Design, Synthesis and in vivo Evaluation of Novel C-Aryl Glucosides as Potent Sodium-Dependent Glucose Cotransporters Inhibitors for the Treatment of Diabetes

Article abstract of DOI:10.1111/cbdd.12547

A series of novel C-aryl glucosides with substituents at the 3′-position or cyclization at 3′, 4′-positions of the distal aryl ring were designed and synthesized, which might decrease the oxidative metabolism of dapagliflozin. Preliminary evaluation for hypoglycemic effect and the risk of hypoglycemia were carried out both in normal and in streptozotocin-induced diabetic mice. Among the synthesized compounds, compound 19a exerted potency-similarity with dapagliflozin and triggered the hypoglycemic effect in a dose-dependent manner. Besides, compound 19a, even at the high dose of 10 mg/kg, revealed a low risk of hypoglycemia. In further studies, 19a exhibited sustained antihyperglycemic effect without particular side-effects in 30-day chronic diabetic mice studies. Moreover, histological changes in the pancreas of diabetic mice indicated 19a might protect pancreatic β-cell from apoptosis by reducing the damage of glucotoxicity. All of these results demonstrated that compound 19a, with excellent in vivo pharmacological activity and safety profile, was considered to be a promising drug candidate for the treatment of diabetes mellitus.

Full text of DOI:10.1111/cbdd.12547

Chem Biol Drug Des 2015; 86: 764–775
Research Article
Design, Synthesis and in vivo Evaluation of Novel C-Aryl
Glucosides as Potent Sodium-Dependent Glucose
Cotransporters Inhibitors for the Treatment of Diabetes
Zheng Li1, Xuekun Wang1, Xue Xu2, Qianqian
Qiu1, Lei Jiao1, Wenlong Huang1,* and Hai Qian1,*
The increasing and alarming prevalence of diabetes mell-
1Center of Drug Discovery, State Key Laboratory of
Natural Medicines, China Pharmaceutical University, 24
itus along with the undesirable side-effects (such as
body weight gain, hypoglycemia, gastric symptoms)
associated with many current hypoglycemic agents has
Tongjiaxiang, Nanjing 210009, China
2Key Laboratory of Drug Quality Control and
motivated a great attempt to evaluate new mechanisms
to achieve preferable antidiabetic agents (1,2). Sodium-
dependent glucose cotransporters (SGLTs), the promi-
nent ones of novel diabetes targets in the last decade,
play a key role in the absorption and reabsorption of glu-
cose from the intestine and kidney (3–5). Among several
subtypes identified in the SGLTs, the expression of
SGLT2 was found kidney specific, whereas SGLT1 was
expressed in the small intestine, heart, brain, and renal
tubules (6) and might cause unexpected adverse effects
(such as glucose–galactose malabsorption) if inhibited (7).
Therefore, selective inhibition of SGLT2 exhibited a safe
mechanism to enhance the caloric output associated
with weight loss due to the urinary glucose excretion (8),
which indicated that selective SGLT2 inhibitor was a
highly appreciated approach to the treatment of diabetes
mellitus.
Pharmacovigilance, China Pharmaceutical University, 24
Tongjiaxiang, Nanjing 210009, China
*Corresponding authors: Wenlong Huang,
ydhuangwenlong@126.com; Hai Qian,
qianhai24@163.com
A series of novel C-aryl glucosides with substituents at
the 30-position or cyclization at 30, 40-positions of the
distal aryl ring were designed and synthesized, which
might decrease the oxidative metabolism of dapagliflo-
zin. Preliminary evaluation for hypoglycemic effect and
the risk of hypoglycemia were carried out both in nor-
mal and in streptozotocin-induced diabetic mice.
Among the synthesized compounds, compound 19a
exerted potency-similarity with dapagliflozin and trig-
gered the hypoglycemic effect in a dose-dependent
manner. Besides, compound 19a, even at the high dose
of 10 mg/kg, revealed a low risk of hypoglycemia. In
further studies, 19a exhibited sustained antihyperglyce-
mic effect without particular side-effects in 30-day
chronic diabetic mice studies. Moreover, histological
changes in the pancreas of diabetic mice indicated 19a
might protect pancreatic b-cell from apoptosis by
reducing the damage of glucotoxicity. All of these
results demonstrated that compound 19a, with excel-
lent in vivo pharmacological activity and safety profile,
was considered to be a promising drug candidate for
the treatment of diabetes mellitus.
A large number of compounds derived from the C-aryl glu-
cosides have been reported as SGLT2 inhibitors (Figure 1)
(9–17); however, an advisory committee vote against the
approval of dapagliflozin in January 2012 for safety con-
cerns (18). It was previously reported that excess quinones
and methine-quinones (Figure S1), arose from dapagliflozin
via oxidative metabolic pathways, might be associated
with adverse events such as breast and bladder cancers
(19,20). On the other hand, homology modeling and
molecular docking demonstrated that the ethoxy oxygen
of dapagliflozin was essential to activities or selectivity
because a hydrogen bond was formed between the main
chain N–H of His80 and the ethoxy oxygen (21). Mean-
while, our previous study also identified the importance of
the ethoxy oxygen to activity and selectivity (22,23).
Therefore, our chemistry efforts were directed toward
decreasing the oxidative metabolism of dapagliflozin and
maintaining the hydrogen bond. Many classic strategies
have been extensively used to block metabolic hotspots
by replacing a hydrogen atom with fluorine or deuterium
(19,24,25). Recently, a new strategy, significantly reducing
Key words: blood glucose, C-aryl glucosides, diabetes,
sodium-dependent glucose cotransporter, urinary glucose
Abbreviations: SGLTs, sodium-dependent glucose cotrans-
porters; EMA, European medicines agency; FDA, food and
drug administration; THF, tetrahydrofuran; DMF, N, N-dimeth-
ylformamide; STZ, streptozotocin; OGTT, oral glucose toler-
ance test; AUC, area under the curve; NMR, nuclear
magnetic resonance; NMM, N-methylmorpholine; Pyr, pyri-
dine; DMAP, 4-dimethylaminopyridine; SD, standard deviation.
Received 18 December 2014, revised 11 February 2015 and
accepted for publication 18 February 2015
764
ª 2015 John Wiley & Sons A/S. doi: 10.1111/cbdd.12547

Novel Sodium-Dependent Glucose Co-transporters Inhibitors
Figure 1: Selected examples of SGLT2 inhibitors.
the oxidative metabolism, was successfully applied to
G protein-coupled receptor 40 agonists by introduction of
a fluorine, methyl group or cyclization at the ortho position
of the phenylpropanoic acid moiety (Figure S2A) (26–28).
Herein, with this new perspective, our research was
devoted to decrease the oxidative metabolism of dapagli-
flozin by introducing substituents at the 30-position or cycli-
zation at 30, 40-positions of the distal aryl ring (Figure S2B).
In this study, we discovered that the steric, rather than
electronic, effect at the 30-position of the distal aryl ring
might influence inhibition activity of SGLTs. Among the
synthesized compounds, compound 19a with good meta-
bolic stability, exhibited excellent in vivo pharmacological
efficacy and safety profile, was considered to be a promis-
ing drug candidate for the treatment of diabetes mellitus.
75 MHz for 13C NMR spectra), chemical shifts are
expressed as values relative to tetramethylsilane as internal
standard, and coupling constants (J values) were given in
hertz (Hz). LC/MS spectra were recorded on a Waters
liquid chromatography–mass spectrometer system (ESI).
Elemental analyses were performed by the Heraeus CHN-
O-Rapid analyzer. Dapagliflozin was synthesized as previ-
ously reported (9).
General procedure for the synthesis of compounds
16a-h
To a stirred ꢀ78 °C solution of 15a-h (1.0 equiv) in 1: 2
THF/toluene (30 mL) under N2 was added n-BuLi (2.5 M in
hexane, 1.2 equiv) dropwise while keeping the tempera-
ture below ꢀ70 °C. After 45 min, this solution was trans-
ferred by a cannula to a stirred ꢀ78 °C solution of 2, 3, 4,
6-tetra-O-trimethylsilyl-b-D-glucolactone 7 (1.5 equiv) in
toluene (5 mL) at a rate that maintained the reaction tem-
perature below ꢀ70 °C. After 3 h, methanesulfonic acid
(0.6 N in MeOH, 3 equiv) was added, whereupon, the
reaction was allowed to slowly warm to room temperature
overnight. The reaction was then quenched with saturated
aqueous NaHCO3 (20 mL) and extracted with EtOAc
(3 9 30 mL), the combined organic layers were washed
once with saturated brine and dried over anhydrous
Na2SO4 prior to concentrating using a rotary evaporator,
the residue was purified by column chromatography
(CH2Cl2: MeOH = 30: 1, v/v) to yielded 16a-h as a glassy
off-white amorphous solid.
Methods and Materials
General chemistry
All reagents and solvents were obtained from commercial
sources and used without further purification unless other-
wise indicated. Purifications by column chromatography
were carried out over silica gel (200–300 mesh) and moni-
tored by thin-layer chromatography performed on GF/UV
254 plates and were visualized using UV light at 254 and
365 nm. Melting points were taken on a RY-1 melting-
point apparatus and were uncorrected. NMR spectra were
recorded on a Bruker ACF-300Q instrument (Bruker BioS-
pin AG, Fllanden, Switzerland) (300 MHz for 1H NMR and
Chem Biol Drug Des 2015; 86: 764–775
765

Li et al.
Synthesis of (3R,4S,5S,6R)-2-(4-chloro-3-(4-
added LiOHꢁH2O (1.5 equiv). After stirring at room temper-
ature overnight, the volatiles were removed under reduced
pressure and the residue, after dissolution in EtOAc
(40 mL), was subsequently washed with 5% aqueous
KHSO4 (2 9 20 mL) and saturated brine (2 9 15 mL) prior
to drying over anhydrous Na2SO4. After filtration and con-
centration using a rotary evaporator, the residue was puri-
fied by column chromatography (CH2Cl2: MeOH = 30: 1,
v/v) to yielded 19a-h as a glassy off-white amorphous
solid.
ethoxy-3-fluorobenzyl)phenyl)-6-(hydroxymethyl)-
2-methoxytetrahydro-2H-pyran-3,4,5-triol (16a)
Yield 60%; mp: 60–62 °C; 1H NMR (300 MHz, DMSO-d6) d:
7.52–7.40 (m, 3H, ArH), 7.05–7.01 (m, 1H, ArH), 6.99, 6.97
(dd, J = 1.80 Hz, 8.42 Hz, 1H, ArH), 6.89 (d, J = 8.46 Hz,
1H, ArH), 4.99 (d, J = 5.46 Hz, 2H, 2 9 OH), 4.54 (t,
J = 5.68 Hz, 1H, -OH), 4.07–3.99 (m, 5H, ArCH2Ar, -OH, -
OCH2), 3.75–3.66 (m, 1H, sugar-OCH2), 3.47–3.40 (m, 1H,
sugar-OCH2), 3.35–3.05 (m, 4H, 49 OCH), 2.92 (s, 3H, -
OCH3), 1.33 (t, J = 6.96 Hz, 3H, -CH3).
Synthesis of (2S,3R,4R,5S,6R)-2-(4-chloro-3-(4-
ethoxy-3-fluorobenzyl)phenyl)-6-(hydroxymethyl)
tetrahydro-2H-pyran-3,4,5-triol (19a)
General procedure for the synthesis of compounds
18a-h
Yield 91%; mp: 66–68 °C; 1H NMR (300 MHz, DMSO-d6)
d: 7.38 (d, J = 8.22 Hz, 1H, ArH), 7.35 (d, J = 1.78 Hz,
1H, ArH), 7.26, 7.24 (dd, J = 1.80 Hz, 8.22 Hz, 1H, ArH),
7.07–6.98 (m, 2H, ArH), 6.93 (d, J = 8.40 Hz, 1H, ArH),
4.96 (d, J = 5.53 Hz, 2H, 29 OH), 4.84 (d, J = 9.57 Hz,
1H, -OCHAr), 4.50 (t, J = 5.68 Hz, 1H, -OH), 4.08–3.99
(m, 5H, ArCH2Ar, -OH, -OCH2), 3.73–3.68 (m, 1H, sugar-
OCH2), 3.49–3.42 (m, 1H, sugar-OCH2), 3.31–3.08 (m,
4H, 49 OCH), 1.31 (t, J = 6.96 Hz, 3H, -CH3). 13C NMR
(75 MHz, DMSO-d6) d: 153.0, 149.8, 139.7, 137.1, 131.8,
130.8, 128.6, 127.5, 124.5, 116.1, 115.8, 114.8, 81.1,
80.6, 78.2, 74.6, 70.2, 64.2, 61.3, 37.4, 14.5. ESI-MS m/
z: 449.1 [M+Na]+. Anal. calcd. For C21H24ClFO6: C, 59.09;
H, 5.67; Cl, 8.31; F, 4.45; Found: C, 59.01; H, 5.65; Cl,
8.32; F, 4.46.
To a stirred ꢀ15 °C solution of O-methylglucoside, 16a-h
(1.0 equiv) in 1: 1 CH2Cl2/MeCN (20 mL) was added
Et3SiH (1.5 equiv) followed by BF3ꢁOEt2(1.2 equiv) at a rate
that maintained the reaction temperature below ꢀ10 °C;
the solution was warm to ꢀ10 °C over 10 h prior to
quenching with saturated aqueous NaHCO3 (20 mL) and
diluted with H2O (25 mL). The aqueous layer was
extracted with EtOAc (3 9 20 mL), and the combined
organic layers were washed with H2O (2 9 10 mL), satu-
rated brine (2 9 15 mL) prior to drying over anhydrous
Na2SO4, filtration and concentration under reduced pres-
sure yielded a yellow foam. Peracetylation was achieved
by addition of Ac2O (10 equiv) and a catalytic amount of
DMAP to a solution of this residue in CH2Cl2 (15 mL) and
pyridine (10 equiv). After 4 h, the reaction mixture was
poured into water (20 mL) and extracted with CH2Cl2
(2 9 25 mL). The combined organic layers were washed
with 1 N HCl (2 9 15 mL) and saturated brine
(2 9 15 mL) prior to drying over anhydrous MgSO4. After
filtration and concentration under reduced pressure, the
residue was recrystallized from EtOH to yield the desired
tetra-acetylated-b-C-glucoside 18a-h as a white solid.
Biological Studies
Animals
All experiments were performed on male KM mice (18–
22 g) that were purchased from Comparative Medicine
Centre of Yangzhou University (Jiangsu, China), acclima-
tized for 1 week before the experiments. The animal room
was maintained under a constant 12-h light/dark cycle
and rooms were maintained at 23 ꢂ 2 °C and relative
humidity 50 ꢂ 10% throughout the experimental period.
They were allowed ad libitum access to standard pellets
and water unless otherwise stated, and the vehicle used
for drug administration was 2% ethanol and 2% Tween-80
for all animal studies. All animal procedures were per-
formed in accordance with the applicable institutional and
governmental regulations concerning the ethical use of
animals.
Synthesis of (2R,3R,4R,5S)-2-(acetoxymethyl)-6-(4-
chloro-3-(4-ethoxy-3-fluorobenzyl)phenyl)
tetrahydro-2H-pyran-3,4,5-triyl triacetate (18a)
Yield 55%; mp: 132–134 °C; 1H NMR (300 MHz, DMSO-
d6) d: 7.43 (d, J = 8.49 Hz, 1H, ArH), 7.28 (d, J = 1.89 Hz,
1H, ArH), 7.25 (s, 1H, ArH), 7.05 (t, J = 8.67 Hz, 1H, ArH),
6.99, 6.96 (dd, J = 1.92 Hz, 8.65 Hz, 1H, ArH), 6.90 (d,
J = 8.45 Hz, 1H, ArH), 5.35 (t, J = 9.48 Hz, 1H, -OCH),
5.07 (t, J = 9.45 Hz, 1H, -OCH), 4.96 (t, J = 9.64 Hz, 1H, -
OCH), 4.66 (d, J = 9.69 Hz, 1H, -OCHAr), 4.10-3.98 (m,
7H, ArCH2Ar, -OCH, 29 OCH2), 2.01 (s, 3H, CH3CO), 1.99
(s, 3H, CH3CO), 1.92 (s, 3H, CH3CO), 1.70 (s, 3H, CH3CO),
1.31 (t, J = 6.96 Hz, 3H, -CH3).
Statistical analysis of the data
Statistical analyses were performed using specific software
(GraphPad InStat version 5.00, GRAPHPAD software, San
Diego, CA, USA). Unpaired comparisons were analyzed
using the two-tailed Student’s t-test, unless otherwise
stated.
General procedure for the synthesis of compounds
19a-h
To a stirred mixture of tetra-acetylated-b-C-glucoside,
18a-h (1.0 equiv) in 2:3:1 THF/MeOH/H2O (18 mL) was
766
Chem Biol Drug Des 2015; 86: 764–775

Novel Sodium-Dependent Glucose Co-transporters Inhibitors
Hypoglycemic and glucosuria effects of
Dose–response relationship of 19a explored in
STZ-induced diabetic mice
compounds 19a-19h evaluated in normal mice
Normal mice 10 weeks old were fasted overnight (12 h),
bled via the tail tip, weighted, and randomized into 11
groups (n = 8). Mice were administrated orally with a sin-
gle doses of vehicle, dapagliflozin (10 mL/kg; 3.68 mol/
kg), metformin (10 mL/kg; 200 mg/kg), or compounds
19a-19h (10 mL/kg; 3.68 mol/kg) and subsequently dosed
orally with 30% aqueous glucose solution (3 g/kg) after
half an hour. Blood samples and urine were collected
immediately before drug administration (ꢀ30 min), before
glucose challenge (0 min), and at 15, 30, 45, 60, and
120 min postdose. The blood glucose was measured by
blood glucose test strips (SanNuo ChangSha, ChangSha,
China), and the urine glucose was determined by Tes-
Tape (Gaoerbao GuangZhou, GuangZhou, China).
To investigate dose–response relationship of 19a, com-
pound 19a (0.3, 1, 3, 10 mg/kg) was administered to
STZ-induced diabetic mice in the fed condition. Blood glu-
cose levels were then measured for 3 h under fasting con-
ditions, to eliminate the influence of feeding during the
experiment.
Effects on normal fasting plasma glucose in
normal mice
Ten-week-old male normal mice were fasted overnight
and randomized into three groups (n = 6). Compound 19a
(10 mg/kg), glibenclamide (10 mg/kg), or vehicle was orally
administered, and blood was collected from tail vein
immediately before administration (0 h) and at 30 min, 1,
2, and 3 h after administration to measure blood glucose
as described above.
Diabetic mice model established by STZ
The mice were made diabetic by a consecutive 5 days
intraperitoneal injection of streptozotocin (Sigma, St Louis,
MO, USA) at 50 mg/kg, dissolved in fresh cold (4 °C)
0.01 mol/L citrate buffer (pH 4.5). The normal control mice
were only injected with the citrate buffer. Five days after
STZ injection, development of diabetes was confirmed by
measuring blood glucose levels. The mice with overnight
fasting blood glucose level 11.1 mmol/L or higher were
considered to be diabetic and were used in the experi-
ment.
Chronic diabetic mice studies
STZ-induced diabetic mice were dosed daily with the vehi-
cle, dapagliflozin (10 mL/kg; 3.68 mol/kg), or compounds
19a (10 mL/kg; 3.68 mol/kg) by gavage administration for
30 days, and a group of normal mice was also taken as a
control. Animals were dosed at 4:00 PM daily. The body
weights were measured every 5 days and the dosage was
adjusted according to the most recent body weight. Water
and food consumption were measured daily at fixed time
intervals. All animals were observed daily and any abnor-
mal state was recorded. Non-fasting blood glucose con-
centrations were determined on days 0, 5, 10, 15, 20, and
28 at 24 h postdose. Fasting blood glucose concentra-
tions were determined on days 1, 3, 8, 13, 18, and 25 at
12 h postdosing under fasting conditions.
Oral glucose tolerance test of 19a and 19h
explored in STZ-induced diabetic mice
STZ-induced diabetic mice were fasted overnight, bled via
the tail tip, weighted, and randomized into four groups
(n = 6). Mice were dosed orally with single doses of vehi-
cle or dapagliflozin (10 mL/kg; 3.68 mol/kg) or compounds
19a and 19h (10 mL/kg; 3.68 mol/kg) and subsequently
dosed orally with 30% aqueous glucose solution (3 g/kg)
after half an hour. Then, mice were bled at 0, 15, 30, 60,
and 120 min postdose to measure blood glucose by blood
glucose test strips (SanNuo ChangSha, ChangSha,
China).
To examine the effects of acute and chronic 19a treatment
on blood glucose levels, the OGTT was performed on
days 1, 12, and 29 of treatment. Mice were fasted over-
night prior to treatment with a single doses of vehicle,
dapagliflozin (10 mL/kg; 3.68 mol/kg), or compounds 19a
(10 mL/kg; 3.68 mol/kg) and subsequently dosed orally
with 30% aqueous glucose solution (3 g/kg) after half an
hour. Mice were bled via tail tip immediately before drug
administration, before glucose challenge, and at 15, 30,
60, and 120 min postdose, and the blood glucose was
measured by blood glucose test strips (SanNuo Chang-
Sha, ChangSha, China).
Hypoglycemic effects of 19a and 19h explored in
STZ-induced diabetic mice
Non-fasted STZ-induced diabetic mice were randomized
into four groups and placed in cages, and a group of non-
fasted normal mice was also taken as a control, then
dosed orally with single doses of vehicle, dapagliflozin
(10 mL/kg; 3.68 mol/kg), or compounds 19a and 19h
(10 mL/kg; 3.68 mol/kg). Blood samples were collected
from the tail vein immediately before administration (0 h)
and at 30 min, 1, 2, 3, 4, 5, and 6 h after administration
under fasting conditions to measure blood glucose by
blood glucose test strips (SanNuo ChangSha, ChangSha,
China).
At the end of treatment, HbA1c levels in whole blood were
determined by automatic biochemical analyzer on day 30,
and the pancreases of 19a (10 mL/kg; 3.68 mol/kg)-trea-
ted, dapagliflozin (10 mL/kg; 3.68 mol/kg)-treated, vehicle-
treated mice, or normal control mice were isolated
immediately after killing and washed with ice-cold saline
before fixed in 10% (v/v) formalin. The sections were
embedded in paraffin after dehydrate. Four-micron
Chem Biol Drug Des 2015; 86: 764–775
767

Li et al.
sections were cut and stained with H&E for histopathologi-
cal assessment. Islet number was estimated by counting
focal islets on five sections for each pancreas, each
spaced 245 lm (35 sections) apart. The area of each islet
(lm) was determined for each section.
chloride, formed from commercially available 5-bromo-2-
chlorobenzoic acid with oxalyl chloride catalyzed by DMF,
generated the desired 10, which was isolated in pure from
ethanol. Reduction of 10 by triethylsilane and BF3ꢁOEt2
provided 11. To afford the desired 12, our initial effort was
to try various reaction conditions of Vilsmeier–Haack–
Arnold reaction. Unfortunately, there was no reaction
detected in compound 11. We speculated that 5-bromo-
2-chlorobenzyl, as a large steric substituent, restrict the
reaction. Thus, our ultimate efforts were directed toward
stronger reaction condition which obtained by Duff reac-
tion with hexamethylenetetramine and trifluoroacetic acid
(29). Then, a mixture of 12, anhydrous potassium carbon-
ate, and dry DMF was heated at 92–94 °C with stirring for
4 h to generate the desired 13. Reduction of 13 by NaBH4
and MeOH in reflux anhydrous THF provided desired com-
pound 14. Alkylation of compound 14 provided desired
intermediate aglycon 15f-15h.
Results and Discussion
Chemistry
The synthesis of the designed compounds 19a-19h was
started from intermediate 15a-15h. Persilylated glucono-
lactone 7 was prepared by dropwise trimethylsilyl chloride
to commercially available gluconolactone in anhydrous
THF and N-methylmorpholine in 99% yield. Compounds
15a-15e were synthesized starting from 13a to 13e as
shown in Scheme 1. Friedel–Crafts acylation of the starting
material 13a-13e with 5-bromo-2-chlorobenzoyl chloride,
formed from commercially available 5-bromo-2-chloroben-
zoic acid with oxalyl chloride catalyzed by DMF, generated
the desired 14a-14e, which were isolated in pure from eth-
anol. Reduction of 14a-14e by triethylsilane and BF3ꢁOEt2
provided desired intermediate aglycon 15a-15e.
The synthesis of the target compounds 19a-19h is
depicted in Scheme 3, and the nascent lithiated aromatic
through lithium halogen exchange was added to 7, yielded
a mixture of lactols, which was treated with methanesulf-
onic acid in methanol to provide the desilylated O-methyl
lactols 16a-16h. Reduction of 16a-16h by BF3ꢁOEt2 and
triethylsilane, followed by peracetylation, obtained tetraace-
tate 18a-18h after recrystallization in pure from ethanol.
Hydrolysis of 18a-18h with lithium hydroxide provided
target compounds 19a-19h in high yield.
Compounds 15f-15h were synthesized starting from phe-
nol 8 as shown in Scheme 2. After stirring at room tem-
perature for 16 h, phenol was alkylated by ethyl
chloroacetate in DMF under the action of K2CO3. Friedel–
Crafts acylation of
9
with 5-bromo-2-chlorobenzoyl
O
O
O
O
TM
SO
H
O
a
TM
SO
TM
O
S
H
O
H
O
TM
O
S
H
O
7
O
F
13a
13b
13c
O
l
C
O
l
C
O
c
b
l
r
B
C
r
B
R1
R1
O
a
=
=
=
a
=
=
=
14 R1
14b R1
14 R1
F
C
15 R1
15b R1
F
l
C
H
C
3
O
l
c
c
H
C
15 R1
3
O
O
l
C
l
C
13d
c
R2
b
Scheme 1: Synthesis of persilylated
gluconolactone 7 and intermediate aglycon
15a-15e. Reagents and conditions: (a)
TMSCl, NMM, THF, 35 °C, 99%; (b)
(COCl)2, CH2Cl2, DMF, then 13a-13e, AlCl3,
0 °C, 60–80%; (c) Et3SiH, BF3ꢁOEt2, CH2Cl2,
CH3CN, 25 °C, 90–98%.
r
B
R2
O
r
B
O
O
=
14d R2
=
15d R2
O
O
=
14 R2
e
=
R2
15
e
13e
768
Chem Biol Drug Des 2015; 86: 764–775

Novel Sodium-Dependent Glucose Co-transporters Inhibitors
O
O
O
O
H
O
l
C
O
O
a
O
l
C
O
b
O
c
l
C
O
C
d
O
O
Br
r
B
Br
H
O
O
12
8
e
9
10
11
l
C
O
,
h
g
r
B
O
l
C
O
O
O
l
C
f
O
15f
O
r
B
H
O
r
B
i
13
14
l
C
l
C
O
O
or
O
Br
r
B
O
15g
15h
Scheme 2: Synthesis of intermediate aglycon 15f-15h. Reagents and conditions: (a) K2CO3, DMF, rt; (b) (COCl)2, CH2Cl2, DMF, then 9,
AlCl3, 0 °C, 55.6%; (c) Et3SiH, BF3•OEt2, CH2Cl2, CH3CN, 25 °C, 72.5%; (d) hexamethylenetetramine, trifluoroacetic acid, reflux; (e)
K2CO3, DMF, 92–94 °C; (f) NaBH4 and MeOH, THF, reflux; (g) SOCl2, 60 °C; (h) tetrahydrofurfuryl alcohol, KOH, THF; (i) BnBr or
bromoethane, KOH, THF.
Cl
Cl
Cl
Cl
Cl
Ar
Ar
Ar
O
O
O
Ar
O
O
HO
HO
HO
HO
AcO
AcO
HO
HO
b
c
a
d
OMe
OH
Ar
Br
OH
OAc
OH
OH
OH
OAc
OH
15a-15h
16a-16h
17a-17h
18a-18h
19a-19h
O
l
C
O
l
Cl
C
O
l
C
O
O
O
O
H
O
HO
H
O
H
O
l
C
F
H
O
H
O
H
O
H
O
HO
H
O
H
O
H
O
19c
19b
H
O
H
O
19d
H
O
a
19
H
O
l
C
O
O
l
C
O
O
O
Cl
O
Cl
O
O
O
O
H
O
HO
HO
O
O
HO
HO
HO
HO
H
O
OH
H
O
O
H
OH
19h
OH
e
19
H
O
OH
19g
OH
19f
Scheme 3: Synthesis of target compounds 19a-19h. Reagents and conditions: (a) n-BuLi, THF, toluene, ꢀ78 °C, then 7 followed by
MeOH, CH3SO3H, 20–72%; (b) Et3SiH, BF3ꢁOEt2, CH2Cl2, CH3CN, ꢀ10 °C; (c) Ac2O, pyr, CH2Cl2, DMAP, 58–60%, two steps; (d)
LiOHꢁH2O, THF, H2O, MeOH, 90–95%.
In vivo efficacy evaluated in the normal mice
Therefore, the hypoglycemic effects of dapagliflozin (30-H)
ꢃ 19a (30-F) > 19b (30-Cl) ꢃ 19c (30-Me) (Figure 2A) sug-
gested that the steric (19a vs 19b and 19c), rather than
electronic (dapagliflozin versus 19a), effect in the 30-posi-
tion might influence inhibition activity of SGLTs. One possi-
ble explanation is that incorporation of bulkier substituents
such as methyl and chloro changes the favorable confor-
mation of ethoxy group and does great harm to the forma-
tion of hydrogen bond between the main chain N–H of
His80 and the ethoxy oxygen of the compound.
To estimate the potency of compounds 19a-19h, the
hypoglycemic effects were firstly evaluated in normal mice
by oral glucose tolerance test (OGTT). The time-dependent
changes of plasma glucose and the area under the curve
(AUC0–2 hr) of the blood glucose levels are shown in Fig-
ure 2. Compounds with electron-withdrawing fluorine and
chlorine and electron-donating methyl group (19a, 19b,
and 19c) were designed to investigate the effects of
diverse substitutions in the 30-position on potency. Mean-
while, the Van der Waals radius of fluorine (19a) is close to
the size of hydrogen (dapagliflozin), and the size of chlorine
On the basis of this assumption, our optimized efforts
were directed to restrict conformational flexibility of ethoxy
ꢀ
ꢀ
(1.75 A) is close to the size of methyl group (1.80 A) (30).
Chem Biol Drug Des 2015; 86: 764–775
769

Li et al.
A
B
C
D
Figure 2: Effects of 19a-19h on blood
glucose levels during an OGTT in normal
mice. A, B, and C represent time-dependent
changes of plasma glucose. D shows the
AUC0–2 h of blood glucose levels. Values are
mean ꢂ SD (n = 8). *p ≤ 0.05 compared to
vehicle normal mice by Student’s t-test.
group to explore the suitable orientation of oxygen atom,
so desired 30, 40-cyclization compound 19d was obtained
(Figure 2B). Compared to the 19b and 19c, the potency
of 19d was increased obviously but still lower than dapa-
gliflozin; we thought the moderate potency of 19d could
be attributed to deviate from the preferential orientation of
oxygen and the lack of hydrophobic effect since in
absence of ethyl group. Therefore, we converted di-
hydrobenzofuran of 19d into benzofuran to explore the
best orientation of oxygen atom. At the same time, three
typically hydrophobic groups were selected to further
improve the activity: planar aromatic hydrophobic substitu-
ent (19e, 19g), cycloalkyl hydrophobic group (19f), and the
small chain alkyl (19h). Interestingly, compound 19h
robustly lowered the blood glucose compared with the
compound 19d just as expected. However, tricyclic skele-
ton such as compound 19e appeared to diminish the
in vivo efficacy in mice, likely suggesting that a planar tem-
plate might be unfavorable. Introduction of a cycloalkyl
hydrophobic group (19f) or benzyl (19g) to the C-2 posi-
tion of benzofuran demonstrated poor in vivo inhibitory
activity against SGLTs, suggesting that a simple alkyl chain
is more appropriate than bulkier ring structure for this
region.
To indirectly elucidate the mechanisms of the novel C-aryl
glucosides, the compounds 19a-19h were selected to
investigate the glucosuria in normal mice (Table 1). Dapa-
gliflozin and compounds 19a, 19d, and 19h, which pre-
sented good hypoglycemic activities, significantly
increased the urinary glucose excretion, while metformin
and control group could not. Besides, the urinary glucose
of the compounds was consistent with the time-dependent
changes of blood glucose. All the result above indicated
that these compounds lowered blood glucose by inhibiting
SGLTs to reduce the glucose reabsorption in kidney.
Table 1: Urine glucose excretion effects of
metformin, dapagliflozin, and 19a-19h in
normal mice
Compound
ꢀ30 min
0 min
15 min
30 min
45 min
60 min
120 min
Vehicle
Metformin
Dapagliflozin
19a
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
++
++
ꢂ
+++
+++
+
+++
+++
+
++++
++++
++
+
++++
++++
+
+++
+++
+
19b
19c
ꢀ
ꢂ
+
++
+
+
+
ꢀ
ꢀ
19d
19e
+
++
ꢂ
+++
+
++
ꢀ
++
ꢀ
ꢀ
19f
19g
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢂ
+
+
ꢀ
19h
++
+++
+++
++++
+++
+++
Symbol represents the mean urine glucose levels of each group (n = 8). ꢀ: no glucose;
ꢂ: 100 mg/dL; +: 250 mg/dL; ++: 500 mg/dL; +++: 1000 mg/dL; ++++: 2000 mg/dL.
770
Chem Biol Drug Des 2015; 86: 764–775

Novel Sodium-Dependent Glucose Co-transporters Inhibitors
Hypoglycemic effects of 19a and 19h explored in
STZ-induced diabetic mice
and dapagliflozin. This result likely suggested that com-
pound 19h appeared to be susceptible to metabolic inacti-
vation.
To further assess antihyperglycemic effects in the diabetic
state, STZ-induced diabetic mice were used to evaluate
the OGTT of 19a and 19h, the most potent inhibitors
among our synthetic compounds against SGLTs. As
shown in Figure 3A and B, compounds 19a and 19h pre-
sented potency-similarity with dapagliflozin. Then, long-
acting effect was explored in non-fasting STZ-induced dia-
betic mice (Figure 3C and D). For the first 2 h after dosing,
all the two compounds lowered blood glucose almost
equivalently, while the hypoglycemic activity of compound
19h had a significant decrease after 2 h compared to 19a
Dose–response relationship of 19a explored in
STZ-induced diabetic mice
Based on these results above, the most potent compound
19a was selected to research the dose–response relation-
ship for lowering blood glucose levels. Figure 4A shows
that single administration of 19a (0.3, 1, 3 and 10 mg/kg)
dose dependently reduces blood glucose level in STZ-
induced diabetic mice. Furthermore, the plasma glucose
A
B
C
D
Figure 3: A and B represent time-dependent changes of plasma glucose and AUC0–2 h of blood glucose levels in OGTT of 19a and 19h
explored in fasting STZ-induced diabetic mice, C and D represent time-dependent changes of plasma glucose and AUC0–6 h of blood
glucose levels in long-acting hypoglycemic effects of compounds 19a and 19h explored in non-fasting STZ-induced diabetic mice. Values
are mean ꢂ SD (n = 6). **p ≤ 0.01 compared to vehicle STZ mice by Student’s t-test.
A
B
Figure 4: (A) Dose–response relationship of 19a explored in non-fasting STZ-induced diabetic mice. (B) Effects of 19a on fasting plasma
glucose in normal mice. Values are expressed as mean ꢂ SD for six animals in each group. *p ≤ 0.05, **p ≤ 0.01 compared to vehicle
STZ mice by Student’s t-test. ##p ≤ 0.01 compared to 19a by Student’s t-test.
Chem Biol Drug Des 2015; 86: 764–775
771

Li et al.
curve of 19a approached to flat after 120 min at the dose
of 10 mg/kg. This result might be at least in part rational-
ized by the low risk of hypoglycemia.
comparison with glibenclamide to further confirm the
above speculation. As shown in Figure 4B, glibenclamide
(10 mg/kg) lowered plasma sugar levels far below normal
fasting levels in KM mice. In contrast, compound 19a,
even at the high dose of 10 mg/kg, only slightly reduced
fasting glucose levels in KM mice, and the change of
blood glucose levels was much smaller compared to that
caused by administration of glibenclamide. Thus, our
results indicated that compound 19a not only effectively
improved hyperglycemia in the diabetic state, but also
Effects of 19a on fasting plasma glucose in normal
mice
Obtaining a positive result in in vivo pharmacological study,
the risk of hypoglycemia was evaluated in fasting normal
KM mice by oral administration of a high dose of 19a in
A
B
C
Figure 5: The OGTT of compound 19a in fasting STZ-induced diabetic mice after long-term treatment. Dapagliflozin, 19a, or vehicle was
orally administered to STZ-induced diabetic mice once daily for 30 days. The blood glucose levels were determined on treatment day 1,
12, and 29. Values are expressed as mean ꢂ SD for six animals in each group. **p ≤ 0.01 compared to vehicle STZ mice by Student’s t-
test.
A
B
C
D
E
F
Figure 6: The antihyperglycemic effects of chronic 19a treatment on non-fasting blood glucose levels at 24 h postdose (A), fasting blood
glucose levels at 12 h postdosing under fasting conditions (B), food intake (C), water intake (D), body weight (E), and the levels of HbA1c
(F) in STZ-induced diabetic mice. Dapagliflozin, 19a, or vehicle was orally administered to STZ-induced diabetic mice once daily for
30 days. Food consumption, water intake, and body weight were measured at fixed time intervals. Values are expressed as mean ꢂ SD
for six animals in each group. ##p ≤ 0.01 compared to control by Student’s t-test. *p ≤ 0.05, **p ≤ 0.01 compared to vehicle STZ mice by
Student’s t-test.
772
Chem Biol Drug Des 2015; 86: 764–775

Novel Sodium-Dependent Glucose Co-transporters Inhibitors
A
B
C
D
E
F
Figure 7: Representative pancreatic islet of mice of each group, red arrow shows pancreatic b-cell. (A). Representative pancreatic islet of
normal control mice. (B). Representative pancreatic islet of diabetic control mice showed depletion of islets and uneven distribution of cell
nuclei. (C). Representative pancreatic islet of dapagliflozin-treated mice showed improved islets. (D). Representative pancreatic islet of
19a-treated mice showed improved islets. (E). Representative the number of islet per mouse for islet observed with the 100 times
magnifying glass. (F). Representative islet area observed with the 200 times magnifying glass. Values are mean ꢂ SD (n = 6), ##p ≤ 0.01
compared to control by Student’s t-test. **p ≤ 0.01 compared to vehicle STZ-induced diabetic mice by Student’s t-test.
revealed a low risk of hypoglycemia, a serious side-effect
to sulfonylureas such as glibenclamide.
values of 55.4% and 52.3% (day 12), and 55.5% and
51.6% (day 29), respectively. This demonstrated that the
antihyperglycemic effect of compound 19a was sustained
throughout the treatment.
Chronic diabetic mice studies
On the basis of the promising in vivo pharmacological and
excellent safety profile of compound 19a, a 30-day chronic
19a treatment study was subsequently carried out in STZ-
induced diabetic mice to assess whether the compound
could maintain long-term effects. In this study, dapagliflo-
zin, 19a, and vehicle were orally administered to STZ-
induced diabetic mice once daily for 30 days, the OGTT
was performed on days 1, 12, and 29 of treatment. As
shown in Figure 5, on the first day of treatment, the acute
administration of dapagliflozin and 19a caused a 44.6%
and 44.9% decrease in the glucose AUC0–2 h values. On
day 12 and 29 of treatment, dapagliflozin or 19a showed
similar effects, with a decrease in the glucose AUC0–2 h
Furthermore, the non-fasting and fasting blood glucose
levels were determined throughout the research. As shown
in Figure 6A and B, the non-fasting and fasting glucose
levels of STZ-induced diabetic mice were significantly
higher than those of the normal control group. The non-
fasting and fasting blood glucose levels were reduced sig-
nificantly in the oral administration of compound 19a and
dapagliflozin compared with the vehicle-treated controls
after 5 days of treatment. Thereafter, the blood glucose
levels remained steady throughout the treatment. The food
consumption and water intake, which shared a similar
change as fasting blood glucose levels, were improved in
the treated group of compound 19a and dapagliflozin
Chem Biol Drug Des 2015; 86: 764–775
773

Li et al.
(Figure 6C and D). The treated groups caused slightly
reductions in the body weight after 30 days of treatment
compared with vehicle-treated controls (Figure 6E). After a
30-day chronic treatment, STZ-induced diabetic mice trea-
ted with compound 19a and dapagliflozin had HbA1c val-
ues of 7.88% ꢂ 0.32% and 7.64% ꢂ 0.25%, respectively,
demonstrating a significant improvement compared with
vehicle-treated group (11.47% ꢂ 0.29%) (Figure 6F).
81273376) and the Natural Science Foundation of Jiangsu
Province (No. BK2012356).
References
1. Levetan C. (2007) Oral antidiabetic agents in type 2
diabetes. Curr Med Res Opin;23:945–952.
2. Phung O.J., Scholle J.M., Talwar M., Coleman C.I.
(2010) Effect of noninsulin antidiabetic drugs added to
metformin therapy on glycemic control, weight gain,
and hypoglycemia in type 2 diabetes. JAMA;303:1410–
1418.
In this chronic 19a treatment study, no particular side-
effects were observed at compound 19a-treated group,
indicating the possibility that minimized off-target pharma-
cology and metabolic toxicity.
3. Wright E.M. (2001) Renal Na+-glucose cotransporters.
Am J Physiol-Renal;280:10–18.
Histological changes in the pancreas of diabetic
mice
4. Jurczak M.J., Lee H.Y., Birkenfeld A.L., Jornayvaz
F.R., Frederick D.W., Pongratz R.L., Zhao X., Moeckel
G.W., Samuel V.T., Whaley J.M., Shulman G.I., Kibbey
R.G. (2011) SGLT2 deletion improves glucose homeo-
stasis and preserves pancreatic b-cell function. Diabe-
tes;60:890–898.
5. Chao E.C., Henry R.R. (2010) SGLT2 inhibition-a novel
strategy for diabetes treatment. Nat Rev Drug Dis-
cov;9:551–559.
Freshly isolated islets from normal control, vehicle-, dapa-
gliflozin-, and compound 19a-treated STZ-induced dia-
betic mice (30-day treatment) were counted and
histologically assessed. As shown in Figure 7, the cyto-
plasm and nuclear in the islet of the STZ-induced diabetic
mice appeared to be lytic and shrunken compared with
normal mice. Dapagliflozin- and compound 19a-treated
groups exhibited a significant improvement in islet number
and area compared with vehicle-treated STZ-induced dia-
betic mice. These results indicated that compound 19a
might protect pancreatic b-cell from apoptosis by reducing
the damage of glucotoxicity.
6. Wright E.M., Loo D.D., Hirayama B.A. (2011) Biology of
human
sodium
glucose
transporters.
Physiol
Rev;91:733–794.
ꢁ
7. Martın M.G., Turk E., Lostao M.P., Kerner C., Wright
E.M. (1996) Defects in Na+/glucose cotransporter
(SGLT1) trafficking and function cause glucose-galac-
tose malabsorption. Nat Genet;12:216–220.
Conclusions and Future Directions
8. List J.F., Whaley J.M. (2011) Glucose dynamics and
mechanistic implications of SGLT2 inhibitors in animals
and humans. Kidney Int;79:20–27.
We have designed and synthesized a series of novel C-aryl
glucosides with various substituents at the 30-position and
cyclization at 30, 40-positions of the distal aryl ring, and the
most potent inhibitors 19a and 19h among our synthetic
compounds were selected to evaluate in the normal and
STZ-induced diabetic mice. Although the hypoglycemic
activity of 19h had a significant decrease after 120 min
owing to be susceptible to metabolic inactivation, the cur-
rent chemistry shown in here allowed us to further modify
the structure of 19h to enhance the metabolic stability. In
further studies, the selected compound 19a exhibited sus-
tained antihyperglycemic effect without particular side-
effects in 30-day chronic diabetic mice studies. Moreover,
histological changes in the pancreas of diabetic mice indi-
cated 19a might protect pancreatic b-cell from apoptosis
by reducing the damage of glucotoxicity. All of these
results demonstrated that compound 19a was meaningful
for further investigation as a drug candidate for the treat-
ment of diabetes mellitus.
9. Meng W., Ellsworth B.A., Nirschl A.A., McCann P.J.,
Patel M., Girotra R.N., Wu G. et al. (2008) Discovery of
dapagliflozin: a potent, selective renal sodium-depen-
dent glucose cotransporter 2 (SGLT2) inhibitor for the
treatment of type 2 diabetes. J Med Chem;51:1145–
1149.
10. Nomura S., Sakamaki S., Hongu M., Kawanishi E.,
Koga Y., Sakamoto T., Yamamoto Y., Ueta K., Kimata
H., Nakayama K., Tsuda-Tsukimoto M. (2010) Discov-
ery of canagliflozin, a novel C-glucoside with thiophene
ring, as sodium-dependent glucose cotransporter 2
inhibitor for the treatment of type 2 diabetes mellitus. J
Med Chem;53:6355–6360.
11. Imamura M., Nakanishi K., Suzuki T., Ikegai K., Shiraki
R., Ogiyama T., Murakami T. et al. (2012) Discovery of
Ipragliflozin (ASP1941): a novel C-glucoside with ben-
zothiophene structure as
a potent and selective
sodium glucose co-transporter 2 (SGLT2) inhibitor for
the treatment of type 2 diabetes mellitus. Bioorg Med
Chem;20:3263–3279.
Acknowledgments
12. Zhang W., Welihinda A., Mechanic J., Ding H., Zhu L.,
Lu Y., Deng Z., Sheng Z., Lv B., Chen Y., Roberge
J.Y., Seed B., Wang Y.X. (2011) EGT1442, a potent
and selective SGLT2 inhibitor, attenuates blood glu-
This work was supported by grants from the National Nat-
ural Science Foundation of China (No. 81172932 and No.
774
Chem Biol Drug Des 2015; 86: 764–775

Novel Sodium-Dependent Glucose Co-transporters Inhibitors
cose and HbA(1c) levels in db/db mice and prolongs
the survival of stroke-prone rats. Pharmacol
Res;63:284–293.
porter 2 (SGLT2) inhibitors. J Mol Model;18:2795–
2804.
23. Wang X., Li Y., Yang B., Li Z., Huang W., Qian H.
(2014) C-Aryl glucosides with substituents at the distal
aryl ring as sodium-dependent glucose co-transporters
inhibitors for the treatment of diabetes mellitus. Chem
Biol Drug Des;86:246–253.
24. Meanwell N.A. (2011) Synopsis of some recent tactical
application of bioisosteres in drug design. J Med
Chem;54:2529–2591.
25. Chauret N., Guay D., Li C., Day S., Silva J., Blouin M.,
Ducharme Y., Yergey J.A., Nicoll-Griffith D.A. (2002)
Improving metabolic stability of phosphodiesterase-4
inhibitors containing a substituted catechol: prevention
of reactive intermediate formation and covalent bind-
ing. Bioorg Med Chem Lett;12:2149–2152.
26. Negoro N., Sasaki S., Mikami S., Ito M., Suzuki M.,
Tsujihata Y., Ito R. et al. (2010) Discovery of TAK-875:
a potent, selective, and orally bioavailable GPR40
agonist. ACS Med Chem Lett;1:290–294.
13. Mascitti V., Maurer T.S., Robinson R.P., Bian J., Bous-
tany-Kari C.M., Brandt T., Collman B.M. et al. (2011)
Discovery of a clinical candidate from the structurally
unique dioxa-bicyclo[3.2.1]octane class of sodium-
dependent glucose cotransporter 2 inhibitors. J Med
Chem;54:2952–2960.
14. Goodwin N.C., Mabon R., Harrison B.A., Shadoan
M.K., Almstead Z.Y., Xie Y., Healy J. et al. (2009)
Novel L-xylose derivatives as selective sodium-depen-
dent glucose cotransporter 2 (SGLT2) inhibitors for the
treatment of type 2 diabetes. J Med Chem;52:6201–
6204.
15. Kasichayanula S., Liu X., LaCreta F., Griffen S.C.,
Boulton D.W. (2014) Clinical pharmacokinetics and
pharmacodynamics of dapagliflozin, a selective inhibi-
tor of sodium-glucose co-transporter type 2. Clin Phar-
macokinet;53:17–27.
16. Freiman J., Ruff D., Frazier K., Combs K., Turnage A.,
Shadoan M., Powell D., Zambrowicz B., Brown P.
(2010) LX4211, a dual SGLT2/SGLT1 inhibitor, shows
rapid and significant improvements in glycemic control
over 28 days in patients with type 2 diabetes (T2DM).
Diabetes;59:511.
27. Negoro N., Sasaki S., Ito M., Kitamura S., Tsujihata Y.,
Ito R., Suzuki M. et al. (2012) Identification of fused-
ring alkanoic acids with improved pharmacokinetic
profiles that act as G protein-coupled receptor 40/free
fatty acid receptor 1 agonists. J Med Chem;55:1538–
1552.
17. Zambrowicz B., Freiman J., Brown P., Frazier K., Tur-
nage A., Bronner J., Ruff D. et al. (2012) LX4211, a
dual SGLT1/SGLT2 inhibitor, improved glycemic con-
trol in patients with type 2 diabetes in a randomized,
placebo-controlled trial. Clin Pharmacol Ther;92:158–
169.
28. Negoro N., Sasaki S., Mikami S., Ito M., Tsujihata Y.,
Ito R., Suzuki M. et al. (2012) Optimization of (2,3-dihy-
dro-1-benzofuran-3-yl)acetic acids: discovery of a non-
free fatty acid-like, highly bioavailable G protein-cou-
pled receptor 40/free fatty acid receptor 1 agonist as a
glucose-dependent insulinotropic agent.
J
Med
18. Mayer P. (2012) Chances and risks of SGLT2 inhibi-
tors. N-S Arch Pharmacol;385:551–554.
Chem;55:3960–3974.
29. Smit W.E. (1972) Formylation of aromatic compounds
with hexamethylenetetramine and trifluoroacetic acid. J
Org Chem;37:3972–3973.
30. Bondi A. (1964) van der Waals volumes and radii. J
Phys Chem;68:441–451.
19. Xu G., Lv B., Roberge J.Y., Xu B., Du J., Dong J.,
Chen Y. (2014) Design, synthesis, and biological evalu-
ation of deuterated C-aryl glycoside as a potent and
long-acting renal sodium-dependent glucose cotrans-
porter 2 inhibitor for the treatment of type 2 diabetes.
J Med Chem;57:1236–1251.
20. Obermeier M., Yao M., Khanna A., Koplowitz B., Zhu
M., Li W., Komoroski B., Kasichayanula S., Discenza
L., Washburn W., Meng W., Ellsworth B.A., Whaley
J.M., Humphreys W.G. (2010) In vitro characterization
and pharmacokinetics of dapagliflozin (BMS-512148),
a potent sodium-glucose cotransporter type II inhibitor,
in animals and humans. Drug Metab Dispos;38:
405–414.
21. Nakka S., Guruprasad L. (2012) Structural insights into
the active site of human sodium dependent glucose
co-transporter 2: homology modelling, molecular dock-
ing, and 3D - QSAR studies. Aust J Chem;65:1314–
1324.
Supporting Information
Additional Supporting Information may be found in the
online version of this article:
Appendix S1. Experimental details and characterization
for the synthesized compounds 19a-19h.
Appendix S2. Figure S1. Possible oxidative metabolic
route of dapagliflozin. Solid lines express determined
metabolites, the dotted line express predicted metabolites.
Figure S2. (A) Takeda’s strategy to resistant to b-oxida-
tion and improve PK profiles by introduction of substitu-
ents or cyclization at the ortho position of the
phenylpropanoic acid moiety. (B) Our strategy might to
decrease the oxidative metabolism of dapagliflozin.
22. Tang C., Zhu X., Huang D., Zan X., Yang B., Li Y.,
Du X., Qian H., Huang W. (2012) A specific pharmaco-
phore model of sodium-dependent glucose co-trans-
Chem Biol Drug Des 2015; 86: 764–775
775