1H, d, J ¼ 6.0, N-H), 5.57 (1H, s, H-12), 4.51–4.47 (1H, m, H- 129.5 (Ar-C), 124.7 (Ar-C), 123.6 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
20), 3.74 (3H, s, CH3), 2.82 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.72 (1H, d,
111.4 (Ar-C), 106.9 (Ar-C), 53.2, 53.1, 52.5, 48.6, 48.5, 46.6, 46.4,
J ¼ 15.0, H-1), 2.12 (1H, d, J ¼ 15.0, H-1), 1.29 (s, CH3), 1.21 (s, CH3), 1.20 (s, 42.3, 42.1, 41.5, 39.7, 38.2, 36.8, 34.3, 33.1, 32.3, 31.0, 27.5, 25.9, 25.7,
CH3), 0.95 (s, CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.84 (s, CH3)
23.7, 17.9, 15.7
161 675
7.84 (1H, s, N-H), 7.37 (1H, d, J ¼ 3.0, Ar-H), 7.20 (1H, d, J ¼ 6.0, Ar-H), 7.07– 177.9 (COO), 172.4 (CON), 143.6 (C-13), 142.6 (Ar-C), 134.6 (Ar-C),
7.03 (1H, m, Ar-H), 6.47 (1H, d, J ¼ 6.0, N-H), 5.56 (1H, s, H-12), 4.47 (1H, t, 129.5 (Ar-C), 124.7 (Ar-C), 123.6 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
J ¼ 3.0, H-20), 3.71 (3H, s, CH3), 2.75–2.65 (2H, m, H-1 and H-18), 2.19 (1H, d, 111.4 (Ar-C), 106.9 (Ar-C), 57.4, 53.2, 52.1, 46.9, 42.5, 42.3, 39.6, 38.1,
J ¼ 15.3, H-1), 1.28 (s, CH3), 1.21 (s, CH3), 1.20 (s, CH3), 0.97 (s, CH3), 0.96 (s, 36.8, 34.3, 33.4, 31.9, 30.9, 27.6, 23.8, 23.4, 18.4, 15.8
CH3), 0.94 (s, CH3), 0.84 (s, CH3)
[M þ H]þ;
720
[M þ 2Na]þ
119 689
7.79 (1H, s, N-H), 7.37 (1H, d, J ¼ 3.0, Ar-H), 7.20 (1H, d, J ¼ 6.0, Ar-H), 7.07– 177.8 (COO), 173.6 (CON), 143.8 (C-13), 142.6 (Ar-C), 134.6 (Ar-C),
[M þ H]þ; 711 7.04 (1H, m, Ar-H), 6.39 (1H, d, J ¼ 6.0, N-H), 5.54 (1H, t, J ¼ 3.0, H-12), 4.59– 129.5 (Ar-C), 124.7 (Ar-C), 123.5 (C-12), 121.2 (Ar-C), 117.6 (Ar-C),
[M þ Na]þ
4.53 (1H, m, H-20), 3.71 (3H, s, CH3), 2.75–2.61 (2H, m, H-1 and H-18), 2.17 111.4 (Ar-C), 106.9 (Ar-C), 53.2, 52.2, 51.2, 46.7, 46.6, 42.4, 42.1, 39.6,
(1H, d, J ¼ 15.3, H-1), 1.29 (s, CH3), 1.21 (s, CH3), 1.20 (s, CH3), 0.96 (s, CH3), 38.1, 36.8, 34.3, 33.1, 33.0, 32.2, 31.0, 30.8, 27.5, 25.6, 25.1, 24.0, 23.7,
0.94 (s, CH3), 0.93 (s, CH3), 0.83 (s, CH3)
23.4, 22.5, 20.6, 16.9, 15.8
160 711
7.95 (1H, s, N-H), 7.37 (1H, d, J ¼ 3.0, Ar-H), 7.20 (1H, d, J ¼ 6.0, Ar-H), 7.07– 177.7 (COO), 172.3 (CON), 143.6 (C-13), 142.6 (Ar-C), 134.5 (Ar-C),
7.04 (1H, m, Ar-H), 6.54 (1H, d, J ¼ 6.0, N-H), 5.56 (1H, t, J ¼ 3.0, H-12), 4.53 129.4 (Ar-C), 124.6 (Ar-C), 123.6 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
(1H, t, J ¼ 6.0, H-20), 3.70 (3H, s, CH3), 2.74–2.69 (2H, m, H-1 and H-18), 2.16 111.4 (Ar-C),106.8 (Ar-C), 56.4, 53.1, 52.1, 46.8, 46.4, 42.3, 39.6, 38.3,
(1H, d, J ¼ 15.3, H-1), 1.29 (s, CH3), 1.21 (s, CH3), 1.20 (s, CH3), 0.97 (s, CH3), 38.1, 36.7, 34.2, 33.1, 31.0, 30.9, 27.6, 25.7, 25.6, 23.6, 19.4, 16.6, 15.7,
[M þ Na]þ
0.96 (s, CH3), 0.94 (s, CH3), 0.85 (s, CH3)
15.3, 11.7
165 745
7.78 (1H, s, N-H), 7.39–7.06 (8H, m, Ar-H), 6.46 (1H, d, J ¼ 6.0, N-H), 5.42 (1H, 177.7 (COO), 171.9 (CON), 143.4 (C-13), 142.5 (Ar-C), 136.1 (Ar-C),
s, H-12), 4.83–4.77 (1H, m, H-20), 3.72 (3H, s, CH3), 3.25–3.05 (2H, m, H-30), 134.6 (Ar-C), 129.3 (Ar-C), 128.5 (Ar-C), 127.1 (Ar-C), 124.5 (Ar-C),
2.75 (1H, d, J ¼ 15.0, H-1), 2.54 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.13 (1H, d, 123.5 (C-12), 121.0 (Ar-C), 117.5 (Ar-C), 111.3 (Ar-C), 106.7 (Ar-C),
J ¼ 15.0, H-1), 1.29 (s, CH3), 1.22 (s, CH3), 1.21 (s, CH3), 0.96 (s, CH3), 0.95 (s, 53.4, 52.2, 46.5, 42.1, 39.5, 37.9, 34.0, 33.0, 32.7, 30.7, 27.3, 25.5,
[M þ Na]þ
CH3), 0.94 (s, CH3), 0.84 (s, CH3)
23.3, 19.2, 16.2, 15.6
250 641
7.89 (1H, s, N-H), 7.35 (1H, d, J ¼ 3.0, Ar-H), 7.18 (1H, d, J ¼ 6.0, Ar-H), 7.05– 179.7 (COO), 171.9 (CON), 144.2 (C-13), 142.6 (Ar-C), 134.5 (Ar-C),
7.02 (1H, m, Ar-H), 6.57 (1H, t, J ¼ 6.0, N-H), 5.55 (1H, t, J ¼ 3.0, H-12), 4.15 129.4 (Ar-C), 124.6 (Ar-C), 123.6 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
(1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-20), 3.83 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-20), 2.71–2.60 111.4 (Ar-C),106.8 (Ar-C), 53.0, 52.5, 46.5, 42.2, 38.1, 34.2, 30.9, 27.4,
(2H, m, H-1 and H-18), 2.16 (1H, d, J ¼ 15.3, H-1), 1.29 (s, CH3), 1.21 (s, CH3), 25.7, 23.7, 19.4, 16.3
[M þ Na]þ
1.20 (s, CH3), 0.96 (s, CH3), 0.95 (s, CH3), 0.94 (s, CH3), 0.84 (s, CH3)
(continued on next page)

2804
J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
Table 5 (continued )
No. Yield Mp ESI-MS m/z
1H NMR (CDCl3)
ppm) J ¼ Hz
13C NMR (CDCl3)
(%)
(ꢃC)
(
d
(d ppm)
4h 88
234 633
7.85 (1H, s, N-H), 7.38 (1H, d, J ¼ 3.0, Ar-H), 7.20 (1H, d, J ¼ 6.0, Ar-H), 7.07– 180.5 (COO), 174.6 (CON), 144.0 (C-13), 142.5 (Ar-C), 134.5 (Ar-C),
7.03 (1H, m, Ar-H), 6.65 (1H, d, J ¼ 6.0, N-H), 5.56 (1H, t, J ¼ 3.0, H-12), 4.55– 129.4 (Ar-C), 124.6 (Ar-C), 124.0 (C-12), 121.2 (Ar-C), 117.6 (Ar-C),
4.41 (1H, m, H-20), 2.70 (1H, d, J ¼ 15.0, H-1), 2.58 (1H, dd, J ¼ 3.0, J0 ¼ 13.5, H- 111.4 (Ar-C), 106.7 (Ar-C), 53.0, 49.1, 46.5, 46.4, 46.2, 42.3, 39.6,
18),1.29 (s, CH3),1.20 (s, CH3),1.19 (s, CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.92 (s, 38.0, 36.8, 34.1, 33.0, 30.8, 27.3, 25.6, 24.1, 23.6, 23.4, 17.4, 16.4, 15.7
CH3), 0.79 (s, CH3)
[M þ H]þ;
655
[M þ Na]þ
4i 89
4j 90
4k 90
4l 88
7a 87
7b 89
7c 86
7d 83
204 661 [M þ H]þ 7.83 (1H, s, N-H), 7.36 (1H, d, J ¼ 3.0, Ar-H), 7.19 (1H, d, J ¼ 6.0, Ar-H), 7.06– 180.0 (COO), 173.5 (CON), 143.6 (C-13), 142.6 (Ar-C), 134.6 (Ar-C),
7.03 (1H, m, Ar-H), 6.46 (1H, d, J ¼ 6.0, N-H), 5.55 (1H, t, J ¼ 3.0, H-12), 4.49– 129.5 (Ar-C), 124.7 (Ar-C), 123.6 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
4.45 (1H, m, H-20), 2.73–2.68 (2H, m, H-1 and H-18), 2.18 (1H, d, J ¼ 15.0, H- 111.4 (Ar-C), 106.9 (Ar-C), 57.4, 52.1, 46.9, 42.5, 39.6, 38.1, 36.8, 34.4,
1), 1.29 (s, CH3), 1.21 (s, CH3), 1.20 (s, CH3), 0.96 (s, CH3), 0.95 (s, CH3), 0.94 (s, 33.5, 31.8, 30.9, 27.8, 23.7, 23.4, 18.4, 15.7
CH3), 0.84 (s, CH3)
197 697
7.86 (1H, s, N-H), 7.37 (1H, d, J ¼ 3.0, Ar-H), 7.22–7.19 (1H, m, Ar-H), 7.07–7.03 180.6 (COO), 174.5 (CON), 144.0 (C-13), 142.5 (Ar-C), 134.5 (Ar-C),
(1H, m, Ar-H), 6.49 (1H, d, J ¼ 6.0, N-H), 5.54 (1H, t, J ¼ 3.0, H-12), 4.48–4.42 129.4 (Ar-C), 124.6 (Ar-C), 123.5 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
(1H, m, H-20), 2.70 (1H, d, J ¼ 15.0, H-1), 2.60 (1H, dd, J ¼ 3.0, J0 ¼ 13.5, H-18), 111.4 (Ar-C), 106.7 (Ar-C), 55.3, 53.0, 51.7, 46.6, 42.4, 39.6, 38.1, 36.7,
2.16 (1H, d, J ¼ 15.0, H-1), 1.28 (s, CH3), 1.21 (s, CH3), 1.20 (s, CH3), 0.96 (s, 34.2, 33.0, 30.8, 25.6, 25.1, 23.1, 22.2, 21.6, 16.7, 15.8, 15.3
CH3), 0.95 (s, CH3), 0.94 (s, CH3), 0.81 (s, CH3)
[M þ Na]þ
224 697
7.94 (1H, s, N-H), 7.38 (1H, d, J ¼ 3.0, Ar-H), 7.20 (1H, d, J ¼ 6.0, Ar-H), 7.07– 179.0 (COO), 175.7 (CON), 143.6 (C-13), 142.5 (Ar-C), 134.6 (Ar-C),
7.03 (1H, m, Ar-H), 6.57 (1H, d, J ¼ 6.0, N-H), 5.57 (1H, s, H-12), 4.52 (1H, t, 129.4 (Ar-C), 124.6 (Ar-C), 123.8 (C-12), 121.1 (Ar-C), 117.6 (Ar-C),
J ¼ 6.0, H-20), 2.72 (1H, d, J ¼ 15.0, H-1), 2.59 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 111.4 (Ar-C),106.7 (Ar-C), 56.4, 53.1, 46.9, 42.4, 39.6, 38.1, 34.2, 33.0,
2.16 (1H, d, J ¼ 15.0, H-1), 1.29 (s, CH3), 1.20 (s, CH3), 1.19 (s, CH3), 0.96 (s, 30.8, 25.6, 23.4, 19.4, 16.7, 15.8, 15.4, 11.7
CH3), 0.95 (s, CH3), 0.94 (s, CH3), 0.83 (s, CH3)
[M þ Na]þ
223 731
7.85 (1H, s, N-H), 7.38–7.04 (8H, m, Ar-H), 6.41 (1H, d, J ¼ 6.0, N-H), 5.28 (1H, 179.5 (COO), 171.4 (CON), 143.5 (C-13), 142.5 (Ar-C), 135.8 (Ar-C),
[M þ Na]þ
s, H-12), 4.69–4.63 (1H, m, H-20), 3.35–3.03 (2H, m, H-30), 2.69 (1H, d,
134.6 (Ar-C), 129.5 (Ar-C), 128.9 (Ar-C), 127.5 (Ar-C), 124.7 (Ar-C),
J ¼ 15.0, H-1), 2.25 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.12 (1H, d, J ¼ 15.0, H-1), 124.0 (C-12), 121.2 (Ar-C), 117.6 (Ar-C), 111.4 (Ar-C), 106.7 (Ar-C),
1.28 (s, CH3), 1.21 (s, CH3), 1.20 (s, CH3), 0.97 (s, CH3), 0.96 (s, CH3), 0.94 (s, 54.1, 53.0, 46.7, 42.2, 39.5, 38.0, 36.7, 34.1, 32.9, 30.7, 27.2, 25.6,
CH3), 0.81 (s, CH3)
23.4, 19.3, 16.3, 15.7
116 562
8.42 (1H, d, J ¼ 3.0, Ar-H), 8.27 (1H, d, J ¼ 3.0, Ar-H), 6.54 (1H, d, J ¼ 6.0, N-H), 178.4 (COO), 170.7 (CON), 159.9 (Ar-C), 150.5 (Ar-C), 144.3 (C-13),
5.54 (1H, t, J ¼ 3.0, H-12), 4.14 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-20), 3.84 (1H, dd, 142.5 (Ar-C), 141.4 (Ar-C), 123.3 (C-12), 52.9, 52.5, 48.3, 46.6, 46.5,
J ¼ 3.0, J0 ¼ 15.0, H-20), 3.76 (3H, s, CH3), 3.0 (1H, d, J ¼ 15.0, H-1), 2.67 (1H, 45.8, 42.4, 42.3, 41.6, 39.5, 39.4, 36.6, 34.2, 33.1, 32.5, 31.8, 30.9,
dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.52 (1H, d, J ¼ 15.0, H-1), 1.30 (s, CH3), 1.29 (s, 27.4, 25.7, 24.3, 23.7, 23.6, 20.2, 16.1, 15.6
CH3), 1.21 (s, CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.80 (s, CH3), 0.73 (s, CH3)
[M þ H]þ;
584
[M þ Na]þ
107 598
8.43 (1H, d, J ¼ 3.0, Ar-H), 8.27 (1H, d, J ¼ 3.0, Ar-H), 6.61 (1H, d, J ¼ 6.0, N-H), 177.5 (COO), 173.8 (CON), 160.0 (Ar-C), 150.5 (Ar-C), 143.8 (C-13),
5.52 (1H, t, J ¼ 3.0, H-12), 4.51–4.43 (1H, m, H-20), 3.73 (3H, s, CH3), 3.00 (1H, 142.5 (Ar-C), 141.2 (Ar-C), 123.2 (C-12), 52.9, 52.5, 48.4, 48.2, 46.4,
d, J ¼ 15.0, H-1), 2.68 (1H, dd, J ¼ 3.0, J0 ¼ 12.0, H-18), 2.53 (1H, d, J ¼ 15.0, H- 45.8, 42.2, 39.5, 36.6, 34.2, 31.8, 30.8, 27.4, 25.7, 24.3, 23.7, 20.2,
1), 1.31 (s, CH3), 1.29 (s, CH3), 1.21 (s, CH3), 0.92 (s, CH3), 0.91 (s, CH3), 0.90 (s, 18.8, 16.3, 15.6
[M þ Na]þ
CH3), 0.80 (s, CH3)
103 604
8.42 (1H, s, Ar-H), 8.27 (1H, s, Ar-H), 6.43 (1H, d, J ¼ 6.0, N-H), 5.52 (1H, s, H- 177.9 (COO), 172.5 (CON), 159.8 (Ar-C), 150.6 (Ar-C), 143.7 (C-13),
12), 4.46 (1H, t, J ¼ 6.0, H-20), 3.70 (3H, s, CH3), 3.00 (1H, d, J ¼ 15.0, H-1), 142.5 (Ar-C), 141.5 (Ar-C), 123.3 (C-12), 57.3, 53.0, 52.1, 48.4, 45.8,
2.69 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.50 (1H, d, J ¼ 15.0, H-1), 1.30 (s, CH3), 42.4, 39.4, 36.6, 34.3, 31.9, 30.9, 27.5, 25.6, 24.3, 23.6, 20.2, 18.9,
1.29 (s, CH3), 1.21 (s, CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.91 (s, CH3), 0.78 (s, 18.4, 16.6, 15.6
[M þ H]þ;
649
[M þ 2Na]þ
CH3)
132 618
8.42 (1H, d, J ¼ 3.0, Ar-H), 8.27 (1H, d, J ¼ 3.0, Ar-H), 6.36 (1H, d, J ¼ 6.0, N-H), 177.7 (COO), 173.6 (CON), 159.8 (Ar-C), 150.5 (Ar-C), 143.9 (C-13),
5.51 (1H, t, J ¼ 3.0, H-12), 4.58–4.51 (1H, m, H-20), 3.70 (3H, s, CH3), 3.00 (1H, 142.5 (Ar-C), 141.4 (Ar-C), 123.2 (C-12), 53.0, 52.3, 51.1, 48.3, 46.5,
d, J ¼ 15.0, H-1), 2.70–2.63 (1H, m, H-18), 2.50 (1H, d, J ¼ 15.0, H-1), 1.31 (s, 45.8, 42.3, 39.4, 36.6, 33.1, 31.8, 30.8, 27.4, 25.1, 25.6, 24.3, 23.6,
CH3), 1.30 (s, CH3), 1.21 (s, CH3), 0.93 (s, CH3), 0.92 (s, CH3), 0.91 (s, CH3), 0.81 22.5, 20.2, 16.5, 15.8
[M þ H]þ;
640
[M þ Na]þ
(s, CH3)
7e 87
7f 83
110 640
8.41 (1H, d, J ¼ 3.0, Ar-H), 8.27 (1H, d, J ¼ 3.0, Ar-H), 6.48 (1H, d, J ¼ 6.0, N-H), 177.6 (COO), 172.4 (CON), 159.8 (Ar-C), 150.6 (Ar-C), 143.7 (C-13),
5.52 (1H, s, H-12), 4.54–4.50 (1H, m, H-20), 3.69 (3H, s, CH3), 2.98 (1H, d, 142.5 (Ar-C), 141.5 (Ar-C), 123.3 (C-12), 56.3, 53.0, 52.0, 48.3, 46.7,
J ¼ 15.0, H-1), 2.50 (1H, d, J ¼ 15.0, H-1), 1.30 (s, CH3), 1.29 (s, CH3), 1.20 (s, 46.5, 46.2, 45.8, 42.6, 42.4, 39.4, 38.3, 36.6, 34.2, 33.1, 31.7, 30.8,
[M þ Na]þ
CH3), 0.92 (s, CH3), 0.91 (s, CH3), 0.88 (s, CH3), 0.77 (s, CH3)
27.4, 25.6, 24.6, 24.3, 23.8, 20.2, 16.5, 15.3, 11.7
127 652 [M þ H]þ 8.42 (1H, d, J ¼ 3.0, Ar-H), 8.27 (1H, d, J ¼ 3.0, Ar-H), 7.28–7.09 (5H, m, Ar-H), 177.7 (COO), 172.1 (CON), 159.8 (Ar-C), 150.6 (Ar-C), 143.6 (C-13),
6.41 (1H, d, J ¼ 6.0, N-H), 5.37 (1H, t, J ¼ 3.0, H-12), 4.80–4.74 (1H, m, H-20), 142.5 (Ar-C), 141.4 (Ar-C), 136.1 (Ar-C), 129.4 (Ar-C), 128.6 (Ar-C),
3.69 (3H, s, CH3), 3.21–3.07 (2H, m, H-30), 2.96 (1H, d, J ¼ 15.0, H-1), 2.72 (1H, 127.2 (Ar-C), 123.3 (C-12), 53.4, 52.9, 52.3, 48.3, 46.5, 45.8, 45.7,
dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.50 (1H, d, J ¼ 15.0, H-1), 1.31 (s, CH3), 1.30 (s, 42.2, 42.1, 41.9, 41.3, 39.5, 39.3, 37.8, 36.7, 36.5, 34.2, 33.9, 32.7, 31.9,
CH3), 1.18 (s, CH3), 0.88 (s, CH3), 0.87 (s, CH3), 0.86 (s, CH3), 0.72 (s, CH3)
29.8, 27.3, 25.8, 24.3, 23.5, 16.3, 15.9
7g 86
7h 88
172 548
8.54 (1H, s, Ar-H), 8.13 (1H, s, Ar-H), 7.02 (1H, s, N-H), 5.69 (1H, s, H-12), 178.7 (COO), 172.0 (CON), 161.7 (Ar-C), 150.3 (Ar-C), 144.0 (C-13),
[M þ H]þ;
4.10–3.94 (2H, m, H-20), 3.79 (1H, d, J ¼ 15.0, H-1), 2.68 (1H, dd, J ¼ 3.0,
143.3 (Ar-C), 138.7 (Ar-C), 124.1 (C-12), 53.0, 47.0, 46.5, 42.9, 42.4,
570
J0 ¼ 15.0, H-18), 2.50 (1H, d, J ¼ 15.0, H-1), 1.30 (s, CH3), 1.29 (s, CH3), 1.21 (s, 39.8, 39.5, 36.2, 33.2, 31.8, 30.9, 27.4, 25.5, 24.3, 20.1, 15.8
[M þ Na]þ
CH3), 0.96 (s, CH3), 0.94 (s, CH3), 0.85 (s, CH3), 0.84 (s, CH3)
152 561 [M þ H]þ 8.52 (1H, d, J ¼ 3.0, Ar-H), 8.14 (1H, d, J ¼ 3.0, Ar-H), 7.12 (1H, d, J ¼ 6.0, N-H), 178.1 (COO), 175.0 (CON), 161.6 (Ar-C), 150.2 (Ar-C), 143.6 (C-13),
5.67 (1H, t, J ¼ 3.0, H-2), 4.45–4.41 (1H, m, H-20), 3.64 (1H, d, J ¼ 15.0, H-1), 143.3 (Ar-C), 124.0 (C-12), 52.9, 48.5, 46.6, 45.8, 42.3, 39.7, 36.3,
2.65 (1H, dd, J ¼ 3.0, J0 ¼ 12.0, H-18), 2.49 (1H, d, J ¼ 15.0, H-1), 1.30 (s, CH3), 33.2, 31.8, 30.9, 25.7, 24.2, 24.1, 18.8, 15.8
1.25 (s, CH3), 1.24 (s, CH3), 0.94 (s, CH3), 0.93 (s, CH3), 0.80 (s, CH3), 0.79 (s,
CH3)
7i 83
7j 83
172 590
8.50 (1H, s, Ar-H), 8.27 (1H, s, Ar-H), 6.77 (1H, d, J ¼ 6.0, N-H), 5.62 (1H, s, H- 178.0 (COO), 173.5 (CON), 161.1 (Ar-C), 149.8 (Ar-C), 143.5 (C-13),
12), 4.49 (1H, t, J ¼ 6.0, H-20), 3.24 (1H, d, J ¼ 15.0, H-1), 2.68 (1H, dd, J ¼ 3.0, 143.2 (Ar-C), 139.7 (Ar-C), 123.6 (C-12), 57.3, 52.8, 47.1, 46.9, 45.7,
J0 ¼ 15.0, H-18), 2.53 (1H, d, J ¼ 15.0, H-1), 1.29 (s, CH3), 1.27 (s, CH3), 1.21 (s, 42.6, 42.2, 39.6, 39.4, 36.4, 34.1, 33.2, 33.1, 31.7, 30.9, 27.6, 25.7,
[M þ H]þ;
612
[M þ Na]þ
CH3), 0.95 (s, CH3), 0.92 (s, CH3), 0.80 (s, CH3), 0.79 (s, CH3)
24.2, 23.9, 23.2, 20.1, 18.8
140 604
8.51 (1H, s, Ar-H), 8.23 (1H, s, Ar-H), 6.83 (1H, d, J ¼ 6.0, N-H), 5.63 (1H, t, 177.9 (COO), 174.6, 161.2 (Ar-C), 149.9 (Ar-C), 143.6 (C-13), 143.3
J ¼ 3.0, H-12), 4.59–4.53 (1H, m, H-20), 3.36 (1H, d, J ¼ 15.0, H-1), 2.67–2.63 (Ar-C), 139.5 (Ar-C), 123.7 (C-12), 52.8, 51.3, 46.7, 45.7, 42.3, 39.6,
(1H, m, H-18), 2.52 (1H, d, J ¼ 15.0, H-1), 1.33 (s, CH3), 1.28 (s, CH3), 0.91 (s, 39.4, 36.3 33.2, 31.8, 30.9, 27.5, 25.1, 24.3, 23.9, 22.9, 16.0, 15.9
CH3), 0.82 (s, CH3), 0.81 (s, CH3)
[M þ H]þ;
626
[M þ Na]þ

J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
2805
Table 5 (continued )
No. Yield Mp ESI-MS m/z
1H NMR (CDCl3)
ppm) J ¼ Hz
13C NMR (CDCl3)
(%)
(ꢃC)
(
d
(d ppm)
7k 86
136 604
8.50 (1H, d, J ¼ 3.0, Ar-H), 8.26 (1H, d, J ¼ 3.0, Ar-H), 6.84 (1H, d, J ¼ 6.0, N-H), 177.7 (COO), 173.4 (CON), 161.1 (Ar-C), 149.8 (Ar-C), 143.6 (C-13),
5.62 (1H, t, J ¼ 3.0, H-12), 4.54 (1H, t, J ¼ 3.0, H-20), 3.26 (1H, d, J ¼ 15.0, H-1), 143.3 (Ar-C), 139.6 (Ar-C), 123.6 (C-12), 56.4, 52.8, 47.0, 45.7, 42.2,
2.67 (1H, dd, J ¼ 3.0, J0 ¼ 12.0, H-18), 2.53 (1H, d, J ¼ 15.0, H-1), 1.26 (s, CH3), 39.6, 39.4, 38.4, 36.4, 31.8, 30.9, 25.7, 24.3, 23.9, 20.1, 16.1, 15.8, 15.3,
[M þ H]þ;
626
[M þ Na]þ
1.23 (s, CH3), 0.90 (s, CH3), 0.89 (s, CH3), 0.81 (s, CH3), 0.80 (s, CH3)
12.0
7l 89
8a 85
8b 83
8c 86
8d 88
151 638
8.53 (1H, s, Ar-H), 8.19 (1H, s, Ar-H), 7.26–7.20 (5H, m, Ar-H), 6.71 (1H, d, 178.7 (COO), 172.5 (CON), 161.5 (Ar-C), 150.2 (Ar-C), 143.2 (C-13),
J ¼ 6.0, N-H), 5.26 (1H, s, H-12), 4.80 (1H, s, H-20), 3.47 (1H, d, J ¼ 15.0, H-1), 143.0 (Ar-C), 139.2 (Ar-C), 136.6 (Ar-C), 129.9 (Ar-C), 128.3 (Ar-C),
3.30–3.21 (2H, m, H-30), 2.40–2.35 (2H, m, H-1 and H-18), 1.31 (s, CH3), 1.24 127.0 (Ar-C), 124.2 (C-12), 53.4, 53.1, 46.8, 45.8, 42.5, 42.4, 39.7,
(s, CH3), 1.20 (s, CH3), 0.93 (s, CH3), 0.86 (s, CH3), 0.74 (s, CH3), 0.72 (s, CH3) 39.5, 37.4, 36.3, 34.3, 30.8, 27.5, 25.4, 24.3, 23.6, 16.2, 15.8
8.02–7.94 (2H, m, Ar-H), 7.67–7.63 (2H, m, Ar-H), 6.56 (1H, s, N-H), 5.56 (1H, 178.4 (COO), 170.6 (CON), 161.1 (Ar-C), 151.9 (Ar-C), 144.2 (C-13),
s, H-12), 4.15 (1H, dd, J ¼ 6.0, J0 ¼ 18.0, H-20), 3.88–3.81 (1H, m, H-20), 3.75 142.2 (Ar-C), 129.0 (Ar-C), 128.9 (Ar-C), 128.7 (Ar-C), 128.1 (Ar-C),
(3H, s, CH3), 3.23 (1H, d, J ¼ 15.0, H-1), 2.69–2.63 (2H, m, H-1 and H-18), 1.42 123.3 (C-12), 53.4, 52.5, 49.4, 46.5, 45.6, 42.2, 41.6, 40.4, 39.3, 36.9,
(s, CH3), 1.30 (s, CH3), 0.93 (s, CH3), 0.92 (s, CH3), 0.91 (s, CH3), 0.81 (s, CH3) 34.2, 33.1, 32.4, 30.8, 27.3, 25.7, 25.4, 23.6, 20.4, 16.2, 15.8
8.03–7.98 (2H, m, Ar-H), 7.67–7.64 (2H, m, Ar-H), 6.61 (1H, d, J ¼ 6.0, N-H), 177.6 (COO), 173.8 (CON), 161.2 (Ar-C), 151.9 (Ar-C), 143.8 (C-13),
5.54 (1H, s, H-12), 4.52–4.45 (1H, m, H-20), 3.73 (3H, s, CH3), 3.25 (1H, d, 142.3 (Ar-C), 129.1 (Ar-C), 128.9 (Ar-C), 128.7 (Ar-C), 128.0 (Ar-C),
J ¼ 15.0, H-1), 2.71–2.64 (2H, m, H-1 and H-18), 1.42 (s, CH3), 1.38 (s, CH3), 123.3 (C-12), 53.5, 52.5, 48.4, 46.4, 45.6, 42.2, 40.5, 39.5, 36.9, 34.2,
[M þ H]þ;
660
[M þ Na]þ
134 612
[M þ H]þ;
634
[M þ Na]þ
97 626
[M þ H]þ;
648
[M þ Na]þ
1.23 (s, CH3), 0.92 (s, CH3), 0.91 (s, CH3), 0.82 (s, CH3)
33.1, 32.5, 30.9, 25.7, 23.7, 20.5, 18.8, 16.4, 15.8
108 654
8.01–7.94 (2H, m, Ar-H), 7.65–7.63 (2H, m, Ar-H), 6.43 (1H, d, J ¼ 6, N-H), 177.8 (COO), 172.5 (CON), 161.1 (Ar-C), 152.0 (Ar-C), 143.6 (C-13),
5.54 (1H, s, H-12), 4.46 (1H, t, J ¼ 6, H-20), 3.68 (3H, s, CH3), 3.23 (1H, d, J ¼ 15, 142.2 (Ar-C), 140.8 (Ar-C), 128.9 (Ar-C), 128.9 (Ar-C), 128.6 (Ar-C),
H-1), 2.71–2.62 (2H, m, H-1 and H-18), 1.42 (s, CH3), 1.22 (s, CH3), 0.92 (s, 128.1 (Ar-C), 123.3 (C-12), 57.3, 53.8, 53.1, 46.9, 45.6, 42.6, 40.6,
[M þ H]þ;
676
[M þ Na]þ
CH3), 0.91 (s, CH3), 0.82 (s, CH3)
39.5, 36.5, 33.2, 32.5, 30.8, 25.3, 23.7, 20.4, 16.4, 15.9
134 668
8.03–7.96 (2H, m, Ar-H), 7.67–7.64 (2H, m, Ar-H), 6.36 (1H, d, J ¼ 6.0, N-H), 177.7 (COO), 173.6 (CON), 163.0 (Ar-C), 161.2 (Ar-C), 151.9 (Ar-C),
5.53 (1H, s, H-12), 4.59–4.52 (1H, m, H-20), 3.70 (3H, s, CH3), 3.25 (1H, d, 143.8 (C-13), 142.3 (Ar-C), 129.0 (Ar-C), 128.9 (Ar-C), 128.7 (Ar-C),
J ¼ 15.0, H-1), 2.69–2.64 (2H, m, H-1 and H-18), 1.43 (s, CH3), 1.24 (s, CH3), 128.0 (Ar-C), 123.3 (C-12), 53.5, 52.3, 51.1, 46.6, 45.6, 42.4, 42.0,
[M þ H]þ;
690
[M þ Na]þ
0.92 (s, CH3), 0.90 (s, CH3), 0.81 (s, CH3)
40.5, 39.4, 37.0, 33.1, 32.5, 30.9, 27.4, 25.6, 25.1, 23.6, 22.9, 22.5,
16.5, 15.8
8e 83
8f 83
98 668
8.02–7.94 (2H, m, Ar-H), 7.67–7.63 (2H, m, Ar-H), 6.49 (1H, d, J ¼ 6.0, N-H), 177.6 (COO), 172.4 (CON), 161.1 (Ar-C), 152.0 (Ar-C), 143.7 (C-13),
5.54 (1H, s, H-12), 4.53 (1H, t, J ¼ 6.0, H-20), 3.69 (3H, s, CH3), 3.24 (1H, d, 142.2 (Ar-C), 129.0 (Ar-C), 128.9 (Ar-C), 128.7 (Ar-C), 128.1 (Ar-C),
J ¼ 15.0, H-1), 2.69–2.63 (2H, m, H-1 and H-18), 1.40 (s, CH3), 1.23 (s, CH3), 123.3 (Ar-C), 122.9 (C-12), 56.4, 53.7, 52.1, 46.7, 45.6, 42.4, 40.5,
[M þ H]þ;
690
[M þ Na]þ
0.92 (s, CH3), 0.91 (s, CH3), 0.86 (s, CH3), 0.84 (s, CH3), 0.81 (s, CH3)
39.4, 38.3, 36.9, 34.3, 33.1, 32.4, 30.9, 27.5, 25.6, 23.6, 20.5, 16.5,
15.8, 15.3, 11.7
101 724
8.03–7.95 (2H, m, Ar-H), 7.67–7.65 (2H, m, Ar-H), 7.29–7.09 (5H, m, Ar-H), 177.7 (COO), 172.1 (CON), 161.2 (Ar-C), 151.9 (Ar-C), 143.6 (C-13),
6.42 (1H, d, J ¼ 6.0, N-H), 5.39 (1H, s, H-12), 4.81–4.75 (1H, m, H-20), 3.69 142.3 (Ar-C), 136.2 (Ar-C), 139.4 (Ar-C), 129.1 (Ar-C), 128.9 (Ar-C),
(3H, s, CH3), 3.25–3.17 (2H, m, H-30), 3.06 (1H, d, J ¼ 15.0, H-1), 2.64 (1H, d, 128.7 (Ar-C), 128.6 (Ar-C), 127.2 (Ar-C), 123.4 (C-12), 57.3, 53.5,
J ¼ 15.0, H-1), 2.45 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 1.42 (s, CH3), 1.20 (s, CH3), 52.3, 49.5, 47.2, 46.6, 45.6, 42.2, 40.5, 39.4, 38.0, 36.9, 33.1, 32.4,
[M þ Na]þ
0.90 (s, CH3), 0.89 (s, CH3), 0.88 (s, CH3), 0.73 (s, CH3)
30.8, 27.4, 25.6, 23.5, 20.4, 16.3, 15.8
8g 87
8h 85
8i 87
8j 83
8k 88
8l 89
159 598
8.02–7.96 (2H, m, Ar-H), 7.70–7.65 (2H, m, Ar-H), 7.15 (1H, s, N-H), 5.75 (1H, 178.8 (COO), 171.8 (CON), 162.2 (Ar-C), 152.4 (Ar-C), 143.8 (C-13),
s, H-12), 4.26–4.07 (3H, m, H-20 and H-1), 2.72 (1H, dd, J ¼ 3.0, J0 ¼ 15.0, H- 142.5 (Ar-C), 138.7 (Ar-C), 129.7 (Ar-C), 129.1 (Ar-C), 129.1 (Ar-C),
18), 2.54 (1H, d, J ¼ 15.0, H-1), 1.42 (s, CH3), 1.38 (s, CH3), 1.29 (s, CH3), 0.98 (s, 125.8 (Ar-C), 124.5 (C-12), 53.6, 47.1, 46.5, 45.5, 43.1, 42.5, 40.6,
[M þ H]þ;
620
[M þ Na]þ
CH3), 0.97 (s, CH3), 0.89 (s, CH3), 0.85 (s, CH3), 0.84 (s, CH3)
39.6, 36.5, 33.1, 32.5, 30.9, 27.4, 25.5, 25.3, 24.0, 20.3, 15.9
172 611 [M þ H]þ 8.01–7.99 (2H, m, Ar-H), 7.69–7.67 (2H, m, Ar-H), 7.17 (1H, s, N-H), 5.71 (1H, 178.4 (COO), 175.0 (CON), 162.1 (Ar-C), 152.4 (Ar-C), 143.5 (C-13),
s, H-12), 4.52 (1H, s, H-20), 4.04 (1H, d, J ¼ 15.0, H-1), 2.65 (1H, dd, J ¼ 3.0, 142.5 (Ar-C), 138.9 (Ar-C), 129.7 (Ar-C), 129.1 (Ar-C), 126.1 (Ar-C),
J0 ¼ 15.0, H-18), 2.55 (1H, d, J ¼ 15.0, H-1), 1.41 (s, CH3), 1.38 (s, CH3), 1.25 (s, 124.3 (C-12), 53.5, 48.6, 46.7, 45.6, 42.4, 40.6, 39.6, 36.6, 33.2, 32.5,
CH3), 0.93 (s, CH3), 0.91 (s, CH3), 0.84 (s, CH3), 0.82 (s, CH3)
25.7, 25.3, 24.0, 23.7, 18.7, 16.0
160 640
8.01–7.98 (2H, m, Ar-H), 7.68–7.65 (2H, m, Ar-H), 6.88 (1H, d, J ¼ 6.0, N-H), 178.3 (COO), 173.6 (CON), 161.9 (Ar-C), 152.3 (Ar-C), 143.1 (C-13),
5.63 (1H, s, H-12), 4.57 (1H, t, J ¼ 6.0, H-20), 3.82 (1H, d, J ¼ 15.0, H-1), 2.72 142.4 (Ar-C), 139.3 (Ar-C), 129.5 (Ar-C), 129.0 (Ar-C), 126.4 (Ar-C),
(1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.67 (1H, d, J ¼ 15.0, H-1), 1.40 (s, CH3), 1.38 124.1 (C-12), 57.0, 53.4, 48.0, 47.0, 45.5, 42.8, 42.3, 40.5, 39.5, 39.0,
(s, CH3), 1.23 (s, CH3), 0.95 (s, CH3), 0.92 (s, CH3), 0.85 (s, CH3), 0.84 (s, CH3) 36.6, 33.3, 32.5, 31.8, 30.9, 27.6, 25.3, 23.8, 20.4, 18.9, 18.5, 15.9
8.02–7.98 (2H, m, Ar-H), 7.69–7.66 (2H, m, Ar-H), 6.93 (1H, d, J ¼ 6.0, N-H), 178.3 (COO), 174.6 (CON), 162.0 (Ar-C), 152.3 (Ar-C), 143.4 (C-13),
5.66 (1H, s, H-12), 4.63–4.57 (1H, m, H-20), 3.89 (1H, d, J ¼ 15.0, H-1), 2.68– 142.5 (Ar-C), 139.2 (Ar-C), 129.6 (Ar-C), 129.1 (Ar-C), 126.3 (Ar-C),
2.55 (2H, m, H-1 and H-18), 1.40 (s, CH3), 1.35 (s, CH3), 1.26 (s, CH3), 1.00 (s, 124.2 (C-12), 53.5, 51.2, 48.0, 46.8, 42.8, 42.4, 40.5, 39.6, 36.6, 33.2,
[M þ H]þ;
662
[M þ Na]þ
161 654
[M þ H]þ;
676
[M þ Na]þ
CH3), 0.98 (s, CH3), 0.96 (s, CH3), 0.87 (s, CH3)
32.5, 30.9, 25.7, 25.2, 23.9, 22.9, 16.1
150 676
8.01–7.97 (2H, m, Ar-H), 7.68–7.65 (2H, m, Ar-H), 6.94 (1H, d, J ¼ 6.0, N-H), 178.0 (COO), 173.6 (CON), 161.9 (Ar-C), 152.3 (Ar-C), 143.2 (C-13),
5.63 (1H, s, H-12), 4.60 (1H, t, J ¼ 3.0, H-20), 3.82 (1H, d, J ¼ 15.0, H-1), 2.70 142.5 (Ar-C), 139.3 (Ar-C), 129.5 (Ar-C), 129.0 (Ar-C), 126.4 (Ar-C),
(1H, dd, J ¼ 3.0, J0 ¼ 15.0, H-18), 2.58 (1H, d, J ¼ 15.0, H-1), 1.40 (s, CH3), 1.38 124.1 (C-12), 56.3, 53.5, 48.1, 46.9, 45.6, 42.4, 40.5, 39.6, 38.2, 36.7,
[M þ Na]þ;
708
[M þ 2Na]þ
(s, CH3), 1.23 (s, CH3), 0.93 (s, CH3), 0.92 (s, CH3), 0.81 (s, CH3)
33.2, 30.9, 27.7, 25.7, 23.9, 20.4, 16.2, 15.4, 12.1
197 688 [M þ H]þ 8.02–7.93 (2H, m, Ar-H), 7.69–7.66 (2H, m, Ar-H), 7.26–7.23 (5H, m, Ar-H), 178.4 (COO), 172.3 (CON), 162.3 (Ar-C), 152.4 (Ar-C), 142.5 (C-13),
6.87 (1H, d, J ¼ 6.0, N-H), 5.23 (1H, s, H-12), 4.95 (1H, s, H-20), 3.91 (1H, d, 136.9 (Ar-C), 130.0 (Ar-C), 129.7 (Ar-C), 129.1 (Ar-C), 128.0 (Ar-C),
J ¼ 15.0, H-1), 3.34–3.19 (2H, m, H-30), 2.45–2.39 (2H, m, H-1 and H-18), 1.42 127.0 (Ar-C), 126.1 (Ar-C), 124.8 (C-12), 53.5, 51.2, 48.0, 46.8, 45.6,
(s, CH3), 1.35 (s, CH3), 1.30 (s, CH3), 1.02 (s, CH3), 1.00 (s, CH3), 0.74 (s, CH3), 42.8, 42.4, 42.2, 40.5, 39.5, 36.6, 34.2, 33.2, 32.8, 32.5, 32.0, 30.9,
0.73 (s, CH3)
27.6, 25.7, 25.3, 25.2, 23.7, 23.0, 20.3, 16.7, 15.8
compounds. After 2 days, each compound was removed and cells
were cultured with fresh medium for 2 more days, and then 20 L of
the percentages of cells’ viability cultured with compounds were
compared to that of the control group.
m
MTT (5 mg/mL) and fresh medium then were added to each well.
After incubation for 4 h, the medium was removed and the crystals
In the assays, all of the tested compounds were dissolved in
DMSO and added at a DMSO concentration of 0.1%, which did not
affect the cells. All of the cultures were performed at 37 ꢃC in
a humidified incubator with 5% CO2 in air.
were solubilized with 150
mL dimethylsulfoxide. The absorbance of
each well was recorded at 570 nm using an ELISA plate reader and

2806
J.-F. Li et al. / European Journal of Medicinal Chemistry 44 (2009) 2796–2806
[11] F.X. Tavares, D.N. Deaton, L.R. Miller, L.L. Wright, J. Med. Chem. 47 (2004)
Acknowledgements
5057–5068.
[12] F.X. Tavares, D.N. Deaton, A.B. Miller, L.R. Miller, L.L. Wright, H.Q. Zhou, J. Med.
Chem. 47 (2004) 5049–5056.
[13] H.J. Jeong, H.B. Chai, S.Y. Park, D.S.H.L. Kim, Bioorg. Med. Chem. Lett. 9 (1999)
1201–1204.
[14] T. Honda, H.J. Finlay, G.W. Gribble, N. Suh, M.B. Sporn, Bioorg. Med. Chem. Lett.
7 (1997) 1623–1628.
This work was supported by National Natural Science Fund for
Creative Research Groups of China (20821063), 973 Program
(2007CB714504) and Specialized Research Fund for the Doctoral
Program of Higher Education (20050284027).
[15] H.J. Finlay, T. Honda, G.W. Gribble, ARKIVOC 7 (2002) 38–46.
[16] M. Urban, J. Sarek, M. Kvasnica, I. Tislerova, M. Hajduch, J. Nat. Prod. 70 (2007)
526–532.
Appendix. Supplementary data
[17] R.P. Thummel, S. Chirayil, C. Hery, J.L. Lim, T.L. Wang, J. Org. Chem. 58 (1993)
1666–1671.
[18] J.M. Liesch, J.A. McMillan, R.C. Pandey, I.C. Paul Jr., K.L. Rinehart, J. Am. Chem.
Soc. 98 (1976) 300–301.
Supplementary data associated with this article can be found in
the online version, at doi:10.1016/j.ejmech.2008.12.024.
[19] M. Brenner, W. Huber, Helv. Chim. Acta 36 (1953) 1109–1115.
[20] J.M. Sanders, Y.C. Song, J.M.W. Chan, J.H. Zhang, S. Jennings, T. Kosztowski,
S. Odeh, R. Flessner, C. Schwerdtfeger, E. Kotsikorou, G.A. Meints, A.O. Gomez,
D. Gonzalez-Pacanowska, A.M. Raker, H. Wang, E.R. van Beek, S.E. Papapoulos,
C.T. Morita, E. Oldfield, J. Med. Chem. 48 (2005) 2957–2963.
[21] L. Widler, K.A. Jaeggi, M. Glatt, K. Muller, R. Bachmann, M. Bisping, A.R. Born,
R. Cortesi, G. Guiglia, H. Jeker, R. Klein, U. Ramseier, J. Schmid, G. Schreiber,
Y. Seltenmeyer, J.R. Green, J. Med. Chem. 45 (2002) 3721–3738.
[22] N. Takahashi, T. Akatsu, N. Udagawa, T. Sasaki, A. Yamaguchi, J.M. Moseley,
T.J. Martin, T. Suda, Endocrinology 123 (1988) 2600–2602.
[23] D.M. Reid, D. Hosking, D. Kendler, M.L. Brandi, J.D. Wark, J.F. Marques-Neto,
G. Weryha, N. Verbruggen, C.M. Hustad, E.M. Mahlis, M.E. Melton, Int. J. Clin.
Pract. 62 (2008) 575–584.
References
[1] S. Epstein, Clin. Ther. 28 (2006) 151–173.
[2] J.Y. Reginster, N. Burlet, Bone 38 (2006) 4–9.
[3] O. Johnell, J.A. Kanis, Osteoporosis Int. 17 (2006) 1726–1733.
[4] C. Farina, S. Gagliardi, Curr. Pharm. Des. 8 (2002) 2033–2048.
[5] J.X. Li, T. Hareyama, Y. Tezuka, Y. Zhang, T. Miyahara, S. Kadota, Planta Med. 71
(2005) 673–679.
[6] Y. Zhang, J.X. Li, J.W. Zhao, S.Z. Wang, Y. Pan, K. Tanaka, S. Kadota, Bioorg. Med.
Chem. Lett. 15 (2005) 1629–1632.
[7] E.M. Giner-Larza, S. Manez, M.C. Recio, R.M. Giner, J.M. Prieto, M. Cerda-Nic-
olas, J.L. Rios, Eur. J. Pharmacol. 428 (2001) 137–143.
[8] H.Y. Hsu, J.J. Yang, C.C. Lin, Cancer Lett. 111 (1997) 7–13.
[9] H.G. Jeong, Toxicol. Lett. 105 (1999) 215–222.
[10] S. Inglis, R. Jones, D. Fritz, C. Stojkoski, G. Booker, S. Pyke, Org. Biomol. Chem. 3
(2005) 2543–2557.
[24] K. Notoya, K. Yoshida, S. Taketomi, I. Yamazaki, M. Kumegawa, Calcif. Tissue
Int. 53 (1993) 206–209.
[25] M.T. Makhija, R.T. Kasliwal, V.M. Kulkarni, N. Neamati, Bioorg. Med. Chem. 12
(2004) 2317–2333.