Synthesis and evaluation of several oleanolic acid glycoconjugates as protein tyrosine phosphatase 1B inhibitors

Article abstract of DOI:10.1016/j.ejmech.2014.03.080

Sixteen novel oleanolic acid triterpenoid saponins were synthesized in an efficient and practical strategy, and their inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) and selectivity over T-cell protein tyrosine phosphatase (TCPTP) were evaluated in vitro. The preliminary structure-activity relationship studies demonstrated that sugar-substituted moiety attached to the C-3 and C-28 positions of OA scaffold greatly affected the inhibitory activity against PTP1B and the selectivity over TCPTP. All the compounds showed inhibitory potencies, and compounds 1h, 1i and 1j exhibited remarkably potent inhibitory activities against PTP1B with IC₅₀ values of 1.03, 0.78 and 3.12 μM, respectively. More significantly, compound 1h showed greater than 4 folds selectivity over highly homologous TCPTP. In parallel, the lipophilicity evaluation of all synthesized compounds was tested as a prediction for pharmacological potency. According to the predicted log P values, the predicted Log P results showed that lipophilicity may correlate with the evaluated biological potency.

Full text of DOI:10.1016/j.ejmech.2014.03.080

European Journal of Medicinal Chemistry 79 (2014) 34e46
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and evaluation of several oleanolic acid glycoconjugates as
protein tyrosine phosphatase 1B inhibitors
,
Qingchao Liu a, Tiantian Guo b, Dong Li a, Fahui Li c, Wenhong Li a
*
a Department of Pharmaceutical Engineering, Northwest University, Xi’an 710069, Shaanxi, PR China
b Department of Chemical Medicine, Xi’an Institute for Food and Drug Control, Xi’an 710054, Shaanxi, PR China
c College of Chemistry and Chemical Engineering and Environmental Engineering, Weifang University, Weifang, Shandong 261061, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Sixteen novel oleanolic acid triterpenoid saponins were synthesized in an efficient and practical strategy,
and their inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) and selectivity over T-cell
protein tyrosine phosphatase (TCPTP) were evaluated in vitro. The preliminary structureeactivity rela-
tionship studies demonstrated that sugar-substituted moiety attached to the C-3 and C-28 positions of
OA scaffold greatly affected the inhibitory activity against PTP1B and the selectivity over TCPTP. All the
compounds showed inhibitory potencies, and compounds 1h, 1i and 1j exhibited remarkably potent
Received 4 February 2014
Received in revised form
17 March 2014
Accepted 28 March 2014
Available online 29 March 2014
inhibitory activities against PTP1B with IC50 values of 1.03, 0.78 and 3.12 mM, respectively. More signif-
Keywords:
Oleanolic acid triterpenoid saponins
PTP1B inhibitors
Glycosylation
Log P
icantly, compound 1h showed greater than 4 folds selectivity over highly homologous TCPTP. In parallel,
the lipophilicity evaluation of all synthesized compounds was tested as a prediction for pharmacological
potency. According to the predicted log P values, the predicted Log P results showed that lipophilicity
may correlate with the evaluated biological potency.
Strucutreeactivity relationships
Ó 2014 Elsevier Masson SAS. All rights reserved.
1. Introduction
independently proved by L. D. klaman et al. [4] A recent study also
revealed that PTP1B antisense oligonucleotides resulted in reduced
Diabetes mellitus is reaching epidemic proportions, which is
becoming the leading causes of public health care burdens all over
the world. According to the World Health Organization (WHO),
more than 346 million people around the world suffer from dia-
betes and its prevalence is projected to continue rising to over
double by 2030 [1]. Type 2 diabetes mellitus (T2DM), constitutes
90% of diabetes mellitus, which is associated with chronic meta-
bolic disorder that results from deficiency in both insulin secretion
and action at target tissues [2]. Protein tyrosine phosphatase 1B
(PTP1B), which is a major nontransmembrane phosphotyrosine
phosphatase in human tissues and also a cytosolic non-receptor
PTPase that has been implicated as a negative regular of insulin
signal transduction, downregulates the insulin signaling pathway
by dephosphorylating the activated insulin receptor (IR) or insulin
receptor substrates (IRS). One research group disclosed that PTP1B
knockout mice displayed enhanced insulin sensitivity, lower
plasma glucose and insulin levels and resistance to high-fat-diet
induced weight gain [3]. These experiment results were
PTP1B expression in insulin sensitive tissues [5]. Thus, PTP1B is
currently considered to be a potent therapeutic target for type 2
diabetes and associated obesity. [6e8]
Considerable efforts have been made in the development of
potent and selective small-molecule PTP1B inhibitors for the
treatment of type 2 diabetes [9e15]. However, the endeavor to
search for therapeutic PTP1B inhibitors proved largely abortive. Up
to now, only Trodusquemine and Ertiprotafib PTP1B inhibitors have
reached clinical trials [16,17]. The major reason could be the nature
of the PTP1B catalytic site with highly conservative and cationic
characteristic, which makes most PTP1B inhibitors with inadequate
cell permeability and low selectivity for PTP1B over the most ho-
mogeneous T-cell protein tyrosine phosphatase (TCPTP) [18,19].
Therefore, there is an urgent need to develop novel potent and
selective PTP1B inhibitors with improved physicochemical prop-
erties and in vivo efficacies.
In order to search for novel PTP1B small molecule inhibitor, our
program was carried out with carbohydrate-based modification on
the C3eOH and C28eCOOH of oleanolic acid (OA) for enhancing the
hydrosolubility and ameliorating the pharmacological and phar-
macokinetic properties. Our previous studies on the structuree
activity relationships (SAR) of sugar-substituted oleanolic acid
* Corresponding author.
E-mail address: liuqc21@nwu.edu.cn (W. Li).
http://dx.doi.org/10.1016/j.ejmech.2014.03.080
0223-5234/Ó 2014 Elsevier Masson SAS. All rights reserved.

Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
35
derivatives showed that both the sugar moiety at the C-3 position
and the long acidic chain at C-28 position of OA strongly influenced
PTP1B activity, and also improved their inhibition gainst murine
in vivo glucose absorption [20,21]. As part of an ongoing investi-
gation, we herein report the synthesis and in vitro PTP1B inhibitory
activities of novel sugar-substituted OA derivatives 1ae1j, 2ae2c
and 3ae3c (Fig. 1), and the selectivity between PTP1B and TCPTP of
selected compounds were also evaluated. The present results ob-
tained have provided valuable clues to the design and development
of potent and selective PTP1B inhibitors.
glycosides 12ae12j with the exclusive 1, 2-trans glycosidic linkages
in isolated yields ranging from 81% to 89%. Subsequent depro-
tection of the benzyl ether with 10% PdeC and the benzoyl ester
with NaOMe in MeOHeCH2Cl2 was achieved to afford the target
compounds 1ae1j in good yields.
Oleanolic acid saponins 2ae2c were afforded according to the
procedure in Scheme 2. Treating 13 [29] (or 14) [30] with MsCl and
NaN3 gave azide 15 (or 16), which was then reacted with phthalic
anhydride, Me3P and BnBr to provide the key intermediate 17 (or
18). Compound 19 (or 20) was obtained via bromination at
anomeric carbon position of 17 (or 18), and then the fully protected
saponin 19a (or 20a) was prepared by Phase transfer catalytic (PTC)
reaction. The final step was conducted similar as that of 1ae1j to
yield the target compounds 2ae2c.
2. Results and discussion
2.1. Chemistry
Compounds 3ae3c were synthesized as shown in Scheme 3.
Treatment of 7 (or 17, 18) with NH2NH2eHOAc in DMF, followed by
trichloroacetonitrile (Cl3CCN) and 1,8-diazabicyclo[5.4.0]undec-7-
ene (DBU) in dry CH2Cl2, afforded the corresponding imidate 7a
(or 17a, 18a) in satisfactory yield. Subsequent glycosylation of
saponin acceptor 21 with trichloroacetimidate donor 7a (or 17a,
18a) in the presence of TMSOTf (0.1 equiv) afforded the desired
product 7b (or 17b,18b) in an excellent yield. Finally, removal of the
benzyl group with 10% PdeC and the benzoyl groups with NaOMe
in MeOHeCH2Cl2 gave the target compounds 3ae3c.
The synthetic route of bidesmosidic oleanolic acid saponins 1ae
1j was shown in Scheme 1. The glycosyl trichloroacetimidates do-
nors 11ae11j (Fig. 2) involved in the synthesis were readily pre-
pared according to the previously reported procedures [20,22e25].
The C6eOH group of compound 4, which was readily synthesized
from D-glucose via two steps reactions reported before [22], was
first transformed into azide with p-toluenesulfonyl chloride (TsCl)
and sodium azide (NaN3), followed by addition of phthalic anhy-
dride in THF to furnish carbamoylbenzoic acid-substituted com-
pound 6 via PMe3 mediated Staudinger protocol [26]. Treatment of
6 with BnBr and K2CO3 in THF afforded the benzyl protected
compound 7 in 87% yield, which was brominated with hydrobromic
acid in glacial acetic acid giving glycosyl bromide 8. Treatment of
oleanolic acid with glucosyl bromide 8 under the modified litera-
ture conditions (K2CO3, TBAB, CH2Cl2eH2O, reflux) [27e28] affor-
ded the desired 28-glucosyl ester 10 in 86% yield. Thereafter,
glycosylation of the C3eOH of 10 with trichloroacetimidate sugar
donors 11ae11j under the promotion of trimethylsilyl tri-
fluoromethanesulfonate (TMSOTf) provided the expected
2.2. Biological evaluations
2.2.1. In vitro PTP1B inhibitory activities assays
The sugar-substituted OA derivatives 1ae1j, 2ae2c and 3ae3c
were evaluated in vitro for their ability to inhibit recombinant
PTP1B activities by the method of pNPP using sodium orthovana-
date as a positive control and results are presented in Fig. 3. We
measured the inhibitory rates of all synthesized compounds at a
concentration of 10
mg/mL, and the compounds with good
Fig. 1. Chemical structures of sugar-substituted OA derivatives 1ae1j, 2ae2c and 3ae3c.

36
Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
Scheme 1. Synthesis of compounds 1ae1j, Reagents and conditions: (a) TsCl, DMAP, Pyridine; NaN3, DMF, 65% for two steps; (b) phthalic anhydride, Me3P, THF, 79%; (c) BnBr,
K2CO3, THF, 87%; (d) 33% HBr in HOAc, CH2Cl2, 71%; (e) oleanolic acid, K2CO3, TBAB, CH2Cl2eH2O, reflux, 86%; (f) 11ae11j, 0.3 equiv TMSOTf, CH2Cl2, ꢀ30 ꢁC, 81%e89% for 12ae12j;
(g) 10% PdeC, H2, MeOHeCH2Cl2; NaOMe, MeOHeCH2Cl2, 63%e79% for 1ae1j.
inhibition rate (>50% at 10
m
g/mL) were selected for further
PTP1B, as compared to those of 1ae1g with monosaccharide-
substituted moiety linked to the C-3 position of OA, indicating
that introduction of more hydrophilic sugar moiety is more favor-
able to the inhibitory activity for PTP1B. And compounds 1h with
lactose moiety and 1i with cellulose moiety exhibited more potent
inhibitory activity than compound 1j with gentiobiose moiety,
which suggested that the spatial configuration of sugar residue had
an important influence on the inhibitory activity against PTP1B.
However, three monodesmosidic saponins derivatives (3ae3c)
with structural modifications on C-3 position of OA led to a dra-
matic decrease in PTP1B inhibitory activity. These data demon-
strated that substituent of sugar moiety on both C-3 and C-28
determination of IC50 values. Among all 16 compounds, three
monodesmosidic saponins derivatives (2ae2c) on C-28 position of
OA were favorable to PTP1B inhibitory activity, especially carba-
moylbenzoic acid-substituted glucosyl saponin 2a showed more
higher inhibition with 54.67% inhibition rate at 10
compounds 2be2c. Interestingly, while OA was linked with the
sugar moiety on C-3 and C-28, the resulting bidesmosidic saponins
1ae1j (>54.67% inhibition rate at 10 mg/mL) exhibited more potent
PTP1B inhibitory activities than 2a. Furthermore, compounds 1he
1j (inhibition%: 1h, 93.14%; 1i, 89.77%; 1j, 79.89%) with
disaccharide-substituted moiety displayed higher activity against
mg/mL than
Fig. 2. Chemical structures of glycosyl trichloroacetimidates donors 11ae11j.

Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
37
Scheme 2. Synthesis of compounds 2ae2c, Reagents and conditions: (a) MsCl, TEA; NaN3, DMF, 71% for 15, 63% for 16 (2 steps); (b) phthalic anhydride, Me3P, THF, 81% for 15a, 83%
for 16a; (c) BnBr, K2CO3, THF, 90% for 17, 89% for 18; (d) 33% HBr in HOAc, CH2Cl2, 75% for 19, 69% for 20; (e) oleanolic acid, K2CO3, TBAB, CH2Cl2eH2O, reflux, 82% for 19a, 79% for
20a; (f) 10% PdeC, H2, MeOHeCH2Cl2; NaOMe, MeOHeCH2Cl2, 75% for 2a, 66% for 2b, 63% for 2c (2 steps).
positions of OA is responsible for enhancing inhibitory activity
against PTP1B.
worth noting that compound 1j showed more potent PTP1B
inhibitory activity than 1ae1g, however, 1j did not show good
PTP1B selectivity over TCPTP.
2.2.2. Selectivity over TCPTP
2.2.3. The prediction of the permeability
To investigate the specificity of sugar-substituted oleanolic acid
derivatives against PTPs, some synthetic derivatives were also
tested for homogeneous TCPTP inhibitory activities. The results
with the IC50 values and the ratio of PTP1B and TCPTP were
depicted in Table 1. The assay results indicated that most of the
synthetic compounds showed potent inhibition of PTP1B and
TCPTP, and these compounds exhibited 0.9e4.0-fold selectivity for
PTP1B over TCPTP. The comparison of 1ae1j (except compound 1f,
Lipophilicity (permeability) of drugs strongly influenced the
absorption, the distribution, the biological availability, and phar-
macological activity of drugs [31]. The prediction of the perme-
ability, which demonstrates the transport of the drugs through
cellular membranes, has been proved to be one of the most
important physical properties of bioactive compounds [32]. In this
study, lipophilicity of all synthesized oleanolic acid saponins 1ae1j,
2ae2c, and 3ae3c, the logarithm of the partition coefficient be-
tween polar (water) and non-polar (octanol) phases (Log P), was
calculated by employing the ACD lab program. The results are
shown in Table 2. As expected, compounds 1he1j possessed the
highest lipophilicity (Log P), while compounds 3ae3c showed the
lowest lipophilicity. Generally, oleanolic acid bidesmosides 1ae1j
(except compounds 1f and 1g) have higher predicted permeability
than oleanolic acid monodesmosides 2ae2c and 3ae3c. These
displayed data showed that the order of PTP1B inhibitory activity
was slightly consistent with the order of lipophilicity, which indi-
cated that lipophilicity of all the synthesized compounds was in
association with the evaluated pharmacological potency.
IC50: 26.49 mM) and 2a (IC50: 20.37 mM) indicated that modified OA
analogs with sugar moiety on C-3 and C-28 positions exhibited
more inhibitory activity than that with sugar moiety only on C-28
position. Moreover, comparison of 1ae1g (IC50: 5.67e26.49
mM)
with 1he1j (IC50 0.78e3.12 M) showed the disaccharide-
:
m
substituted derivatives showed more PTP1B inhibitory activity
than the monosaccharide-substituted derivatives on C-3 position.
Obviously, compound 1i (IC50: 0.78
on C-3 position is around 4-fold more active than compound 1j
(IC50: 3.12 M) with -gentiobiose moiety on C-3 position, and for
mM) with D-cellobiose moiety
m
D
1i, the selectivity of TCPTP reached to 2.8-fold with relatively more
potent on PTP1B activity, demonstrating the specific stereochem-
istry of
PTP1B inhibitory activity. For comparison, compounds 1h (IC50
1.03 M) and 1i (IC50: 0.78 M) showed a similar activity against
D-cellobiose moiety on C-3 position of OA was favorable to
:
3. Conclusions
m
m
PTP1B. Interestingly, compound 1h exhibited the best selectivity
(TCPTP/PTP1B: 4.0) between the two homogenous enzymes. It was
In conclusion, we have prepared a series of novel oleanolic acid
saponins in a highly concise and practical strategy, and their PTP1B

38
Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
clarify action mechanism for this series of sugar-substituted OA
PTP1B inhibitors are currently under way in our research group and
will be reported in due time.
4. Experimental section
4.1. Chemistry
Commercial reagents were used without further purification
unless specialized. Solvents 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 performed on silica gel (200e300 mesh).
Optical rotations 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
standard, and chemical shifts are recorded in d values. Mass spectra
were recorded on a Q-TOF Global mass spectrometer.
4.1.1. Typical procedure for the synthesis of compounds 5, 15 and 16
A solution of compound 4 (or 13e14) (2 g, 3.35 mmol), 4-
(dimethylamino)pyridine (0.82 g, 6.70 mmol) in pyridine (10 mL)
and CH2Cl2 (3 mL) was treated with p-toluenesulfonyl chloride
(0.96 g, 5.03 mmol), and the mixture was stirred at room temper-
ature. After 20 h, the reaction mixture was concentrated and the
residue was dissolved in CH2Cl2, which was then washed with 1 N
HCl, aq. sat. NaHCO3, brine, dried over Na2SO4, and concentrated.
The residue was dissolved in DMF (15 mL), and then sodium azide
(0.87 g, 13.4 mmol) was added to the above reaction mixture. After
stirring for 24 h at 60 ꢁC, the reaction mixture was concentrated
under reduced pressure. The residue was diluted with CH2Cl2,
washed with water, brine, dried over Na2SO4, and concentrated.
The residue was purified by a silica gel column chromatography
(5:1, petroleum ether-EtOAc) to afford the product 5 (or 15e16) as a
white solid.
Scheme 3. Synthesis of compounds 3ae3c, Reagents and conditions: (a) NH2NH2-
HOAc, DMF; CNCCl3, DBU, CH2Cl2, 83% for 7a, 85% for 17a, 78% for 18a (2 steps); (b)
TMSOTf, CH2Cl2, 0 ꢁC, 91% for 7b, 87% for 17b, 89% for 18b; (c) 10% PdeC, H2, MeOHe
CH2Cl2; NaOMe, MeOHeCH2Cl2, 69% for 3a, 67% for 3b, 71% for 3c.
4.1.1.1. 6-Azide-1,2,3,4-tetra-O-benzoyl-6-deoxy-b-D-glucopyranose
27
inhibitory activity was evaluated in vitro. The preliminary struc-
tureeactivity relationship acquired demonstrated that sugar-
substituted moieties attached to the C-3 and C-28 positions of OA
scaffold have greatly helped to enhance the inhibitory activity
against PTP1B. These sugar-substituted moieties may facilitate the
binding to the active site of PTP1B. Among these derivatives,
compounds 1h, 1i and 1j exhibited potent inhibitory activities
(5). Yield: 65%; [
600 MHz):
a
]
D
þ 68.5 (c 1.15, CHCl3); 1H NMR (CDCl3,
d
7.27e8.11 (m, 20H, Ph-H), 6.31 (d, J ¼ 7.9 Hz, 1H, H-1),
6.07 (t, J ¼ 9.6 Hz, 1H, H-3), 5.79 (dd, J ¼ 9.6, 7.9 Hz, 1H, H-2), 5.57 (t,
J ¼ 9.6 Hz, 1H, H-4), 4.07 (m, 1H, H-5), 3.47 (dd, J ¼ 12.8, 5.1 Hz, 1H,
H-6e1), 3.32 (dd, J ¼ 12.8, 3.0 Hz, 1H, H-6e2); 13C NMR (CDCl3,
150 MHz):
d 166.5, 165.9, 165.3, 164.9, 134.1, 133.9, 133.5, 133.3,
130.3, 130.1, 129.9129.8, 128.7, 128.5, 128.3, 93.1 (C-1), 75.6, 72.6,
70.8, 69.3, 60.3; HRESIMS: m/z calcd for C34H27N3O9Na [MþNaþ]
644.1640; found: 644.1623.
against PTP1B with IC50 values of 1.03, 0.78 and 3.12 mM, respec-
tively. More importantly, compound 1h showed a remarkably 4
folds selectivity over TCPTP. In parallel, the lipophilicity evaluation
of all synthesized compounds was tested as a prediction for phar-
macological potency. The predicted Log P results showed that lip-
ophilicity may correlate with the evaluated biological potency.
Further investigations to improve pharmacological profile and
4.1.1.2. 6-Azide-1,2,3,4-tetra-O-benzoyl-6-deoxy-b-D-galactopyr-
anose (15). Yield: 71%; [
600 MHz):
a
]
D
27 þ 47.1 (c 1.03, CHCl3); 1H NMR (CDCl3,
d
7.27e8.09 (m, 20H, Ph-H), 6.23 (d, J ¼ 8.0 Hz, 1H, H-1),
5.89 (dd, J ¼ 9.7, 3.7 Hz, 1H, H-3), 5.83 (dd, J ¼ 9.7, 8.0 Hz, 1H, H-2),
5.43 (t, J ¼ 3.7 Hz, 1H, H-4), 4.23 (m, 1H, H-5), 3.51 (dd, J ¼ 12.3,
5.1 Hz, 1H, H-6-1), 3.31 (dd, J ¼ 12.3, 3.2 Hz, 1H, H-6-2); 13C NMR
(CDCl3, 150 MHz):
d 166.5, 165.7, 165.3, 164.9, 134.0, 133.7, 133.5,
133.1, 130.3, 130.1, 129.9, 129.7, 128.7, 128.5, 128.1, 94.3 (C-1), 73.9,
72.3, 70.3, 69.5, 59.9; HRESIMS: m/z calcd for C34H27N3O9Na
[MþNaþ] 644.1640; found: 644.1658.
4.1.1.3. 6-Azide-1,2,3,4-tetra-O-benzoyl-6-deoxy-a-D-mannopyr-
anose (16). Yield: 63%; [
600 MHz):
a
]
27 þ 78.1 (c 1.12, CHCl3); 1H NMR (CDCl3,
D
d
7.23e8.01 (m, 20H, Ph-H), 6.39 (s, 1H, H-1), 5.99 (dd,
J ¼ 3.9, 2.1 Hz, 1H, H-2), 5.65 (dd, J ¼ 9.6, 3.9 Hz, 1H, H-3), 5.51 (t,
J ¼ 9.6 Hz, 1H, H-4), 4.10 (m, 1H, H-5), 3.41 (dd, J ¼ 11.9, 5.3 Hz, 1H,
H-6-1), 3.29 (dd, J ¼ 11.9, 3.2 Hz, 1H, H-6-2); 13C NMR (CDCl3,
Fig. 3. PTP1B inhibitory activity of oleanolic acid saponins 1ae1j, 2ae2c and 3ae3c
(10
m
g/mL in DMSO). Positive Control: Sodium orthovanadate (100
m
g/mL in DMSO).
150 MHz): d 166.3,165.7,165.3,165.1,134.1,133.9,133.7,133.5,130.3,

Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
39
Table 1
4.1.2.2. 6-Phthalimido-1,2,3,4-tetra-O-benzoyl-6-deoxy-
b
-
D
-gal-
27
actopyranose (15a). Yield: 81%; [
NMR (CDCl3, 600 MHz):
a
]
þ 59.3 (c 0.95, CHCl3); 1H
In vitro PTP1B and TCPTP inhibitory activities of oleanolic acid derivatives.
D
Compounds
IC50
PTP1B
(
m
M)a
TCPTP/PTP1Bc
d
7.17e8.00 (m, 24H, Ph-H), 6.69 (m, 1H,
NHCO), 6.35 (d, J ¼ 8.3 Hz, 1H, H-1), 5.89 (dd, J ¼ 9.7, 8.3 Hz, 1H, H-
2), 5.79 (dd, J ¼ 9.7, 3.6 Hz,1H, H-3), 5.36 (t, J ¼ 3.6 Hz,1H, H-4), 4.23
(m, 1H, H-5), 3.49 (dd, J ¼ 12.1, 5.6 Hz, 1H, H-6-1), 3.35 (dd, J ¼ 12.1,
TCPTP
1a
1b
1c
1d
1e
1f
1g
1h
17.23 ꢂ 2.11
15.87 ꢂ 1.73
6.53 ꢂ 0.71
16.56 ꢂ 1.24
5.67 ꢂ 0.83
26.49 ꢂ 2.32
10.36 ꢂ 0.97
1.03 ꢂ 0.16
0.78 ꢂ 0.09
3.12 ꢂ 0.53
20.37 ꢂ 1.96
7.83 ꢂ 0.91
30.51 ꢂ 2.97
ndb
14.57 ꢂ 1.59
15.49 ꢂ 1.71
12.39 ꢂ 1.31
nd
8.73 ꢂ 0.97
4.11 ꢂ 0.34
2.16 ꢂ 0.43
2.98 ꢂ 0.62
24.42 ꢂ 3.01
nd
1.8
2.9 Hz, 1H, H-6-2); 13C NMR (CDCl3, 150 MHz):
d 166.5, 166.1, 165.7,
2.2
0.9
2.2
165.1,164.9,137.5, 136.9,134.5,133.7,133.3,132.9,132.2,131.7,130.5,
130.0, 129.9, 129.7, 128.9, 128.5, 128.3, 127.9, 125.7, 95.2 (C-1), 75.6,
73.9, 71.8, 69.9, 50.1; HRESIMS: m/z calcd for C42H33NO12Na
[M þ Naþ] 766.1895; found: 766.1911.
0.8
4.0
2.8
1.0
1.2
1i
1j
2a
4.1.2.3. 6-Phthalimido-1,2,3,4-tetra-O-benzoyl-6-deoxy-a-D-man-
nopyranose (16a). Yield: 83%; [
(CDCl3, 600 MHz):
a
]
27 þ 23.4 (c 0.87, CHCl3); 1H NMR
D
Sodium orthorandated
d
7.27e8.07 (m, 24H, Ph-H), 6.67 (m, 1H, NHCO),
a
Results are expressed as IC50 values (mM), determined by regression analyses
6.41 (d, J ¼ 2.3 Hz, 1H, H-1), 6.00 (dd, J ¼ 9.3, 3.3 Hz, 1H, H-3), 5.76
(dd, J ¼ 3.3, 2.3 Hz,1H, H-2), 5.57 (t, J ¼ 9.3 Hz,1H, H-4), 4.03 (m, 1H,
H-5), 3.59 (dd, J ¼ 11.9, 4.7 Hz, 1H, H-6-1), 3.34 (dd, J ¼ 11.9, 3.1 Hz,
and expressed as the mean ꢂ SD of three replicates.
b
nd, not determined.
TCPTP/PTP1B, the ratio of IC50 of TCPTP and PTP1B.
Sodium orthovanadate was used as the positive control, of which the max in-
c
1H, H-6-2); 13C NMR (CDCl3, 150 MHz):
d 166.9, 165.9, 165.7, 165.1,
d
hibition concentration is 100 mg/mL.
164.9,137.5,136.3,135.0,133.7,133.5,133.1,132.2,131.5,130.3,130.0,
129.9, 129.5, 128.9, 128.5, 128.3, 128.1, 124.8, 92.0 (C-1), 77.3, 72.9,
71.8, 68.9, 50.3; HRESIMS: m/z calcd for C42H33NO12Na [M þ Naþ]
766.1895; found: 766.1873.
130.1, 129.6, 129.1, 128.9, 128.5, 128.1, 91.9 (C-1), 75.3, 71.8, 69.9,
69.1, 60.5; HRESIMS: m/z calcd for
644.1640; found: 644.1629.
C
34H27N3O9Na [MþNaþ]
4.1.3. Typical procedure for the synthesis of compounds 7, 17 and 18
A solution of compound 6 (or 15ae16a) (800 mg, 1.08 mmol),
K2CO3 (1.50 g, 10.8 mmol) in THF (25 mL) was treated with BnBr
(0.21 mL, 1.62 mmol), and the mixture was stirred at 60 ꢁC for 5 h,
then concentrated. The residue was diluted with CH2Cl2, and the
extract was washed successively with HCl (1M), H2O, and brine,
dried over Na2SO4, filtered, and concentrated. The residue was
purified by a silica gel column chromatography (6:1, petroleum
ether-EtOAc) to afford the product 7 (or 17e18) as a white solid.
4.1.2. Typical procedure for the synthesis of compounds 6, 15a and
16a
A solution of compound 5 (or 15e16) (1 g, 1.61 mmol) in THF
(20 mL) was treated with Me3P (3.22 mL, 3.22 mmol), and the
mixture was stirred at room temperature. When no N2 appeared,
the resulting mixture was treated with phthalic anhydride (360 mg,
2.42 mmol) and stirred at room temperature for 5 d. The reaction
mixture was concentrated and the residue was dissolved in EtOAc,
washed with water, brine, dried over Na2SO4, and concentrated.
The residue was purified by a silica gel column chromatography
(3:1, petroleum ether-EtOAc) to afford the product 6 (or 15ae16a)
as a white solid.
4.1.3.1. 6-(20-O-Benzyl-phthalimido)-1,2,3,4-tetra-O-benzoyl-6-
27
deoxy-
b
-
D
-glucopyranose (7). Yield: 87%; [
a]
þ 43.7 (c 0.72,
D
CHCl3); 1H NMR (CDCl3, 600 MHz):
d
7.21e8.05 (m, 29H, Ph-H), 6.71
(m, 1H, NHCO), 6.21 (d, J ¼ 7.9 Hz, 1H, H-1), 6.06 (t, J ¼ 9.7 Hz, 1H, H-
3), 5.83 (dd, J ¼ 9.7, 7.9 Hz, 1H, H-2), 5.63 (m, 2H, PhCH2), 5.53 (t,
J ¼ 9.7 Hz, 1H, H-4), 4.10 (m, 1H, H-5), 3.57 (dd, J ¼ 12.7, 5.1 Hz, 1H,
H-6-1), 3.27 (dd, J ¼ 12.7, 3.3 Hz, 1H, H-6-2); 13C NMR (CDCl3,
4.1.2.1. 6-Phthalimido-1,2,3,4-tetra-O-benzoyl-6-deoxy-b-D-gluco-
27
pyranose (6). Yield: 79%; [
(CDCl3, 600 MHz):
a
]
þ 57.9 (c 0.91, CHCl3); 1H NMR
D
150 MHz):
d 166.5, 166.0, 165.7, 165.5, 164.7, 136.9, 136.3, 134.3,
d
7.20e8.07 (m, 24H, Ph-H), 6.67 (m, 1H, NHCO),
133.9, 133.8, 133.5, 133.3, 132.1, 131.7, 131.3, 130.3, 130.1130.0, 129.9,
129.6, 128.8, 128.5, 128.2, 128.0, 125.7, 93.3 (C-1), 74.9, 73.5, 71.7,
6.27 (d, J ¼ 8.0 Hz, 1H, H-1), 6.03 (t, J ¼ 9.6 Hz, 1H, H-3), 5.81 (dd,
J ¼ 9.6, 8.0 Hz, 1H, H-2), 5.54 (t, J ¼ 9.6 Hz, 1H, H-4), 4.15 (m, 1H, H-
5), 3.53 (dd, J ¼ 13.2, 5.3 Hz,1H, H-6-1), 3.31 (dd, J ¼ 13.2, 3.5 Hz,1H,
70.3, 50.3; HRESIMS: m/z calcd for
856.2365; found: 856.2381.
C
49H39NO12Na [MþNaþ]
H-6-2); 13C NMR (CDCl3, 150 MHz):
d 166.3, 166.0, 165.7, 165.3,
164.9, 137.1, 136.3, 134.3, 133.7, 133.5, 133.1, 132.2, 131.7, 130.3, 130.0,
129.9, 129.7, 128.9, 128.5, 128.3, 128.0, 125.9, 93.6 (C-1), 75.1, 73.5,
71.8, 70.6, 50.3; HRESIMS: m/z calcd for C42H33NO12Na [MþNaþ]
766.1895; found: 766.1879.
4.1.3.2. 6-(20-O-Benzyl-phthalimido)-1,2,3,4-tetra-O-benzoyl-6-
27
deoxy-
b
-
D
-galactopyranose (17). Yield: 90%; [
a
]
þ 87.1 (c 0.79,
D
CHCl3); 1H NMR (CDCl3, 600 MHz):
d
7.27e8.11 (m, 29H, Ph-H), 6.68
(m, 1H, NHCO), 6.37 (d, J ¼ 8.0 Hz, 1H, H-1), 6.00 (dd, J ¼ 9.6, 3.8 Hz,
1H, H-3), 5.87 (dd, J ¼ 9.6, 8.0 Hz,1H, H-2), 5.59 (m, 2H, PhCH2), 5.47
(t, J ¼ 3.8 Hz, 1H, H-4), 4.24 (m, 1H, H-5), 3.63 (dd, J ¼ 11.9, 5.3 Hz,
1H, H-6-1), 3.23 (dd, J ¼ 11.9, 3.7 Hz, 1H, H-6-2); 13C NMR (CDCl3,
Table 2
Prediction of lipophilicity (Log P) of oleanolic acid derivatives 1ae1j, 2ae2c, and 3ae
3c.
150 MHz):
d 166.9, 166.3, 165.7, 165.1, 164.7, 136.9, 136.3, 134.5,
133.9, 133.7, 133.5, 133.1, 132.1, 131.7, 130.7, 130.3, 130.1, 129.8, 129.7,
129.3, 128.8, 128.5, 128.2, 127.9, 125.9, 95.1 (C-1), 75.2, 73.1, 70.5,
Compound
Log Pa
Compound
Log Pa
1a
1b
1c
1d
1e
1f
6.63 ꢂ 0.70
6.63 ꢂ 0.70
6.63 ꢂ 0.70
8.45 ꢂ 0.81
8.45 ꢂ 0.81
8.95 ꢂ 0.81
8.95 ꢂ 0.81
5.95 ꢂ 0.83
1i
1j
5.95 ꢂ 0.83
6.08 ꢂ 0.84
8.60 ꢂ 0.67
8.60 ꢂ 0.67
8.60 ꢂ 0.67
9.64 ꢂ 0.69
9.64 ꢂ 0.69
9.64 ꢂ 0.69
68.9, 49.7; HRESIMS: m/z calcd for
856.2365; found: 856.2349.
C
49H39NO12Na [MþNaþ]
2a
2b
2c
3a
3b
3c
4.1.3.3. 6-(20-O-Benzyl-phthalimido)-1,2,3,4-tetra-O-benzoyl-6-
27
deoxy-
a
-
D
-mannopyranose (18). Yield: 89%; [
a
]
þ 8.73 (c 0.56,
D
CHCl3); 1H NMR (CDCl3, 600 MHz):
d
7.25e8.01 (m, 29H, Ph-H), 6.73
1g
1h
(m, 1H, NHCO), 6.39 (s, 1H, H-1), 5.99 (dd, J ¼ 9.1, 3.5 Hz, 1H, H-3),
a
Predicted octanol/water partition coefficient by ACD/Log P ver. 1.0.
5.81 (br s, 1H, H-2), 5.56 (t, J ¼ 9.1 Hz, 1H, H-4), 5.50 (m, 2H, PhCH2),

40
Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
4.23 (m, 1H, H-5), 3.49 (dd, J ¼ 12.1, 5.3 Hz, 1H, H-6-1), 3.31 (dd,
4.1.5.1. Benzyl oleanate 3-O-6-(20-O-benzyl-phthalimido)-2,3,4-tri-
J ¼ 12.1, 3.7 Hz, 1H, H-6-2); 13C NMR (CDCl3, 150 MHz):
d
167.0,
O-benzoyl-6-deoxy-
b
-
D
-glucopy-ranoside
(7b). Yield:
91%;
166.5,165.7,165.1, 164.7, 137.1, 136.3,134.3,133.9,133.6,133.5,133.0,
132.1, 131.7, 131.3, 130.3,130.1, 130.0,129.9,129.6,128.7, 128.5,128.2,
127.7, 125.9, 91.7 (C-1), 75.1, 73.5, 71.3, 69.7, 50.3; HRESIMS: m/z
calcd for C49H39NO12Na [MþNaþ] 856.2365; found: 856.2390.
[a
]
27 þ 37.2 (c 1.29, CHCl3); 1H NMR (CDCl3, 600 MHz):
d
7.29e8.07
D
(m, 29H, Ph-H), 6.71 (m, 1H, NHCO), 5.96 (t, J ¼ 9.6 Hz, 1H, H-30),
5.60e5.65 (m 2H, H-20, H-40), 5.43 (m, 2H, PhCH2), 5.30 (t,
J ¼ 3.6 Hz, 1H, H-12), 5.12 (dd, J ¼ 29.8, 12.4 Hz, 2H, PhCH2), 4.95 (d,
J ¼ 7.9 Hz, 1H, H-10), 4.67 (dd, J ¼ 12.0, 3.4 Hz, 1H, H-60-1), 4.59 (dd,
J ¼ 12.0, 6.3 Hz, 1H, H-60-2), 4.27 (m, 1H, H-50), 3.12 (dd, J ¼ 11.9,
4.6 Hz, 1H, H-3), 2.87 (dd, J ¼ 13.7, 4.3 Hz, 1H, H-18), 1.07, 0.95, 0.91,
0.80, 0.69, 0.63, 0.51 (s each, 3H each, CH3 ꢃ 7); 13C NMR (CDCl3,
4.1.4. Typical procedure for the synthesis of compounds 7a, 17a and
18a
To a solution of compound 7 (or 17e18) (500 mg, 0.60 mmol) in
7 mL of DMF, NH2NH2eHOAc (83 g, 0.90 mmol) was added at 0 ꢁC.
The mixture was stirred for 12 h, then concentrated. The residue
was diluted with CH2Cl2, and the extract was washed successively
with satd aq NaHCO3, brine, dried over Na2SO4, filtered, and
concentrated. The residue was then dissolved in dry CH2Cl2 (10 mL),
CNCCl3 (0.45 mL, 4.80 mmol) and DBU (0.11 mL, 0.30 mmol) were
added at 0 ꢁC. The reaction mixture was stirred for 3 h at room
temperature, then the solvent was evaporated in vacuo to give a
residue, which was purified by a silica gel column chromatography
(5:1, petroleum ether-EtOAc) to afford the product 7a (or 17ae18a)
as a white solid.
150 MHz):
d 177.3 (C-28), 166.3, 165.9, 165.7, 165.6, 143.9 (C-13),
137.1,136.1,133.3,133.0,132.9,130.1,130.0,129.9,129.8,129.5,129.3,
128.9, 128.3, 128.2, 127.6, 127.1, 122.9 (C-12), 105.1 (C-10), 89.9 (C-3),
74.5, 72.3, 70.9, 69.3, 67.6, 65.7, 56.9, 52.1, 47.9, 46.8, 45.9, 41.6, 39.9,
38.7, 38.5, 37.1, 36.3, 34.1, 32.7, 31.8, 30.6, 29.7, 27.9, 25.7, 25.4, 23.8,
17.6, 16.4, 15.1; HRMALDIMS: m/z calcd for
C79H87NO13Na
[M þ Naþ] 1280.6070; found: 1280.6089.
4.1.5.2. Benzyl oleanate 3-O-6-(20-O-benzyl-phthalimido)-2,3,4-tri-
O-benzoyl-6-deoxy-
b
-
D
-galactopy-ranoside
(17b). Yield:
87%;
[a
]
27 þ 56.3 (c 1.03, CHCl3); 1H NMR (CDCl3, 600 MHz):
d 7.21e8.11
D
(m, 29H, Ph-H), 6.73 (m, 1H, NHCO), 5.97 (t, J ¼ 3.7 Hz, 1H, H-40),
5.85 (dd, J ¼ 9.7, 8.2 Hz, 1H, H-20), 5.67 (dd, J ¼ 9.7, 3.7 Hz, 1H, H-30),
5.45 (m, 2H, PhCH2), 5.27 (t, J ¼ 3.5 Hz, 1H, H-12), 5.09 (dd, J ¼ 29.5,
12.9 Hz, 2H, PhCH2), 4.89 (d, J ¼ 8.2 Hz, 1H, H-10), 4.69 (dd, J ¼ 11.9,
6.1 Hz, 1H, H-60-1), 4.49 (dd, J ¼ 11.9, 4.9 Hz, 1H, H-60-2), 4.33 (m,
1H, H-50), 3.13 (dd, J ¼ 11.9, 4.6 Hz, 1H, H-3), 2.91 (dd, J ¼ 14.3,
3.7 Hz, 1H, H-18), 1.09, 0.93, 0.90, 0.83, 0.69, 0.67, 0.53 (s each, 3H
4.1.4.1. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
a-
D
-glucopyranoside
trichloroacet-imidate
(7a). Yield:
83%;
[
a
]
27 þ 23.5 (c 0.21, CHCl3); 1H NMR (CDCl3, 600 MHz):
d 8.55 (s, 1H,
D
NeH), 7.21e8.11 (m, 24H, Ph-H), 6.71 (m, 1H, NHCO), 6.60 (d,
J ¼ 3.7 Hz,1H, H-1), 6.01 (t, J ¼ 9.6 Hz, 1H, H-3), 5.67 (m, 2H, PhCH2),
5.53 (t, J ¼ 9.6 Hz, 1H, H-4), 5.41 (dd, J ¼ 9.6, 3.7 Hz, 1H, H-2), 3.99
(m, 1H, H-5), 3.89 (dd, J ¼ 11.5, 5.3 Hz, 1H, H-6-1), 3.67 (dd, J ¼ 11.5,
3.4 Hz, 1H, H-6-2); HRESIMS: m/z calcd for C44H36Cl3N2O11 [MþHþ]
873.1379; found: 873.1393.
each, CH3 ꢃ 7); 13C NMR (CDCl3, 150 MHz):
d 176.9 (C-28), 166.1,
165.9, 165.7, 165.3, 143.5 (C-13), 136.9, 136.1, 133.6, 133.1, 132.9,
130.1, 130.0, 129.9, 129.8, 129.5, 129.1, 128.9, 128.3, 128.2, 127.6,
126.8, 122.7 (C-12), 104.3 (C-10), 89.7 (C-3), 73.9, 72.1, 71.3, 69.5,
67.6, 65.3, 57.3, 56.1, 47.9, 46.9, 45.9, 41.7, 39.9, 38.7, 38.3, 37.1, 36.3,
34.1, 32.7, 31.7, 30.6, 29.7, 27.9, 25.7, 25.4, 23.8, 17.3, 16.4, 15.3;
HRMALDIMS: m/z calcd for C79H87NO13Na [MþNaþ] 1280.6070;
found: 1280.6053.
4.1.4.2. 6-(20-O-benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
a-
D
-galactopyranoside trichloroace-timidate (17a). Yield: 85%;
[
a
]
27 þ 7.81 (c 0.31, CHCl3); 1H NMR (CDCl3, 600 MHz):
d 8.51 (s, 1H,
D
NeH), 7.21e8.06 (m, 24H, Ph-H), 6.73 (m, 1H, NHCO), 6.57 (d,
J ¼ 3.6 Hz, 1H, H-1), 5.99 (dd, J ¼ 9.7, 3.7 Hz, 1H, H-3), 5.67 (m, 2H,
PhCH2), 5.61 (t, J ¼ 3.7 Hz, 1H, H-4), 5.37 (dd, J ¼ 9.7, 3.6 Hz, 1H, H-
2), 4.19 (m, 1H, H-5), 3.73 (dd, J ¼ 11.9, 5.0 Hz, 1H, H-6-1), 3.57 (dd,
J ¼ 11.9, 3.4 Hz, 1H, H-6-2); HRESIMS: m/z calcd for C44H36Cl3N2O11
[MþHþ] 873.1379; found: 873.1390.
4.1.5.3. Benzyl oleanate 3-O-6-(20-O-benzyl-phthalimido)-2,3,4-tri-
O-benzoyl-6-deoxy-
a
-
D
-mannopyr-anoside
(18b). Yield:
89%;
[a
]
27 þ 10.3 (c 0.85, CHCl3); 1H NMR (CDCl3, 600 MHz):
d 7.27e8.07
D
(m, 29H, Ph-H), 6.69 (m, 1H, NHCO), 5.87 (dd, J ¼ 9.9, 3.6 Hz, 1H, H-
30), 5.81 (dd, J ¼ 3.6, 1.9 Hz, 1H, H-20), 5.69 (t, J ¼ 9.9 Hz, 1H, H-40),
5.39 (m, 2H, PhCH2), 5.29 (t, J ¼ 3.7 Hz, 1H, H-12), 5.13 (dd, J ¼ 29.7,
12.5 Hz, 2H, PhCH2), 4.93 (d, J ¼ 1.9 Hz, 1H, H-10), 4.63 (dd, J ¼ 12.1,
5.6 Hz, 1H, H-60-1), 4.41 (dd, J ¼ 12.1, 3.9 Hz, 1H, H-60-2), 4.30 (m,
1H, H-50), 3.10 (dd, J ¼ 12.1, 4.3 Hz, 1H, H-3), 2.89 (dd, J ¼ 13.7,
3.7 Hz, 1H, H-18), 1.07, 0.93, 0.90, 0.81, 0.69, 0.65, 0.51 (s each, 3H
4.1.4.3. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
a-
D
-mannopyranose
trichloroacet-imidate
(18a). Yield:
78%;
[
a
]
27 þ 30.9 (c 0.19, CHCl3); 1H NMR (CDCl3, 600 MHz):
d 8.60 (s, 1H,
D
NeH), 7.23e8.11 (m, 24H, Ph-H), 6.65 (m, 2H, H-1, NHCO), 6.11 (dd,
J ¼ 9.3, 3.7 Hz, 1 H, H-3), 5.89 (s, 1H, H-2), 5.64 (m, 3H, H-4, PhCH2),
4.29 (m, 1H, H-5), 3.75 (dd, J ¼ 12.1, 5.1 Hz, 1 H, H-6-1), 3.52 (dd,
J ¼ 12.1, 3.3 Hz, 1H, H-6-2); HRESIMS: m/z calcd for C44H36Cl3N2O11
[MþHþ] 873.1379; found: 873.1361.
each, CH3 ꢃ 7); 13C NMR (CDCl3, 150 MHz):
d 177.1 (C-28), 166.3,
165.9, 165.5, 165.1, 143.3 (C-13), 136.3, 136.1, 133.6, 133.3, 132.9,
130.1, 130.0, 129.9, 129.7, 129.5, 129.1, 128.9, 128.3, 128.2, 127.3,
126.1, 122.5 (C-12), 94.3 (C-10), 88.9 (C-3), 74.5, 72.3, 70.7, 69.3, 67.7,
65.9, 57.8, 56.1, 47.8, 46.9, 45.9, 41.7, 39.3, 38.7, 37.9, 37.1, 36.3, 34.1,
32.7, 31.7, 30.5, 29.7, 27.8, 25.7, 25.3, 23.8, 17.1, 16.3, 15.1; HRMAL-
DIMS: m/z calcd for C79H87NO13Na [MþNaþ] 1280.6073; found:
1280.6087.
4.1.5. Typical procedure for the synthesis of compounds 7b, 17b and
18b
A
mixture of compound 21 (100 mg, 0.18 mmol), tri-
chloroacetimidates 7a, 17b or 18b (0.22 mmol, 1.2 equiv.) and
ꢀ
powdered 4 A molecular sieves in dry CH2Cl2 (8 mL) were stirred
4.1.6. Typical procedure for the synthesis of compounds 8, 19 and
20
for 30 min at room temperature and then cooled to 0 ꢁC. TMSOTf
(10
m
L, 0.05 mmol, 0.3 equiv.) was added. After being stirred at 0 ꢁC
A solution of compound 7 (or 17e18) (700 mg, 0.84 mmol) in
dry CH2Cl2 (20 mL) was treated with 33% HBr in HOAc (0.56 mL),
and the mixture was stirred at room temperature for 6 h, then
concentrated. The residue was purified by a silica gel column
chromatography (5:1, petroleum ether-EtOAc) to afford the product
8 (or 19e20) as a white solid;
for 30 min, the reaction mixture was warmed up to room tem-
perature for 1 h. The reaction was quenched by addition of Et3N and
then filtered. The filtrate was concentrated and purified by a silica
gel column chromatography (petroleum ether-EtOAc) to afford the
products 7b, 17b and 18b.

Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
41
4.1.6.1. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
a
-
4.1.7.2. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
b
-
27
27
D-glucopyranosyl bromide (8). Yield: 71%; [
a]
þ 6.70 (c 0.45,
D
-galactopyranosyl oleanate (19a). Yield: 82%; [
a
]
þ 56.1 (c 0.36,
D
D
CHCl3); 1H NMR (CDCl3, 600 MHz):
d
7.23e8.01 (m, 24H, Ph-H), 6.85
CHCl3); 1H NMR (CDCl3, 600 MHz):
d 7.19e8.05 (m, 24H, Ph-H), 6.59
(d, J ¼ 3.7 Hz, 1H, H-1), 6.69 (m, 1H, NHCO), 6.41 (t, J ¼ 9.6 Hz, 1H, H-
3), 5.70 (t, J ¼ 9.6 Hz,1H, H-4), 5.65 (dd, J ¼ 9.6, 3.7 Hz,1H, H-2), 5.61
(m, 2H, PhCH2), 4.24 (m, 1H, H-5), 3.87 (dd, J ¼ 12.8, 4.7 Hz, 1H, H-
6e1), 3.71 (dd, J ¼ 12.8, 2.9 Hz, 1H, H-6e2); 13C NMR (CDCl3,
(m, 1H, NHCO), 6.01 (dd, J ¼ 9.6, 3.6 Hz, 1H, H-30), 5.93 (d, J ¼ 7.9 Hz,
1H, H-10), 5.75 (dd, J ¼ 9.6, 7.9 Hz, 1H, H-20), 5.63 (m, 2H, PhCH2),
5.59 (t, J ¼ 3.6 Hz, 1H, H-40), 5.31 (t, J ¼ 3.3 Hz, 1H, H-12), 4.53 (dd,
J ¼ 11.9, 4.3 Hz, 1H, H-60-1), 4.29e4.33 (m, 2H, H-50, H-60-2), 3.17
(dd, J ¼ 12.1, 3.7 Hz, 1H, H-3), 2.78 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-18),
150 MHz):
d 166.3, 165.9, 165.3, 164.5, 136.7, 135.3, 133.9, 133.5,
133.1,132.3,131.7,131.3,130.3,130.0,129.9,129.6,128.5,128.3,128.1,
0.99, 0.93, 0.87, 0.81, 0.76, 0.73, 0.51 (s each, 3H each, CH3 ꢃ 7); 13
C
125.7, 90.1 (C-1), 73.6, 72.1, 71.7, 69.3, 51.5; HRESIMS: m/z calcd for
NMR (CDCl3, 150 MHz): d 175.9 (C-28), 166.0, 165.7, 165.3, 164.6,
C
42H34NO10BrNa [MþNaþ] 814.1258; found: 814.1273.
143.5 (C-13), 133.5, 133.3, 133.0, 132.9, 130.1, 130.0, 129.9, 129.8,
129.7,129.5,129.3,128.7,128.3,128.1,127.9,122.5 (C-12), 92.7 (C-10),
89.9 (C-3), 75.1, 73.3, 70.6, 69.7, 65.3, 52.7, 47.9, 46.8, 45.3, 42.3, 40.7,
38.7, 38.5, 37.9, 36.3, 33.9, 32.7, 31.8, 30.6, 29.7, 27.9, 25.7, 25.6, 23.4,
17.1, 16.5, 14.9; HRESIMS: m/z calcd for C72H81NO13Na [MþNaþ]
1190.5601; found: 1190.5590.
4.1.6.2. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
a-
27
D
-galactopyranosyl bromide (19). Yield: 75%; [
a
]
D
þ 21.7 (c 0.53,
CHCl3); 1H NMR (CDCl3, 600 MHz):
d 7.27e8.00 (m, 24H, Ph-H),
6.69 (m, 1H, NHCO), 6.37 (d, J ¼ 3.5 Hz, 1H, H-1), 6.11 (dd, J ¼ 9.3,
3.7 Hz, 1 H, H-3), 5.65 (t, J ¼ 3.6 Hz, 1 H, H-4), 5.63 (m, 2H, PhCH2),
5.59 (dd, J ¼ 9.3, 3.5 Hz, 1H, H-2), 4.27 (m, 1H, H-5), 3.80 (dd,
4.1.7.3. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
b-
27
J ¼ 12.3, 4.7 Hz, 1H, H-6-1), 3.69 (dd, J ¼ 12.3, 3.1 Hz, 1H, H-6-2); 13
C
D
-mannopyranosyl oleanate (20a). Yield: 79%; [
a
]
D
þ 61.3 (c 0.41,
NMR (CDCl3, 150 MHz):
d
166.6, 165.9, 164.8, 164.5, 136.7, 135.0,
CHCl3); 1H NMR (CDCl3, 600 MHz):
d 7.27e8.00 (m, 24H, Ph-H),
133.9, 133.5, 132.9, 132.3, 131.7, 131.1, 130.3, 130.0, 129.9, 129.3,
128.5, 128.3, 127.9, 125.6, 89.8 (C-1), 74.1, 72.0, 69.9, 69.3, 50.3;
6.66 (m,1H, NHCO), 6.13 (dd, J ¼ 9.3, 3.3 Hz,1H, H-30), 5.87 (s,1H, H-
10), 5.79 (t, J ¼ 9.3 Hz, 1H, H-40), 5.63 (br s, 1H, H-20), 5.59 (m, 2H,
PhCH2), 5.23 (t, J ¼ 3.6 Hz,1H, H-12), 4.57 (dd, J ¼ 12.3, 4.1 Hz,1H, H-
60-1), 4.37 (dd, J ¼ 12.3, 2.9 Hz, 1H, H-60-2), 4.31 (m, 1H, H-50), 3.19
(dd, J ¼ 12.3, 3.7 Hz, 1H, H-3), 2.78 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-18),
HRESIMS: m/z calcd for
C
42H34NO10BrNa [MþNaþ] 814.1258;
found: 814.1241.
4.1.6.3. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
a
-
1.00, 0.95, 0.87, 0.81, 0.78, 0.73, 0.49 (s each, 3H each, CH3 ꢃ 7); 13
C
27
D-mannopyranosyl bromide (20). Yield: 69%; [
a
]
D
þ 10.2 (c 0.31,
NMR (CDCl3, 150 MHz): d 175.3 (C-28), 165.9, 165.3, 165.1, 164.3,
CHCl3); 1H NMR (CDCl3, 600 MHz):
d
7.21e7.99 (m, 24H, Ph-H), 6.71
143.1 (C-13), 133.6, 133.3, 133.0, 132.9, 130.1, 130.0, 129.9, 129.7,
129.5, 129.1, 128.7, 128.3, 128.2, 127.8, 122.3 (C-12), 94.3 (C-10), 90.1
(C-3), 76.1, 72.9, 71.5, 69.3, 66.1, 52.9, 47.9, 46.7, 45.7, 42.3, 40.7, 38.9,
38.4, 38.1, 36.5, 33.9, 32.7, 31.9, 30.6, 29.7, 27.9, 25.7, 25.3, 23.4, 17.1,
(s, 1H, H-1), 6.63 (m, 1H, NHCO), 6.29 (dd, J ¼ 9.6, 3.3 Hz, 1 H, H-3),
6.03 (s, 1 H, H-2), 5.68 (t, J ¼ 9.6 Hz, 1H, H-4), 5.63 (m, 2H, PhCH2),
4.27 (m, 1H, H-5), 3.67 (dd, J ¼ 11.9, 5.1 Hz, 1H, H-6-1), 3.52 (dd,
J ¼ 11.9, 3.1 Hz, 1H, H-6-2); 13C NMR (CDCl3, 150 MHz):
d
165.9,
16.5, 15.9; HRESIMS: m/z calcd for
1190.5601; found: 1190.5627.
C
72H81NO13Na [MþNaþ]
165.7, 165.1, 164.5, 136.7, 135.3, 133.9, 133.7, 133.1, 132.7, 131.7, 131.3,
130.3, 129.9, 129.6, 129.1, 128.5, 128.3, 128.1, 126.0, 90.9 (C-1), 74.9,
72.3, 70.3, 68.9, 52.1; HRESIMS: m/z calcd for C42H34NO10BrNa
[MþNaþ] 814.1258; found: 814.1281.
4.1.8. Typical procedure for the synthesis of compounds 12ae12j
mixture of compound 10 (100 mg, 0.086 mmol), tri-
A
chloroacetimidates 11ae11j (0.10 mmol, 1.2 equiv.) and powdered
ꢀ
4.1.7. Typical procedure for the synthesis of compounds 10, 19a and
20a
4 A molecular sieves in dry CH2Cl2 (5 mL) were stirred for 30 min at
room temperature and then cooled to ꢀ30 ꢁC. TMSOTf (5
mL,
To a solution of oleanolic acid (240 mg, 0.53 mmol) and bromide
8 (or 19e20) (544 mg, 0.68 mmol) in CH2Cl2 (8 mL) were added
K2CO3 (187 mg, 1.33 mmol), water (5.0 mL), and Bu4NBr (69 mg,
0.21 mmol). The resulting mixture was refluxed for 6 h, and then
diluted with CH2Cl2. The organic phase, after being washed with
water and brine, was dried with Na2SO4, and then concentrated in
vacuo. The residue was purified by a silica gel column chromatog-
raphy (6:1 to 4:1, petroleum ether-EtOAc) to afford the product 10
(or 19ae20a) as a white solid.
0.03 mmol, 0.3 equiv.) was added. After being stirred at ꢀ30 ꢁC for
30 min, the reaction mixture was warmed up to room temperature
for 1 h. The reaction was quenched by addition of Et3N and then
filtered. The filtrate was concentrated and purified by a silica gel
column chromatography (petroleum ether-EtOAc) to afford the
products 12ae12j.
4.1.8.1. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
deoxy-
glucopyranoside (12a). Yield: 88%; [
NMR (CDCl3, 600 MHz): d 7.09e8.03 (m, 44H, Ph-H), 6.59 (m, 1H,
b-D-glucopyranosyl oleanate 3-O-2,3,4,6-tetra-O-benzoyl-b-D-
23
a]
þ 40.3 (c 0.87, CHCl3); 1H
D
4.1.7.1. 6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-deoxy-
b
-
27
D-glucopyranosyl oleanate (10). Yield: 86%; [
a]
þ 43.7 (c 0.85,
NHCO), 5.99 (t, J ¼ 9.7 Hz, 1H, H-3ʺ), 5.95 (d, J ¼ 8.1 Hz, 1H, H-1ʺ),
5.79 (t, J ¼ 9.6 Hz, 1H, H-30), 5.75 (t, J ¼ 9.7 Hz, 1H, H-4ʺ), 5.69 (t,
J ¼ 9.6 Hz, 1H, H-40), 5.65 (dd, J ¼ 9.7, 8.1 Hz, 1H, H-2ʺ), 5.62 (t,
J ¼ 9.6 Hz, 1H, H-40), 5.59 (m, 2H, PhCH2), 5.55 (dd, J ¼ 9.6, 7.9 Hz,
1H, H-20), 5.41 (d, J ¼ 7.9 Hz, 1H, H-10), 5.30 (t, J ¼ 3.7 Hz, 1H, H-12),
4.67 (dd, J ¼ 12.3, 3.2 Hz, 1H, H-60-1), 4.53 (dd, J ¼ 12.3, 5.6 Hz, 1H,
H-60-2), 4.49 (dd, J ¼ 11.9, 2.8 Hz, 1H, H-6ʺ-1), 4.39 (dd, J ¼ 11.9,
5.3 Hz, 1H, H-6ʺ-2), 4.35 (d, J ¼ 11.3 Hz, 1H, H-23e1), 4.27 (m, 1H, H-
5ʺ), 4.19 (m, 1H, H-50), 3.23 (dd, J ¼ 11.7, 3.7 Hz, 1H, H-3), 2.79 (dd,
J ¼ 13.7, 4.3 Hz, 1H, H-18), 0.93, 0.89, 0.81, 0.75, 0.71, 0.65, 0.51 (s
D
CHCl3); 1H NMR (CDCl3, 600 MHz):
d 7.28e8.04 (m, 24H, Ph-H),
6.63 (m, 1H, NHCO), 6.07 (t, J ¼ 9.6 Hz, 1H, H-30), 5.97 (d, J ¼ 8.0 Hz,
1H, H-10), 5.76 (t, J ¼ 9.6 Hz, 1H, H-40), 5.69 (dd, J ¼ 9.6, 8.0 Hz, 1H,
H-20), 5.59 (m, 2H, PhCH2), 5.28 (t, J ¼ 3.2 Hz, 1H, H-12), 4.51 (dd,
J ¼ 12.0, 4.5 Hz, 1H, H-60-1), 4.37 (dd, J ¼ 12.0, 2.3 Hz, 1H, H-60-2),
4.28 (m, 1H, H-50), 3.20 (dd, J ¼ 11.5, 3.8 Hz, 1H, H-3), 2.80 (dd,
J ¼ 14.1, 3.7 Hz, 1H, H-18), 0.97, 0.95, 0.87, 0.83, 0.78, 0.74, 0.47 (s
each, 3H each, CH3 ꢃ 7); 13C NMR (CDCl3, 150 MHz):
d 175.6 (C-28),
165.9, 165.6, 165.2, 164.6, 143.0 (C-13), 133.3, 133.1, 133.0, 132.9,
130.1, 130.0, 129.9, 129.8, 129.7, 129.5, 129.3, 128.9, 128.3, 128.2,
128.0, 122.7 (C-12), 91.9 (C-10), 89.7 (C-3), 74.9, 73.5, 71.9, 69.3, 65.7,
52.9, 47.9, 46.8, 45.7, 41.6, 40.7, 38.9, 38.5, 38.1, 36.3, 33.9, 32.7, 31.8,
30.6, 29.7, 27.9, 25.7, 25.4, 23.4, 17.0, 16.4, 15.3; HRESIMS: m/z calcd
for C72H81NO13Na [MþNaþ] 1190.5601; found: 1190.5619.
each, 3H each, CH3 ꢃ 7); 13C NMR (CDCl3, 150 MHz):
d 175.4 (C-28),
165.9, 165.7, 165.5, 165.3, 165.2, 165.1, 164.7, 163.9, 143.3 (C-13),
138.3, 138.1, 137.9, 137.8, 137.6, 136.5, 136.3, 136.1, 135.9, 133.7, 133.4,
133.2, 133.1, 132.9, 129.7, 129.6, 128.7, 128.3, 128.1, 122.5 (C-12),
101.9 (C-10), 91.7 (C-1ʺ), 90.3 (C-3), 78.9, 76.5, 73.3, 72.9, 71.9, 70.1,

42
Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
68.8, 66.9, 66.2, 65.8, 62.5, 55.7, 52.9, 47.8, 46.7, 41.9, 39.3, 36.7, 33.3,
33.3, 31.9, 27.9, 26.7, 25.7, 24.7, 17.9, 16.4, 15.1; HRMALDIMS: m/z
calcd for C98H101O20NNa [MþNaþ] 1634.6809; found: 1634.6821.
31.8, 27.9, 26.7, 25.6, 24.7, 17.9, 16.4,15.1; HRMALDIMS: m/z calcd for
C
106H107O22NNa [M þ Naþ] 1768.7179; found: 1768.7191.
4.1.8.5. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
deoxy-
arabinopyranoside (12e). Yield: 86%; [
NMR (CDCl3, 600 MHz):
b-D-glucopyranosyl oleanate 3-O-2,3,4,6-tetra-Obenzoyl-a-L-
4.1.8.2. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
a]
D
23 þ 29.3 (c 0.97, CHCl3); 1H
deoxy-
mannopyranoside (12b). Yield: 86%; [
NMR (CDCl3, 600 MHz):
b-D-glucopyranosyl oleanate 3-O-2,3,4,6-tetra-O-benzoyl-a-D-
a]
23 ꢀ 8.76 (c 0.73, CHCl3); 1H
d
7.31e8.05 (m, 39H, Ph-H), 6.57 (m, 1H,
D
NHCO), 5.95 (t, J ¼ 9.5 Hz,1H, H-3ʺ), 5.89 (d, J ¼ 8.5 Hz,1H, H-1ʺ), 5.78
(dd, J ¼ 8.6, 3.7 Hz, 1H, H-30), 5.75 (t, J ¼ 9.5 Hz, 1H, H-4ʺ), 5.68 (dd,
J ¼ 9.5, 8.5 Hz,1H, H-2ʺ), 5.63(dd, J ¼ 8.6, 6.5 Hz,1H, H-20), 5.53(m, 2H,
PhCH2), 5.45 (m, 1H, H-40), 5.26 (t, J ¼ 3.4 Hz, 1H, H-12), 4.77 (d,
J ¼ 6.5 Hz,1H, H-10), 4.47e4.53 (m, 2H, H-6ʺ-1, H-6ʺ-2), 4.31e4.39 (m,
3H, H-50-1, H-50-2, H-5ʺ), 3.19 (dd, J ¼ 14.3, 3.7 Hz, 1H, H-3), 2.81 (dd,
J ¼ 13.9, 3.7 Hz,1H, H-18), 0.93, 0.87, 0.81, 0.75, 0.71, 0.65, 0.50 (s each,
d
7.11e8.02 (m, 44H, Ph-H), 6.61 (m, 1H,
NHCO), 5.97 (t, J ¼ 9.6 Hz, 1H, H-3ʺ), 5.89 (d, J ¼ 7.9 Hz, 1H, H-1ʺ),
5.80 (t, J ¼ 9.6 Hz, 1H, H-40), 5.75 (dd, J ¼ 9.6, 3.2 Hz, 1H, H-30), 5.71
(t, J ¼ 9.6 Hz, 1H, H-4ʺ), 5.65 (dd, J ¼ 9.6, 8.0 Hz, 1H, H-2ʺ), 5.55 (m,
2H, PhCH2), 5.50 (dd, J ¼ 3.2, 2.0 Hz,1H, H-20), 5.38 (d, J ¼ 2.0 Hz,1H,
H-10), 5.23 (br s, 1H, H-12), 4.53e4.60 (m, 3H, H-50, H-60-1, H-6ʺ-1),
4.49 (dd, J ¼ 12.1, 3.7 Hz, 1H, H-60-2), 4.29e4.32 (m, 2H, H-5ʺ, H-6ʺ-
2), 3.21 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-3), 2.78 (dd, J ¼ 14.1, 3.7 Hz, 1H,
H-18), 0.95, 0.91, 0.84, 0.75, 0.70, 0.67, 0.53 (s each, 3H each,
3H each, CH3 ꢃ 7); 13C NMR (CDCl3, 150 MHz):
d 175.6 (C-28), 165.8,
165.7, 165.4, 164.1, 163.7, 163.5, 143.3 (C-13), 138.9, 137.9, 137.7, 137.5,
137.3, 136.8, 136.3, 135.7, 133.6, 133.2, 132.9, 132.5, 129.8, 128.6, 128.5,
127.5, 122.5 (C-12), 103.6 (C-10), 92.3 (C-10’), 89.3 (C-3), 78.1, 76.7, 74.3,
71.1, 70.2, 69.3, 66.3, 65.7, 61.9, 56.1, 52.7, 47.9, 45.5, 42.3, 39.1, 36.7,
33.5, 31.9, 27.9, 26.7, 25.6, 24.7,17.9,16.3,15.1; HRMALDIMS: m/z calcd
for C98H101O20NNa [MþNaþ] 1634.6809; found: 1634.6798.
CH3 ꢃ 7); 13C NMR (CDCl3, 150 MHz):
d 175.3 (C-28), 165.9, 165.8,
165.5, 165.4, 165.1, 165.0, 164.9, 163.5, 143.1 (C-13), 138.5, 138.3,
138.0, 137.7, 137.5, 136.7, 136.3, 136.1, 135.8, 133.5, 133.3, 133.1, 132.9,
132.7, 129.9, 129.7, 128.9, 128.3, 127.9, 122.3 (C-12), 95.7 (C-10), 91.9
(C-1ʺ), 89.5 (C-3), 78.1, 75.1, 73.3, 72.5, 71.6, 70.0, 68.5, 66.3, 66.1,
65.8, 60.9, 55.3, 52.7, 47.9, 45.7, 42.1, 39.3, 36.7, 33.5, 31.8, 27.8, 26.7,
25.6, 24.9, 17.9, 16.4, 15.1; HRMALDIMS: m/z calcd for
4.1.8.6. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
C
106H107O22NNa [MþNaþ] 1768.7179; found: 1768.7168.
deoxy-
rhamnopyranoside (12f). Yield: 83%; [
NMR (CDCl3, 600 MHz):
b-D-glucopyranosyl oleanate 3-O-2,3,4,6-tetra-O-benzoyl-a-L-
a
]
23 þ 14.7 (c 0.65, CHCl3); 1H
D
d
7.23e8.07 (m, 39H, Ph-H), 6.60 (m, 1H,
4.1.8.3. 28-O-6-(20-O-benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
NHCO), 5.95 (t, J ¼ 9.7 Hz, 1H, H-3ʺ), 5.91 (d, J ¼ 8.3 Hz, 1H, H-1ʺ),
5.81 (dd, J ¼ 9.7, 3.3 Hz, 1H, H-30), 5.69e5.75 (m, 3H, H-20, H-40, H-
4ʺ), 5.63 (dd, J ¼ 9.7, 8.3 Hz, 1H, H-2ʺ), 5.51 (m, 2H, PhCH2), 5.27 (t,
J ¼ 3.7 Hz, 1H, H-12), 5.01 (d, J ¼ 1.3 Hz, 1H, H-10), 4.47e4.51 (m, 2H,
H-50, H-6ʺ-1), 4.39 (dd, J ¼ 12.1, 5.1 Hz, 1H, H-6ʺ-2), 4.21 (m, 1H, H-
5ʺ), 3.97 (m, 1H, H-50), 3.21 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-3), 2.83 (dd,
J ¼ 13.7, 3.9 Hz, 1H, H-18), 1.36 (d, J ¼ 5.9 Hz, 3H, H-60), 0.97, 0.86,
0.80, 0.73, 0.71, 0.65, 0.51 (s each, 3H each, CH3 ꢃ 7); 13C NMR
deoxy-
galactopyranoside (12c). Yield: 87%; [
NMR (CDCl3, 600 MHz):
b-D-glucopyranosyl oleanate 3-O-2,3,4,6-tetra-O-benzoyl-b-D-
a]
23 þ 27.9 (c 0.87, CHCl3); 1H
D
d
7.13e8.01 (m, 44H, Ph-H), 6.63 (m, 1H,
NHCO), 5.97 (t, J ¼ 9.6 Hz, 1H, H-3ʺ), 5.86 (d, J ¼ 8.1 Hz, 1H, H-1ʺ),
5.69 (t, J ¼ 9.6 Hz, 1H, H-4ʺ), 5.65 (dd, J ¼ 9.6, 8.1 Hz, 1H, H-2ʺ), 5.63
(dd, J ¼ 9.3, 3.6 Hz, 1H, H-30), 5.56 (t, J ¼ 3.6 Hz, 1H, H-40), 5.53 (m,
2H, PhCH2), 5.46 (dd, J ¼ 9.3, 7.9 Hz, 1H, H-20), 5.24 (br s, 1H, H-12),
5.21 (d, J ¼ 7.9 Hz,1H, H-10), 4.56e4.65 (m, 3H, H-50, H-60-1, H-6ʺ-1),
4.23e4.29 (m, 2H, H-60-2, H-6ʺ-2), 4.17 (m, 1H, H-5ʺ), 3.19 (dd,
J ¼ 14.3, 3.6 Hz, 1H, H-3), 2.79 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-18), 0.99,
0.91, 0.86, 0.77, 0.70, 0.63, 0.51 (s each, 3H each, CH3 ꢃ 7); 13C NMR
(CDCl3, 150 MHz):
d 175.9 (C-28), 166.0, 165.9, 165.4, 164.1, 163.9,
163.5, 143.3 (C-13), 138.9, 137.9, 137.6, 137.5, 137.1, 136.8, 136.3,
135.9, 133.6, 133.2, 132.9, 132.3, 129.8, 128.6, 128.3, 127.5, 122.6 (C-
12), 98.3 (C-10), 92.0 (C-10’), 88.9 (C-3), 78.1, 76.7, 72.7, 71.6, 70.2,
69.3, 66.5, 65.9, 63.1, 56.7, 52.3, 48.1, 45.5, 42.3, 39.1, 36.7, 33.7, 31.9,
27.9, 26.9, 25.6, 24.9, 23.8, 17.9, 16.3, 15.1; HRMALDIMS: m/z calcd
for C99H103O20NNa [MþNaþ] 1648.6966; found: 1648.6979.
(CDCl3, 150 MHz):
d 175.3 (C-28), 165.9, 165.5, 165.4, 165.3, 165.1,
164.9, 164.7, 163.1, 143.5 (C-13), 138.5, 137.9, 137.7, 137.5, 137.1, 136.9,
136.0, 135.9, 135.8, 133.7, 133.3, 133.1, 132.9, 132.8, 129.9, 129.6,
128.9, 128.5, 128.1, 122.5 (C-12), 97.6 (C-10), 91.9 (C-1ʺ), 89.9 (C-3),
78.1, 77.3, 76.6, 74.9, 73.6, 72.5, 70.0, 69.1, 68.3, 66.3, 65.8, 60.9, 55.3,
52.9, 47.9, 45.7, 42.3, 39.3, 36.7, 33.5, 31.9, 27.8, 26.7, 25.7, 24.9, 17.9,
16.4, 15.3; HRMALDIMS: m/z calcd for C106H107O22NNa [MþNaþ]
1768.7179; found: 1768.7193.
4.1.8.7. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
deoxy-
fucopyranoside (12g). Yield: 85%; [
NMR (CDCl3, 600 MHz):
b-D-glucopyranosyl oleanate 3-O-2,3,4,6-tetra-O-benzoyl-a-L-
23
a
]
ꢀ 31.7 (c 0.73, CHCl3); 1H
D
d
7.27e8.11 (m, 39H, Ph-H), 6.55 (m, 1H,
NHCO), 5.91 (t, J ¼ 9.7 Hz, 1H, H-3ʺ), 5.87 (d, J ¼ 8.1 Hz, 1H, H-1ʺ),
5.63e5.67 (m, 3H, H-20, H-40, H-4ʺ), 5.63 (dd, J ¼ 9.7, 8.3 Hz, 1H, H-
2ʺ), 5.57 (dd, J ¼ 9.9, 3.6 Hz, 1H, H-30), 5.49 (m, 2H, PhCH2), 5.30 (t,
J ¼ 3.3 Hz, 1H, H-12), 4.79 (d, J ¼ 7.6 Hz, 1H, H-10), 4.48 (dd, J ¼ 11.9,
3.4 Hz, 1H, H-6ʺ-1), 4.37 (dd, J ¼ 11.9, 5.5 Hz, 1H, H-6ʺ-2), 4.27 (m,
1H, H-5ʺ), 4.03 (m, 1H, H-50), 3.27 (dd, J ¼ 13.7, 4.4 Hz, 1H, H-3), 2.70
(dd, J ¼ 14.3, 3.9 Hz, 1H, H-18), 1.27 (d, J ¼ 6.4 Hz, 3H, H-60), 0.99,
0.90, 0.81, 0.73, 0.69, 0.65, 0.51 (s each, 3H each, CH3 ꢃ 7); 13C NMR
4.1.8.4. 28-O-6-(20-O-benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
deoxy-
xylopyranoside (12d). Yield: 81%; [
NMR (CDCl3, 600 MHz):
b-D-glucopyranosyl oleanate 3-O-2,3,4,6-tetra-O-benzoyl-b-D-
23
a
]
þ 37.1 (c 1.01, CHCl3); 1H
D
d
7.33e8.03 (m, 39H, Ph-H), 6.59 (m, 1H,
NHCO), 5.97 (t, J ¼ 9.6 Hz, 1H, H-3ʺ), 5.91 (d, J ¼ 8.3 Hz, 1H, H-1ʺ),
5.77 (t, J ¼ 8.6 Hz, 1H, H-30), 5.72 (t, J ¼ 9.6 Hz, 1H, H-4ʺ), 5.69 (dd,
J ¼ 9.6, 8.3 Hz, 1H, H-2ʺ), 5.50 (m, 2H, PhCH2), 5.46 (dd, J ¼ 8.6,
6.4 Hz, 1H, H-20), 5.32 (m, 1H, H-40), 5.27 (t, J ¼ 3.6 Hz, 1H, H-12),
4.82 (d, J ¼ 6.4 Hz, 1H, H-10), 4.55 (dd, J ¼ 11.9, 5.1 Hz, 1H, H-6ʺ-1),
4.46 (dd, J ¼ 11.9, 2.9 Hz,1H, H-6ʺ-2), 4.41 (dd, J ¼ 11.9, 4.7 Hz,1H, H-
50-1), 4.23e4.26 (m, 1H, H-5ʺ), 3.65 (dd, J ¼ 11.9, 6.9 Hz, 1H, H-50-2),
3.13 (dd, J ¼ 12.3, 4.1 Hz, 1H, H-3), 2.79 (dd, J ¼ 13.3, 3.6 Hz, 1H, H-
18), 0.95, 0.87, 0.83, 0.75, 0.72, 0.63, 0.47 (s each, 3H each, CH3 ꢃ 7);
(CDCl3, 150 MHz):
d 175.5 (C-28), 166.1, 165.7, 165.5, 164.1, 163.8,
163.5, 143.7 (C-13), 138.9, 137.9, 137.7, 137.5, 137.0, 136.8, 136.3,
135.9, 133.7, 133.2, 132.9, 132.7, 129.8, 128.7, 128.3, 128.0, 122.8 (C-
12), 98.9 (C-10), 92.3 (C-1ʺ), 88.7 (C-3), 77.9, 76.3, 71.9, 71.0, 69.1,
66.5, 65.9, 65.3, 63.1, 55.7, 52.1, 48.1, 45.5, 42.5, 39.1, 36.7, 33.9, 31.9,
27.9, 26.7, 25.6, 24.9, 23.9,17.9,16.1,15.3; HRMALDIMS: m/z calcd for
13C NMR (CDCl3, 150 MHz):
d
175.1 (C-28), 165.9, 165.7, 165.5, 165.4,
C
99H103O20NNa [MþNaþ] 1648.6966; found: 1648.6951.
164.7, 164.0, 163.3, 143.7 (C-13), 138.9, 137.9, 137.5, 137.3, 136.9,
136.3, 135.9, 133.7, 133.1, 132.9, 132.8, 129.8, 128.9, 128.5, 127.9,
122.3 (C-12), 102.3 (C-10), 92.1 (C-10’), 89.9 (C-3), 78.3, 76.5, 74.3,
73.6, 70.0, 69.3, 68.1, 65.7, 60.9, 55.1, 52.7, 47.9, 45.5, 42.3, 39.1, 36.7,
4.1.8.8. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
deoxy-
benzoyl-
b
-
b
D
-glucopyranosyl oleanate 3-O-2,3,6,20,30,40,60-hepta-O-
23
-
D
-lactopyranoside (12h). Yield: 89%; [
a
]
þ 71.3 (c 1.12,
D

Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
43
CHCl3); 1H NMR (CDCl3, 600 MHz):
d
7.12e8.01 (m, 59H, Ph-H), 6.51
HRMALDIMS: m/z calcd for C133H129O30NNa [MþNaþ] 2242.8490;
(m,1H, NHCO), 5.87 (t, J ¼ 9.6 Hz,1H, H-3ʺ), 5.81 (t, J ¼ 9.4 Hz,1H, H-
30), 5.76 (d, J ¼ 7.8 Hz, 1H, H-1ʺ), 5.73 (t, J ¼ 9.9 Hz, 1H, H-3ʺ), 5.70 (t,
J ¼ 9.9 Hz, 1H, H-4ʺ), 5.63e5.67 (m, 2H, H-2ʺ, H-4ʺ), 5.51e5.54 (m,
3H, H-2ʺ, PhCH2), 5.38 (dd, J ¼ 12.1, 3.6 Hz, 1H, H-60-1), 5.32 (t,
J ¼ 3.7 Hz,1H, H-12), 4.91 (d, J ¼ 7.9 Hz,1H, H-10’), 4.75 (d, J ¼ 8.0 Hz,
1H, H-10), 4.51e4.55 (m, 2H, H-60-2, H-6ʺ-1), 4.49 (dd, J ¼ 11.9,
5.3 Hz, 1H, H-6ʺ-1), 4.23e4.31 (m, 4H, H-40, H-50’’, H-6ʺ-2, H-6ʺ-2),
3.99 (dd, J ¼ 9.4, 8.0 Hz, 1H, H-20), 3.87e3.97 (m, 2H, H-50, H-5ʺ),
3.15 (dd, J ¼ 12.1, 4.3 Hz, 1H, H-3), 2.72 (dd, J ¼ 14.3, 3.7 Hz, 1H, H-
18), 1.01, 0.90, 0.81, 0.73, 0.69, 0.65, 0.55 (s each, 3H each, CH3 ꢃ 7);
found: 2242.8501.
4.1.9. Typical procedure for the target compounds 1ae1j, 2ae2c
and 3ae3c
To a solution of 12ae12j, 10, 19ae20a, 7b, 17be18b (50 mg) in
CH2Cl2eMeOH (V:V/1:1, 8 mL) was added 10% PdeC (30 mg) under
1 atm of H2 for 5 h. The reaction mixture was then filtered and the
filtrate was concentrated to dryness to give a white solid. The solid
was dissolved in CH2Cl2eMeOH (V:V/1:2, 9 mL), and then NaOMe
(45 mg) was added. After stirring at room temperature for 9 h, the
solution was neutralized with ion-exchange resin (Hþ), then
filtered and concentrated. The residue was purified by column
chromatography on silica gel (8:1 to 6:1, CHCl3eMeOH) to give the
target compounds (1ae1j, 2ae2c and 3ae3c) as white amorphous
solids.
13C NMR (CDCl3, 150 MHz):
d 175.7 (C-28), 166.0, 165.9, 165.8, 165.5,
165.3, 164.9, 164.5, 163.7, 143.9 (C-13), 138.9, 137.9, 137.5, 136.9,
136.7, 135.9, 133.8, 133.6, 133.2, 132.9, 132.3, 130.2, 130.0, 129.8,
128.9, 128.7, 128. 5, 122.7 (C-12), 103.6 (C-10), 101.0 (C-10’), 91.3 (C-
10’’), 90.3 (C-3), 78.1, 75.3, 73.1, 72.9, 71.6, 71.3, 70.2, 69.1, 67.8, 66.0,
65.9, 64.5, 63.1, 61.4, 56.7, 51.7, 48.1, 45.5, 42.3, 39.5, 36.7, 34.3, 34.1,
33.2, 32.7, 27.9, 26.9, 25.6, 24.9, 23.8, 18.5, 17.9, 16.3, 15.4; HRMAL-
DIMS: m/z calcd for C133H129O30NNa [MþNaþ] 2242.8492; found:
2242.8501.
4.1.9.1. 28-O-6-Phthalimido-6-deoxy-
O- -glucopyranoside (1a). Yield: 79%;
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.95 (dd, J ¼ 6.3, 0.9 Hz, 1H,
b-D-glucopyranosyl oleanate 3-
23
b-
D
[
a]
þ 10.6 (c 0.31,
D
d
HeAr), 7.69 (d, J ¼ 7.2 Hz, 1H, HeAr), 7.61 (m, 2H, HeAr), 6.93 (m,
1H, NHCO), 5.36 (d, J ¼ 8.2 Hz, 1H, H-1ʺ), 5.26 (t, J ¼ 3.7 Hz, 1H, H-
12), 4.39 (d, J ¼ 7.9 Hz, 1H, H-10), 3.87 (dd, J ¼ 11.9, 2.3 Hz, 1H, H-
60-1), 3.81 (t, J ¼ 9.6 Hz, 1H, H-4ʺ), 3.69e3.73 (m, 2H, H-40, H-6ʺ-1),
3.47 (t, J ¼ 9.6 Hz, 1H, H-30), 3.35e3.39 (m, 4H, H-50, H-5ʺ, H-60-2,
H-6ʺ-2), 3.31 (dd, J ¼ 9.6, 8.2 Hz, 1H, H-2ʺ), 3.25e3.29 (m, 2H, H-20,
H-3ʺ), 3.10 (dd, J ¼ 11.9, 4.6 Hz, 1H, H-3), 2.81 (dd, J ¼ 14.3, 4.3 Hz,
1H, H-18), 1.13, 1.02, 0.95, 0.91, 0.89, 0.83, 0.79 (s each, 3H each,
4.1.8.9. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
deoxy-
benzoyl-
CHCl3); 1H NMR (CDCl3, 600 MHz):
b
-
b
D
-glucopyranosyl oleanate 3-O-2,3,6,20,30,40,60-hepta-O-
23
-
D
-cellopyranoside (12i). Yield: 81%; [
a
]
þ 46.7 (c 0.91,
D
d
7.15e8.02 (m, 59H, Ph-H), 6.47
(m, 1H, NHCO), 5.89 (t, J ¼ 9.9 Hz, 1H, H-30’’), 5.79 (t, J ¼ 9.6 Hz, 1H,
H-30), 5.73 (t, J ¼ 9.9 Hz,1H, H-3ʺ), 5.70 (d, J ¼ 8.1 Hz,1H, H-10’’), 5.68
(t, J ¼ 9.9 Hz, 1H, H-40’’), 5.65 (t, J ¼ 9.9 Hz, 1H, H-40’), 5.70 (dd,
J ¼ 9.9, 8.1 Hz, 1H, H-20’’), 5.53 (m, 2H, PhCH2), 5.49 (dd, J ¼ 9.9,
7.8 Hz,1H, H-2ʺ), 5.31e5.35 (m, 2H, H-60-1, H-12), 4.95 (d, J ¼ 7.8 Hz,
1H, H-10’), 4.81 (d, J ¼ 7.9 Hz, 1H, H-10), 4.47e4.52 (m, 3H, H-60-2, H-
60’-1, H-60’’-1), 4.17e4.23 (m, 4H, H-40, H-50’’, H-60’-2, H-60’’-2),
3.93e3.98 (m, 3H, H-20, H-50, H-50’), 3.09 (dd, J ¼ 11.9, 3.7 Hz, 1H, H-
3), 2.63 (dd, J ¼ 14.3, 4.3 Hz, 1H, H-18), 0.99, 0.91, 0.83, 0.71, 0.69,
0.63, 0.49 (s each, 3H each, CH3 ꢃ 7); 13C NMR (CDCl3, 150 MHz):
CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d 178.3 (C-28), 167.5, 167.0,
144.6 (C-13), 137.9, 134.1, 132.9, 129.7, 129.1, 128.3, 123.7 (C-12),
106.9 (C-10), 95.9 (C-1ʺ), 90.7 (C-3), 80.5, 78.9, 78.3, 76.5, 75.3, 74.3,
71.9, 71.3, 62.5, 62.3, 55.5, 48.1, 46.9, 42.7, 41.9, 39.9, 37.9, 35.7,
33.9, 33.3, 31.8, 28.9, 27.1, 26.3, 24.6, 24.1, 19.4, 17.8, 17.0, 16.3;
HRESIMS: m/z calcd for C50H74O15N [MþHþ] 928.5053; found:
928.5071.
d
175.5 (C-28), 166.3, 165.9, 165.7, 165.5, 165.3, 165.1, 164.3, 163.9,
4.1.9.2. 28-O-6-Phthalimido-6-deoxy-
3-O- -mannopyranoside (1b). Yield: 73%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.93 (dd, J ¼ 6.3, 1.0 Hz, 1H,
b-D-glucopyranosyl oleanate
143.5 (C-13), 138.9, 137.1, 137.0, 136.9, 136.5, 135.7, 133.8, 133.5,
133.1, 132.9, 132.5, 130.2, 130.0, 129.7, 128.9, 128.5, 128.1, 122.5 (C-
12), 102.7 (C-10), 100.1 (C-10’), 91.7 (C-10’’), 89.9 (C-3), 77.9, 74.9,
73.3, 72.7, 71.6, 71.3, 70.2, 68.9, 67.8, 66.3, 65.9, 63.5, 63.1, 61.8, 55.7,
51.7, 48.1, 45.5, 42.5, 39.5, 36.7, 34.9, 34.1, 33.2, 32.7, 27.9, 26.9, 25.6,
24.9, 23.9, 18.7, 17.9, 16.5, 15.3; HRMALDIMS: m/z calcd for
23
a-D
a
]
þ 17.8 (c 0.21,
D
d
HeAr), 7.70 (d, J ¼ 7.2 Hz, 1H, HeAr), 7.59 (m, 2H, HeAr), 6.89 (m,
1H, NHCO), 5.37 (d, J ¼ 8.0 Hz, 1H, H-1ʺ), 5.30 (t, J ¼ 3.6 Hz, 1H, H-
12), 4.89 (s, 1H, H-10), 3.82 (t, J ¼ 9.6 Hz, 1H, H-4ʺ), 3.79 (dd, J ¼ 11.0,
1.9 Hz, 1H, H-60-1), 3.73 (dd, J ¼ 12.3, 3.4 Hz, 1H, H-6ʺ-1), 3.67e3.70
(m, 2H, H-50, H-60-2), 3.65 (t, J ¼ 9.1 Hz, 1H, H-40), 3.51 (dd, J ¼ 9.1,
3.7 Hz, 1H, H-30), 3.37e3.42 (m, 3H, H-20, H-50’, H-60’-2), 3.34 (dd,
J ¼ 9.6, 8.0 Hz, 1H, H-20’), 3.27 (t, J ¼ 9.6 Hz, 1H, H-3ʺ), 3.18 (dd,
J ¼ 13.7, 4.1 Hz, 1H, H-3), 2.80 (dd, J ¼ 14.3, 3.7 Hz, 1H, H-18), 1.15,
1.03, 0.95, 0.93, 0.90, 0.85, 0.79 (s each, 3H each, CH3 ꢃ 7); 13C NMR
C
133H129O30NNa [MþNaþ] 2242.8492; found: 2242.8479.
4.1.8.10. 28-O-6-(20-O-Benzyl-phthalimido)-2,3,4-tri-O-benzoyl-6-
deoxy-
benzoyl-
CHCl3); 1H NMR (CDCl3, 600 MHz):
b-D
-glucopyranosyl oleanate 3-O-2,3,4,20,30,40,60-hepta-O-
b-D
-gentiopyranoside (12j). Yield: 83%; [
a
]
D
23 þ 59.3 (c 0.89,
d
7.13e8.07 (m, 59H, Ph-H), 6.50
(CD3OD, 150 MHz): d 178.5 (C-28), 167.5, 167.1, 144.5 (C-13), 137.9,
(m, 1H, NHCO), 5.93 (t, J ¼ 10.1 Hz, 1H, H-30’’), 5.77 (t, J ¼ 9.9 Hz, 1H,
H-30), 5.69 (t, J ¼ 9.9 Hz, 1H, H-3ʺ), 5.67 (t, J ¼ 9.9 Hz, 1H, H-4ʺ), 5.65
(t, J ¼ 10.0 Hz, 1H, H-40’’), 5.62 (d, J ¼ 8.3 Hz, 1H, H-10’’), 5.55e5.59
(m, 4H, H-20’, H-20’’, PhCH2), 5.32 (t, J ¼ 3.3 Hz, 1H, H-12), 5.07 (d,
J ¼ 7.9 Hz, 1H, H-1ʺ), 4.79 (d, J ¼ 7.9 Hz, 1H, H-10), 4.53e4.57 (m, 4H,
H-60-1, H-60-2, H-60’-1, H-60’’-1), 4.25e4.29 (m, 4H, H-20, H-40, H-60’-
2, H-60’’-2), 4.03e4.07 (m, 3H, H-50’’, H-50, H-50’), 3.06 (dd, J ¼ 12.9,
4.3 Hz, 1H, H-3), 2.77 (dd, J ¼ 13.7, 4.3 Hz, 1H, H-18), 0.97, 0.89, 0.83,
0.70, 0.69, 0.65, 0.53 (s each, 3H each, CH3 ꢃ 7); 13C NMR (CDCl3,
133.9, 132.9, 129.8, 129.1, 128.5, 123.4 (C-12), 97.9 (C-10), 95.7 (C-10’),
85.3 (C-3), 79.3, 78.3, 76.5, 75.3, 74.3, 73.1, 72.7, 71.3, 68.6, 62.5, 56.7,
48.1, 46.9, 42.5, 41.9, 39.7, 37.9, 35.7, 33.7, 33.3, 31.9, 28.9, 27.3, 26.3,
24.6, 23.9, 19.4, 17.8, 17.1, 16.3; HRESIMS: m/z calcd for C50H74O15
N
[MþHþ] 928.5053; found: 928.5029.
4.1.9.3. 28-O-6-Phthalimido-6-deoxy-
3-O- -galactopyranoside (1c). Yield: 69%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.97 (dd, J ¼ 6.5, 1.2 Hz, 1H,
b-D-glucopyranosyl oleanate
23
b-
D
a]
þ 21.5 (c 0.31,
D
d
150 MHz):
d
175.3 (C-28), 165.9, 165.8, 165.7, 165.5, 165.3, 165.1,
HeAr), 7.68 (d, J ¼ 7.3 Hz, 1H, HeAr), 7.61 (m, 2H, HeAr), 6.85 (m,
1H, NHCO), 5.39 (d, J ¼ 8.3 Hz, 1H, H-1ʺ), 5.27 (t, J ¼ 3.6 Hz, 1H, H-
12), 4.41 (d, J ¼ 8.2 Hz, 1H, H-10), 3.86 (t, J ¼ 9.7 Hz, 1H, H-4ʺ), 3.76
(dd, J ¼ 12.3, 3.7 Hz, 1H, H-60-1), 3.70e3.74 (m, 3H, H-50, H-60-2, H-
6ʺ-1), 3.65 (dd, J ¼ 9.6, 3.7 Hz, 1H, H-30), 3.56 (t, J ¼ 3.7 Hz, 1H, H-40),
3.49 (dd, J ¼ 9.6, 8.2 Hz, 1H, H-20), 3.41e3.45 (m, 2H, H-5ʺ, H-6ʺ-2),
3.37 (dd, J ¼ 9.7, 8.3 Hz, 1H, H-2ʺ), 3.29 (t, J ¼ 9.7 Hz, 1H, H-3ʺ), 3.20
164.7, 164.0, 143.9 (C-13), 139.0, 137.8, 137.3, 136.7, 136.5, 135.7,
133.9, 133.8, 133.6, 133.3, 132.9, 132.7, 132.5, 130.1, 130.0, 129.7,
128.9, 128.7, 127.9, 122.3 (C-12), 102.7 (C-10), 99.7 (C-1ʺ), 91.9 (C-
10’’), 89.3 (C-3), 78.3, 75.1, 73.3, 72.7, 71.6, 71.1, 69.9, 68.9, 67.3, 66.5,
65.7, 63.5, 63.1, 61.5, 56.3, 51.7, 48.3, 45.5, 42.5, 39.7, 36.7, 35.2, 34.1,
33.2, 32.7, 27.9, 26.9, 25.6, 24.8, 23.9, 19.3, 17.9, 16.0, 15.1;

44
Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
(dd, J ¼ 12.3, 3.7 Hz, 1H, H-3), 2.79 (dd, J ¼ 13.7, 4.3 Hz, 1H, H-18),
4.1.9.7. 28-O-6-Phthalimido-6-deoxy-
3-O-3-O- -fucopyranoside (1g). Yield: 65%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.93 (dd, J ¼ 6.5, 1.1 Hz, 1H,
b-D-glucopyranosyl oleanate
23
1.15, 1.01, 0.93, 0.90, 0.89, 0.83, 0.79 (s each, 3H each, CH3 ꢃ 7); 13
C
a-L
a]
þ 11.3 (c 0.12,
D
NMR (CD3OD, 150 MHz):
d
178.1 (C-28), 167.6, 167.1, 144.5 (C-13),
d
137.9, 133.7, 132.9, 129.7, 129.1, 128.3, 123.4 (C-12), 102.1 (C-10), 95.9
(C-10’), 89.7 (C-3), 79.1, 78.5, 75.6, 74.5, 73.1, 72.3, 71.3, 68.9, 62.5,
56.9, 48.3, 46.9, 42.5, 41.0, 39.7, 37.9, 35.7, 33.9, 33.3, 31.9, 28.9, 27.3,
26.5, 24.6, 23.9, 19.5, 17.8, 17.3, 16.0; HRESIMS: m/z calcd for
HeAr), 7.66 (d, J ¼ 7.5 Hz, 1H, HeAr), 7.53 (m, 2H, HeAr), 6.81 (m,
1H, NHCO), 5.35 (d, J ¼ 8.1 Hz, 1H, H-1ʺ), 5.32 (t, J ¼ 3.6 Hz, 1H, H-
12), 4.26 (d, J ¼ 6.7 Hz, 1H, H-10), 3.81 (t, J ¼ 9.6 Hz, 1H, H-4ʺ), 3.59e
3.64 (m, 3H, H-20, H-30, H-60’-1), 3.49 (dd, J ¼ 12.1, 3.1 Hz, 1H, H-60’-
2), 3.43e3.46 (m, 3H, H-20’, H-40, H-50), 3.34 (m, 2H, H-30’, H-50’),
3.18 (dd, J ¼ 13.7, 4.3 Hz, 1H, H-3), 2.81 (dd, J ¼ 12.9, 3.7 Hz, 1H, H-
18), 1.26 (d, J ¼ 6.4 Hz, 3H, H-60), 1.17, 1.03, 0.97, 0.91, 0.89, 0.85, 0.79
C
50H74O15N [MþHþ] 928.5055; found: 928.5073.
4.1.9.4. 28-O-6-Phthalimido-6-deoxy-
3-O- -xylopyranoside (1d). Yield: 71%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.95 (dd, J ¼ 6.3, 1.1 Hz, 1H,
b-D-glucopyranosyl oleanate
23
(s each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d 178.0 (C-
b
-D
a
]
þ 15.7 (c 0.19,
D
28), 167.3, 166.7, 144.3 (C-13), 137.9, 133.5, 132.3, 129.6, 129.1, 127.5,
123.1 (C-12), 102.8 (C-10), 95.1 (C-10’), 87.1 (C-3), 79.1, 75.3, 72.4,
71.7, 70.9, 68.8, 66.7, 63.7, 59.7, 48.7, 47.6, 42.3, 41.9, 39.7, 37.8, 35.5,
33.9, 33.5, 31.7, 28.9, 27.3, 26.3, 24.7, 23.7, 19.3, 18.1, 17.3, 15.9, 14.7;
HRESIMS: m/z calcd for C50H74O14N [M þ Hþ] 912.5104; found:
912.5097.
d
HeAr), 7.69 (d, J ¼ 7.4 Hz,1H, HeAr), 7.62 (m, 2H, H-Ar), 6.83 (m,1H,
NHCO), 5.36 (d, J ¼ 8.2 Hz, 1H, H-1ʺ), 5.25 (t, J ¼ 3.6 Hz, 1H, H-12),
4.27 (d, J ¼ 6.9 Hz, 1H, H-10), 3.85 (dd, J ¼ 11.9, 5.6 Hz, 1H, H-50-1),
3.81 (t, J ¼ 9.7 Hz, 1H, H-4ʺ), 3.69 (dd, J ¼ 12.5, 4.6 Hz, 1H, H-6ʺ-1),
3.45e3.48 (m, 1H, H-40), 3.43 (t, J ¼ 9.3 Hz, 1H, H-30), 3.34e3.38 (m,
2H, H-5ʺ, H-50-1), 3.31 (dd, J ¼ 12.5, 2.9 Hz, 1H, H-6ʺ-2), 3.27 (dd,
J ¼ 9.7, 8.2 Hz, 1H, H-2ʺ), 3.19e3.24 (m, 2H, H-20, H-3ʺ), 3.15 (dd,
J ¼ 11.9, 4.3 Hz, 1H, H-3), 2.86 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-18), 1.15,
1.03, 0.95, 0.93, 0.89, 0.84, 0.79 (s each, 3H each, CH3 ꢃ 7); 13C NMR
4.1.9.8. 28-O-6-Phthalimido-6-deoxy-
3-O- -lactopyranoside (1h). Yield: 71%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.97 (dd, J ¼ 6.3, 1.1 Hz, 1H,
b-D-glucopyranosyl oleanate
23
b-
D
a]
þ 50.3 (c 0.33,
D
d
HeAr), 7.64 (d, J ¼ 7.3 Hz, 1H, HeAr), 7.55 (m, 2H, HeAr), 6.79 (m,
1H, NHCO), 5.38 (d, J ¼ 8.1 Hz, 1H, H-10’’), 5.23 (t, J ¼ 3.7 Hz, 1H, H-
12), 4.36 (d, J ¼ 7.6 Hz, 1H, H-10), 4.31 (d, J ¼ 7.8 Hz, 1H, H-10’), 3.78
(dd, J ¼ 9.3, 3.8 Hz, 1H, H-30’), 3.74 (t, J ¼ 3.8 Hz, 1H, H-40’), 3.72 (dd,
J ¼ 11.9, 6.3 Hz, 1H, H-60-1), 3.67 (dd, J ¼ 12.1, 4.5 Hz, 1H, H-60’-1),
3.53e3.57 (m, 4H, H-60-2, H-60’-2, H-60’’-1, H-60’’-2), 3.47 (t,
J ¼ 9.6 Hz,1H, H-40’’), 3.44 (t, J ¼ 9.3 Hz,1H, H-30), 3.39e3.43 (m, 3H,
H-20’’, H-30’’, H-40), 3.34e3.37 (m, 2H, H-20, H-20’), 3.21e3.26 (m, 3H,
H-50, H-50’, H-50’’), 3.12 (dd, J ¼ 11.9, 4.0 Hz, 1H, H-3), 2.79 (dd,
J ¼ 13.7, 4.3 Hz, 1H, H-18), 1.07, 1.03, 0.97, 0.89, 0.87, 0.85, 0.79, 0.75
(CD3OD, 150 MHz):
d 177.5 (C-28), 167.5, 166.9, 144.3 (C-13), 137.9,
133.4, 132.9, 129.7, 129.3, 128.1, 123.3 (C-12), 106.0 (C-10), 95.3 (C-
10’), 82.7 (C-3), 79.3, 75.9, 74.5, 73.1, 71.7, 70.3, 66.7, 64.6, 59.8, 48.5,
47.6, 42.5, 41.7, 39.7, 37.9, 35.6, 33.9, 33.3, 31.9, 28.7, 27.3, 26.5, 24.7,
23.9, 19.5, 17.8, 17.3, 16.1; HRESIMS: m/z calcd for C49H72O14
N
[MþHþ] 898.4947; found: 898.4963.
4.1.9.5. 28-O-6-Phthalimido-6-deoxy-
3-O- -arabinopyranoside (1e). Yield: 65%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.95 (dd, J ¼ 6.3, 1.2 Hz, 1H,
b-D-glucopyranosyl oleanate
23
a-L
a
]
þ 39.5 (c 0.31,
D
(s each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d 178.3 (C-
d
HeAr), 7.66 (d, J ¼ 7.3 Hz,1H, HeAr), 7.59 (m, 2H, H-Ar), 6.87 (m,1H,
NHCO), 5.39 (d, J ¼ 8.2 Hz, 1H, H-1ʺ), 5.27 (t, J ¼ 3.6 Hz, 1H, H-12),
4.38 (d, J ¼ 7.1 Hz, 1H, H-10), 3.86e3.89 (m, 2H, H-4ʺ, H-50-1), 3.65
(dd, J ¼ 11.9, 5.3 Hz, 1H, H-60’-1), 3.47e3.50 (m, 2H, H-30, H-40), 3.37
(dd, J ¼ 11.9, 2.7 Hz, 1H, H-60’-2), 3.29e3.35 (m, 4H, H-20’, H-30’, H-
50’, H-50-1), 3.27 (dd, J ¼ 9.3, 7.1 Hz, 1H, H-20), 3.17 (dd, J ¼ 11.9,
3.7 Hz, 1H, H-3), 2.83 (dd, J ¼ 14.3, 4.3 Hz, 1H, H-18), 1.13, 1.01, 0.97,
0.91, 0.89, 0.83, 0.79 (s each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD,
28), 167.5, 166.5, 144.7 (C-13), 137.9, 133.6, 132.3, 129.7, 129.1, 127.3,
123.6 (C-12), 106.5 (C-10), 104.5 (C-10’), 95.6 (C-10’’), 90.5 (C-3), 79.8,
78.6, 77.1, 76.5, 76.2, 75.3, 74.9, 73.7, 72.7, 71.6, 71.3, 70.2, 63.8, 62.5,
61.9, 51.7, 48.1, 47.5, 42.3, 39.7, 36.7, 34.9, 34.0, 33.4, 31.7, 27.9, 26.5,
25.6, 24.9, 23.8, 19.5, 17.8, 17.0, 16.1; HRESIMS: m/z calcd for
C
56H84NO20 [MþHþ] 1090.5581; found: 1090.5597.
4.1.9.9. 28-O-6-Phthalimido-6-deoxy-
3-O- -cellopyranoside (1i). Yield: 65%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.99 (dd, J ¼ 6.3, 1.2 Hz, 1H,
b-D-glucopyranosyl oleanate
150 MHz):
d
177.8 (C-28), 167.5, 167.0, 144.3 (C-13), 137.9, 133.5,
23
b-
D
a
]
þ 27.9 (c 0.21,
D
132.9, 129.6, 129.3, 127.9, 123.7 (C-12), 102.9 (C-10), 95.9 (C-10’), 89.0
(C-3), 79.1, 74.9, 73.5, 72.9, 71.7, 69.9, 66.7, 63.6, 60.1, 48.5, 47.6, 42.5,
41.9, 39.7, 37.9, 35.7, 33.9, 33.3, 31.9, 28.9, 27.3, 26.5, 24.7, 23.9, 19.3,
17.8, 17.3, 16.0; HRESIMS: m/z calcd for C49H72O14N [MþHþ]
898.4947; found: 898.4966.
d
HeAr), 7.64 (d, J ¼ 7.2 Hz, 1H, HeAr), 7.56 (m, 2H, HeAr), 6.86 (m,
1H, NHCO), 5.33 (d, J ¼ 8.0 Hz, 1H, H-10’’), 5.21 (t, J ¼ 3.6 Hz, 1H, H-
12), 4.37 (d, J ¼ 8.0 Hz, 1H, H-10), 4.29 (d, J ¼ 8.0 Hz, 1H, H-1ʺ), 3.81
(t, J ¼ 9.6 Hz, 1H, H-4ʺ), 3.76e3.79 (m, 2H, H-60-1, H-6ʺ-1), 3.73 (dd,
J ¼ 11.9, 4.7 Hz, 1H, H-6ʺ-2), 3.60 (dd, J ¼ 12.3, 3.4 Hz, 1H, H-60-2),
3.53e3.55 (m, 2H, H-60’’-1, H-60’’-2), 3.49 (t, J ¼ 9.5 Hz, 1H, H-40’’),
3.46 (t, J ¼ 9.5 Hz,1H, H-30’’), 3.43 (t, J ¼ 9.3 Hz,1H, H-30’), 3.35e3.39
(m, 2H, H-20’’, H-40), 3.29e3.35 (m, 3H, H-20, H-50, H-2ʺ), 3.16e3.19
(m, 2H, H-5ʺ, H-50’’), 3.10 (dd, J ¼ 11.9, 3.9 Hz, 1H, H-3), 2.81 (dd,
J ¼ 13.2, 3.7 Hz, 1H, H-18), 1.09, 1.01, 0.97, 0.89, 0.87, 0.85, 0.79, 0.75
4.1.9.6. 28-O-6-Phthalimido-6-deoxy-
3-O- -rhamnopyranoside (1f). Yield: 69%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
7.99 (dd, J ¼ 6.0, 1.3 Hz, 1H,
b-D-glucopyranosyl oleanate
23
a-L
a]
ꢀ 8.76 (c 0.24,
D
d
HeAr), 7.65 (d, J ¼ 7.5 Hz,1H, HeAr), 7.55 (m, 2H, H-Ar), 6.83 (m,1H,
NHCO), 5.33 (d, J ¼ 8.2 Hz, 1H, H-10’), 5.30 (t, J ¼ 3.7 Hz, 1H, H-12),
4.72 (d, J ¼ 2.1 Hz, 1H, H-10), 3.86 (t, J ¼ 9.6 Hz, 1H, H-40’), 3.82 (dd,
J ¼ 3.8, 2.1 Hz, 1H, H-20), 3.73 (dd, J ¼ 9.6, 3.8 Hz, 1H, H-30), 3.65 (dd,
J ¼ 11.9, 4.7 Hz, 1H, H-60’-1), 3.37 (dd, J ¼ 11.9, 2.3 Hz, 1H, H-60’-2),
3.35 (t, J ¼ 9.6 Hz, 1H, H-40), 3.31e3.34 (m, 2H, H-20’, H-30’), 3.27e
3.30 (m, 2H, H-50, H-50’), 3.11 (dd, J ¼ 12.3, 3.7 Hz, 1H, H-3), 2.86 (dd,
J ¼ 13.7, 3.7 Hz, 1H, H-18), 1.24 (d, J ¼ 6.4 Hz, 3H, H-60), 1.15, 1.03,
0.95, 0.93, 0.89, 0.85, 0.80 (s each, 3H each, CH3 ꢃ 7); 13C NMR
(s each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d 178.2 (C-
28), 167.3, 166.5, 144.5 (C-13), 137.8, 133.5, 132.3, 129.7, 129.0, 127.3,
123.1 (C-12), 106.3 (C-10), 103.9 (C-1ʺ), 95.9 (C-10’’), 90.7 (C-3), 80.1,
78.6, 78.3, 79.7, 77.9, 76.5, 76.3, 75.3, 74.9, 73.5, 71.6, 71.3, 68.9, 63.8,
62.5, 61.9, 57.2, 48.1, 47.5, 42.3, 39.7, 36.9, 34.9, 34.0, 33.4, 31.9, 27.9,
26.5, 25.6, 24.7, 23.8, 19.6, 17.8, 17.0, 16.1; HRESIMS: m/z calcd for
C
56H84NO20 [MþHþ] 1090.5581; found: 1090.5568.
(CD3OD, 150 MHz):
d 177.7 (C-28), 167.3, 166.7, 144.5 (C-13), 137.8,
133.5, 132.5, 129.6, 129.1, 127.9, 123.3 (C-12), 103.3 (C-10), 95.4 (C-
10’), 87.9 (C-3), 79.1, 72.4, 71.7, 71.3, 70.9, 69.9, 68.8, 66.7, 63.6, 59.3,
48.5, 47.6, 42.7, 41.9, 39.7, 37.8, 35.7, 33.9, 33.5, 31.9, 28.9, 27.3, 26.5,
24.7, 23.9, 19.3, 18.1, 17.8, 17.3, 15.9, 14.7; HRESIMS: m/z calcd for
4.1.9.10. 28-O-6-Phthalimido-6-deoxy-
3-O- -gentiopyranoside (1j). Yield: 63%; [
CH3OH); 1H NMR (CD3OD, 600 MHz):
b-D-glucopyranosyl oleanate
23
b-
D
a
]
þ 9.43 (c 0.19,
D
d
7.98 (dd, J ¼ 6.1, 0.9 Hz, 1H,
HeAr), 7.64 (d, J ¼ 7.3 Hz, 1H, HeAr), 7.57 (m, 2H, HeAr), 6.81 (m,
C
50H74O14N [MþHþ] 912.5104; found: 912.5121.
1H, NHCO), 5.36 (d, J ¼ 8.1 Hz, 1H, H-10’’), 5.23 (t, J ¼ 3.6 Hz, 1H, H-

Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
45
12), 4.39 (d, J ¼ 8.0 Hz, 1H, H-10), 4.23 (d, J ¼ 8.1 Hz, 1H, H-1ʺ), 3.73e
3.77 (m, 3H, H-4ʺ, H-60-1, H-60’-1), 3.65e3.68 (m, 2H, H-60-2, H-6ʺ-
2), 3.51 (t, J ¼ 9.6 Hz, 1H, H-30’’), 3.44 (t, J ¼ 9.3 Hz, 1H, H-30’), 3.39 (t,
J ¼ 9.6 Hz, 1H, H-40’’), 3.33e3.39 (m, 4H, H-20’’, H-40, H-60’’-1, H-60’’-
2), 3.29e3.32 (m, 2H, H-20, H-2ʺ), 3.17e3.22 (m, 3H, H-50, H-50’, H-
50’’), 3.06 (dd, J ¼ 12.3, 3.7 Hz, 1H, H-3), 2.79 (dd, J ¼ 13.7, 4.3 Hz, 1H,
H-18), 1.07, 1.01, 0.99, 0.89, 0.87, 0.83, 0.79, 0.73 (s each, 3H each,
1H, HeAr), 7.53 (m, 2H, H-Ar), 6.89 (m, 1H, NHCO), 5.25 (t,
J ¼ 3.5 Hz, 1H, H-12), 5.01 (d, J ¼ 7.9 Hz, 1H, H-10), 3.67 (dd, J ¼ 11.9,
5.1 Hz, 1H, H-60-1), 3.54 (m, 1H, H-50), 3.47 (dd, J ¼ 11.9, 3.3 Hz, 1H,
H-60-2), 3.29 (t, J ¼ 9.7 Hz, 1H, H-40), 3.21 (dd, J ¼ 9.7, 7.9 Hz, 1H, H-
20), 3.12 (dd, J ¼ 9.7 Hz, 1H, H-30), 3.05 (dd, J ¼ 13.7, 3.7 Hz, 1H, H-3),
2.81 (dd, J ¼ 13.3, 3.7 Hz, 1H, H-18), 1.10, 0.99, 0.89, 0.87, 0.83, 0.75,
0.57 (s each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d 177.5
CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d
178.5 (C-28), 167.1, 166.5,
(C-28), 167.1, 166.7, 144.5 (C-13), 137.1, 133.7, 132.9, 129.3, 129.0,
127.9, 123.7 (C-12), 105.7 (C-10’), 90.3 (C-3), 75.6, 73.9, 71.6, 69.8,
63.1, 55.3, 48.7, 47.6, 43.1, 41.5, 39.7, 37.8, 35.3, 33.7, 33.5, 31.7, 28.9,
27.3, 26.5, 24.8, 23.6, 19.5, 18.1, 17.9, 16.3, 15.0; HRESIMS: m/z calcd
for C44H64O10N [MþHþ] 766.4525; found: 766.4507.
144.5 (C-13), 137.9, 133.5, 132.1, 129.7, 129.3, 127.1, 123.5 (C-12),
106.6 (C-10), 104.3 (C-1ʺ), 95.3 (C-10’’), 90.5 (C-3), 79.9, 78.5, 78.3,
79.5, 77.9, 76.5, 75.9, 75.3, 74.9, 73.5, 71.5, 71.3, 68.3, 63.8, 62.5, 61.3,
57.9, 48.1, 47.9, 42.3, 39.7, 36.9, 34.9, 34.1, 33.4, 31.9, 27.9, 26.5, 25.7,
24.7, 23.9, 19.6, 17.8, 17.3, 16.1; HRESIMS: m/z calcd for C56H84NO20
[MþHþ] 1090.5581; found: 1090.5599.
4.1.9.15. Oleanate 3-O-6-phthalimido -6-deoxy-b-D-galactopyrano-
side (3b). Yield: 67%; [
600 MHz):
a
]
23 þ 23.1 (c 0.34, CH3OH); 1H NMR (CD3OD,
D
4.1.9.11. Oleanate 28-O-6-phthalimido-6-deoxy-
b
-
D
-glucopyranoside
d
7.90 (dd, J ¼ 6.3, 1.0 Hz, 1H, HeAr), 7.67 (d, J ¼ 7.2 Hz,
23
(2a). Yield: 75%; [
600 MHz):
a
]
D
þ 23.7 (c 0.33, CH3OH); 1H NMR (CD3OD,
1H, HeAr), 7.49 (m, 2H, HeAr), 6.77 (m, 1H, NHCO), 5.30 (t,
J ¼ 3.7 Hz, 1H, H-12), 4.83 (d, J ¼ 7.7 Hz, 1H, H-10), 3.70 (t, J ¼ 3.5 Hz,
1H, H-40), 3.63 (dd, J ¼ 11.9, 4.7 Hz,1H, H-60-1), 3.51e3.55 (m, 2H, H-
50, H-60-2), 3.15e3.20 (m, 2H, H-20, H-30), 3.07 (dd, J ¼ 11.9, 3.7 Hz,
1H, H-3), 2.81 (dd, J ¼ 13.7, 4.1 Hz, 1H, H-18), 1.09, 0.97, 0.89, 0.85,
0.79, 0.75, 0.63 (s each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD,
d
7.90 (dd, J ¼ 6.3, 1.2 Hz, 1H, HeAr), 7.63 (d, J ¼ 7.3 Hz,
1H, HeAr), 7.49 (m, 2H, HeAr), 6.84 (m, 1H, NHCO), 5.28 (d,
J ¼ 8.0 Hz, 1H, H-10), 5.27 (t, J ¼ 3.7 Hz, 1H, H-12), 3.89 (t, J ¼ 9.7 Hz,
1H, H-40), 3.53 (dd, J ¼ 12.1, 5.3 Hz, 1H, H-60-1), 3.39 (dd, J ¼ 9.7,
8.0 Hz, 1H, H-20), 3.35 (dd, J ¼ 12.1, 3.4 Hz, 1H, H-60-2), 3.33 (dd,
J ¼ 9.7 Hz, 1H, H-30), 3.30 (m, 1H, H-50), 3.09 (dd, J ¼ 11.9, 3.7 Hz, 1H,
H-3), 2.80 (dd, J ¼ 14.3, 3.7 Hz, 1H, H-18), 1.13, 1.01, 0.97, 0.93, 0.89,
0.85, 0.78 (s each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
150 MHz):
d 177.1 (C-28), 167.3, 166.6, 144.3 (C-13), 137.3, 133.5,
132.7, 129.3, 129.1, 127.5, 123.5 (C-12), 103.1 (C-1ʺ), 89.7 (C-3), 75.1,
72.6, 71.0, 69.7, 61.9, 55.6, 48.7, 47.6, 43.1, 41.5, 39.7, 37.9, 35.3, 33.7,
33.1, 31.7, 28.7, 27.3, 26.5, 24.9, 23.6, 19.3, 18.1, 17.5, 16.3, 15.1;
HRESIMS: m/z calcd for C44H64O10N [MþHþ] 766.4525; found:
766.4551.
d
177.3 (C-28), 167.1, 166.9, 144.3 (C-13), 137.3, 133.5, 132.7, 129.5,
129.1, 127.9, 123.5 (C-12), 95.3 (C-1ʺ), 87.9 (C-3), 73.1, 71.5, 69.9,
66.7, 63.1, 59.3, 48.5, 47.6, 42.9, 41.7, 39.7, 37.8, 35.6, 33.9, 33.5, 31.9,
28.9, 27.3, 26.5, 24.7, 23.9, 19.5, 18.3, 17.8, 17.1, 15.9, 14.7; HRESIMS:
m/z calcd for C44H64O10N [MþHþ] 766.4525; found: 766.4541.
4.1.9.16. Oleanate 3-O-6-phthalimido-6-deoxy-a-D-mannopyrano-
side (3c). Yield: 71%; [
600 MHz):
a
]
23 þ 30.1 (c 0.21, CH3OH); 1H NMR (CD3OD,
D
4.1.9.12. Oleanate 28-O-6-phthalimido -6-deoxy-
b
-
D
-galactopyrano-
d
7.88 (dd, J ¼ 6.0, 0.9 Hz, 1H, HeAr), 7.67 (d, J ¼ 7.3 Hz,
side (2b). Yield: 66%; [
a
]
23 þ 15.8 (c 0.21, CH3OH); 1H NMR (CD3OD,
1H, HeAr), 7.49 (m, 2H, HeAr), 6.73 (m, 1H, NHCO), 5.21 (t,
J ¼ 3.7 Hz, 1H, H-12), 4.67 (s, 1H, H-10), 3.59 (dd, J ¼ 12.1, 5.7 Hz, 1H,
H-60-1), 3.49 (t, J ¼ 9.3 Hz, 1H, H-40), 3.47 (dd, J ¼ 12.1, 2.9 Hz, 1H, H-
60-2), 3.44 (m, 1H, H-50), 3.23e3.27 (m, 2H, H-20, H-30), 3.10 (dd,
J ¼ 14.3, 3.7 Hz, 1H, H-3), 2.79 (dd, J ¼ 13.3, 4.1 Hz, 1H, H-18), 1.07,
0.97, 0.89, 0.89, 0.81, 0.75, 0.60 (s each, 3H each, CH3 ꢃ 7); 13C NMR
D
600 MHz):
d
7.95 (dd, J ¼ 6.3,1.1 Hz,1H, HeAr), 7.59 (d, J ¼ 7.5 Hz,1H,
HeAr), 7.50 (m, 2H, HeAr), 6.81 (m,1H, NHCO), 5.37 (d, J ¼ 8.2 Hz,1H,
H-10), 5.23(t,J¼ 3.6Hz,1H, H-12), 3.79(t, J¼ 3.7Hz,1H, H-40),3.51(dd,
J ¼ 11.9, 5.7 Hz,1H, H-60-1), 3.41 (dd, J ¼ 11.9, 3.3 Hz,1H, H-60-2), 3.25e
3.32 (m, 3H, H-20, H-30, H-50), 3.10 (dd, J ¼ 11.5, 4.1 Hz, 1H, H-3), 2.81
(dd, J ¼ 13.7, 4.1 Hz, 1H, H-18), 1.07, 0.97, 0.93, 0.89, 0.85, 0.78, 0.67 (s
(CD3OD, 150 MHz):
d 176.9 (C-28), 166.9, 166.3, 144.3 (C-13), 137.1,
each, 3H each, CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d
177.5 (C-28),
133.9, 132.7, 129.3, 129.1, 127.9, 123.7 (C-12), 94.1 (C-10’), 88.9 (C-3),
74.1, 72.6, 70.5, 69.6, 65.2, 55.3, 48.7, 47.3, 43.1, 41.5, 39.7, 37.9, 35.3,
33.7, 33.5, 31.9, 28.9, 27.3, 26.5, 24.9, 22.7, 19.5, 18.1, 17.9, 17.1, 14.7;
HRESIMS: m/z calcd for C44H64O10N [MþHþ] 766.4523; found:
766.4561.
167.3, 166.7, 144.7 (C-13), 137.1, 133.6, 131.9, 129.3, 129.1, 127.5, 123.3
(C-12), 94.0 (C-1ʺ), 88.7 (C-3), 73.5, 70.9, 68.7, 66.5, 64.3, 59.9, 48.7,
47.6, 42.7, 41.6, 39.7, 37.8, 35.3, 33.9, 33.5, 31.9, 28.7, 27.3, 26.5, 24.7,
23.9,19.1,18.3,17.8,16.7,15.3,14.7;HRESIMS:m/zcalcdforC44H64O10
N
[MþHþ] 766.4525; found: 766.4512.
4.2. Biological testing
4.1.9.13. Oleanate 28-O-6-phthalimido-6-deoxy-a-D-mannopyrano-
side (2c). Yield: 63%; [
600 MHz):
a
]
23 þ 31.1 (c 0.18, CH3OH); 1H NMR (CD3OD,
The inhibitory activities of all synthesized OA derivatives against
PTP1B and TCPTP were evaluated according to the published assay
[17]. Inhibitory activity was determined by the release of p-nitro-
phenol from the hydrolysis of substrate, p-nitrophenyl phosphate
(pNPP), for the PTP1B assay was purchased from Sigma in the
di(Tris) salt form. The positive reference compound Sodium
Orthovanadate was purchased from GSK.
D
d
7.93 (dd, J ¼ 6.1, 1.2 Hz, 1H, HeAr), 7.61 (d, J ¼ 7.3 Hz,
1H, HeAr), 7.55 (m, 2H, HeAr), 6.83 (m, 1H, NHCO), 5.23 (t,
J ¼ 3.6 Hz, 1H, H-12), 4.97 (s, 1H, H-10), 3.65 (dd, J ¼ 12.1, 5.3 Hz, 1H,
H-60-1), 3.53 (s, 1H, H-20), 3.45 (dd, J ¼ 12.1, 4.2 Hz, 1H, H-60-2), 3.37
(t, J ¼ 9.7 Hz, 1H, H-40), 3.35 (m, 1H, H-50), 3.29e3.33 (m, 2H, H-20,
H-30), 3.17 (dd, J ¼ 11.5, 4.1 Hz,1H, H-3), 2.79 (dd, J ¼ 13.3, 4.1 Hz,1H,
H-18), 1.07, 0.95, 0.89, 0.87, 0.85, 0.73, 0.67 (s each, 3H each,
CH3 ꢃ 7); 13C NMR (CD3OD, 150 MHz):
d
176.3 (C-28), 166.9, 166.5,
4.2.1. PTP1B and TCPTP inhibitory activity
144.5 (C-13),136.9,133.3,131.7,129.3,128.9,127.3,123.7 (C-12), 92.1
(C-1ʺ), 87.9 (C-3), 72.9, 70.1, 69.2, 67.5, 65.7, 59.3, 48.7, 47.3, 42.7,
41.5, 39.7, 37.8, 35.3, 33.9, 33.5, 31.9, 28.9, 27.5, 26.3, 24.7, 23.9, 19.1,
PTP1B enzyme (or TCPTP) was diluted to appropriate concen-
trations 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 (or TCPTP) 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 determine the amount of released p-nitrophenol.
18.3, 17.8, 16.9, 16.7, 15.1; HRESIMS: m/z calcd for C44H64O10
N
[MþHþ] 766.4523; found: 766.4542.
4.1.9.14. Oleanate 3-O-6-phthalimido-6-deoxy-b-D-glucopyranoside
23
(3a). Yield: 69%; [
600 MHz):
a
]
D
þ 7.83 (c 0.64, CH3OH); 1H NMR (CD3OD,
For a typical 50
mL reaction, inhibitor (5.0
mL) was added to a re-
d
7.96 (dd, J ¼ 6.5, 1.0 Hz, 1H, HeAr), 7.65 (d, J ¼ 7.5 Hz,
action mixture containing PTP1B (or TCPTP) enzyme (5.0 m
L),

46
Q. Liu et al. / European Journal of Medicinal Chemistry 79 (2014) 34e46
[9] G. Liu, Recent advances in protein-tyrosine-phosphatase 1B (PTP1B) inhibitors
5 ꢃ buffer A (10
mL), and H2O (25 mL). Meanwhile, Blank control
for the treatment of type 2 diabetes and obesity, Drugs of the Future 29 (2004)
1245e1259.
[10] Y.F. Li, J. Li, Q. Shen, L.H. Hu, Benzoquinones from Ardisia japonica with
inhibitory activity towards human protein tyrosine phosphatase 1B (PTP1B),
Chem. Biodiversity 4 (2007) 961e965.
[11] S. Zhang, Z.Y. Zhang, PTP1B as a drug target: recent developments in PTP1B
inhibitor discovery, Drug Discovery Today 12 (2007) 373e381.
[12] A.P. Combs, Recent advances in the discovery of competitive protein tyrosine
phosphatase 1B inhibitors for the treatment of diabetes, obesity, and cancer,
Journal of Medicinal Chemistry 53 (2010) 2333e2344.
[13] L. Luo, X.P. He, Q. Shen, J.Y. Li, X.X. Shi, J. Xie, J. Li, G.R. Chen, Synthesis of
(Glycopyranosyl-triazolyl)-purines and their inhibitory activities against
protein tyrosine phosphatase 1B (PTP1B), Chemistry and Biodiversity 8 (2011)
2035e2044.
(without PTP1B or TCPTP enzyme and samples) and negative
control (without samples) were established. After the mixture had
been incubated at 37 ꢁC for 10 min, the PTP1B (or TCPTP) 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 (or TCPTP) enzyme
was calculated. When inhibition rate is larger than 50% at 10 mg/mL,
the 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 ex-
periments and summarized in Fig. 3 and Table 1.
[14] B. Jiang, S.J. Guo, D.Y. Shi, C. Guo, T. Wang, Discovery of novel bromophenol
3,4-dibromo-5-(2-bromo-3,4-dihydroxy-6-(isobutoxymethyl)
benzyl)ben-
zene-1,2-diol as protein tyrosine phosphatase 1B inhibitor and its anti-dia-
betic properties in C57BL/KsJ-db/db mice, European Journal of Medicinal
Chemistry 64 (2013) 129e136.
[15] J.Z. Liu, S.E. Zhang, F.L. Nie, Y. Yang, Y.B. Tang, W.W. Yin, J.Y. Tian, F. Ye,
Z.Y. Xiao, Discovery of novel PTP1B inhibitors via pharmacophore-oriented
scaffold hopping from Ertiprotafib, Bioorganic & Medicinal Chemistry Let-
ters 23 (2013) 6217e6222.
[16] K.A. Lantz, S.G. Emeigh Hart, S.L. Planey, M.F. Roitman, I.A. Ruiz-White,
H.R. Wolfe, M.P. McLane, Inhibition of PTP1B by trodusquemine (MSI-1436)
causes fat-specific weight loss in diet-induced obese mice, Obesity 18 (2010)
1516e1523.
[17] Z.Y. Zhang, S.Y. Lee, PTP1B inhibitors as potential therapeutics in the treat-
ment of Type 2 diabetes and obesity, Expert Opinion on Investigational Drugs
12 (2003) 223e233.
[18] L.F. Iversen, K.B. Moller, A.K. Pedersen, G.H. Peters, A.S. Petersen,
H.S. Andersen, S. Branner, S.B. Mortensen, N.P. Moller, Structure determina-
tion of T cell protein-tyrosine phosphatase, Journal of Biological Chemistry
277 (2002) 19982e19990.
[19] S.D. Taylor, B. Hill, Recent advances in protein tyrosine phosphatase 1B in-
hibitors, Expert Opinion on Investigational Drugs 13 (2004) 199e214.
[20] Q.C. Liu, T.T. Guo, L. Zhang, Y. Yu, P. Wang, J.F. Yang, Y.X. Li, Synthesis and
biological evaluation of oleanolic acid derivatives as PTP1B inhibitors, Euro-
pean Journal of Medicinal Chemistry 63 (2013) 511e522.
[21] F. Qu, Y.X. Li, Y.C. Zhang, J. Zang, Synthesis of oleanolic acid glycoconjugates,
Chinese Journal of Organic Chemistry 23 (2003) 249e257 (in Chinese).
[22] T.T. Guo, Q.C. Liu, P. Wang, L. Zhang, W. Zhang, Y.X. Li, Facile synthesis of three
bidesmosidic oleanolic acid saponins with strong inhibitory activity on
pancreatic lipase, Carbohydrate Research 344 (2009) 1167e1174.
[23] Q.C. Liu, Z. Fan, D. Li, W.H. Li, T.T. Guo, Facile synthesis of several oleanane-
type triterpenoid saponins, Journal of Carbohydrate Chemistry 29 (2010)
386e402.
4.2.2. Lipophilicity calculations
Converting the logarithm of the partition coefficient for n-
octanol/water (log K) to the lipophilicity coefficient (Log P) was
calculated using the program ACD/LogP ver 1.0 (Advanced Chem-
istry Development Inc. Toronto, Canada) software. The results are
displayed in Table 2.
Acknowledgments
This work was financial supported by the Doctoral Program
Foundation of Institutions of Higher Education of China
(No.20116101120025), HYPERLINKChina Postdoctoral Science Foun-
dation funded project (No. 2012M512023, 2013T60887), the Post-
doctoral Science Foundation of Northwest University (BSH11012) and
the Foundation of Shaanxi Educational Committee (11JK0676).
Appendix A. Supplementary data
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.ejmech.2014.03.080.
[24] Q.C. Liu, T.T. Guo, S.D. Guo, W.H. Li, D. Li, Synthesis and evaluation of four
References
hederagenin glycosides as a-glucosidase inhibitor, Helvetica Chimica Acta 96
(2013) 142e148.
[1] S. Wild, G. Roglic, A. Green, R. Sicree, H. King, Global prevalence of diabetes:
estimates for the year 2000 and projections for 2030, Diabetes Care 27 (2004)
1047e1053.
[2] M.I. McCarthy, Genomics, type 2 diabetes, and obesity, New England Journal of
Medicine 363 (2010) 2339e2350.
[25] Q.C. Liu, H.C. Liu, L. Zhang, T.T. Guo, P. Wang, M.Y. Geng, Y.X. Li, Synthesis and
antitumor activities of naturally occurring oleanolic acid triterpenoid sapo-
nins and their derivatives, European Journal of Medicinal Chemistry 64 (2013)
1e15.
[26] Z. Györgydeák, Z. Hadady, N. Felföldi, A. Krakomperger, V. Nagy, M. Tóth,
[3] 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, Increased insulin sensitivity and
obesity resistance in mice lacking the protein tyrosine phosphatase-1B gene,
Science 283 (1999) 1544e1548.
A. Brunyánszki, T. Docsa, P. Gergely, L. Somsák, Synthesis of N-(
b-glucopyr-
anosyl) and N-(2-acetamido-2-deoxy- -glucopyranosyl) amides as inhibitors
b
of glycogen phosphorylase, Bioorganic and Medicinal Chemistry 12 (2004)
4861e4870.
[27] C. Bliard, G. Massiot, S. Nazabadioko, Glycosylation of acids under phase
transfer conditions. Partial synthesis of saponins, Tetrahedron Letters 35
(1994) 6107e6108.
[28] W.J. Peng, J.S. Sun, F. Lin, X.W. Han, B. Yu, Facile synthesis of ginsenoside Ro,
Synlett 2 (2004) 259e262.
[4] 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. Kahn, Increased energy expenditure, decreased
adiposity, and tissue-specific insulin sensitivity in protein-tyrosine phospha-
tase 1B-deficient mice, Molecular and Cellular Biology 20 (2000) 5479e5489.
[5] 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, Proceedings of the National Academy of
Sciences of the United States of America 99 (2002) 11357e11362.
[6] M. Traurig, R.L. Hanson, S. Kobes, C. Bogardus, L.J. Baier, Protein tyrosine
phosphatase 1B is not a major susceptibility gene for type 2 diabetes mellitus
or obesity among Pima Indians, Diabetologia 50 (2007) 985e989.
[7] H. Park, B.R. Bhattarai, S.W. Ham, H. Cho, Structure-based virtual screening
approach to identify novel classes of PTP1B inhibitors, European Journal of
Medicinal Chemistry 44 (2009) 3280e3284.
[29] W. Birberg, H. Loenn,
a
-Selectivity and glycal formation are temperature
(2-6)Gal
dependent in glycosylation with sialic acid, synthesis of a Neu5Ac
a
thioglycoside building block, Tetrahedron Letters 32 (1991) 7453e7456.
[30] D. Liu, W.J. Xie, L. Liu, H.Q. Yao, J.Y. Xu, G. Tanabe, O. Muraoka, X.M. Wu,
Synthetic study on neoponkoranol and its side chain epimer as potent
glucosidase inhibitors, optimization of protecting group, Tetrahedron Letters
54 (2013) 6333e6336.
a-
[31] T. Hartmann, J. Schmitt, Lipophilicity-beyond octanol/water: a short com-
parison of modern technologies, Drug Discov. Today Technol 1 (2004) 431e
439.
[32] P. Wils, A. Warnery, V. Phung-Ba, S. Legrain, D. Scherman, High lipophilicity
decreases drug transport across intestinal epithelial cells, Journal of Phar-
macology and Experimental Therapeutics 269 (1994) 654e658.
[8] S. Thareja, S. Aggarwal, T.R. Bhardwaj, M. Kumar, Protein tyrosine phosphatase
1B inhibitors: a molecular level legitimate approach for the management of
diabetes mellitus, Medicinal Research Reviews 32 (2012) 459e517.