Synthesis and biological evaluation of oleanolic acid derivatives as PTP1B inhibitors

Article abstract of DOI:10.1016/j.ejmech.2013.03.001

Twenty-four sugar-substituted oleanolic acid derivatives (1a-1f, 2a-2j, and 3a-3h) were synthesized in a concise and efficient strategy and their effects on the inhibition of protein tyrosine phosphatase 1B (PTP1B) and insulin-sensitizing response were ev

Full text of DOI:10.1016/j.ejmech.2013.03.001

European Journal of Medicinal Chemistry 63 (2013) 511e522
Contents lists available at SciVerse ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and biological evaluation of oleanolic acid derivatives
as PTP1B inhibitors
Qing-Chao Liu a, Tian-Tian Guo c, Lei Zhang c, Yue Yu c, Peng Wang c, Ju-Fang Yang d,
,
Ying-Xia Li b
*
a Department of Pharmaceutical Engineering, Northwest University, Xi’an 710069, China
b School of Pharmacy, Fudan University, Shanghai 201203, China
c School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
d Diao Group Chengdu Pharmaceutical Co. Ltd, Chengdu, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Twenty-four sugar-substituted oleanolic acid derivatives (1ae1f, 2ae2j, and 3ae3h) were synthesized in
a concise and efficient strategy and their effects on the inhibition of protein tyrosine phosphatase 1B
(PTP1B) and insulin-sensitizing response were evaluated in vitro. Several derivatives showed moderate to
good inhibitory activities against PTP1B, and especially compounds 2f, 2h, 3d and 3e exhibited the most
Received 16 August 2012
Received in revised form
27 February 2013
Accepted 1 March 2013
Available online 14 March 2013
potent inhibitory activities with the IC50 values of 1.91, 12.2, 9.21 and 0.56 mM against PTP1B, respectively.
Furthermore, compounds 2ge2h and 3be3e displayed good insulin-sensitizing activities with the
response values ranging from 21.52% to 59.58%. Structureeactivity relationship study of these sugar-
substituted oleanolic acid derivatives demonstrated that PTP1B inhibitory activity and insulin-
sensitizing response were strongly influenced by both the carbohydrate moiety at the C-3 position
and the long acidic chain at C-28 position of oleanolic acid.
Keywords:
Oleanolic acid derivatives
PTP1B
Insulin-sensitizing response
Regioselective oxidation
IC50 value
Ó 2013 Elsevier Masson SAS. All rights reserved.
1. Introduction
dephosphorylating the tyrosine residues of proteins. Although
several PTPs (such as leukocyte common antigen-related phos-
Type II diabetes is associated with chronic metabolic disorder
that results from deficiency in both insulin secretion and action at
target tissues, which results in increased blood glucose level [1]. So
the aim of antidiabetic therapy is to achieve normoglycemia by
improving the functions of insulin. According to different mecha-
nisms of action, antidiabetic drugs are currently classified into
several classes: insulin sensitizers such as thiazolidinediones and
biguanides, insulin secretagogues such as sulfonylureas, glucagon-
like peptide-1 receptor (GLP-1R) agonists [2e8], dipeptidyl pepti-
phatase PTP-Lar, PTP-a, SH2-domain containing phosphatase
SHP2, and T-cell protein tyrosine phosphatase TCPTP) have been
mainly regarded as negative regulators of insulin signaling, there
is substantial evidence that PTP1B is the critical PTP controlling
insulin signaling pathway [15]. Two independent research teams
disclosed that PTP1B-depleted mice showed increased insulin
sensitivity in liver and muscle tissues, lower plasma glucose and
insulin levels, and resistance to high-fat-diet induced weight gain
compared to control mice [16]. A recent study also provided
compelling evidence that novel PTP1B antisense oligonucleotides
resulted in reduced PTP1B expression in insulin sensitive tissues,
which enhanced insulin sensitivity and stabilized blood glucose
levels in preclinical models [17]. Consequently, PTP1B has
emerged to be a promising drug target for therapeutic interven-
tion in type II diabetes, obesity, and other associated metabolic
syndromes [18].
dase IV (DPP-IV) inhibitors [9e12],
a-glucosidase inhibitors, and
protein tyrosine phosphatases (PTPs) inhibitors [13,14]. However,
some of these antidiabetic drugs have serious side effects in some
patients or lose their pharmacological effectiveness over time.
Therefore, searching for new antidiabetic drugs has yet continued
to hold an intense interest.
Among these known targets, protein tyrosine phosphatases
(PTPs) have a key role in the regulation of insulin action by
In the past decade, there have been many reports on the
design of a variety of synthetic PTP1B inhibitors with phospho-
tyrosine mimetics and covalent inactivators [15e-f,16a,19].
However, two serious drawbacks with low cell permeability and
low bioavailability limited the application of most of these
* Corresponding author. Tel./fax: þ86 21 51980127.
E-mail address: liyx417@fudan.edu.cn (Y.-X. Li).
0223-5234/$ e see front matter Ó 2013 Elsevier Masson SAS. All rights reserved.
http://dx.doi.org/10.1016/j.ejmech.2013.03.001

512
Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
inhibitors for further development to clinical trials [20]. There-
fore, the need for potent and selective PTP1B inhibitors with
improved physicochemical properties and in vivo efficacies is
required.
2. Results and discussion
2.1. Chemistry
Recently, compounds with a pentacyclic triterpene core have
been studied for seeking new small-molecule PTP1B inhibitors
[21], and especially triterpenoids derived from oleanolic acid (OA)
exhibit potential PTP1B inhibitory activity. However, a major
inconvenience for these pentacyclic triterpenoids is their poor
water solubility and selectivity against PTPs [22]. In a recent study,
carbohydrate has been observed as an expected principal scaffold
for drug design due to its unique spatial structure, which is
capable of covalently linking to pharmacophores of the enzymatic
targets [23], and it is generally accepted that glycosides are
more water-soluble than the corresponding aglycones. Therefore,
carbohydrate-based modification on the aglycones is an effective
strategy for enhancing the hydrosolubility and ameliorating the
pharmacological and pharmacokinetic properties. Our previous
investigation on the structureeactivity relationships (SAR) of
oleanolic acid derivatives indicated that modification of the C-3
substituent with glycosyl moiety and introduction of an acidic
chain to C-28 of OA could improve their inhibition against murine
in vivo glucose absorption [24]. With a continuing interest in
seeking carbohydrate-based inhibitors for the treatment of type II
diabetes and obesity, here we report the synthesis, PTP1B inhibi-
tory activities, and SAR of sugar-substituted oleanolic acid de-
rivatives 1ae1f, 2ae2j and 3ae3h (Fig. 1).
So far many synthetic strategies for the preparation of oleanolic
acid glycosides have already been reported [25]. Previous experi-
ences showed that construction of the glycosidic linkage of sapo-
nins was critical, and especially the conditions for glycosylation of
the aglycone are best developed at the monosaccharide level [26].
Based on the structural characteristics of all target compounds, we
think that a synthetic approach by employing the readily available
trichloacetimidate sugar donors for assembling glycon and aglycon
moieties is efficient and convenient. Furthermore, a notable feature
of saponins 1ee1f, 2ee2h and 3ee3f is the presence of uronic acid
residues. So, the combination of functionalities will make it
possible to introduce a sugar moiety with a free C6eCOOH through
a selective oxidation of the C6eCH2OH of sugar at the late stage,
which is not only generally favorable to eradicate problematic
glycosylation, but also greatly simplifies the protecting group
manipulations.
The synthetic route of 1ae1f is outlined in Scheme 1. Treatment
of commercially available OA 4 with triphenylmethyl chloride (TrCl)
and 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) in dry THF was
firstly converted to its triphenylmethyl (Tr) ester 2 in a high yield of
91% [25a]. Thereafter, glycosylation of compound 2 with tri-
chloroacetimidate sugar donors 6ae6d [27] under the promotion of
trimethylsilyl trifluoromethanesulfonate (TMSOTf) at ꢀ78 ꢁC,
Fig. 1. Chemical structures of oleanolic acid derivatives 1, 1ae1f, 2, 2ae2j, 3 and 3ae3h.

Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
513
Scheme 1. Reagents and conditions: a) TrCl, DBU, THF, 91%; b) 0.2 equiv TMSOTf, CH2Cl2, ꢀ78 ꢁC / r.t, 84% for 7a, 83% for 7b, 86% for 7c, 90% for 7d; c) O3, CHCl3eCH3OH, ꢀ78 ꢁC,
75% for 8a, 72% for 8b, 74% for 8c, 75% for 8d; d) NaOMe, CH2Cl2eCH3OH, 93% for 1a, 96% for 1b, 94% for 1c, 97% for 1d; e) TEMPO, NaOCl, NaBr, H2O-t-BuOH (1:4), 74% for 1e, 75%
for 1f.
followed by deprotection of the Tr group by warming the reaction
mixture to room temperature, providing the expected glycosides
7ae7d with the exclusive 1,2-trans glycosidic linkages in isolated
yields ranging from 83% to 90%. Ozonolysis of compounds 7ae7d
along with lactonization using ozone in CHCl3eCH3OH at ꢀ78 ꢁC
afforded compounds 8ae8d in satisfactory yields (72%e75%) [28].
Global removal of the benzoyl groups in the presence of NaOMe in
MeOH overnight finished the synthesis of target compounds 1ae
1d, which were confirmed by 1H and 13C NMR spectra. Subse-
quently, the hydroxymethyl groups of compounds 1a and 1b were
selectively oxidated to carboxylic acid using a TEMPOeNaOCle
NaBr system in 1:4H2Oet-BuOH, affording target compounds 1e
and 1f in satisfactory yields. Meanwhile, the secondary C12eOH of
the aglycone remained intact [29].
The synthetic access to target compounds 2ae2j and 3ae3h was
described in Scheme 2. Glycosylation of aglycone acceptor 2 [24]
with glycosyl donors 6ae6d in the presence of TMSOTf afforded
the key intermediates 9ae9d. Meanwhile, coupling of N-phenyl-
trifluoroacetimidate 6e [30] and 2 under the fixed conditions
(0.2 equiv of TBSOTf, 1:1 CH2Cl2/CH3CN, 4 Å MS, Ar, ꢀ70 ꢁC) pro-
vided the products 9e and 9f with a ratio of 2:1 in 78% yield.
Thereafter, removal of the benzoyl and acetyl groups of compounds
9ae9f using NaOMe in CH3OH successfully generated the expected
saponins 2ae2d and 2ie2j in isolated yields from 80% to 98%. The
synthesis of 2e (or 2f) from compound 2a (or 2b) was achieved by
employing the same oxidation protocol (TEMPOeNaOCleNaBr
system in 1:4H2O-t-BuOH) mentioned above. Subsequent saponi-
fication of the methyl esters with sodium hydroxide afforded the
desired target compounds 3ae3h in good yields. Finally, the methyl
ester 2g (or 2h) was obtained by treatment 2e (or 2f) with iodo-
methane in the presence of K2CO3.
2.2. Biological evaluations
Taking sodium orthovanadate as a positive control, we measured
the PTP1B percentage inhibitory rates of all the synthesized com-
pounds by the method of pNPP. Compounds with good inhibition
rate (>70% at 10 mg/mL) were selected for further determination of
IC50 values. As shown in Table 1, the oleanolic hydroxyl-olide de-
rivative 1 and its sugar-based derivatives 1ae1f showed weak
inhibitory activity, indicating that sugar-based modification at C-3
position of compound 1 may not favor the PTP1B inhibitory activity.
Introduction of an acidic chain to C-28 of OA (2 and 3) did not display
much improved inhibitory activity compared to 1, but interestingly,
while the sugar moieties were connected with compound 2 (or 3),
the resulting glycoconjugates 2fe2j and 3ae3h exhibited
moderate-to-good inhibitory activities against PTP1B. Obviously,
compounds 2f (inhibition % ¼ 98.60%), 2h (inhibition % ¼ 81.88%),
and 2j (inhibition % ¼ 55.99%) exhibited more potent inhibitory
activity than other sugars (such as
nopyrannose, -fucopyrannose,
curonopyranoside) linked to the C-3 position of aglycone 2,
indicating that the specific stereochemistry of -mannuronic acid
and -sialic acid could have a beneficial effect on the PTP1B
inhibitory activity.
b
-D
-glucopyrannose,
a
-D
-man-
b-
D
b
-D
-lactopyrannose and
b-D-glu-
a-D
b-D
Interestingly, compounds 3ae3h with parent 3 as aglycone
exhibited more potent inhibitory activity toward PTP1B with the
inhibition values ranging from 46.03% to 83.72%, and especially

514
Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
Scheme 2. Reagents and Conditions: a) 0.1 equiv TMSOTf, CH2Cl2, ꢀ30 ꢁC, 90% for 9a, 89% for 9b, 89% for 9c, 93% for 9d; 0.2 equiv TBSOTf, CH2Cl2/CH3CN (1:1), ꢀ70 ꢁC, 52% for 9e,
26% for 9f; b) NaOMe, CH2Cl2eCH3OH, 95% for 2a, 97% for 2b, 96% for 2c, 98% for 2d, 89% for 2i, 90% for 2j; c) 2 mol/L NaOH in CH3OH/THF (2:3), 97% for 3a, 94% for 3b, 93% for 3c,
95% for 3d, 91% for 3e, 93% for 3f, 86% for 3g, 88% for 3h; d) TEMPO, NaOCl, NaBr, H2O-t-BuOH (1:4), 79% for 2e, 77% for 2f; e) MeI, K2CO3, acetone, 81% for 2g, 76% for 2h.
compound 3d (Inhibition % ¼ 83.72%) increased the potency 21.6
time compared to 2d (Inhibition % ¼ 3.87%). Compound 3e with
to C-28 of OA could favor the corresponding inhibitory activity
appreciably. Moreover, according to the IC50 values of 2f
b-
D
-glucuronic acid moiety at the C-3 position also exerted strong
(IC50 ¼ 1.91
m
M), 2h (IC50 ¼ 12.2
m
M) and 3f (IC50 ¼ 16.1
mM),
inhibitory activity against PTP1B (3e: Inhibition % ¼ 71.99%;
methylation on sugar moiety or the acidic chain also affected the
inhibitory activity significantly. Compared with 2j (inhibition
% ¼ 55.99%) and 3g (inhibition % ¼ 69.04%), compound 2i (Inhibi-
tion % ¼ 8.34%) decreased the inhibition against PTP1B, suggesting
IC50 ¼ 0.56 M), while compounds 1e (Inhibition % ¼ 16.11%), 2e
m
(Inhibition % ¼ 11.78%) and 2g (Inhibition % ¼ 36.68%) showed weak
inhibition toward PTP1B. These SAR analyzes indicated that a free
carboxyl group at C-28 carbon chain terminal could play an
important role in binding them to N-terminal residues of PTP1B. It
the existence of b-D-sialic acid and free carboxyl group of b-D-sialic
acid could enhance the inhibitory activity. In terms of SARs, these
in vitro results suggest that PTP1B inhibitory activity is strongly
influenced by both the carbohydrate moiety at the C-3 position and
the long carbon chain at C-28 position.
To examine the potential ability of the designed sugar-
substituted oleanolic acid derivatives (1ae1f, 2ae2j, and 3ae3h),
their insulin-sensitizing response by studying glucose uptake in
should be noted that, despite the presence of the common
mannuronic acid moiety, compounds 2f (Inhibition % ¼ 98.60%
IC50 ¼ 1.91 M), 2h (Inhibition % ¼ 81.88% IC50 ¼ 12.2 M) and 3f
M) exhibited 17.4-to-26.5-fold
a-D-
m
m
(Inhibition % ¼ 64.75% IC50 ¼ 16.1
m
more potent PTP1B inhibitory activity than compound 1f (Inhibi-
tion % ¼ 3.72%), demonstrating introduction of an acidic chain

Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
515
Table 1
compounds for further pharmacological studies and preclinical
developments. Work on the evaluation of the mechanism of action
of these new lead compounds (2f, 2h, 3d and 3e) is currently in
progress in our laboratory and results will be reported in due
course.
Inhibitory activities of the synthesized oleanolic acid derivatives against PTP1B.
Compound Inhibitions IC50
Compound
Inhibitions IC50
(%)
M) ꢄ SD
36.68
(%)a
(
m
M)b ꢄ SD
(m
1
9.50
6.00
2.90
e
e
e
e
e
e
e
e
e
e
e
e
e
2g
2h
2i
2j
3
3a
3b
3c
3d
3e
3f
3g
e
1a
1b
1c
1d
1e
1f
2
2a
2b
2c
2d
2e
2f
81.88
8.34
12.2 ꢄ 3.1
e
4. Experimental section
ꢀ1.55
55.99
14.31
57.59
56.99
63.23
83.72
71.99
64.75
69.04
46.03
100.41
e
2.55
e
4.1. Chemistry
16.11
3.72
4.89
5.82
1.52
1.91
3.87
11.78
98.60
e
e
e
Reagents were all analytically or chemically pure and used
without further purification unless specified. All anhydrous sol-
vents were dried and redistilled prior to use in the usual way. Thin-
layer chromatography (TLC) was performed on precoated E. Merck
Silica Gel 60 F254 plates. Flash column chromatography was per-
formed on silica gel (200e300 mesh, Qingdao, China). Optical ro-
tations were determined with a PerkineElmer Model 241 MC
polarimeter. 1H NMR and 13C NMR spectra were taken on a JEOL
JNM-ECP 600 spectrometer with tetramethylsilane as the internal
9.21 ꢄ 2.3
0.56 ꢄ 0.2
16.1 ꢄ 4.3
e
3h
e
1.91 ꢄ 0.4
Soduim
8.54 ꢄ 1.6
orthorandatec
a
The max inhibition concentration is 10 mg/mL.
Values are means of three experiments. ‘e’: The IC50 value was not determined.
Sodium orthovanadate was used as the positive control, of which the max in-
b
c
standard, and chemical shifts are recorded in d values. Mass spectra
hibition concentration is 100 mg/mL.
were recorded on a Q-TOF Global mass spectrometer.
3T3-L1 adipocytes was also investigated. Table 2 shows the insulin-
sensitizing response values of compounds 2ge2j and 3ae3h.
Compounds 2ge2h and 3be3e displayed good insulin-sensitizing
response with the values ranging from 21.52% to 59.58%, while
4.1.1. General procedure for synthesizing compounds 7ae7d
Compound 5 (0.20 mmol, 1.0 equiv.), appropriate trichloroaceti
midates 6ae6d (0.24 mmol,1.2 equiv.) and powdered 4 A molecular
ꢀ
sieves in dry CH2Cl2 (10 mL) were stirred for 30 min at room
temperature and then cooled to ꢀ78 ꢁC. TMSOTf (5
m
L) was added
compounds 2ie2j and 3ge3h with b-D-sialic acid at C-3 of parents
dropwise. After being stirred at ꢀ78 ꢁC for 30 min, the reaction
mixture was warmed up to room temperature for 30 min. The re-
action was quenched by addition of Et3N, and then filtered. The
filtrate was concentrated and purified by a silica gel column chro-
matography to afford the product 7ae7d, respectively.
2 and 3 exhibited weak insulin-sensitizing response. These results
indicated that the introduction of different sugars to C-3 of parent 2
(or 3) had important effect on insulin-sensitizing response.
3. Conclusion
4.1.1.1. 3-O-2,3,4,6-tetra-O-benzoyl-b-D-glucopyranoside oleanolic
In summary, we have shown in this study that a series of sugar-
substituted OA derivatives (1ae1f, 2ae2j, and 3ae3h) was syn-
thesized efficiently, and their effects on the inhibition of protein
tyrosine phosphatase 1B (PTP1B) and insulin-sensitizing response
were evaluated in vitro. The preliminary results suggested that
modification on C-28 of OA with an acidic chain was essential for
enhancing biological activities, and notably introduction of the
sugar moiety to C-3 of OA could significantly improve the inhibitory
activities against PTP1B and insulin-sensitizing response. Within
acid (7a). Yield: 84% (after chromatograph with EtOAc/CH2Cl2,
1:100) as a white amorphous powder. Rf ¼ 0.41 (EtOAc/petroleum
ether, 1:3). ½a 2D5
ꢂ
¼ þ56.1 (c 1.1, CHCl3). 1H NMR (600 MHz, DMSO-
d6):
d 12.03 (s, 1H, COOH), 7.43e7.85 (m, 20H, Ph-H), 5.99 (t,
J ¼ 9.4 Hz, 1H, H-40), 5.53 (t, J ¼ 9.4 Hz, 1H, H-30), 5.38 (dd, J ¼ 9.4,
8.2 Hz, 1H, H-20), 5.17 (d, J ¼ 8.2 Hz, 1H, H-10), 5.16 (br s, 1H, H-12),
4.56 (dd, J ¼ 12.1, 7.1 Hz, 1H, H-60-1), 4.43e4.48 (m, 2H, H-50, H-60-
2), 3.12 (dd, J ¼ 12.1, 4.4 Hz, 1H, H-3), 2.74 (dd, J ¼ 13.7, 3.9 Hz, 1H,
H-18), 1.06, 0.87, 0.87, 0.76, 0.65, 0.64, 0.51 (s each, 3H each,
these compounds, 3
mannuronopyranosyl-6-methyl ester 2h, 3
side 3d and 3 -O- -glucuronopyranoside 3e showed the most
b
-O-a
-D
-mannuronopyranoside 2f, 3
b-O-a-D-
CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 184.0 (C-28), 166.2, 166.1,
b
-O- -lactopyrano-
b-D
165.3, 165.2, 143.8 (C-13), 133.5, 133.4, 133.3, 130.1, 130.0, 129.9,
129.1, 129.0, 128.8, 128.6, 128.5, 128.4, 122.8 (C-12), 103.5 (C-10),
91.0 (C-3), 73.2, 72.3, 72.2, 70.5, 63.6, 60.6, 55.6, 47.8, 46.7, 46.1,
41.7, 41.1, 39.4, 38.9, 38.4, 36.8, 34.0, 33.3, 32.7, 32.6, 30.9, 27.8, 26.1,
26.0, 23.8, 23.5, 23.1, 18.2, 17.2, 16.3, 15.3, 14.4. HR-MS (ESI): m/z
calcd for C64H74O12Na [M þ Na]þ 1057.5093, found 1057.5078.
b
b-D
potent PTP1B inhibitory activities, which represented promising
Table 2
Insulin sensitizing response of the synthesized oleanolic acid derivatives.
Compounds
Response (%)a
Compounds
Response (%)
4.1.1.2. 3-O-2,3,4,6-tetra-O-benzoyl-a-D-mannopyranoside oleanolic
1
e
e
e
e
e
e
e
e
e
e
e
e
e
e
2g
2h
2i
2j
3
3a
3b
3c
3d
3e
3f
3g
28.29
39.18
ꢀ7.74
9.54
acid (7b). Yield: 83% (after chromatograph with EtOAc/CH2Cl2,
1:100) as a white amorphous powder. Rf ¼ 0.37 (EtOAc/petroleum
1a
1b
1c
1d
1e
1f
2
2a
2b
2c
2d
2e
2f
a 25
ether, 1:3). ½ ꢂD ¼ þ43.1 (c 0.9, CHCl3). 1H NMR (600 MHz, DMSO-
e
d6):
d 12.05 (s, 1H, COOH), 7.37e8.42 (m, 20H, Ph-H), 5.97 (t,
6.11
J ¼ 10.1 Hz, 1H, H-40), 5.73 (dd, J ¼ 10.1, 3.2 Hz, 1H, H-30), 5.53 (dd,
J ¼ 3.2, 1.9 Hz, 1H, H-20), 5.37 (s, 1H, H-10), 5.17 (br s, 1H, H-12), 4.66
(m, 1H, H-60-1), 4.49e4.54 (m, 2H, H-50, H-60-2), 3.31 (m, 1H, H-3),
2.74 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-18), 1.11, 1.09, 0.93, 0.91, 0.88, 0.88,
57.55
59.58
39.13
21.52
3.91
10.31
ꢀ16.69
100.00
0.74 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 184.0
(C-28), 166.4, 165.8, 143.8 (C-13), 133.3, 133.2, 130.1, 130.0, 129.9,
128.8, 128.7, 128.6, 128.5, 122.8 (C-12), 94.7 (C-10), 84.7 (C-3), 71.8,
70.5, 69.7, 67.2, 63.3, 55.8, 47.9, 46.7, 46.1, 41.8, 41.1, 39.5, 38.7, 38.2,
37.2, 34.0, 33.3, 32.8, 32.6, 30.9, 29.2, 27.9, 26.2, 23.8, 23.6, 23.1, 22.3,
3h
Rosiglitazone
a
Response values were tested at 10 mg/mL concentration. Values are means of
three experiments. ‘e’: not determined.

516
Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
18.5, 17.4, 16.9, 15.6. HR-MS (ESI): m/z calcd for C64H74O12Na
[M þ Na]þ 1057.5078, found 1057.5071.
72.2, 63.6, 55.6, 51.3, 44.9, 44.7, 42.4, 42.2, 39.6, 39.1, 38.9, 36.3,
34.3, 34.0, 33.5, 31.8, 29.0, 28.1, 27.7, 26.1, 24.1, 21.4, 18.7, 18.6, 17.7,
16.4, 16.1. HR-MS (ESI): m/z calcd for C64H74O13Na [M þ Na]þ
1073.5027, found 1073.5060.
4.1.1.3. 3-O-2,3,4-tri-O-benzoyl-a-L-fucopyranoside oleanolic acid
(7c). Yield: 86% (after chromatograph with EtOAc/CH2Cl2, 1:120) as
a white amorphous powder. Rf ¼ 0.45 (EtOAc/petroleum ether, 1:3).
4.1.2.2. 3-O-2,3,4,6-tetra-O-benzoyl-a-D-mannopyranoside oleander-
½
a 2D5
ꢂ
¼ ꢀ20.1 (c 1.3, CHCl3). 1H NMR (600 MHz, DMSO-d6):
d
12.05
olide (8b). Yield: 72% (after chromatograph with EtOAc/petroleum
ether, 1:6) as a white amorphous powder. Rf ¼ 0.37 (EtOAc/petro-
(s, 1H, COOH), 7.34e7.99 (m, 15H, Ph-H), 5.71 (dd, J ¼ 10.1, 3.2 Hz,
1H, H-30), 5.59 (d, J ¼ 4.1 Hz, 1H, H-40), 5.44 (dd, J ¼ 10.6, 8.3 Hz, 1H,
H-20), 5.14 (t-like, J ¼ 3.7, 3.2 Hz,1H, H-12), 5.07 (d, J ¼ 8.3 Hz,1H, H-
10), 4.29 (dd, J ¼ 13.3, 6.4 Hz, 1H, H-50), 3.27 (dd, J ¼ 11.4, 4.1 Hz, 1H,
H-3), 2.72 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-18), 1.20 (d, J ¼ 6.4 Hz, 3H, H-
60), 1.09, 0.99, 0.87, 0.87, 0.70, 0.68, 0.58 (s each, 3H each, CH3 ꢃ 7).
leum ether, 1:5); ½a D25
ꢂ
¼ ꢀ20.3 (c 0.8, CHCl3). 1H NMR (600 MHz,
DMSO-d6):
d
7.36e8.04 (m, 20H, Ph-H), 5.97 (t-like, J ¼ 10.3, 9.6 Hz,
1H, H-40), 5.74 (dd, J ¼ 10.3, 3.2 Hz,1H, H-30), 5.50 (dd, J ¼ 3.2, 1.9 Hz,
1H, H-20), 5.39 (d, J ¼ 1.9 Hz, 1H, H-10), 5.00 (d, J ¼ 3.2 Hz, 1H, C12
-
OH), 4.66 (m, 1H, H-60-1), 4.50-4.55 (m, 2H, H-50, H-60-2), 3.68 (br s,
13C NMR (150 MHz, CDCl3):
d
184.0 (C-28), 166.4, 166.0, 165.4, 143.9
1H, H-12), 3.40 (dd, J ¼ 11.6, 4.5 Hz,1H, H-3), 2.14-2.19 (m, 1H, H-18),
(C-13), 133.5, 133.4, 133.3, 130.2, 130.1, 130.0, 129.9, 129.8, 129.6,
129.4, 128.8, 128.5, 128.4, 122.7 (C-12), 99.0 (C-10), 85.3 (C-3), 72.5,
71.6, 70.2, 69.6, 56.0, 47.7, 46.7, 46.1, 41.7, 41.1, 39.5, 38.4, 37.0, 33.9,
33.3, 32.8, 32.6, 30.8, 28.3, 27.8, 26.1, 23.8, 23.6, 23.0, 18.4, 17.3, 16.6,
16.4, 15.4. HR-MS (ESI): m/z calcd for C57H70O10Na [M þ Na]þ
937.4867, found 937.4835.
1.26, 1.10, 1.05, 0.94, 0.90 0.88, 0.87 (s each, 3H each, CH3 ꢃ 7). 13
C
NMR (150 MHz, CDCl3):
d 180.2 (C-28), 166.4, 165.8, 165.7, 133.7,
133.4, 133.3, 130.0, 129.9, 129.6, 129.4, 129.2, 128.8, 128.6, 128.5,
128.4, 94.7 (C-10), 90.8 (C-13), 84.4 (C-3), 76.4 (C-12), 71.8, 70.4, 69.6,
67.1, 63.2, 55.7, 51.3, 44.9, 44.7, 42.5, 42.2, 39.5, 38.8, 38.5, 36.6, 34.3,
34.1, 33.5, 31.7, 29.1, 29.0, 28.2, 27.7, 24.1, 22.4, 21.4, 18.8, 18.7, 17.9,
16.7, 16.5. HR-MS (ESI): m/z calcd for C64H74O13Na [M þ Na]þ
1073.5027, found 1073.4994.
4.1.1.4. 3-O-2,3,6,20,30,40,60-hepta-O-benzoyl-
b-D-lactopyranoside
oleanolic acid (7d). Yield: 90% (after chromatograph with petro-
leum ether/acetone, 10:1) as a white amorphous powder. Rf ¼ 0.21
4.1.2.3. 3-O-2,3,4-tri-O-benzoyl-a-L-fucopyranosideoleanderolide(8c).
Yield: 74% (after chromatograph with EtOAc/petroleum ether, 1:6) as
a white amorphous powder. Rf ¼ 0.41 (EtOAc/petroleum ether, 1:5).
(EtOAc/petroleum ether, 1:3). ½a D25
ꢂ
¼ þ55.4 (c 0.9, CHCl3). 1H NMR
(600 MHz, DMSO-d6):
d
12.04 (s, 1H, COOH), 7.22e7.97 (m, 35H, Ph-
H), 5.75e5.79 (m, 2H, H-30, H-300), 5.67 (d, 1H, J ¼ 3.2 Hz, H-400), 5.43
(dd, J ¼ 7.8, 10.1 Hz,1H, H-200), 5.31 (d, J ¼ 7.8 Hz, 1H, H-100), 5.24 (dd,
J ¼ 9.7, 8.2 Hz, 1H, H-20), 5.16 (br s, 1H, H-12), 5.00 (d, J ¼ 8.2 Hz, 1H,
H-10), 4.62 (dd, J ¼ 11.9, 8.2 Hz, 1H, H-60-1), 4.52 (d, J ¼ 10.6 Hz, 1H,
H-60-2), 4.43 (t-like, J ¼ 6.9, 6.8 Hz, 1H, H-500), 4.31 (t, J ¼ 9.6 Hz, 1H,
H-40), 4.09 (t, J ¼ 9.6 Hz, 1H, H-50), 3.82 (dd, J ¼ 11.5, 6.9 Hz, 1H, H-
600-1), 3.60 (dd, J ¼ 11.0, 6.4 Hz,1H, H-600-2), 3.00 (dd, J ¼ 11.9, 4.1 Hz,
1H, H-3), 2.73 (dd, J ¼ 13.3, 3.7 Hz, 1H, H-18), 1.05, 0.89, 0.88, 0.71,
0.64 0.58, 0.47 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz,
½
a 2D5
ꢂ
¼ ꢀ96.5 (c 1.2, CHCl3). 1H NMR (600 MHz, DMSO-d6):
d 7.34e
7.99 (m, 15H, Ph-H), 5.71 (dd, J ¼ 10.6, 3.7 Hz, 1H, H-30), 5.59 (d,
J ¼ 3.7 Hz, 1H, H-40), 5.44 (dd, J ¼ 10.6, 8.3 Hz, 1H, H-20), 5.08 (d,
J ¼ 7.8 Hz,1H, H-10), 4.97 (d, J ¼ 4.6 Hz,1H, C12-OH), 4.29 (dd, J ¼ 13.7,
6.4 Hz,1H, H-50), 3.64 (br s,1H, H-12), 3.27 (dd, J ¼ 11.9, 4.6 Hz,1H, H-
3), 2.15 (td, J ¼ 13.8, 5.5 Hz, 1H, H-18), 1.30e1.93 (m, 14H), 1.20 (d,
J ¼ 6.4 Hz, 3H, H-60), 1.24, 0.99, 0.98, 0.93, 0.86, 0.65, 0.57 (s each, 3H
each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 180.2 (C-28), 166.4,
166.0,165.4, 133.5,133.4,133.3,130.2, 130.1, 130.0, 129.9, 129.8, 129.6,
128.8, 128.6, 128.5, 128.4, 98.9 (C-10), 90.8 (C-13), 84.9 (C-3), 76.5 (C-
12), 72.5, 71.5, 70.2, 69.7, 56.0, 51.3, 44.9, 44.7, 42.5, 42.2, 39.6, 38.7,
38.5, 36.4, 34.3, 34.1, 33.5, 31.8, 29.0, 28.2, 28.1, 27.6, 24.1, 23.0, 21.4,
18.8,18.7,17.9,16.6,16.4,16.2. HR-MS (ESI): m/z calcd for C57H70O11Na
[M þ Na]þ 953.4816, found 953.4826.
CDCl3): d 183.8 (C-28), 166.0, 165.8, 165.4, 165.3, 143.8 (C-13), 133.8,
133.6, 133.5, 130.0, 129.9, 129.8, 129.7, 128.8, 128.6, 128.5, 128.4,
122.8 (C-12), 103.4 (C-10), 101.3 (C-100), 90.9 (C-3), 73.2, 73.0, 72.1,
71.9, 71.6, 70.1, 67.8, 62.9, 61.4, 55.6, 47.7, 46.7, 46.1, 41.7, 41.1, 39.4,
38.8, 38.4, 36.8, 33.9, 33.3, 32.6, 30.8, 29.9, 27.8, 26.1, 25.9, 23.8,
23.0, 18.1, 17.2, 16.3, 15.3. HR-MS (MALDI): m/z calcd for
C
91H96O20Na [M þ Na]þ 1531.6379, found 1531.6387.
4.1.2.4. 3-O-2,3,6,20,30,40,60-Hepta-O-benzoyl-
b-D-lactopyranoside
oleanderolide (8d). Yield: 75% (after chromatograph with EtOAc/
petroleum ether, 1:5) as a white amorphous powder. Rf ¼ 0.36
4.1.2. General procedure for synthesizing compounds 8ae8d
A solution of 7ae7d (0.11 mmol) in CH2Cl2 (5 mL) and CH3OH
(5 mL) was cooled to ꢀ78 ꢁC. Ozone was bubbled through this
solution until a lavender blue color persisted (saturated solution),
which usually took 30 min. The reaction was monitored by TLC. The
solution was purged with N2 to displace residual ozone, and then
concentrated and purified by a silica gel column chromatography to
afford the product 8ae8d, respectively.
(EtOAc/petroleum ether, 1:4). ½a D25
ꢂ
¼ þ46.3 (c 0.8, CHCl3). 1H NMR
(600 MHz, DMSO-d6): d 7.22-7.97 (m, 35H, Ph-H), 5.77e5.79 (m, 2H,
H-30, H-300), 5.68 (d, J ¼ 3.2 Hz,1H, H-400), 5.42 (dd, J ¼ 10.1, 8.3 Hz,1H,
H-200), 5.32 (d, J ¼ 7.8 Hz, 1H, H-100), 5.25 (t-like, J ¼ 9.7, 8.2 Hz,1H, H-
20), 5.16 (d, J ¼ 5.0 Hz, 1H, C12-OH), 5.02 (d, J ¼ 8.3 Hz, 1H, H-10), 4.63
(d, J ¼ 10.0 Hz, 1H, H-60-1), 4.44-4.50 (m, 2H, H-500, H-60-2), 4.31 (t-
like, J ¼ 9.6, 9.2 Hz,1H, H-40), 4.10 (t-like, J ¼ 9.6, 7.4 Hz,1H, H-50), 3.83
(dd, J ¼ 11.5, 6.4 Hz, 1H, H-600-1), 3.67 (br s, 1H, H-12), 3.62 (dd,
J ¼ 11.0, 6.4 Hz, 1H, H-600-2), 3.05 (dd, J ¼ 11.5, 3.7 Hz, 1H, H-3), 2.11-
2.15 (m, 1H, H-18), 1.21, 0.96, 0.94, 0.88, 0.69, 0.60, 0.48 (s each, 3H
4.1.2.1. 3-O-2,3,4,6-tetra-O-benzoyl-b-D-glucopyranoside oleander-
olide (8a). Yield: 75% (after chromatograph with EtOAc/petroleum
ether, 1:6) as a white amorphous powder. Rf ¼ 0.35 (EtOAc/petro-
each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 180.1 (C-28), 166.0,
leum ether, 1:5). ½a D25
ꢂ
¼ þ29.1 (c 1.0, CHCl3). 1H NMR (600 MHz,
165.8,165.6,165.0,133.6,133.4,133.2,130.0,129.9,129.8,129.6,128.8,
128.7, 128.5, 128.4, 103.4 (C-10), 101.1 (C-10), 90.7 (C-13), 90.5 (C-3),
76.8 (C-12), 73.1, 73.0, 72.1, 71.9, 71.6, 70.1, 67.7, 62.8, 61.3, 55.5, 51.2,
44.8, 44.6, 42.4, 42.2, 39.5, 39.0, 38.8, 36.2, 34.3, 34.0, 33.5, 31.8, 28.9,
28.1, 27.6, 26.0, 24.1, 21.3, 18.7, 18.6, 17.6, 16.3, 16.1. HR-MS (MALDI):
m/z calcd for C91H96O21Na [M þ Na]þ 1547.6341, found 1547.6336.
DMSO-d6):
d
7.39e7.97 (m, 20H, Ph-H), 5.99 (t, J ¼ 9.6 Hz, 1H, H-30),
5.53 (t-like, J ¼ 9.6, 9.0 Hz, 1H, H-40), 5.38 (dd, J ¼ 9.6, 7.7 Hz, 1H, H-
20), 5.19 (d, J ¼ 7.7 Hz,1H, H-10), 5.10 (d, J ¼ 4.5 Hz,1H, C12-OH), 4.51-
4.53 (m, 1H, H-60-1), 4.45-4.48 (m, 2H, H-50, H-60-2), 3.68 (br s, 1H,
H-12), 3.18 (dd, J ¼ 11.5, 4.5 Hz, 1H, H-3), 2.11e2.17 (m, 1H, H-18),
1.23, 0.98, 0.94, 0.88, 0.74, 0.66, 0.51 (s each, 3H each, CH3 ꢃ 7). 13
C
NMR (150 MHz, CDCl3):
d
180.1 (C-28), 166.2, 166.1, 165.5, 165.2,
4.1.3. General procedure for synthesizing compounds 9ae9d
Compound 2 (0.20 mmol, 1.0 equiv.), appropriate trichloro
133.5, 133.4, 133.3, 130.0, 129.9, 129.8, 129.6, 129.4, 128.6, 128.5,
128.4, 103.6 (C-10), 90.7 (C-13), 90.6 (C-3), 76.5 (C-12), 73.1, 72.3,
ꢀ
acetimidates 6ae6d (0.24 mmol, 1.2 equiv.) and powdered 4 A

Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
517
molecular sieves in dry CH2Cl2 (8 mL) were stirred for 30 min at
powder. Rf ¼ 0.30 (EtOAc/petroleum ether, 1:2). ½a D25
ꢂ
¼ þ67.0 (c 1.1,
room temperature and then cooled to ꢀ30 ꢁC. TMSOTf (5
mL) was
CHCl3). 1H NMR (600 MHz, CDCl3):
d 7.13e8.00 (m, 35H, Ph-H), 5.95
added dropwise. After being stirred at ꢀ30 ꢁC for 30 min, the re-
action mixture was warmed up to room temperature for 30 min.
The reaction was quenched by addition of Et3N, and then filtered.
The filtrate was concentrated and purified by a silica gel column
chromatography to afford the product 9ae9d, respectively.
(t, J ¼ 5.5 Hz, 1H, NeH), 5.80 (t-like, J ¼ 9.6, 9.2 Hz, 1H, H-30), 5.71-
5.74 (m, 2H, H-300, H-400), 5.48 (dd, J ¼ 8.2, 10.0 Hz, 1H, H-200), 5.40
(dd, J ¼ 3.7,10.6 Hz,1H, H-60-1), 5.36 (t, J ¼ 3.7 Hz,1H, H-12), 4.86 (d,
J ¼ 7.7 Hz, 1H, H-100), 4.71 (d, J ¼ 8.2 Hz, 1H, H-10), 4.59 (d,
J ¼ 10.1 Hz,1H, H-60-2), 4.48 (dd, J ¼ 5.5,11.9 Hz,1H, H-600-1), 4.17 (t-
like, J ¼ 9.6, 9.2 Hz, 1H, H-40), 4.12 (dd, J ¼ 7.3, 14.2 Hz, 1H, H-600-2),
3.92 (t-like, J ¼ 6.4, 7.3 Hz, 1H, H-20), 3.81e3.84 (m, 1H, H-50), 3.67e
3.75 (m, 2H, H-31-1, H-31-2), 3.65 (s, 3H, H-37), 3.33e3.37(m, 1H,
H-16-1), 3.01 (dd, J ¼ 4.6, 11.9 Hz, 1H, H-3), 2.95e2.99 (m, 1H, H-16-
2), 2.48 (dd, J ¼ 3.7, 13.3 Hz, 1H, H-18), 2.31 (t, J ¼ 7.3 Hz, 2H, H-35-1,
H-35-2), 1.16e1.95 (m, 23H), 1.10, 0.91, 0.90, 0.79, 0.68, 0.64, 0.59 (s
4.1.3.1. 28-N-methyl hexanoate oleanate 3-O-2,3,4,6-tetra-O-ben-
zoyl-b-D-glucopyranoside (9a). Yield: 90% (after chromatograph
with EtOAc/petroleum ether, 1:3) as a white amorphous powder.
Rf ¼ 0.33 (EtOAc/petroleum ether, 1:2). ½a D25
¼ þ58.4 (c 0.7, CHCl3).
ꢂ
1H NMR (600 MHz, CDCl3):
d 7.26e8.03 (m, 20H, Ph-H), 5.92 (t,
J ¼ 9.6 Hz, 1H, H-30), 5.91 (t, J ¼ 5.9 Hz, 1H, NeH), 5.60 (t, J ¼ 10.1 Hz,
1H, H-40), 5.56 (dd, J ¼ 7.8, 10.1 Hz, 1H, H-20), 5.38 (t, J ¼ 3.2 Hz, 1H,
H-12), 4.86 (d, J ¼ 7.8 Hz, 1H, H-10), 4.58 (dd, J ¼ 8.3, 11.5 Hz, 1H, H-
60-1), 4.54 (dd, J ¼ 6.4, 11.9 Hz, 1H, H-60-2), 4.14 (m, 1H, H-50), 3.66
(s, 3H, H-37), 3.32e3.38 (m, 1H, H-31-1), 3.10 (dd, J ¼ 4.1, 11.5 Hz,
1H, H-3), 2.95e2.99 (m,1H, H-31-2), 2.50 (dd, J ¼ 3.7,13.3 Hz,1H, H-
18), 2.31 (t, J ¼ 7.4 Hz, 2H, H-35-1, H-35-2), 1.12, 0.92, 0.92, 0.83,
0.70, 0.68, 0.63 (s each, 3 H each, CH3 ꢃ 7). HR-MS (ESI): m/z calcd
for C71H88NO13 [M þ H]þ 1162.6256, found 1162.6260.
each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 178.3 (C-28),
174.2 (C-36), 166.0, 165.8, 165.6, 165.4, 165.3, 165.0, 145.3 (C-13),
133.8, 133.6, 133.5, 133.3, 130.2, 130.0, 129.9, 129.6, 129.5, 129.1,
128.8, 128.7, 128.6, 128.5, 122.9 (C-12), 103.4 (C-10), 101.2 (C-100),
90.8 (C-3), 73.2, 73.0, 72.2, 71.9, 71.6, 70.2, 67.8, 63.8, 62.9, 61.4, 55.5,
51.7, 47.6, 47.0, 46.4, 42.5, 42.2, 39.5, 39.4, 38.9, 38.5, 36.7, 34.3, 34.1,
33.2, 32.7, 32.4, 30.9, 29.2, 27.8, 27.4, 26.8, 25.9, 24.7, 23.8, 23.7, 18.2,
17.0, 16.3, 15.4.
4.1.4. General procedure for synthesizing compounds 9ee9f
Compound 2 (0.20 mmol, 1.0 equiv.), N-phenyltrifluoroace
timidate 6e (0.24 mmol, 1.2 equiv.) and powdered 4 A molecular
4.1.3.2. 28-N-Methyl hexanoate oleanate 3-O-2,3,4,6-tetra-O-ben-
ꢀ
zoyl-
a-D
-mannopyranoside (9b). Yield: 89% (after chromatograph
with EtOAc/petroleum ether, 1:3) as a white amorphous powder.
sieves in dry CH2Cl2 (4 mL) and CH3CN (4 mL) were stirred for
Rf ¼ 0.34 (EtOAc/petroleum ether,1:2). ½a D25
ꢂ
¼ ꢀ63.6 (c 1.2, CHCl3).1H
30 min at room temperature and then cooled to ꢀ70 ꢁC. TBSOTf
NMR (600 MHz, CDCl3):
d
7.26e8.09 (m, 20H, Ph-H), 5.96 (t,
(10
m
L) was added dropwise. After being stirred at ꢀ70 ꢁC for 1 h,
J ¼ 6.9 Hz, 1H, NeH), 5.90 (dd, J ¼ 3.2, 10.0 Hz, 1H, H-30), 5.61 (dd,
J ¼ 1.9, 3.2 Hz, 1H, H-20), 5.38 (t, J ¼ 3.2 Hz, 1H, H-12), 5.28 (d,
J ¼ 1.4 Hz,1H, H-10), 4.69 (dd, J ¼ 2.3,11.9 Hz,1H, H-60-1), 4.54 (m,1H,
H-50), 4.46 (dd, J ¼ 5.0, 11.9 Hz, 1H, H-60-2), 3.68 (s, 3H, H-37), 3.36e
3.40 (m, 2H, H-3, H-18), 2.98e3.03 (m, 1H, H-31-1), 2.49e2.52 (m,
1H, H-31-2), 2.33 (t, J ¼ 7.4 Hz, 2H, H-35-1, H-35-2), 1.20e1.99 (m,
26H), 1.02e1.06 (m, 1H), 1.17, 1.12, 0.97, 0.97, 0.91, 0.91, 0.77 (s each,
the reaction mixture was warmed up to room temperature for
30 min. The reaction was quenched by addition of Et3N, and then
filtered. The filtrate was concentrated and purified by a silica gel
column chromatography to afford the products 9e and 9f.
4.1.4.1. 28-N-Methyl hexanoate oleanate 3-O-5-acetamido-4,7,8,9-
tetra-O-acetyl-3,5-dideoxy-b-D-glycero-a-D-galacto-2-nonulopyrano
3H each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d
178.4 (C-28), 174.2
sonate (9e). -anomer, Yield: 52% (after chromatograph with
a
(C-26), 166.4, 165.7, 145.3 (C-13), 133.7, 133.4, 133.2, 130.0, 129.9,
129.8,129.6,129.4,128.8,128.7,128.6,128.5,122.8 (C-12), 94.7 (C-10),
84.6 (C-3), 71.8, 70.4, 69.7, 67.1, 63.2, 55.6, 51.7, 47.7, 47.0, 46.4, 42.5,
42.3, 39.6, 38.7, 38.2, 37.1, 34.3, 34.1, 33.2, 32.7, 32.5, 30.9, 29.3, 29.1,
27.5, 26.8, 26.0, 24.7, 24.0, 23.8, 22.3,18.5,17.1,16.9,15.6. HR-MS (ESI):
m/z calcd for C71H88NO13 [M þ H]þ 1162.6256, found 1162.6279.
EtOAc/petroleum ether, 1:3.5) as a white amorphous powder.
Rf ¼ 0.28 (EtOAc/petroleum ether, 1:2). ½a D25
¼ þ10.3 (c 1.1, CHCl3).
ꢂ
1H NMR (600 MHz, CDCl3):
d
6.00 (d, J ¼ 2.8 Hz, 1H), 5.94 (t,
J ¼ 4.6 Hz, 1H), 5.49 (m, 1H), 5.36 (t, J ¼ 3.6 Hz, 1H, H-12), 5.33 (m,
1H), 5.29 (dd, J ¼ 8.3, 1.4 Hz, 1H), 5.20 (d, J ¼ 9.6 Hz, 1H), 4.83 (td,
J ¼ 12.4, 4.6 Hz, 1H), 4.38 (dd, J ¼ 12.4, 2.8 Hz, 1H), 4.18 (td, J ¼ 11.9,
6.9 Hz, 1H), 4.04 (dd, J ¼ 12.4, 5.9 Hz, 1H), 3.87 (dd, J ¼ 10.6, 1.9 Hz,
1H), 3.76, 3.66 (s each, 3H each, COOCH3), 3.34 (dd, J ¼ 13.3, 6.4 Hz,
1H), 3.00 (m, 1H, H-31-1), 2.97 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-3), 2.65
(dd, J ¼ 12.8, 4.6 Hz, 1H, H-30eq), 2.50 (m, 1H, H-31-2), 2.30 (t,
J ¼ 7.3 Hz, 2H, H-35-1, H-35-2), 2.13, 2.10, 2.05, 2.02, 2.02 (s each, 3H
each, OAc and NAc), 1.18, 0.97, 0.89, 0.89, 0.89, 0.75, 0.74 (s each, 3H
4.1.3.3. 28-N-Methyl hexanoate oleanate 3-O-2,3,4-tri-O-benzoyl-
a-
L
-fucopyranoside (9c). Yield: 89% (after chromatograph with EtOAc/
petroleum ether, 1:3) as a white amorphous powder. Rf ¼ 0.39
(EtOAc/petroleum ether, 1:2). ½a D25
ꢂ
¼ ꢀ47.2 (c 1.3, CHCl3). 1H NMR
(600 MHz, CDCl3)
d
: 7.24e8.12 (m, 15H, Ph-H), 5.91 (t-like, J ¼ 4.4,
6.0 Hz, 1H, NeH), 5.67e5.70 (m, 2H, H-20, H-40), 5.54 (dd, J ¼ 10.4,
3.3 Hz,1H, H-30), 5.35(t, J ¼ 3.3 Hz,1H, H-12), 4.77 (d, J ¼ 7.7Hz,1H, H-
10), 4.00 (dd, J ¼ 13.2, 6.6 Hz, 1H, H-50), 3.65 (s, 3H, H-37), 3.33e3.38
(m,1H, H-31-1), 3.30 (dd, J ¼ 12.1, 4.4 Hz,1H, H-3), 2.96e3.00 (m,1H,
H-31-2), 2.49 (dd, J ¼ 13.7, 4.4 Hz,1H, H-18), 2.30 (t, J ¼ 7.2 Hz, 2H, H-
35-1, H-35-2), 1.14, 1.06, 0.90, 0.90, 0.78, 0.72, 0.70 (s each, 3H each,
each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 178.3 (C-28), 174.1 (C-
36), 171.1, 170.6, 170.3, 169.9, 169.1, 145.3 (C-13), 122.8 (C-12), 97.1
(C-20), 80.2 (C-3), 76.7, 72.3, 70.6, 69.3, 69.0, 67.8, 67.7, 67.6, 62.6,
62.0, 55.1, 52.6, 51.6, 49.8, 47.2, 46.4, 42.5, 42.2, 39.5, 39.3, 38.6, 36.7,
34.0, 33.1, 30.8, 29.2, 28.1, 27.4, 26.7, 25.8, 24.6, 23.7, 20.9, 20.8, 18.5,
17.0, 16.6, 15.4.
CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 178.3 (C-28), 174.2 (C-36),
166.4,165.9,165.4,145.4 (C-13),133.5,133.3,133.1,129.9,129.8,129.7,
129.6, 128.7, 128.6, 128.5, 128.4, 122.8 (C-12), 99.0 (C-10), 85.1 (C-3),
72.5, 71.5, 70.3, 69.6, 55.9, 51.7, 47.7, 47.0, 46.4, 42.5, 42.2, 39.6, 39.4,
38.4, 36.9, 34.3, 34.1, 33.2, 32.7, 32.5, 30.9, 29.2, 28.2, 27.4, 26.8, 25.9,
24.7, 24.0, 23.8, 23.7, 23.0, 18.5, 17.1, 16.6, 16.5, 15.4. HR-MS (ESI): m/z
calcd for C64H84NO11 [M þ H]þ 1042.6044, found 1042.6024.
4.1.4.2. 28-N-Methyl hexanoate oleanate 3-O-5-acetamido-4,7,8,9-
tetra-O-acetyl-3,5-dideoxy-b-D-glycero -b-D-galacto-2-nonulopyrano
sonate (9f). -anomer, Yield: 26% (after chromatograph with
b
EtOAc/petroleum ether, 1:3.5) as a white amorphous powder.
Rf ¼ 0.21 (EtOAc/petroleum ether, 1:2). ½a D25
¼ þ5.6 (c 0.9, CHCl3).
ꢂ
1H NMR (600 MHz, CDCl3):
d
5.90 (t, J ¼ 5.0 Hz, 1H), 5.65 (m, 1H),
5.40 (t, J ¼ 3.2 Hz, 1H, H-12), 5.24 (dd, J ¼ 10.1, 4.1 Hz, 1H), 5.10 (m,
1H), 4.96 (dd, J ¼ 12.4,1.9 Hz,1H), 4.59 (dd, J ¼ 12.4, 3.2 Hz,1H), 4.40
(dd, J ¼ 12.4, 2.7 Hz, 1H), 4.16 (dd, J ¼ 11.8, 6.7 Hz, 1H), 4.01 (dd,
J ¼ 12.4, 5.8 Hz, 1H), 3.79, 3.66 (s each, 3H each, COOCH3), 3.34 (m,
4.1.3.4. 28-N-Methyl hexanoate oleanate 3-O-2,3,6,20,30,40,60-hepta-
O-benzoyl-
b-D-lactopyranoside (9d). Yield: 93% (after chromato-
graph with EtOAc/petroleum ether, 1:3) as a white amorphous

518
Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
1H, H-31-1), 3.04 (dd, J ¼ 11.5, 4.6 Hz, 1H, H-3), 3.00 (m, 1H, H-31-
2), 2.54 (dd, J ¼ 12.8, 4.6 Hz, 1H, H-30eq), 2.49 (dd, J ¼ 13.7, 3.7 Hz,
1H, H-18), 2.29 (t, J ¼ 7.3 Hz, 2H, H-35-1, H-35-2), 2.12, 2.11, 2.07,
2.06, 2.03, 2.02 (s each, 3H each, OAc and NAc), 1.14, 0.92, 0.91, 0.88,
0.88, 0.86, 0.85 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz,
CH3 ꢃ 7). 13C NMR (150 MHz, DMSO-d6):
d
178.8 (C-28), 101.5 (C-10),
90.6 (C-13), 84.3 (C-3), 74.3 (C-12), 73.8, 71.1, 70.3, 69.7, 55.3, 50.3,
43.9, 43.8, 41.8, 41.6, 38.4, 38.2, 37.9, 35.9, 33.7, 33.5, 33.1, 31.2, 28.2,
27.9, 27.3, 27.2, 23.8, 23.1, 20.7, 18.4, 17.9, 17.4, 16.7, 16.6, 16.1. HR-MS
(ESI): m/z calcd for C36H59O8 [M þ H]þ 619.4210, found 619.4238.
CDCl3):
d 178.2 (C-28), 171.3, 170.9, 170.5, 170.3, 169.2, 167.3, 161.7,
145.1 (C-13), 122.5 (C-12), 100.1 (C-20), 85.7 (C-3), 73.7, 72.4, 69.2,
68.9, 63.0, 60.5, 55.5, 52.7, 49.7, 47.5, 46.9, 46.7, 42.5, 42.3, 42.1, 39.3,
39.0, 38.1, 34.2, 32.6, 32.3, 29.8, 28.2, 27.3, 25.6, 25.0, 24.2, 23.9,
23.8, 23.3, 21.1, 18.4, 16.7, 14.3. HR-MS (ESI): m/z calcd for
4.1.5.4. 3-O-b-D-Lactopyranoside oleanderolide (1d). Yield: 97%
(after chromatograph with MeOH/CHCl3, 1:5) as a white amor-
phous powder. Rf ¼ 0.46 (MeOH/CHCl3, 1:4). ½a D25
ꢂ
¼ þ20.0 (c 0.4,
CH3OH). 1H NMR (600 MHz, DMSO-d6):
d
5.13 (d, J ¼ 4.1 Hz, 1H, C2
-
00
C
57H89N2O16 [M þ H]þ 1057.6212, found 1057.6207.
OH), 5.07 (d, J ¼ 5.5 Hz, 1H, C2 -OH), 4.94 (d, J ¼ 4.1 Hz, 1H, C12-OH),
0
0
00
00
4.82 (d, J ¼ 5.0 Hz, 1H, C3 -OH), 4.66e4.69 (m, 2H, C3 -OH, C6 -OH),
0
0
4.1.5. General procedure for synthesizing compounds 1ae1d, 2ae2d
and 2ie2j
4.55 (d, J ¼ 4.6 Hz, 1H, C4 -OH), 4.47 (t, J ¼ 5.9 Hz, 1H, C6 -OH), 4.22
(d, J ¼ 7.7 Hz, 1H, H-100), 4.19 (d, J ¼ 6.8 Hz, 1H, H-10), 3.73 (dd,
J ¼ 10.6, 4.6 Hz, 1H, H-60-1), 3.66 (br s, 1H, H-12), 3.46e3.61 (m, 5H,
H-300, H-400, H-60-2, H-600-1, H-600-2), 3.24e3.33 (m, 3H, H-200, H-30,
H-50), 3.07 (dd, J ¼ 11.5, 4.1 Hz, 1H, H-3), 2.99e3.03 (m, 1H, H-20),
2.12e2.17 (m, 1H, H-18),1.24,1.02, 0.98, 0.94, 0.86, 0.81, 0.74 (s each,
Compounds 8ae8d or 9ae9f (0.10 mmol) was dissolved in a
solution of MeOH (5 mL) and CH2Cl2 (5 mL). Sodium methoxide
(50%, 100 mg) was added to the solution and stirred at room tem-
perature for about 5 h, after completion by TLC, the reaction
mixture was neutralized with Dowex 50 ꢃ 8 (Hþ) resin until pH ¼ 7,
filtered and concentrated. The residue was purified by a silica gel
column chromatography to afford the product 1ae1d, 2ae2d and
2ie2j, respectively.
3H each, CH3 ꢃ 7). 13C NMR (150 MHz, DMSO-d6):
d 178.9 (C-28),
105.1 (C-10), 103.9 (C-100), 90.6 (C-13), 88.1 (C-3), 81.3 (C-12), 75.5,
75.2, 74.6, 74.3, 73.6, 73.2, 70.6, 68.1, 60.8, 60.4, 54.9, 50.3, 43.9, 41.8,
41.6, 35.7, 33.7, 33.6, 33.1, 31.2, 28.1, 27.4, 27.3, 25.6, 23.8, 20.7, 18.4,
18.0, 17.2, 16.2, 16.1. HR-MS (ESI): m/z calcd for C42H69O14 [M þ H]þ
797.4687, found 797.4670.
4.1.5.1. 3-O-b-D-Glucopyranoside oleanderolide (1a). Yield: 93%
(after chromatograph with MeOH/CHCl3, 1:6) as a white amor-
phous powder. Rf ¼ 0.45 (MeOH/CHCl3, 1:5). ½a D25
ꢂ
¼ þ59.4 (c 0.5,
4.1.5.5. 28-N-Methyl hexanoate oleanate 3-O-
(2a). Yield: 95% (after chromatograph with MeOH/CHCl3, 1:10) as a
b-D-glucopyranoside
CH3OH). 1H NMR (600 MHz, DMSO-d6):
d 4.88e4.94 (m, 4H, C2΄-OH,
0
C3΄-OH, C4 -OH, C12-OH), 4.37 (bs, 1H, C6΄-OH), 4.14 (d, J ¼ 7.8 Hz, 1H,
H-1΄), 3.34-3.65 (m, 3H, H-12, H-60-1, H-60-2), 3.12 (t-like, J ¼ 8.7,
8.3 Hz, 1H, H-30), 3.01-3.05 (m, 3H, H-3, H-40, H-50), 2.95 (m, 1H, H-
20), 2.11e2.16 (m, 1H, H-18), 1.33e1.93 (m, 16H), 1.24,1.02, 0.97, 0.93,
0.86, 0.81, 0.74 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz,
white amorphous powder. Rf
¼
0.39 (MeOH/CHCl3, 1:8).
½
a 2D5
ꢂ
¼ þ20.3 (c 0.4, CH3OH). 1H NMR (600 MHz, DMSO-d6):
d 7.23
(t, J ¼ 5.5 Hz, 1H, NeH), 5.20 (t, J ¼ 3.2 Hz, 1H, H-12), 4.85e4.87 (m,
0
0
0
0
3H, C2 -OH, C3 -OH, C4 -OH), 4.37 (br s, 1H, C6 -OH), 4.13 (d,
J ¼ 7.8 Hz, 1H, H-10), 3.63-3.65 (m, 1H, H-60-1), 3.57 (s, 3H, H-37),
3.40e3.42 (m, 1H, H-60-2), 3.09e3.12 (t, J ¼ 8.7 Hz, 1H, H-3), 3.00e
3.07 (m, 4H, H-30, H-40, H-50, H-31-1), 2.92e2.96 (m, 2H, H-20, H-31-
2), 2.78 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-18), 2.27 (apparent t, J ¼ 7.7,
7.4 Hz, 2H, H-35-1, H-35-2), 1.87e1.91 (m, 1H, H-16-1), 1.08, 0.97,
0.88, 0.86, 0.85, 0.75, 0.66 (s each, 3H each, CH3 ꢃ 7). 13C NMR
DMSO-d6):
d
178.9 (C-28), 105.5 (C-10), 90.6 (C-13), 87.8 (C-3), 76.9
(C-12), 76.6, 74.3, 73.9, 70.3, 61.3, 54.9, 50.3, 43.9, 41.8, 41.6, 38.8,
38.6, 38.4, 35.7, 33.7, 33.6, 33.1, 31.2, 28.1, 27.4, 27.4, 27.3, 25.6, 23.8,
20.7, 18.4, 18.0, 17.2, 16.2, 16.2. HR-MS (ESI): m/z calcd for C36H59O9
[M þ H]þ 635.4159, found 635.4174.
(150 MHz, CD3OD):
d 180.3 (C-28), 175.8 (C-36), 145.4 (C-13), 123.9
4.1.5.2. 3-O-
a
-
D
-Mannopyranoside oleanderolide (1b). Yield: 96%
(C-12), 106.7 (C-10), 90.7 (C-3), 78.3, 77.7, 75.6, 71.6, 62.8, 56.9, 52.0,
47.7, 47.5, 42.9, 42.6, 40.7, 40.6, 40.2,39.8, 37.7, 35.1, 34.7, 34.3, 33.9,
33.6, 31.6, 30.1, 28.5, 27.7, 27.0, 26.5, 25.7, 24.6, 24.0, 19.3, 17.9, 17.0,
15.7. HR-MS (ESI): m/z calcd for C43H72NO9 [M þ H]þ 746.5207,
found 746.5185.
(after chromatograph with MeOH/CHCl3, 1:6) as a white amor-
phous powder. Rf ¼ 0.44 (MeOH/CHCl3, 1:5). ½a D25
¼ þ59.4 (c 0.7,
ꢂ
CH3OH). 1H NMR (600 MHz, DMSO-d6):
d
4.96 (d, J ¼ 4.1 Hz,1H, C12
-
OH), 4.78 (s, 1H, H-10), 4.72 (d, J ¼ 4.6 Hz, 1H, C3΄-OH), 4.66 (d,
J ¼ 3.7 Hz, 1H, C2΄-OH), 4.54 (d, J ¼ 5.5 Hz, 1H, C4΄-OH), 4.37 (t-like,
J ¼ 5.5, 5.0 Hz, 1H, C6΄-OH), 3.66 (br s, 1H, H-12), 3.60e3.63 (m, 1H,
H-60-1), 3.52 (br s, 1H, H-20), 3.45e3.48 (m, 1H, H-30), 3.42e3.44 (m,
2H, H-50, H-60-2), 3.38e3.41 (m, 1H, H-40), 3.19 (dd, J ¼ 11.5, 3.7 Hz,
1H, H-3), 2.12e2.17 (m, 1H, H-18), 1.33e1.96 (m, 17H), 1.25, 1.02,
0.95, 0.93, 0.86, 0.82, 0.72 (s each, 3H each, CH3 ꢃ 7). 13C NMR
4.1.5.6. 28-N-Methyl hexanoate oleanate 3-O-a-D-mannopyranoside
(2b). Yield: 97% (after chromatograph with MeOH/CHCl3, 1:10)
as a white amorphous powder. Rf ¼ 0.37 (MeOH/CHCl3, 1:8).
½
a 2D5
ꢂ
¼ þ87.8 (c 0.7, CH3OH). 1H NMR (600 MHz, DMSO-d6):
d 7.24
(t, J ¼ 5.5 Hz, 1H, NeH), 5.20 (t, J ¼ 3.2 Hz, 1H, H-12), 4.77 (s, 1H, H-
0
178.9 (C-28), 95.9 (C-10), 90.6 (C-13), 80.2
1 ), 4.72 (d, J ¼ 5.0 Hz, 1H, C3 -OH), 4.67 (d, J ¼ 4.1 Hz, 1H, C2 -OH),
0
0
(150 MHz, DMSO-d6):
d
0
0
(C-3), 79.2 (C-12), 74.5, 74.3, 71.2, 71.0, 66.9, 61.4, 54.8, 50.3, 44.0,
43.9, 41.8, 41.6, 38.4, 38.0, 37.9, 35.9, 33.7, 33.5, 33.1, 31.2, 28.4, 27.4,
23.8, 21.2, 20.7, 18.4, 18.0, 17.3, 16.4, 16.1. HR-MS (ESI): m/z calcd for
4.55 (d, J ¼ 5.9 Hz, 1H, C4 -OH), 4.39 (t, J ¼ 5.9 Hz, 1H, C5 -OH), 3.59-
3.62 (m, 1H, H-60-1), 3.57 (s, 3H, H-37), 3.52 (m, 1H, H-20), 3.4e3.47
(m, 4H, H-30, H-40, H-50, H-60-2), 3.18 (dd, J ¼ 11.5, 4.1 Hz, 1H, H-3),
2.99-3.03 (m, 1H, H-31-1), 2.92-2.95 (m, 1H, H-31-2), 2.78 (dd,
J ¼ 13.3, 4.1 Hz, 1H, H-18), 2.27 (t, J ¼ 7.3 Hz, 2H, H-35-1, H-35-2),
1.20e1.89 (m, 22H), 1.09, 0.95, 0.88, 0.87, 0.87, 0.73, 0.67 (s each, 3H
C
36H59O9 [M þ H]þ 635.4159, found 635.4178.
4.1.5.3. 3-O-a-L-Fucopyranoside oleanderolide (1c). Yield: 94% (af-
ter chromatograph with MeOH/CHCl3, 1:6) as a white amorphous
each, CH3 ꢃ 7). 13C NMR (150 MHz, CD3OD):
d 180.3 (C-28),175.8 (C-
powder. Rf ¼ 0.52 (MeOH/CHCl3, 1:5). ½a D25
ꢂ
¼ þ42.6 (c 0.5, CH3OH).
36), 145.4 (C-13), 123.9 (C-12), 97.7 (C-10), 83.1 (C-3), 75.1, 73.1, 72.7,
68.5, 62.9, 56.8, 52.0, 42.9, 42.6, 40.7, 40.6, 40.5, 39.4, 39.2, 38.1, 35.1,
34.7, 34.3, 33.9, 33.6, 31.6, 30.1, 29.4, 28.5, 27.7, 26.5, 25.7, 24.6, 24.0,
23.9, 22.6,19.4, 18.0,17.1,15.9. HR-MS (ESI): m/z calcd for C43H72NO9
[M þ H]þ 746.5207, found 746.5190.
1H NMR (600 MHz, DMSO-d6):
d
4.96 (d, J ¼ 4.6 Hz, 1H, C12-OH),
4.62 (d, J ¼ 5.0 Hz, 1H, C3΄-OH), 4.57 (d,, J ¼ 4.6 Hz, 1H, C2΄-OH), 4.38
(d, J ¼ 4.6 Hz, 1H, C4΄-OH), 4.09 (d, J ¼ 7.3 Hz, 1H, H-10), 3.66 (bs, 1H,
H-12), 3.45 (dd, J ¼ 13.3, 6.4 Hz, 1H, H-50), 3.39 (m, 1H, H-40), 3.26
(m, 1H, H-30), 3.16e3.20 (m, 1H, H-20), 3.10 (dd, J ¼ 11.5, 3.7 Hz, 1H,
H-3), 2.12e2.18 (m, 1H, H-18), 1.10 (d, J ¼ 6.4 Hz, 3H, H-60), 1.10e1.96
(m, 23H), 1.24, 1.02, 0.95, 0.94, 0.86, 0.82, 0.72 (s each, 3H each,
4.1.5.7. 28-N-Methyl hexanoate oleanate 3-O-a-L-fucopyranoside
(2c). Yield: 96% (after chromatograph with MeOH/CHCl3, 1:10) as

Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
519
a
white amorphous powder. Rf
¼
0.46 (MeOH/CHCl3, 1:8).
(dd, J ¼ 13.3, 4.6 Hz, 1H, H-18), 2.50 (dd, J ¼ 12.8, 4.6 Hz, 1H, H-30eq),
2.32 (t, J ¼ 7.3 Hz, 2H, H-35-1, H-35-2), 2.00 (s, 3H, NAc), 1.16, 0.97, 0.94,
0.93, 0.90, 0.86, 0.77 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz,
½
a 2D5
ꢂ
¼ þ70.0 (c 0.7, CH3OH). 1H NMR (150 MHz, DMSO-d6):
d 7.23 (t,
J ¼ 5.5 Hz, 1H, NeH), 5.20 (t-like, J ¼ 3.2, 3.7 Hz, 1H, H-12), 4.60 (d,
0
0
J ¼ 5.5 Hz, 1H, C2 -OH), 4.53 (d, J ¼ 4.6 Hz, 1H, C3 -OH), 4.36 (d,
CDCl3): d 179.0, 174.5, 173.4, 169.7, 144.1 (C-13), 122.6 (C-12), 100.1 (C-
0
J ¼ 4.6 Hz, 1H, C4 -OH), 4.07 (d, J ¼ 7.8 Hz, 1H, H-1 ), 3.57 (s, 3H, H-
37), 3.45 (dd, J ¼ 12.8, 5.9 Hz, 1H, H-50), 3.38 (t-like, J ¼ 4.1, 4.6 Hz,
1H, H-40), 3.24e3.27 (m, 1H, H-30), 3.15e3.19 (m, 1H, H-20), 3.08 (dd,
J ¼ 11.9, 4.1 Hz, 1H, H-3), 2.99e3.04 (m, 1H, H-31-1), 2.91e2.96 (m,
1H, H-31-2), 2.79 (dd, J ¼ 12.4, 3.2 Hz, 1H, H-18), 2.27 (t, J ¼ 7.3 Hz,
2H, H-35-1, H-35-2), 1.04e1.92 (m, 30H), 0.94, 0.88, 0.86, 0.86, 0.86,
0.73, 0.66 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz, CD3OD):
20), 85.3 (C-3), 71.3, 70.3, 69.4, 66.2, 63.7, 55.7, 52.6, 51.9, 50.7, 46.4, 46.2,
41.9, 41.6, 41.3, 39.3, 39.2, 38.5, 37.9, 36.5, 33.8, 33.4, 33.0, 32.5, 32.3,
31.8, 30.3, 29.4, 29.2, 28.8, 27.5, 27.2, 26.4, 25.1, 24.4, 24.3, 23.3, 22.7,
22.6, 21.5, 18.1, 16.6, 15.9, 14.5. HR-MS (ESI): m/z calcd for
0
C
49H80N2O12Na [M þ Na]þ 911.5609, found 911.5633.
4.1.6. General procedure for synthesizing compounds 1ee1f and
2ee2f
d
180.3 (C-28), 175.8 (C-36), 145.4 (C-13), 123.9 (C-12), 102.7 (C-10),
86.3 (C-3), 75.3, 73.2, 72.4, 71.6, 57.4, 51.9, 47.7, 47.5, 42.9, 42.6, 40.7,
40.6, 39.6, 39.2, 38.0, 35.1, 34.7, 34.3, 33.9, 33.6, 31.6, 30.1, 28.9, 28.5,
27.7, 26.7, 26.5, 26.1, 25.7, 24.6, 24.1, 24.0, 19.5, 18.0, 17.2, 16.8, 15.9.
HR-MS (ESI): m/z calcd for C43H72NO8 [M þ H]þ 730.5258, found
730.5251.
To a solution of compound 1ae1b or 2ae2b (0.1 mmol) in t-
BuOH (1.2 mL) containing TEMPO (1 mg) was added a solution of
satd aq NaHCO3 (0.5 mL, its pH was adjusted to 9.5 with satd aq
Na2CO3) containing NaBr (3 mg), and TBAB (2 mg). The mixture was
cooled to 0 ꢁC. Under vigorous stirring, NaOCl (0.3 mL) was added
slowly. After 1 h at 0 ꢁC, the reaction was quenched with Na2S2O3.
After addition of water (1 mL) and EtOAc (5 mL), aq HCl (6 mol/L)
was added to adjust the final pH to pH 3. Then the organic phase
was separated, and the remaining aq phase was extracted with
EtOAc. The combined organic phase was washed with brine, dried
by Na2SO4, and then concentrated. The residue was purified by a
silica gel column chromatography to afford the product 1ee1f and
2ee2f, respectively.
4.1.5.8. 28-N-Methyl hexanoate oleanate 3-O-b-D-lactopyranoside
(2d). Yield: 98% (after chromatograph with MeOH/CHCl3, 1:6)
as a white amorphous powder. Rf ¼ 0.37 (MeOH/CHCl3, 1:4).
a 25
½ ꢂD ¼ ꢀ14.1 (c 0.4, CH3OH). 1H NMR (600 MHz, DMSO-d6):
d
7.24 (t,
00
J ¼ 5.5 Hz,1H, NeH), 5.20 (br s, 1H, H-12), 5.12 (d, J ¼ 4.1 Hz,1H, C2
-
0
0
OH), 5.06 (d, J ¼ 5.5 Hz, 1H, C2 -OH), 4.81 (d, J ¼ 5.0 Hz, 1H, C3 -OH),
00
00
00
4.65e4.68 (m, 2H, C3 -OH, C6 -OH), 4.53 (d, J ¼ 4.6 Hz, 1H, C4 -OH),
0
00
0
4.47 (t-like, J ¼ 6.3, 5.9 Hz,1H, C6 -OH), 4.19-4.22 (m, 2H, H-1 , H-1 ),
3.72 (dd, J ¼ 11.0, 5.5 Hz, 1H, H-60-1), 3.45e3.60 (m, 8H, H-300, H-400,
H-600-1, H-600-2, H-60-2, H-37), 3.24e3.31 (m, 4H, H-30, H-40, H-50, H-
500), 2.92e3.06 (m, 4H, H-20, H-3, H-31-1, H-31-2), 2.78 (dd, J ¼ 13.7,
5.0 Hz,1H, H-18), 2.27 (aparent t, J ¼ 7.7, 7.3 Hz, 2H, H-35-1, H-35-2),
4.1.6.1. 3-O-b-D-glucuronopyranoside oleanderolide (1e). Yield: 74%
(after chromatograph with MeOH/CHCl3, 1:6) as a white amor-
phous powder. Rf ¼ 0.40 (MeOH/CHCl3, 1:4). ½a D25
¼ þ9.6 (c 0.6,
ꢂ
CH3OH). 1H NMR (600 MHz, DMSO-d6):
d 5.46 (br s, 1H, C12-OH),
1.08, 0.98, 0.88, 0.86, 0.85, 0.75, 0.66 (s each, 3H each, CH3 ꢃ 7). 13
C
4.87e4.96 (m, 3H, C2 -OH, C3 -OH, C4 -OH), 4.15 (d, J ¼ 7.8 Hz, 1H, H-
10), 3.66 (br s, 1H, H-12), 3.25 (br s, 1H, H-20), 3.13 (br s, 2H, H-30, H-
40), 3.02 (dd, J ¼ 11.7, 4.1 Hz,1H, H-3), 2.96 (br s,1H, H-18),1.03, 0.97,
0.95, 0.88, 0.88, 0.82, 0.75 (s each, 3H each, CH3 ꢃ 7). 13C NMR
0
0
0
NMR (150 MHz, CD3OD):
d 178.9 (C-28), 174.5 (C-36), 144.1 (C-13),
122.7 (C-12), 105.2 (C-10), 103.8 (C-100), 89.6 (C-3), 79.4, 75.7, 75.3,
74.9, 73.9, 73.5, 71.2, 69.1, 61.2, 60.7, 55.7, 50.7, 46.4, 46.2, 41.6, 41.3,
39.4, 39.3, 39.1, 38.5, 36.6, 33.8, 33.4, 33.0, 32.6, 32.3, 30.3, 28.8, 27.2,
26.4, 25.7, 25.1, 24.4, 23.3, 22.7, 22.6,17.9,16.7,15.7,15.0,14.6. HR-MS
(ESI): m/z calcd for C49H82NO14 [M þ H]þ 908.5735, found 908.5765.
(150 MHz, CD3OD): d
182.5, 106.7 (C-10), 93.3 (C-13), 91.0 (C-3), 77.9
(C-12), 76.5, 75.5, 56.9, 52.5, 46.2, 45.8, 43.5, 43.3, 40.3, 40.2, 39.9,
37.4, 35.2, 35.1, 33.7, 32.4, 30.8, 29.6, 28.9, 28.7, 28.4, 26.9, 24.2, 22.3,
19.2, 19.0, 18.8, 16.9. HR-MS (ESI): m/z calcd for C36H57O10 [M þ H]þ
649.3952, found 649.3945.
4.1.5.9. 28-N-Methyl hexanoate oleanate 3-O-5-acetamido-3,5-dideoxy-
b-D-glycero-a-D-galacto-2-nonulo -pyranosonate (2i). Yield: 89% (after
chromatograph with MeOH/CHCl3, 1:5) as a white amorphous pow-
4.1.6.2. 3-O-
a
-
D
-Mannocuronopyranoside
oleanderolide
(1f).
der. Rf ¼ 0.31 (MeOH/CHCl3,1:8). ½a D25
ꢂ
¼ þ12.1 (c 0.6, CH3OH). 1H NMR
Yield: 75% (after chromatograph with MeOH/CHCl3, 1:6) as a
(600 MHz, CD3OD):
d
5.34 (t, J ¼ 3.2 Hz, 1H, H-12), 3.87 (m,1H), 3.85 (t,
white amorphous powder. Rf
¼
0.43 (MeOH/CHCl3, 1:4).
J ¼ 3.2 Hz, 1H), 3.83 (t, J ¼ 2.3 Hz, 1H), 3.82 (s, 3H, COOCH3), 3.74 (t,
J ¼ 10.0 Hz, 1H), 3.65 (s, 3H, COOCH3), 3.60e3.64 (m, 3H), 3.48
(dd, J ¼ 9.3,1.8 Hz,1H), 3.38 (dd, J ¼ 10.5,1.8 Hz,1H), 3.20 (m,1H, H-31-
1), 3.08 (m,1H, H-31-2), 3.04 (m,1H, H-3), 2.79 (dd, J ¼ 13.7, 3.7 Hz,1H,
H-18), 2.70 (dd, J ¼ 12.8, 4.6 Hz, 1H, H-30eq), 2.32 (t, J ¼ 7.3 Hz, 2H, H-
35-1, H-35-2), 2.00 (s, 3H, NAc), 1.17, 1.02, 0.95, 0.94, 0.91, 0.78, 0.77 (s
½
a 2D5
d
ꢂ
¼ þ21.0 (c 0.4, CH3OH). 1H NMR (600 MHz, DMSO-d6):
0
0 0
5.01e5.03 (m, 2H, C12-OH, H-1 ), 4.70-4.74 (m, 2H, C2 -OH, C3 -
OH), 3.74 (d, J ¼ 9.6 Hz, 1H, H-50), 3.67 (s, 1H, H-12), 3.59 (t-like,
J ¼ 9.2, 9.1 Hz, 1H, H-40), 3.50 (br s, 1H, H-20, H-30), 3.17e3.20 (m,
1H, H-3), 2.12e2.16 (m, 1H, H-18), 1.24, 1.03, 0.94, 0.93, 0.86, 0.83,
0.73 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz, DMSO-d6):
each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d
179.0, 174.5,
d
178.8, 96.1 (C-10), 90.5 (C-13), 80.6 (C-3), 74.2 (C-12), 72.3, 71.0,
174.1, 170.7, 144.1 (C-13), 122.6 (C-12), 97.7 (C-20), 80.6 (C-3), 73.7, 71.5,
68.9, 67.2, 63.5, 55.9, 52.5, 46.4, 46.2, 41.6, 41.3, 40.8, 39.3, 39.2, 38.2,
36.5, 33.8, 33.4, 33.1, 32.5, 32.2, 30.3, 29.4, 28.8, 28.3, 27.2, 26.4, 25.2,
24.5, 24.4, 23.2, 22.7, 21.3, 18.3, 16.7, 15.7, 14.6. HR-MS (ESI): m/z calcd
for C49H81N2O12 [M þ H]þ 889.5790, found 889.5748.
68.7, 59.7, 55.0, 50.3, 44.0, 43.9, 41.8, 41.6, 38.4, 38.0, 37.9, 35.9,
35.8, 34.7, 33.7, 33.6, 33.1, 31.2, 28.3, 28.2, 27.3, 27.2, 23.7, 21.4,
20.7, 18.3, 17.9, 16.3, 16.1, 14.1. HR-MS (ESI): m/z calcd for C36H57O10
[M þ H)þ 649.3952, found 649.3976.
4.1.6.3. 28-N-methyl hexanoate oleanate 3-O-b-D-glucuronopyrano-
4.1.5.10. 28-N-methyl hexanoate oleanate 3-O-5-acetamido-3,5-
side (2e). Yield: 79% (after chromatograph with MeOH/CHCl3, 1:5)
as a white amorphous powder. Rf ¼ 0.31 (MeOH/CHCl3, 1:4).
dideoxy-
b
-
D
-glycero-
b
-
D
-galacto-2-nonulo-pyranosonate
(2j). Yield:
90% (after chromatograph with MeOH/CHCl3, 1:5) as a white amor-
½
a 2D5
ꢂ
¼ þ8.3 (c 0.2, CH3OH). 1H NMR (600 MHz, DMSO-d6):
d
7.26 (t,
phous powder. Rf ¼ 0.25 (MeOH/CHCl3, 1:8). ½a D25
ꢂ
¼ þ6.1 (c 0.4,
J ¼ 5.5 Hz, 1H, NeH), 5.20 (s, 1H, H0-12), 4.91e4.94 (m, 2H, C2 -OH,
0
CH3OH). 1H NMR (600 MHz, CD3OD):
d
5.33 (t, J ¼ 3.6 Hz, 1H, H-12),
C4 -OH), 4.16 (d, J ¼ 7.8 Hz, 1H, H-1 ), 3.57 (s, 3H, H-37), 3.30 (br s,
0
0
0
0
0
4.07 (td, J ¼ 11.0, 4.6 Hz, 1H), 4.01 (d, J ¼ 10.5 Hz, 1H), 3.87 (t,
J ¼ 10.5 Hz, 1H), 3.83 (s, 3H, COOCH3), 3.80 (dd, J ¼ 11.4, 3.2 Hz, 1H),
3.77 (m, 1H), 3.68 (dd, J ¼ 11.5, 5.0 Hz, 1H), 3.65 (s, 3H, COOCH3), 3.48
(d, J ¼ 8.7 Hz, 1H), 3.20 (m, 1H, H-31-1), 3.07 (m, 2H, H-3, H-31-2), 2.79
1H, C3 -OH), 3.13-3.17 (m, 2H, H-3 , H-4 ), 3.00e3.04 (m, 2H, H-5 ,
H-31-1), 2.91e2.96 (m, 2H, H-20, H-31-2), 2.78 (dd, J ¼ 12.8, 3.2 Hz,
1H, H-3), 2.27 (t, J ¼ 7.3 Hz, 2H, H-35), 1.19-1.89 (m, 20H), 1.08, 0.97,
0.87, 0.86, 0.85, 0.75, 0.66 (s each, 3H each, CH3 ꢃ 7). 13C NMR

520
Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
(150 MHz, DMSO-d6):
d
176.0,173.3, 144.2 (C-13), 121.3 (C-12), 105.4
4.1.8. General procedure for synthesizing compounds 3ae3f
(C-10), 87.9 (C-3), 76.6, 74.4, 73.8, 72.1, 54.9, 51.2, 47.1, 46.0, 45.2,
41.2, 40.4, 38.1, 36.3, 33.6, 33.3, 32.9, 32.7, 32.4, 30.4, 28.7, 27.6, 26.9,
26.0, 25.6, 25.4, 24.2, 23.6, 22.9, 22.0, 18.9, 17.7, 16.8, 16.5, 15.1. HR-
MS (ESI): m/z calcd for C43H70NO10 [M þ H]þ 760.5000, found
760.4979.
To a solution of compounds 2ae2f or 2ie2j (0.1 mmol) in CH3OH
(6 mL) was added 2 mol/L NaOH in CH3OH/THF (2:3) (1 mL). The
mixture was stirred for 2 h. After completion by TLC, the reaction
mixture was concentrated. The residue was purified by a silica gel
column chromatography to afford the product 3ae3f, respectively.
4.1.6.4. 28-N-Methyl hexanoate oleanate 3-O-
a-D
-mannocuronopyr-
4.1.8.1. Hexanoate oleanate 3-O-b-D-glucopyranoside (3a). Yield: 97%
anoside (2f). Yield: 77% (after chromatograph with MeOH/CHCl3,
1:5) as a white amorphous powder. Rf ¼ 0.29 (MeOH/CHCl3, 1:4).
(after chromatograph with MeOH/CHCl3, 1:10) as a white amor-
phous powder. Rf ¼ 0.32 (MeOH/CHCl3, 1:8). ½a D25
¼ þ15.7 (c 0.3,
ꢂ
½
a 2D5
ꢂ
¼ þ22.4 (c 0.3, CH3OH). 1H NMR (600 MHz, DMSO-d6):
d
7.23
CH3OH). 1H NMR (600 MHz, CD3OD):
d
5.35 (t, J ¼ 3.6 Hz, 1H, H-12),
(t, J 0¼ 5.0 Hz, 1H, NeH), 5.20 (t, J ¼ 3.8 Hz, 1H, H-12), 5.00 (br s, 1H,
4.32 (d, J ¼ 7.7 Hz,1H, H-10), 3.85 (dd, J ¼ 11.9,1.8 Hz,1H, H-60-1), 3.67
(dd, J ¼ 11.9, 5.5 Hz, 1H, H-60-2), 3.34 (t, J ¼ 9.0 Hz, 1H, H-30), 3.28 (t,
J ¼ 9.6 Hz, 1H, H-40), 3.23-3.26 (m, 2H, H-20, H-50), 3.20 (m, 1H, H-31-
1), 3.18 (dd, J ¼ 13.5, 3.7 Hz,1H, H-3), 2.80 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-
0
0
0
H-1 ), 4.73 (m, 3H, C2 -OH, C3 -OH, C4 -OH), 3.75 (d, J ¼ 9.9 Hz,1H, H-
50), 3.62 (t-like, J ¼ 9.4, 8.8 Hz, 1H, H-40), 3.57 (s, 3H, H-37), 3.49 (m,
2H, H-20, H-30), 3.19 (dd, J ¼ 11.5, 4.1 Hz, 1H, H-3), 3.00e3.04 (m, 1H,
H-31-1), 2.92e2.95 (m, 1H, H-31-2), 2.79 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-
18), 2.27 (t, J ¼ 7.1 Hz, 2H, H-35-1, H-35-2), 1.09, 0.93, 0.87, 0.86,
0.85, 0.73, 0.66 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz,
18),1.17,1.06, 0.95, 0.94, 0.91, 0.85, 0.79 (s each, 3H each, CH3 ꢃ 7). 13
C
NMR (150 MHz, CD3OD):
d 180.3 (C-28), 145.5 (C-13), 124.0 (C-12),
106.8 (C-10), 90.8 (C-3), 78.3, 77.7, 75.7, 71.7, 62.8, 57.0, 47.7, 47.5, 43.0,
42.6, 40.7, 40.5, 40.2, 39.8, 37.9, 35.2, 34.4, 33.9, 33.6, 31.7, 30.2, 28.6,
27.8, 27.1, 26.5, 25.9, 24.6, 24.1, 19.3, 18.0, 17.0, 16.0. HR-MS (ESI): m/z
calcd for C42H70NO9 [M þ H]þ 732.5051, found 732.5036.
CD3OD):
d
180.4, 177.8, 145.6 (C-13), 124.0 (C-12), 98.5 (C-10), 84.5
(C-3), 72.7, 72.4, 70.0, 56.9, 47.9, 47.8, 43.1, 42.8, 40.8, 40.6, 39.5,
39.4, 38.2, 35.2, 35.0, 34.4, 34.0, 33.7, 31.7, 30.8, 30.2, 29.5, 28.6, 27.8,
26.6, 25.9, 24.7, 24.2, 22.9, 19.5, 18.1, 17.2, 16.1. HR-MS (ESI): m/z
calcd for C43H69NO10 [M þ H]þ 760.5000, found 760.5013.
4.1.8.2. Hexanoate oleanate 3-O-
a-D-mannopyranoside (3b).
Yield: 94% (after chromatograph with MeOH/CHCl3, 1:10) as a
4.1.7. General procedure for synthesizing compounds 2g and 2h
To a solution of compound 2e or 2f (0.1 mmol) in acetone (5 mL)
was added K2CO3 (2.5 equiv.). The mixture was stirred for 30 min,
and then MeI (1.2 equiv.) was added to the above reaction mixture
and stirred at room temperature for another 1 h, and then the re-
action mixture was concentrated. The residue was purified by a
silica gel column chromatography to afford the product 2ge2h,
respectively.
white amorphous powder. Rf
¼
0.31 (MeOH/CHCl3, 1:8).
½
a 2D5
ꢂ
¼ þ43.2 (c 0.2, CH3OH). 1H NMR (600 MHz, CD3OD):
d 5.35 (t,
J ¼ 3.6 Hz, 1H, H-12), 4.94 (s, 1H, H-10), 3.81 (dd, J ¼ 10.6, 1.2 Hz, 1H,
H-60-1), 3.73 (m, 1H, H-60-2), 3.70 (t, J ¼ 9.1 Hz, 1H, H-40), 3.68 (m,
1H, H-50), 3.76 (dd, J ¼ 9.2, 3.6 Hz, 1H, H-30), 3.63 (m,1H, H-20), 3.23
(m, 1H, H-31-1), 3.19 (dd, J ¼ 13.5, 4.1 Hz, 1H, H-3), 3.07 (m, 1H, H-
31-2), 2.80 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-18), 1.17, 1.04, 0.96, 0.95, 0.91,
0.81, 0.79 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz, CD3OD):
d
180.2 (C-28), 145.4 (C-13), 124.0 (C-12), 97.7 (C-10), 83.2 (C-3),
4.1.7.1. 28-N-Methyl hexanoate oleanate 3-O-
b
-D-glucuronopyrano-
75.2, 73.1, 72.8, 68.6, 63.0, 56.8, 47.7, 47.5, 43.0, 42.6, 40.8, 40.5,
39.5, 39.3, 38.2, 35.2, 35.1, 34.4, 33.9, 33.6, 31.7, 30.2, 29.5, 28.6,
27.8, 26.5, 24.6, 24.1, 24.0, 22.7, 19.4, 18.1, 17.1, 16.0. HR-MS (ESI): m/
z calcd for C42H70NO9 [M þ H]þ 732.5051, found 732.5018.
side methyl ester (2g). Yield: 81% (after chromatograph with
MeOH/CHCl3, 1:6) as a white amorphous powder. Rf ¼ 0.43 (MeOH/
CHCl3, 1:4). ½a 2D5
ꢂ
¼ þ10.1 (c 0.3, CH3OH). 1H NMR (600 MHz,
CD3OD):
d
5.35 (t, J ¼ 3.7 Hz, 1H, H-12), 4.31 (d, J ¼ 7.8 Hz, 1H, H-10),
3.83 (d, J ¼ 9.6 Hz, 1H, H-50), 3.66, 3.64 (s each, 3H each,
COOCH3 ꢃ 2), 3.46 (m, 1H, H-30), 3.42 (m, 1H, H-40), 3.27 (t,
J ¼ 7.8 Hz, 1H, H-20), 3.18e3.20 (m, 2H, H-3, H-31-1), 3.07 (m, 1H, H-
31-2), 2.79 (dd, J ¼ 13.3, 3.7 Hz, 1H, H-18), 2.32 (t, J ¼ 7.3 Hz, 2H, H-
35), 1.17, 1.05, 0.95, 0.94, 0.90, 0.85, 0.78 (s each, 3H each, CH3 ꢃ 7).
4.1.8.3. Hexanoate oleanate 3-O-a-L-fucopyranoside (3c). Yield: 93%
(after chromatograph with MeOH/CHCl3, 1:10) as a white amor-
phous powder. Rf ¼ 0.40 (MeOH/CHCl3, 1:8). ½a D25
¼ þ34.1 (c 0.1,
ꢂ
CH3OH). 1H NMR (600 MHz, CD3OD):
d
5.36 (t, J ¼ 3.6 Hz, 1H, H-12),
4.21 (d, J ¼ 6.8 Hz, 1H, H-10), 3.55-3.58 (m, 2H, H-20, H-30), 3.42e
3.46 (m, 2H, H-40, H-50), 3.23 (m, 1H, H-31-1), 3.19 (dd, J ¼ 13.7,
3.7 Hz, 1H, H-3), 3.06e3.10 (m, 1H, H-31-2), 2.80 (dd, J ¼ 13.3,
3.7 Hz, 1H, H-18), 1.25 (d, J ¼ 6.4 Hz, 1H, H-60), 1.18, 1.02, 0.97, 0.95,
0.91, 0.82, 0.79 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz,
13C NMR (150 MHz, CD3OD):
d 180.4, 175.9, 145.6 (C-13), 124.1 (C-
12),106.9 (C-10), 91.3 (C-3), 77.9, 75.5, 73.8, 57.1, 52.2, 47.9, 47.6, 43.1,
42.8, 40.8, 40.7, 40.3, 40.0, 38.0, 35.3, 34.9, 34.5, 34.0, 33.8, 31.8,
30.2, 28.8, 27.8, 27.0, 26.7, 25.8, 24.8, 24.2, 24.1, 19.5, 18.2, 17.3, 16.2.
HR-MS (ESI): m/z calcd for C43H70NO10 [M-CH3þH]þ 760.5000,
found 760.4998.
CD3OD): d
180.3 (C-28), 145.4 (C-13), 124.0 (C-12), 102.7 (C-10), 86.4
(C-3), 75.4, 73.3, 72.4, 71.7, 57.4, 47.7, 47.6, 43.0, 42.7, 40.8, 40.6, 39.7,
39.3, 38.1, 35.2, 34.9, 34.8, 34.4, 34.0, 33.6, 31.7, 30.2, 28.9, 28.6, 27.8,
26.5, 25.8, 24.7, 24.2, 24.1, 19.5,18.1, 17.3, 16.9,15.9. HR-MS (ESI): m/z
calcd for C42H70NO8 [M þ H]þ 716.5101, found 716.5130.
4.1.7.2. 28-N-Methyl hexanoate oleanate 3-O-a-D-mannocuronopyr-
anoside-mannocuronopyranoside methyl ester (2h). Yield: 76% (af-
ter chromatograph with MeOH/CHCl3, 1:6) as a white amorphous
powder. Rf ¼ 0.38 (MeOH/CHCl3, 1:4). ½a D25
ꢂ
¼ þ19.7 (c 0.2, CH3OH).
4.1.8.4. Hexanoate oleanate 3-O-b-D-lactopyranoside (3d). Yield: 98%
1H NMR (600 MHz, CD3OD):
d
7.23 (t, J ¼ 5.5 Hz, 1H, N-H), 5.35 (t,
(after chromatograph with MeOH/CHCl3, 1:6) as a white amorphous
J ¼ 3.8 Hz,1H, H-12), 4.59 (br s, 2H, H-10, H-20), 3.75e3.80 (m, 3H, H-
30, H-40, H-50), 3.70, 3.65 (s each, 3H each, COOCH3 ꢃ 2), 3.19e3.22
(m, 2H, H-3, H-31-1), 3.06-3.09 (m, 1H, H-31-2), 2.80 (dd, J ¼ 13.7,
4.1 Hz, 1H, H-18), 2.33 (t, J ¼ 7.1 Hz, 2H, H-35-1, H-35-2), 1.17, 1.03,
0.96, 0.95, 0.91, 0.82, 0.79 (s each, 3H each, CH3 ꢃ 7). 13C NMR
powder. Rf ¼ 0.31 (MeOH/CHCl3, 1:4). ½a D25
¼ ꢀ10.2 (c 0.2, CH3OH).
ꢂ
1H NMR (600 MHz, CD3OD):
d
5.36 (t, J ¼ 3.2 Hz, 1H, H-12), 4.38 (t,
J ¼ 9.6 Hz, 1H, H-30), 4.35 (t, J ¼ 9.6 Hz, 1H, H-40), 3.85 (m, 2H, H-300,
H-400), 3.82 (m, 1H, H-60-1), 3.78 (dd, J ¼ 11.4, 7.7 Hz, 1H, H-600-1),
3.69 (dd, J ¼ 11.5, 4.1 Hz, 1H, H-600-2), 3.58 (d, J ¼ 7.8 Hz, 1H, H-10),
3.56 (t, J ¼ 8.5 Hz, 1H, H-20), 3.53 (dd, J ¼ 12.9, 4.6 Hz, 1H, H-60-2),
3.50 (d, J ¼ 8.0 Hz,1H, H-100), 3.40 (m,1H, H-50), 3.35 (t, J ¼ 4.1 Hz,1H,
H-500), 3.26 (t, J ¼ 7.7 Hz, 1H, H-200), 3.16e3.23 (m, 2H, H-3, H-31-1),
3.08 (m, 1H, H-31-2), 2.79 (dd, J ¼ 14.6, 4.1 Hz, 1H, H-18), 2.29 (t,
J ¼ 7.3 Hz, 2H, H-35), 1.17, 1.06, 0.95, 0.94, 0.91, 0.85, 0.79 (s each, 3H
(150 MHz, CD3OD): d 180.4, 176.1, 145.5 (C-13), 124.1 (C-12), 93.2 (C-
10), 81.3 (C-3), 77.7, 72.5, 69.4, 57.2, 54.6, 52.1, 47.7, 43.1, 41.0, 40.8,
40.6, 38.2, 34.9, 33.7, 32.9, 31.8, 31.0, 30.8, 30.2, 29.5, 28.7, 27.8, 25.8,
24.5, 24.2, 19.5, 18.2, 17.3, 16.1, 14.5. HR-MS (ESI): m/z calcd for
C
43H70NO10 [M-CH3 þ H]þ 760.5000, found 760.4931.

Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
521
each, CH3 ꢃ 7). 13C NMR (150 MHz, CD3OD):
d
178.9 (C-28), 176.2 (C-
2), 3.04 (m, 1H, H-3), 2.78 (dd, J ¼ 13.3, 3.2 Hz, 1H, H-18), 2.49 (dd,
J ¼ 12.8, 4.6 Hz, 1H, H-30eq), 2.28 (t, J ¼ 7.3 Hz, 2H, H-35-1, H-35-2),
2.00 (s, 3H, NAc), 1.16, 1.00, 0.94, 0.94, 0.90, 0.87, 0.77 (s each, 3H
36), 144.1 (C-13), 122.7 (C-12), 105.3 (C-10), 103.7 (C-100), 89.6 (C-3),
79.4, 75.8, 75.3, 74.9, 73.9, 73.5, 71.3, 69.0, 61.2, 60.7, 55.7, 46.4, 46.2,
41.6, 41.3, 39.4, 39.2, 38.8, 38.4, 36.6, 33.8, 33.5, 33.0, 32.6, 32.3, 30.3,
29.4, 28.8, 28.5, 27.2, 26.4, 25.7, 25.1, 24.5, 23.3, 22.7, 18.0, 16.7, 15.7,
14.6. HR-MS (ESI): m/z calcd for C48H80NO14 [M þ H]þ 894.5579,
found 894.5596.
each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 178.9, 176.2, 173.3,
144.1 (C-13), 122.7 (C-12), 99.7 (C-20), 84.6 (C-3), 71.2, 70.1, 69.4,
66.6, 63.9, 55.8, 52.7, 46.4, 46.2, 42.2, 41.6, 41.3, 39.3, 39.2, 38.5,
38.0, 36.5, 33.8, 33.5, 33.0, 32.6, 32.2, 31.7, 30.3, 29.4, 28.8, 27.6, 27.2,
26.4, 25.1, 24.5, 23.3, 22.7, 21.4, 18.1, 16.7, 16.1, 14.5, 13.1. HR-MS
(ESI): m/z calcd for C47H77N2O12Na [M þ Na]þ 861.5477, found
861.5446.
4.1.8.5. Hexanoate oleanate 3-O-b-D-glucuronopyranoside (3e).
Yield: 91% (after chromatograph with MeOH/CHCl3, 1:5) as a white
amorphous powder. Rf ¼ 0.26 (MeOH/CHCl3, 1:4). ½a D25
¼ þ7.8 (c
ꢂ
0.1, CH3OH). 1H NMR (600 MHz, CD3OD):
d
5.34 (t, J ¼ 3.2 Hz, 1H, H-
4.2. Biological testing
12), 4.37 (d, J ¼ 7.3 Hz, 1H, H-10), 3.70 (d, J ¼ 8.2 Hz, 1H, H-50), 3.49
(t, J ¼ 9.2 Hz, 1H, H-30), 3.44 (t, J ¼ 8.7 Hz, 1H, H-40), 3.26 (t,
J ¼ 7.7 Hz, 1H, H-20), 3.16-3.22 (m, 2H, H-3, H-31-1), 3.08 (m, 1H, H-
31-2), 2.79 (dd, J ¼ 13.3, 3.2 Hz, 1H, H-18), 2.32 (t, J ¼ 7.3 Hz, 2H, H-
35), 1.17, 1.06, 0.94, 0.94, 0.91, 0.86, 0.78 (s each, 3H each, CH3 ꢃ 7).
A substrate, p-nitrophenyl phosphate (pNPP), for the PTP1B
assay was purchased from Sigma in the di(Tris) salt form. The
positive reference compounds Sodium Orthovanadate and Rosi-
glitazone were purchased from GSK. The glucose assay kit was
purchased from Chengdu Mike Technology Company. The native
form of PTP1B was expressed in an Escherichia coli expression
systems, and purified as described previously.
13C NMR (150 MHz, CD3OD):
d 178.9 (C-28), 174.5 (C-36), 144.1 (C-
13), 122.6 (C-12), 105.4 (C-10), 89.9 (C-3), 76.6, 75.1, 74.0, 72.4, 55.7,
50.7, 46.4, 46.2, 41.7, 41.3, 39.4, 39.3, 38.9, 38.5, 36.6, 33.8, 33.4,
33.0, 32.6, 32.3, 30.3, 28.8, 27.3, 27.2, 26.4, 25.6, 25.3, 24.4, 23.3,
22.8, 22.7, 18.0, 16.7, 15.8, 14.7. HR-MS (ESI): m/z calcd for
4.2.1. PTP1B inhibitory activity
C
42H68NO10 [M þ H]þ 746.4843, found 746.4863.
PTP1B was diluted to appropriate concentrations in enzyme
dilution buffer (25 mM HEPES, 50 mM NaCl, 2.5 mM EDTA, 0.1%
bovine serum albumin, pH 7.2), and inhibitors were dissolved in
DMSO. The PTP1B enzyme activity was measured at 37 ꢁC by
monitoring the hydrolysis of pNPP in buffer A (50 mM HEPES,
2.5 mM EDTA, pH 7.0). The absorbance at 405 nm was measured to
4.1.8.6. Hexanoate oleanate 3-O-a-D-mannocuronopyranoside (3f).
Yield: 93% (after chromatograph with MeOH/CHCl3, 1:5) as a white
amorphous powder. Rf ¼ 0.25 (MeOH/CHCl3, 1:4). ½a D25
¼ þ13.7 (c
ꢂ
0.1, CH3OH). 1H NMR (600 MHz, CD3OD):
d 5.36 (br s,1H, H-12), 5.00
(s, 1H, H-10), 4.14 (d, J ¼ 9.2 Hz, 1H, H-50), 3.89 (t, J ¼ 9.2 Hz, 1H, H-
40), 3.74 (m, 2H, H-20, H-30), 3.26 (m, 1H, H-31-1), 3.20 (dd, J ¼ 13.7,
3.8 Hz, 1H, H-3), 3.09 (m, 1H, H-31-2), 2.78 (dd, J ¼ 12.4, 3.2 Hz, 1H,
H-18), 2.31 (t, J ¼ 7.3 Hz, 2H, H-35), 1.17, 1.04, 0.96, 0.94, 0.90, 0.82,
determine the amount of released p-nitrophenol. For a typical 50
reaction, inhibitor (5.0 L) was added to a reaction mixture con-
taining PTP1B enzyme (5.0 L), and H2O (25 L).
L), 5ꢃ buffer A (10
mL
m
m
m
m
Meanwhile, Blank control (without PTP1B enzyme and samples)
and negative control (without samples) were established. After the
mixture had been incubated at 37 ꢁC for 10 min, the PTP1B enzyme
reaction was initiated by the addition of pNPP. After 30 min at 37 ꢁC,
the reaction was quenched by the addition of 2 M Na2CO3, with the
absorbance at 405 nm measured to quantify the produced p-
nitrophenol, providing the optical density (OD) values. According to
the OD values, the inhibition rate against PTP1B enzyme was
0.79 (s each, 3H each, CH3 ꢃ 7). 13C NMR (150 MHz, CD3OD):
d 180.4
(C-28), 177.8 (C-36), 145.6 (C-13), 124.0 (C-12), 98.5 (C-10), 84.5 (C-
3), 72.7, 72.4, 70.0, 56.9, 47.9, 47.8, 43.1, 42.8, 40.8, 40.6, 39.5, 39.4,
38.2, 35.2, 35.0, 34.4, 34.0, 33.7, 31.7, 30.8, 30.2, 29.5, 28.6, 27.8, 26.6,
25.9, 24.7, 24.2, 22.9, 19.5, 18.1, 17.2, 16.1. HR-MS (ESI): m/z calcd for
C
42H68NO10 [M þ H]þ 746.4843, found 746.4879.
4.1.8.7. Hexanoate oleanate 3-O-5-acetamido-3,5-dideoxy-
b
-D-glyc-
calculated. When inhibition rate is larger than 70% at 10 mg/mL, the
ero- -D-galacto-2-nonulopyranosonate (3g). Yield: 86% (after
a
IC50 values of the inhibitors were determined by measuring the
pNPP hydrolase activity in a range of different concentrations of
inhibitor, and calculated by 4 Parameter Logistic Model (Xlfit soft-
ware). The results were obtained from duplicate or triplicate
experiments.
chromatograph with MeOH/CHCl3, 1:5) as a white amorphous
powder. Rf ¼ 0.23 (MeOH/CHCl3, 1:8). ½a D25
¼ þ5.7 (c 0.2, CH3OH).
ꢂ
1H NMR (600 MHz, CD3OD):
d
5.34 (t, J ¼ 3.2 Hz, 1H, H-12), 3.88 (m,
1H), 3.85 (d, J ¼ 2.4 Hz, 1H), 3.83 (d, J ¼ 2.2 Hz, 1H), 3.72 (t,
J ¼ 10.1 Hz, 1H), 3.60-3.67 (m, 3H), 3.50 (dd, J ¼ 8.7, 1.4 Hz, 1H), 3.39
(dd, J ¼ 10.1, 1.8 Hz, 1H), 3.19 (m, 1H, H-31-1), 3.08 (m, 1H, H-31-2),
3.05 (m, 1H, H-3), 2.79 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-18), 2.72 (dd,
J ¼ 12.8, 4.1 Hz, 1H, H-30eq), 2.29 (t, J ¼ 7.3 Hz, 2H, H-35-1, H-35-2),
2.00 (s, 3H, NAc), 1.17, 1.02, 0.94, 0.94, 0.90, 0.79, 0.77 (s each, 3H
4.2.2. Insulin-sensitizing activity
3T3-L1 cells were incubated in high glucose culture medium
with phenol red DMEM and 10% FBS in 6-well plates. When 3T3-L1
cells were confluent to the degree of 90%, induction of differenti-
ation of 3T3-L1 cells in high glucose culture medium with phenol
red DMEM, 10% FBS, Ins, Dex and IBMX was carried out. After 4
days, differentiation 3T3-L1 cells were inoculated in 24-well plates,
and incubated in high glucose culture medium with phenol red
DMEM and 10% FBS for 2 days, and then induced insulin resistance
in high glucose culture medium with 10% FBS, low concentration
Ins and high concentration Dex. After 4 days, the culture medium
was substituted with high glucose culture medium including the
samples to be tested. At the same time, Blank control (after in-
duction of differentiation of normal cells) and negative control
(after induction of differentiation insulin resistance cells) without
samples were established. After incubating for 50 h, the superna-
each, CH3 ꢃ 7). 13C NMR (150 MHz, CDCl3):
d 178.9, 176.1, 174.2,
171.8, 144.1 (C-13), 122.6 (C-12), 97.6 (C-20), 80.7 (C-3), 73.7, 71.9,
68.8, 67.5, 63.3, 56.0, 52.6, 46.3, 46.2, 41.6, 41.2, 41.0, 39.3, 39.2, 38.4,
38.3, 36.5, 33.8, 33.5, 33.0, 32.5, 32.3, 30.3, 29.4, 28.8, 28.3, 27.2,
26.4, 24.5, 24.3, 23.2, 22.7, 21.3, 18.3, 16.7, 15.8, 14.6. HR-MS (ESI): m/
z calcd for C47H77N2O12 [M þ H]þ 861.5477, found 861.5474.
4.1.8.8. Hexanoate oleanate 3-O-5-acetamido-3,5-dideoxy-
b-D-glyc-
ero- -galacto-2-nonulopyranosonate (3h). Yield: 88% (after
b-D
chromatograph with MeOH/CHCl3, 1:5) as a white amorphous
powder. Rf ¼ 0.20 (MeOH/CHCl3,1:8). ½a D25
ꢂ
¼ þ4.3 (c 0.1, CH3OH). 1H
NMR (600 MHz, CD3OD):
d
5.34 (t, J ¼ 3.2 Hz, 1H, H-12), 4.06 (td,
J ¼ 10.5, 5.1 Hz, 1H), 4.03 (d, J ¼ 10.5 Hz, 1H), 3.87 (t, J ¼ 10.1 Hz, 1H),
3.81 (dd, J ¼ 11.0, 2.7 Hz, 1H), 3.72 (m, 1H), 3.66 (dd, J ¼ 11.4, 5.0 Hz,
1H), 3.46 (d, J ¼ 9.2 Hz, 1H), 3.20 (m, 1H, H-31-1), 3.08 (m, 1H, H-31-
tant (10 mL) was taken suction to the ELISA plate, and glucose level
was detected by glucose assay kit. According to the OD values at
490 nm, the insulin-sensitizing response was calculated. The

522
Q.-C. Liu et al. / European Journal of Medicinal Chemistry 63 (2013) 511e522
(g) A.P. Combs, E.W. Yue, M. Bower, P.J. Ala, B. Wayland, B. Douty,
concentration of samples was 10 mg/mL, and the results were ob-
tained from duplicate or triplicate experiments.
A. Takvorian, P. Polam, Z. Wasserman, W.Y. Zhu, M.L. Crawley, J. Pruitt,
R. Sparks, B. Glass, D. Modi, E. Mclaughlin, L. Bostrom, M. Li, L. Galya, K. Blom,
M. Hillman, L. Gonneville, B.G. Reid, M. Wei, M. Becker-Pasha, R. Klabe,
R. Huber, Y. Li, G. Holiss, T.C. Burn, R. Wynn, P. Liu, B. Metcalf, J. Med. Chem. 48
(2005) 6544e6548;
Acknowledgments
(h) L. Bialy, H. Waldmann, Angew. Chem. Int. Ed. Engl. 44 (2005) 3814e3839;
(i) S. Koren, I.G. Fantus, Best Pract. Res. Clin. Endocrinol. Metab. 21 (2007)
621e640;
(j) S. Lee, Q. Wang, Med. Res. Rev. 27 (2007) 553e573;
(k) S. Zhang, Z.Y. Zhang, Drug Discovery Today 12 (2007) 373e381;
(l) B. Douty, B. Wayland, P.J. Ala, M.J. Bower, J. Pruitt, L. Bostrom, M. Wei,
R. Klabe, L. Gonneville, R. Wynn, T.C. Burn, P. Liu, A.P. Combs, E.W. Yue, Bioorg.
Med. Chem. Lett. 18 (2008) 66e71.
This project was financially supported by the National Natural
Science Foundation of China (No. 30701046) and Doctoral Program
Foundation of Institutions of Higher Education of China (No.
20116101120025). We would also like to thank the Biology Team at
Diao Group for their kind help in screening the compounds for
biological activities.
[20] (a) S.J. Liu, L.F. Zeng, L. Wu, X. Yu, T. Xue, A.M. Gunawan, Y.Q. Long, Z.Y. Zhang,
J. Am.Chem. Soc. 130 (2008) 17075e17084;
(b) H. Park, B.R. Bhattarai, S.W. Ham, H. Cho, Eur. J. Med. Chem. 44 (2009)
3280e3284;
Appendix A. Supplementary data
(c) D.J. Ye, Y. Zhang, F. Wang, M.F. Zheng, X. Zhang, X.M. Luo, X. Shen,
H.L. Jiang, H. Liu, Bioorg. Med. Chem. 18 (2010) 1773e1782.
[21] (a) W. Zhang, D. Hong, Y.Y. Zhou, Y.N. Zhang, Q. Shen, J.Y. Li, L.H. Hu, J. Li,
Biochim. Biophys. Acta 1760 (2006) 1505e1512;
Supplementary data related to this article can be found at
http://dx.doi.org/10.1016/j.ejmech.2013.03.001.
(b) M. Na, L. Cui, B.S. Min, K. Bae, J.K. Yoo, B.Y. Kim, W.K. Oh, J.S. Ahn, Bioorg.
Med. Chem. Lett. 18 (2006) 3273e3276;
References
(c) W.W. Qiu, Q. Shen, F. Yang, B. Wang, H. Zou, J.Y. Li, J. Li, J. Tang, Bioorg. Med.
Chem. Lett. 19 (2009) 6618e6622;
(d) S. Qian, H.J. Li, Y. Chen, W.Y. Zhang, S.Y. Yang, Y. Wu, J. Nat. Prod. 73 (2010)
1743e1750.
[1] M.I. McCarthy, N. Engl. J. Med. 363 (2010) 2339e2350.
[2] M.A. Nauck, N. Kleine, C. Orskov, J.J. Holst, Diabetologia 36 (1993) 741e744.
[3] M.A. Nauck, D. Wollschlager, J. Werner, J.J. Holst, C. Orskov, W. Creutzfeldt,
B. Willms, Diabetologia 39 (1996) 1546e1553.
[4] M.A. Nauck, A. Sauerwald, R. Ritzel, J.J. Holst, W. Schmiegel, Diabetes Care 21
(1998) 1925e1931.
[22] (a) Y.H. Chung, S.C. Jang, S.J. Kim, N.D. Sung, J. Appl. Biol. Chem. 50 (2007)
52e57;
(b) Z.H. Lin, Y. Zhang, Y.N. Zhang, H. Shen, L.H. Hu, H.L. Jiang, X. Shen, Bio-
chem. Pharmacol. 76 (2008) 1251e1262;
[5] B. Ahren, Drug Discovery Today 1 (2004) 207e212.
(c) Y.N. Zhang, W. Zhang, D. Hong, L. Shi, Q. Shen, J.Y. Li, J. Li, L.H. Hu, Bioorg.
Med. Chem. 16 (2008) 8697e8705.
[23] (a) W. Meutermans, G.T. Le, B. Becker, ChemMedChem 1 (2006) 1164e1194;
(b) B. Ernst, J.L. Magnani, Nat. Rev. Drug Discovery 8 (2009) 661e667;
(c) C. Li, X.P. He, Y.J. Zhang, Z. Li, L.X. Gao, X.X. Shi, J. Xie, J. Li, G.R. Chen,
Y. Tang, Eur. J. Med. Chem. 46 (2011) 4212e4218.
[6] B. Ahren, O. Schmitz, Horm. Metab. Res. 36 (2004) 867e876.
[7] J.F. Gautier, S. Fetita, E. Sobngwi, C. Salaun-Martin, Diabetes Metab. 31 (2005)
233e242.
[8] M.M.J. Combettes, Curr. Opin. Pharmacol. 6 (2006) 598e605.
[9] R.P. Pauly, F. Rosche, M. Wermann, C.H.S. McIntosh, R.A. Pederson,
H.U. Demuth, J. Biol. Chem. 271 (1996) 23222e23229.
[24] F. Qu, Y.X. Li, Y.C. Zhang, J. Zang, Chin. J. Org. Chem. 23 (2003) 249e257 (in
Chinese).
[25] (a) B. Yu, J.M. Xie, S.J. Deng, Y.Z. Hui, J. Am. Chem. Soc. 121 (1999) 12196e
12197;
[10] T. Nagakura, N. Yasuda, K. Yamazaki, H. Ikuta, S. Yoshikawa, O. Asano,
I. Tanaka, Biochem. Biophys. Res. Commun. 284 (2001) 501e506.
[11] H.F. McIntyre, P. Grant, Br. J. Hosp. Med. 68 (2007) 599e602.
[12] C.H.S. McIntosh, Front. Biosci. 13 (2008) 1753e1773.
[13] Y. Kido, D.J. Burks, D. Withers, J.C. Bruning, C.R. Kahn, M.F. White, D. Accili,
J. Clin. Invest. 105 (2000) 199e205.
(b) M.S. Cheng, M.C. Yan, Y. Liu, L.G. Zheng, J. Liu, Carbohydr. Res. 341 (2006)
60e67;
(c) S.L. Zhu, Y.X. Li, B. Yu, J. Org. Chem. 73 (2008) 4978e4985;
(d) B. Yu, J.S. Sun, Chem.– Asian J. 4 (2009) 642e654;
(e) T.T. Guo, Q.C. Liu, P. Wang, L. Zhang, W. Zhang, Y.X. Li, Carbohydr. Res. 344
(2009) 1167e1174;
[14] P.C. Reifsnyder, E.H. Leiter, Diabetes 51 (2002) 825e832.
[15] (a) F. Ahmad, R.V. Considine, B.J. Goldstein, J. Clin. Invest. 95 (1995) 2806e2812;
(b) K.F. Byth, L.A. Conroy, S. Howlett, A.J. Smith, J. May, D.R. Alexander,
N. Holmes, J. Exp. Med. 183 (1996) 1707e1718;
(f) Q.C. Liu, P. Wang, L. Zhang, T.T. Guo, G.K. Lv, Y.X. Li, Carbohydr. Res. 344
(2009) 1276e1281;
(g) Q.C. Liu, L. Zhang, X.P. Li, T.T. Guo, P. Wang, Y.X. Li, J. Carbohydr. Chem. 28
(2009) 506e519.
(c) R. Lammers, N.P. Moller, A. Ullrich, FEBS. Lett. 404 (1997) 37e40;
(d) P.G. Drake, B.I. Posner, Mol. Cell. Biochem. 182 (1998) 79e89;
(e) E. Asante-Appiah, B.P. Kennedy, Am. J. Physiol. 284 (2003) E663eE667;
(f) S. Galic, C. Hauser, B.B. Kahn, F.G. Haj, B.G. Neel, N.K. Tonks, T. Tiganis, Mol.
Cell. Biol. 25 (2005) 819e829;
[26] (a) S. Saito, J. Ebashi, S. Sumita, T. Furumoto, Y. Nagamura, K. Nishida, I. Isiguro,
Chem. Pharm. Bull. 41 (1993) 1395e1401;
(g) C.M. Taniguchi, B. Emanuelli, C.R. Kahn, Nat. Rev. Mol. Cell. Biol. 7 (2006)
85e96.
(b) S. Saito, Y. Sasaki, K. Kuroda, Y. Hayashi, S. Sumita, Y. Nagamura, K. Nishida,
I. Isiguro, Chem. Pharm. Bull. 41 (1993) 539e543;
(c) L.N. Atopkina, N.I. Uvarova, G.B. Elyakov, Carbohydr. Res. 303 (1997)
449e451;
(d) V.P. Anufriev, G.V. Malinovskaya, V.A. Denisenko, N.I. Uvarova,
G.B. Elyakov, S.I. Kim, N.I. Baek, Carbohydr. Res. 304 (1997) 179e182;
(e) B. Yu, Y.Z. Hui, in: P.G. Wang, C.R. Bertozzi (Eds.), Glycochemistry:
Principles Synthesis and Applications, Marcel Dekker, New York, 2001, pp.
167e174.
[16] (a) M. Elchebly, P. Payette, E. Michaliszyn, W. Cromlish, S. Collins, A.L. Loy,
D. Normandin, A. Cheng, J. Himms-Hagen, C.C. Chan, C. Ramachandran,
M.J. Gresser, M.L. Tremblay, B.P. Kennedy, Science 283 (1999) 1544e1548;
(b) L.D. Klaman, O. Boss, O.D. Peroni, J.K. Kim, J.L. Martino, J.M. Zabolotny,
N. Moghal, M. Lubkin, Y.B. Kim, A.H. Sharpe, A. Stricker-Krongrad,
G.I. Shulman, B.G. Neel, B.B. Khan, Mol. Cell. Biol. 20 (2000) 5479e5489.
[17] B.A. Zinker, C.M. Rondinone, J.M. Trevillyan, R.J. Gum, J.E. Clampit, J.F. Waring,
N. Xie, D. Wilcox, P. Jacobson, L. Frost, P.E. Kroeger, R.M. Reilly, S. Koterski,
T.J. Opgenorth, R.G. Ulrich, S. Crosby, M. Butler, S.F. Murray, R.A. McKay,
S. Bhanot, B.P. Monia, M.R. Jirousek, Proc. Natl. Acad. Sci. U. S. A. 99 (2002)
11357e11362.
[27] (a) S.J. Deng, B. Yu, J.M. Xie, Y.Z. Hui, J. Org. Chem. 64 (1999) 7265e7266;
(b) Y.P. Liu, N. Ding, H.L. Xiao, J. Carbohydr. Chem. 25 (2006) 471e489;
(c) C.X. Li, T.T. Guo, P. Wang, H.S. Guan, Y.X. Li, Chin. J. Chem. 24 (2006)
917e922.
[28] M.S. Ali, M. Jahangir, S.S. Hussan, M.I. Choudhary, Phytochemistry 60 (2002)
255e299.
[18] Z.Y. Zhang, S.Y. Lee, Expert Opin. Invest. Drugs 12 (2003) 223e233.
[19] (a) F. Ahmad, J.L. Azevedo, R. Cortright, G.L. Dohm, B.J. Goldstein, J. Clin. Invest.
100 (1997) 449e458;
[29] (a) A.E. de Nooy, A.C. Besemer, H. Bekkum, Synthesis 10 (1996) 1153e1174;
(b) M. Boukaib, A. Atmani, C. Rolando, Tetrahedron Lett. 43 (2002) 6263e
6266;
(c) F. Lin, W.J. Peng, W. Xu, X.W. Han, B. Yu, Carbohydr. Res. 339 (2004) 1219e
1223.
[30] Y.P. Liu, X.H. Ruan, X.P. Li, Y.X. Li, J. Org. Chem. 73 (2008) 4287e4290.
(b) M.A. Blaskovich, H.O. Kim, Expert Opin. Ther. Pat 12 (2002) 871e905;
(c) G. Liu, Curr. Med. Chem. 10 (2003) 1407e1421;
(d) Z.H. Pei, G. Liu, T.H. Lubben, B.G. Szczepankiewicz, Curr. Pharm. Des. 10
(2004) 3481e3504;
(e) S.D. Taylor, B. Hill, Expert Opin. Invest. Drugs 13 (2004) 199e214;
(f) L. Costantino, D. Barlocco, Curr. Med. Chem. 11 (2004) 2725e2747;