4-(Phenylsulfonamidomethyl)benzamides as potent and selective inhibitors of the 11β-hydroxysteroid dehydrogenase type 1 with efficacy in diabetic ob/ob mice

Article abstract of DOI:10.1016/j.bmcl.2009.05.033

Selective inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) have considerable potential as treatments for type 2 diabetes. Presented herein are the syntheses, structure-activity relationships, and efficacy evaluation of 4-(phenylsulfonamido

Full text of DOI:10.1016/j.bmcl.2009.05.033

Bioorganic & Medicinal Chemistry Letters 19 (2009) 4455–4458
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
4-(Phenylsulfonamidomethyl)benzamides as potent and selective inhibitors
of the 11b-hydroxysteroid dehydrogenase type 1 with efficacy in diabetic
ob/ob mice
*
*
Xu Zhang , Zhou Zhou , Huaiyu Yang, Junhua Chen, Ying Feng, Lili Du, Ying Leng , Jianhua Shen
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Selective inhibitors of 11b-hydroxysteroid dehydrogenase type 1 (11b-HSD1) have considerable potential
as treatments for type 2 diabetes. Presented herein are the syntheses, structure–activity relationships,
and efficacy evaluation of 4-(phenylsulfonamidomethyl)benzamides as 11b-HSD1 inhibitors. Through
modification of our initial lead 5, we have identified potent and selective 11b-HSD1 inhibitors, such as
11n, which demonstrated improved glycemic control, decreased serum lipids, and enhanced insulin sen-
sitivity when dosed ip in diabetic ob/ob mice.
Received 18 April 2009
Revised 8 May 2009
Accepted 11 May 2009
Available online 15 May 2009
Keywords:
Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved.
11b-HSD1 inhibitors
4-(Phenylsulfonamidomethyl)benzamide
Type 2 diabetes
Type 2 diabetes (T2D) is a combination of metabolic abnormal-
ities, including hyperglycemia, hyperlipidemia, and insulin resis-
tance. The prevalence of diabetes around the world is estimated
to be 2.8% in 2000 and expected to increase at an alarming rate.1
At present, there are several drugs on the market that partially
lower glucose levels and improve insulin sensitivity, however,
more effective therapies with fewer side effects are needed.2 In this
respect, numerous research labs are continuing to develop new
agents aimed at novel anti-diabetic targets. Over the past few
years, one biological target that has attracted significant attention
is 11b-hydroxysteroid dehydrogenase type 1 (11b-HSD1).
11b-HSD1 is a key enzyme that acts as an NADPH-dependent
reductase and converts inactive cortisone into the receptor-active
glucorticoid cortisol in humans. It is highly expressed in liver and
adipose tissues. Conversely, 11b-hydroxysteroid dehydrogense-2
(11b-HSD2) oxidizes cortisol to cortisone utilizing NAD as a cofac-
tor and is primarily expressed in kidney, colon, and other tissues.3,4
Inhibition of 11b-HSD2 might lead to sodium retention, hypokale-
mia, and hypertension,3 indicating that inhibitors for 11b-HSD1
must be selective over 11b-HSD2.
central obesity, glucose intolerance, and insulin resistance.5,6 In
contrast, 11b-HSD1 deficient mice were resistant to development
of high-fat diet-induced obesity and exhibited improved insulin
sensitivity and lipid profiles.7,8 These data suggest that 11b-HSD1
could be a drug target for the treatment of metabolic syndrome
as well as type 2 diabetes.
In the past few years, a number of small molecule inhibitors of
11b-HSD1 have been disclosed, and Incyte’s small molecule inhib-
itor INCB-13739 is currently in phase II clinical trials.9
Early in our 11b-HSD1 program, 3-chloro-N-p-benzenesulfon-
amide (5, Fig. 1) was identified through structure-based virtual
screening on the chemical database of our group.10 The compound
is a modest inhibitor of 11b-HSD1, with an IC50 of 576 nM in mouse
11b-HSD1 and 1672 nM in human 11b-HSD1. This paper describes
the structure–activity relationships (SAR) of a series of analogues
to 5 that led to the identification of a potent inhibitor of 11b-
HSD1 with in vivo activity.
4-(Phenylsulfonamidomethyl)benzamides were prepared via
the route shown in Scheme 1. Protection of 4-(aminomethyl)-ben-
zoic acid 6 as its methyl ester by the usual way of refluxing with
acidic methanol gave 7. Sulfonylation of the amino ester 7 using
various arylsulfonyl chlorides in the presence of triethylamine
afforded intermediate 9 in excellent yield. Hydrolysis of the methyl
esters 9 in methanol using potassium hydroxide gave the carbox-
ylic acids in high yields. Final products 5 and 11 were obtained
by treatment of the intermediate acids 10 with various amines
using 1-hydroxybenzotriazole and 1-[3-(dimethylamino)propyl]-
3-ethylcarbodiimide hydrochloride as amide coupling reagents,
or by converting the carboxylic acids 10 to the corresponding acyl
The connection between 11b-HSD1 and T2D has been demon-
strated in mouse genetic models. Mice overexpressing 11b-HSD1
in adipose showed metabolic syndrome-like phenotypes such as
* Corresponding authors. Tel.: +86 21 50806059; fax: +86 21 50807088 (Y.L.), tel.:
+86 21 50806072; fax: +86 21 50807088 (J.S.).
E-mail addresses: yleng@mail.shcnc.ac.cn (Y. Leng), jhshen@mail.shcnc.ac.cn (J.
Shen).
Authors equally contributed to this work.
0960-894X/$ - see front matter Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2009.05.033

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X. Zhang et al. / Bioorg. Med. Chem. Lett. 19 (2009) 4455–4458
Table 1
O
O
Inhibition of 11b-HSD1: sulfonamide aryl modification
Cl
S
N
H
O
O
N
O
S
N
H
O
R1
O
5
N
Figure 1. Representative initial compound 5.
O
Compound
R1
IC50 (nM) of 11b-HSD1
chloride using thionyl chloride followed by reaction with 1-ada-
mantanamine in the presence of pyridine. The noncommercially
available N-substituted cycloheptanamines 14 were prepared
according to methodologies described in the literature.11
The inhibitory properties of synthesized molecules and the ref-
erence compounds (Glycyrrhizic acid and Carbenoxolone) were
evaluated in a scintillation proximity assay (SPA)10,12 (for details,
see Supplementary data) with human and mouse 11b-HSD1 (from
HEK293 cells transfected with full-length pcDNA3-derived expres-
sion plasmid), and selected compounds were evaluated in human
and mouse 11b-HSD2 assays.
We initially focused our efforts on modification of the sulfon-
amide aryl ring (Table 1). Replacement of the 3-Cl with 4-Cl
(11a) resulted in about twofold loss of potency in both human
and mouse enzymatic assays as compared to 5. However, introduc-
tion of 2-Cl (11b) or 3-CF3 (11c) only resulted in reduction of po-
tency in mouse assays. Such discrepancies in 11b-HSD1 activity
between species might be anticipated, because the mouse and hu-
man 11b-HSD1 enzymes display only 79% amino acid identity.13
Introduction of an additional fluorine atom at the 4-position
(11d) led to approximately a twofold decrease in potency.
We then turned our attention to modification and replacement
of the 2,6-dimethylmorpholine ring (Table 2). Removal of the 2,6-
dimethyl group (11e) or replacement of the 2,6-dimethylmorpho-
line with N-methylpiperazine (11f) resulted in a substantial reduc-
tion in activity. When the 2,6-dimethylmorpholine was replaced
by piperidine (11g), the potency had approximately a threefold in-
crease, while replacement by pyrrolidine (11h) or diethylamine
(11i) had similar potency to 5.
Human
Mouse
5
11a
11b
11c
3-Cl
4-Cl
2-Cl
3-CF3
3-Cl-4-F
1672
2698
1130
1208
2631
10
576
1404
5843
5614
1024
8
11d
Glycyrrhizic acid
piperidine ring. At the same time, we also synthesized cyclopentyl-
amine and cycloheptylamine derivates (11k and 11l). Compound
11j had similar potency to 11g, while decrease of the ring size
(11k) resulted in a substantial reduction in activity. However, in-
crease of the ring size (11l) resulted in about 10-fold improvement
of the potency. The most potent compound from this series, the
cycloheptylamine analogue 11l, was a selective inhibitor for 11b-
HSD1 and exhibited no appreciable activity against 11b-HSD2 (Ta-
ble 3).
Based on the structure of 11l, we prepared analogues with alkyl
substitute at the nitrogen of the cycloheptylamine (11m–o) and
replacement of the cycloheptylamine by 1-adamantanamine
(11p) (Table 3). All of the compounds showed improved potency
over 11l, except 11m in human assays. The most potent com-
pound, 11n (human-1 IC50 = 2 nM, mouse-1 IC50 = 2 nM), exhibited
high selectivity versus 11b-HSD2, and was selected for in vivo effi-
cacy evaluation in type 2 diabetic animal models, ob/ob mice.
As shown in Figure 2, ob/ob mice displayed significant higher
blood glucose, plasma HbA1c, serum insulin, triglyceride and total
cholesterol level when compared with its lean littermates (C57
mice). After 4 days of treatment with compound 11n (50 mg/kg)
On the basis of the compound 11g, we synthesized a cyclohex-
ylamine derivate (11j), which drew out the nitrogen atom from
H2N
H2N
HCl
a
OH
O
O
O
6
7
O
O
O
O
S
c
S
b
N
R1
Cl
H
R1
O
O
9
8
O
O
O
O
S
S
N
H
N
R1
d or e
R3
R1
H
R2
OH
10
5 and 11
O
O
HN
O
R3
f
H2N
+
14
13
12
Scheme 1. Reagents and conditions: (a) SOCl2, MeOH, reflux; (b) Et3N, CH2Cl2; (c) 1 M NaOH, MeOH, reflux; (d) HOBt, EDCI, CH2Cl2; (e) (i) SOCl2, CH2Cl2, reflux; (ii) C5H5N, 1-
adamantanamine; (f) (i) Ti(OiPr)4; (ii) NaBH3CN.

X. Zhang et al. / Bioorg. Med. Chem. Lett. 19 (2009) 4455–4458
4457
Table 2
Table 3
Inhibition of 11b-HSD1: 2,6-dimethylmorpholine replacements
Inhibition of 11b-HSD1 and 11b-HSD2 of compounds 11l–11p
O
O
O
O
Cl
S
Cl
S
N
H
N
R2
H
R2
O
O
Compound
R2
IC50 (nM) of 11b-
IC50 (nM) of 11b-HSD2
Compound
R2
IC50 (nM) of 11b-HSD1
Human Mouse
HSD1
Human
Mouse
Human
>10,000
Mouse
H
N
O
O
5
1672
14,490
15,900
647
576
3379
1319
131
480
395
302
732
15
11l
49
15
>10,000
N
N
11e
11f
11g
11h
11i
11j
11k
11l
N
11m
11n
11o
11p
638
2
2
2
2487
>1,000,000
N
N
N
N
N
N
N
2
>1,000,000 >1,000,000
47
>100,000
>1,000,000
1733
2106
411
H
N
14
10
10
8
>100,000
1
>1,000,000
82
Glycyrrhizic acid
Carbenoxolone
H
N
11n for 23 days decreased the Hemoglobin A1c (HbA1c) level by
0.57% (P <0.05), compared with vehicle mice, which reflected the
beneficial effect of compound 11n on glycemic control in ob/ob
mice (Fig. 2c). Treatment of ob/ob mice with compound 11n for
23 days resulted in a significant reduction of 28% in serum insulin
level compared with vehicle mice, which suggested enhanced insu-
lin sensitivity (Fig. 2d). Moreover, the serum triglyceride and total
cholesterol level were also lowered significantly by the 23 days
treatment of compound 11n in ob/ob mice (Fig. 2e and f). There-
fore, chronic treatment with selective 11b-HSD1 inhibitor com-
pound 11n improved glycemic control, decreased serum lipids
and enhanced insulin sensitivity in ob/ob mice, indicating that
compound 11n exhibited good in vivo efficacy against type 2 dia-
betes in a mouse model.
H
N
8512
H
N
49
In summary, we have identified a novel class of 11b-HSD1
inhibitors containing a 4-(phenylsulfonamidomethyl)benzamide
core structure. Our initial lead compound 5, in this series, was
modestly potent. Significant improvements in potent were
achieved by modification of the parent compound 5. Some com-
pounds showed high potency in 11b-HSD1 and exhibited high
selectivity for 11b-HSD1 versus 11b-HSD2. The most potent com-
pound 11n was selected for an in vivo experiment, and it demon-
strated improved glycemic control, decreased serum lipids, and
enhanced insulin sensitivity in diabetic ob/ob mice.
by intraperitoneal injection, the fasting blood glucose level of ob/
ob mice were reduced by 42%, compared with vehicle control mice
(P < 0.01). A significant reduction of 36% in non-fasting blood glu-
cose level was also observed in ob/ob mice after 8 days treatment
with compound 11n. During the 23 days treatment, compound
11n reduced the fasting and non-fasting blood glucose level in
ob/ob mice by an average rate of 35% and 28%, respectively
(Fig. 2a and b). Consistent with the reduced fasting and non-fasting
blood glucose levels, chronic treatment with 50 mg/kg compound

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X. Zhang et al. / Bioorg. Med. Chem. Lett. 19 (2009) 4455–4458
Figure 2. Anti-diabetic efficacy study of compound 11n in ob/ob mice. Ob/ob mice were administered with compound 11n (50 mg/kg) once daily by intraperitoneal injection
for 23 days. Fasting (a) and non-fasting (b) blood glucose levels were measured every four days. HbA1c (c), serum insulin (d), triglyceride (e), and total cholesterol (f) levels
were measured after 23 days treatment. Values are expressed as means SEM for n = 8 mice. *P < 0.05 and **P < 0.01 versus vehicle control mice.
3. Tomlinson, J. W.; Walker, E. A.; Bujalska, I. J.; Draper, N.; Lavery, G. G.; Cooper,
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Acknowledgment
We gratefully acknowledge financial support from the National
Basic Research Program of China (973 Program, 2009CB522300),
the 863 Hi-Tech Program of China (Grants 2006AA020602), and the
National Natural Science Foundation of China (Grants 90813029).
The project was also supported by the Science and Technology Com-
mission of Shanghai Municipality (Grants 08ZR1422600).
5. Masuzaki, H.; Paterson, J.; Shinyama, H.; Morton, N. M.; Mullins, J. J.; Seckl, J. R.;
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Supplementary data
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.bmcl.2009.05.033.
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