Design, synthesis and evaluation of novel azasugar-based MMP/ADAM inhibitors

Article abstract of DOI:10.1016/S0960-894X(03)00531-6

In order to verify whether azasugar would be a useful scaffold for inhibitory activity against metalloproteinases, we synthesized some azasugar-based compounds. As a result, it is clarified that azasugar moiety could function as successful inhibitor of ma

Full text of DOI:10.1016/S0960-894X(03)00531-6

Bioorganic & Medicinal Chemistry Letters 13 (2003) 2741–2744
Design, Synthesis and Evaluation of Novel Azasugar-Based
MMP/ADAM Inhibitors
Hideki Moriyama,a,b Takahiro Tsukida,a,b,*,y Yoshimasa Inoue,b Hirosato Kondo,b,y
Kohichiro Yoshinob and Shin-Ichiro Nishimurac,*
aJapan Bioindustry Association, Hokkaido Collaboration Center, N-21, W-12, Kita-Ku, Sapporo 001-0021, Japan
bR&D Laboratories, Nippon Organon K.K., 1-5-90, Tomobuchi-cho, Miyakojima-ku, Osaka 534-0016, Japan
cDivision of Biological Sciences, Graduate School of Science, Hokkaido University, N-21, W-12, Kita-Ku, Sapporo 001-0021, Japan
Received 17 February 2003; accepted 16 May 2003
Abstract—In order to verify whether azasugar would be a useful scaffold for inhibitory activity against metalloproteinases, we
synthesized some azasugar-based compounds. As a result, it is clarified that azasugar moiety could function as successful inhibitor
of matrix metalloproteinase-1, -3 and -9 and TACE.
# 2003 Elsevier Ltd. All rights reserved.
Metalloproteinases,
a
family of zinc-containing
showed blocking activities against both MMPs and
TACE.10 The most widely pursued approach toward
MMP inhibition has been the design of substrates that
bind to the catalytic site of the enzymes. Namely, pep-
tidemimetics that incorporate a zinc ligand and P10 side
chain are the most common class of MMP inhibitors
such as Marimastat11 (Chart 1). Then, as a second gen-
eration, sulfonamide-based inhibitors, including
AG334012 (Chart 1) have been studied. On the other
hand, based on their structural relationships to sugars,
azasugars, namely polyhydroxypiperidine derivatives,
are interesting candidates for the inhibition of various
glycosidase. For example, 1-deoxynojirimycin is a well-
known specific inhibitor for glucosidase13 (Chart 1).
However, azasugar scaffold has never been adapted in
the field of metalloproteinase inhibitors yet.
enzymes, are classified into two types. One is matrix
metalloproteinases (MMPs), comprised of collagenases,
stromelysins, gelatinases and membrane-type MMPs
(MT-MMPs), which mediate the breakdown of con-
nective tissue and are therefore targets for therapeutic
inhibitors in many inflammatory, malignant and degen-
erative diseases.1À4 The other is a disintegrin and
metalloproteinases (ADAMs),5 which mediate the pro-
cessing of membrane-bound cytokine such as tumor
necrosis factor a (TNF-a) into soluble form. TNF-a is a
major mediator of inflammatory and immune respon-
ses6 and a strong inducer of other cytokines such as IL-
lb, IL-6 and IL-8. Elevated TNF-a levels are implicated
in pathologies of rheumatoid arthritis,7 multiple sclero-
sis,8 type II diabetes,9 and other human ailments.
Therefore, TNF-a converting enzyme (TACE or
ADAM17) inhibitor is an attractive target for medicinal
chemists.10
Actually, there have been considerable efforts in the
design and synthesis of MMP/ADAM inhibitors and a
lot of small molecule inhibitors have been reported and
*Corresponding authors. Takahirio Tsukida Tel.: +81-6-6401-8199;
Shun-Ichiro Nishimura Tel.: +81-11-706-9043; fax: +81-11-706-
9042; e-mail: takahiro.tsukida@shionogi.co.jp; shin@glyco.sci.hoku-
dai.ac.jp.
yPresent address: Manufacturing Technology R&D Laboratories,
Shionogi & Co., Ltd., 1-3 Kuise Terajima 2-chome, Amagasaki,
Hyogo 660-0813, Japan.
Chart 1.
0960-894X/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0960-894X(03)00531-6

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H. Moriyama et al. / Bioorg. Med. Chem. Lett. 13 (2003) 2741–2744
In this letter, we describe the design and synthesis of
azasugar-based MMP/ADAM inhibitors bearing a
novel scaffold and their biological profiles.
(PPh3)]16 provided azasugar derivatives 9 in good yield
without epimerization at C-2 position. After hydro-
genolysis of compound 9 in the presence of a catalyst,
10% palladium-carbon, under hydrogen atmosphere,
corresponding carboxylic acid was subject to the
condensation with benzyloxyamine hydrochloride
(NH2OBn) in the presence of 1-(3-dimethylamino-pro-
pyl)-3-ethyl-carbodiimide hydrochloride (WSC) and 1-
hydroxy- triazole (HOBt), followed by the treatment of
sodium methoxide to give compound 10 in 59% yield.
Compound 10 was subjected to deprotection of iso-
propylidene group using DOWEX-H+, followed by the
treatment of 2,2-dimethoxypropane in the presence of p-
TsOH to afford compound 12 in good yield. Finally,
deprotection of benzyl group for compound 12 in the
presence of a catalyst, 10% palladium-carbon, under
hydrogen atmosphere provided the target compound 1
bearing 3,4-O-isopropylidene group.17 On the other
hand, compound 10 was hydrogenated to afford target
compound 2 in excellent yield.18 Next, triol derivative
11 was transformed, by removal of protective group, to
hydroxamic acid 3 in 96% yield.17 Finally, compound 9
was subjected to deprotection of benzyl ester, con-
densation of NH2OBn in the presence of WSC and
HOBt followed by hydrogenolysis to provide target
compound 4 in 63% yield.17 The configuration of com-
pound 4 was comfirmed by small coupling constants,
J2,3=1.8 Hz between 2-H and 3-H, and J3,4=2.2 Hz
between 3-H and 4-H (Scheme 1).
Chemistry
Our interest is to verify whether azasugar scaffold would
be useful for inhibitory activities against metalloprotein-
ases, including TACE and MMP-1, -3, -9. We focused
on an azasugar scaffold bearing a six-membered ring as
shown in Figure 1. For many of sulfonamide-based
MMP inhibitors, the zinc binding group and the P10-
substituent appear to be primarily responsible for the
interactions with MMPs and ADAMs. Moreover, in the
case of sulfonamide derivatives including AG3340, it
was well-known that R-configuration at hydroxamic
acid moiety would be important for desirable inhibitory
activity against metalloproteinases.14 In addition to the
importance of R-configuration of spatially oriented
hydroxamic acid group at the C-2 position, the intro-
duction of arylsulfonyl group at the N-1 position would
become crucial for practical design of the potential
metalloproteinase inhibitors. We designed a new series of
MMP/ADAM inhibitors 1-4 based on azasugar scaffold
readily obtainable from the l-Threitol, illustrated in
Figure 2. In this study, at first, the stereochemistry of
trihydroxy-piperidine unit was fixed as 2R,3S,4R,5S-
configuration, according to the literature.15a
After deprotonation of glycine ester 5 with an excess of
lithium diisopropylamide (LDA) and subsequent trans-
metalation with tin chloride, addition of chiral aldehyde
6, prepared easily from l-Threitol, gave rise to the aldol
product 7 as an epimeric mixture at the C-2 position. As
anticipated, it was demonstrated that highly stereo-
selective reaction at the C-3 position was performed by
using of the condition reported previously.15a Com-
pound 7 was subjected to acetylation followed by
deprotection of silyl group using tetrabutylammonium
fluoride (TBAF), to afford diasteromerically pure 8
after purification with column chromatography in 37%
yield. Cyclization of 8 under Mitsunobu condition [di-
ethyl azodicarboxylate (DEAD)-triphenylphospine
Biological Evaluation
Inhibitory activities of compound 1–4 against TACE
and MMPs (MMP-1, MMP-3, MMP-9) were summar-
ized in Table 1.18 Compound 3 having three hydroxyl
groups exhibited moderate inhibitory activities against
all metallo-proteinase (MMP-1, -3, -9 and TACE), Ki
values were 84 nM against MMP-1, 17 nM against
MMP-3, 157 nM against MMP-9 and 71 nM against
TACE, respectively. On the other hand, compound 1
and 2, having 3,4-O-isopropylidene group or 4,5-O-iso-
propylidene group, also showed potent inhibitory activ-
ity against target enzymes. Interestingly, compound 2
with 4,5-O-isopropylidene group exhibited 12–21 times
more potent inhibitory activity against MMP-1, MMP-
3 and MMP-9 than those of compound 1. This result
indicated that structural difference based on iso-
propylidene group at the 3,4-position or 4,5-position
would play important role for interaction with MMP-1,
-3, -9. Compound 4 bearing acetyl group showed 6–13
times weak activity against MMP-1 and -3 than com-
pound 2. In addition, regarding the inhibitory activity
toward MMP-3, it was found that azasugar compounds
synthesized exhibited more potent than representative
MMP inhibitor, Marimastat. In this investigation, it
was clarified that azasugars could function as a useful
scaffold for inhibition toward metalloproteinases.
Figure 1. Design of novel azasugar-based metalloproteinase inhibitor.
In conclusion, we synthesized novel azasugar-based metal-
loproteinase inhibitors 1-4 which exhibited desirable inhib-
itory activities against TACE and MMP-1, -3, -9. This
result suggests that azasugar skeleton could be useful as
Figure 2. Structure of azasugar-based metalloproteinase inhibitors
with 2R,3S,4R,5S-configuration.

H. Moriyama et al. / Bioorg. Med. Chem. Lett. 13 (2003) 2741–2744
2743
Scheme 1. (a) LDA, SnCl2; (b) Ac2O, pyridine; (c) TBAF, AcOH, THF; (d) DEAD, Ph3P, THF; (e) Pd/C, H2; (f) NH2OBn, WSC, HOBt;
(g) NaOMe, MeOH; (h) DOWEX-H+; (i) 2,2-dimethoxypropane, p-TsOH, DMF.
5. Black, R. A.; White, J. M. Curr. Opin. Cell. Biol. 1998, 10,
654.
Table 1. Inhibitory activities of azasugar derivatives 1–4 against
MMPs and TACE
6. Bemelmans, M. H.; van Tits, L. J.; Buurman, W. Crit. Rev.
Immunol. 1996, 16, 1.
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Compd
rMMP-1
Ki (nM)a
rMMP-3
Ki (nM)a
rMMP-9
Ki (nM)a
TACE
Ki (nM)a
1
2
3
4
554
26
84
162
44
3.7
17
50
310
21
157
47
22
40
71
21
Marimastat
1.1
84
11
0.40
aSee ref 18 for assay conditions.
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61, 795.
scaffold for the synthesis of successful metalloproteinase
inhibitors. Moreover, sulfonaminyl azasugars could
attain much improvement of water solubility, compared
to other class of metalloproteinase inhibitor. Therefore,
these findings would be useful for design of novel
metalloproteinase inhibitors. We are now investigating
optimization of azasugar compounds.
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The present work was supported by a grant for
‘Research and Development on Glycocluster Control-
ling Biomolecules’ from the New Energy and Industrial
Technology Development Organization (NEDO).
References and Notes
16. Mitsunobu, O. Synthesis 1981, 1.
17. All new compounds gave satisfactory characteristics data.
Characteristics are given for a representative compound: 3; 1H
NMR (DMSO-d6, 250 MHz) d 3.25–3.7 (m, 5H), 3.83 (s, 3H),
4.34 (d, 1H, J=2.0 Hz), 4.7–5.2 (m, 3H), 7.05 (d, 2H, J=8.9
Hz), 7.72 (d, 2H, J=8.9 Hz), 8.88 (s, 1H), 10.86 (s, 1H).
MALDI-TOF: 385 (M+Na+).
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