The myo-1,2-diaminocyclitol scaffold defines potent glucocerebrosidase activators and promising pharmacological chaperones for gaucher disease

Article abstract of DOI:10.1021/ml200098j

A series of cyclitol derivatives with myo-configuration are β-glucocerebrosidase (GCase) inhibitors and show excellent characteristics for the development of pharmacological chaperones for enzyme deficiency in Gaucher disease (GD). The most potent inhibit

Full text of DOI:10.1021/ml200098j

LETTER
pubs.acs.org/acsmedchemlett
The myo-1,2-Diaminocyclitol Scaffold Defines Potent
Glucocerebrosidase Activators and Promising Pharmacological
Chaperones for Gaucher Disease
Ana Trapero and Amadeu Llebaria*
Research Unit on Bioactive Molecules (RUBAM), Departament de Química Biomꢀedica, Institut de Química Avanc-ada de Catalunya
(IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
S Supporting Information
b
ABSTRACT: A series of cyclitol derivatives with myo-configuration are β-glucocerebrosidase
(GCase) inhibitors and show excellent characteristics for the development of pharmacological
chaperones for enzyme deficiency in Gaucher disease (GD). The most potent inhibitor,
(1S,2R,3R,4S,5R,6S)-5,6-bis(nonylamino)cyclohexane-1,2,3,4-tetraol, displayed a Ki value of
26 nM in isolated enzyme and also inhibited GCase in wild-type (wt) human fibroblasts at
nanomolar concentrations. This diaminocyclitol produced maximum increases of GCase
activities of 60% in N370S lymphoblasts at 100 nM and 30% in L444P at 1 nM following a
3-day incubation, showing the permeability, subcellular distribution, and cell metabolism
characteristics for use as pharmacological chaperone.
KEYWORDS: Gaucher disease, β-glucocerebrosidase, pharmacological chaperone, L444P
mutation, N370S mutation, cyclitol
aucher disease (GD) is the most prevalent lysosomal
storage disorder caused by inherited mutations in the gene
In recent years, several distinct structural classes of pharma-
cological chaperones have been reported, such as N-nonyl-
deoxynojirimycin (NN-DNJ),6 isofagomine,7 and R-1-C-octyl-
1-deoxynojirimycin (CO-DNJ)8 (Figure 1). In this context, we
have been actively working on the development of new amino-
cyclitol derivatives with potential applicability as pharmacologi-
cal chaperones of this enzyme.9ꢀ11 Recently, we have described a
family of bicyclic compounds that inhibit GCase in human
fibroblasts at nanomolar concentrations.12 In addition, these
compounds increased GCase activity in GD lymphoblasts derived
from N370S and L444P variants at low concentrations, showing the
potency and cellular properties required for GCase pharmacological
chaperones. These included some bicyclic guanidines that define a
new diaminocyclitol scaffold as possible GCase pharmacological
chaperone (Figure 1). This scaffold can also be regarded as an
inositol derivative arising from the replacement of two contiguous
hydroxyls by amino functionalities, namely 1D-1,2-diamino-1,2-
dideoxy-myo-inositol. In order to verify the myo-diaminocyclitol
GCase activity hypothesis, we obtained compounds 1ꢀ5 and the
related ether 6, to be tested on GCase enzymes including N370S
and L444P lymphoblasts of GD patients.
G
encoding acid β-glucosidase (GCase, β-glucocerebrosidase, EC
3.2.1.45),1 the lysosomal enzyme responsible for glucosylcera-
mide metabolism into glucose and ceramide. These mutations
lead to significant protein misfolding during translation in the
endoplasmic reticulum (ER) and reduced enzyme trafficking to
the lysosome.2 GCase deficiency results in the accumulation of
undegraded substrate in the lysosomes of macrophages, which
often leads to hepatosplenomegaly, anemia, bone lesions, re-
spiratory failure, and, in more severe cases, central nervous
system involvement.1 The two most prevalent GCase missense
mutant forms reported in GD patients are N370S, which typically
results in non-neuronopathic disease, and L444P, which causes a
more severe neuronopathic form.
Currently, enzyme replacement therapy and substrate reduc-
tion therapy are the only approved treatments for patients with
the non-neuronopathic GD.3 Recently, a third promising ther-
apeutic option, the pharmacological chaperone therapy (PCT),
has emerged.4,5 PCT is based on the use of reversible competitive
GCase inhibitors that are capable of enhancing its residual
hydrolytic activity at subinhibitory concentrations by stabilizing
the functional form of the misfolded protein and preventing its
premature degradation in the ER. This improves enzyme traffick-
ing to the lysosome and enhances its hydrolytic activity. Thus,
PCT is highly promising for GD, because it combines the benefits
of the small-molecule approach, including oral bioavailability and
the potential to cross the bloodꢀbrain barrier, with the specificity
of an enzyme-directed approach. In addition, a combined therapy
based on the coadministration of pharmacological chaperones and
recombinant enzyme is undergoing clinical trials.4
Our group reported9,13,14 synthetic methodologies for ami-
nocyclitols, based on the regioselective opening of conduritol B
epoxide, which have been applied to the stereocontrolled synthe-
sis of aminocyclitols and 1,2-diaminocyclitols. Diaminocyclitol 1
was obtained by reductive amination of nonanal with the enan-
tiomerically pure 2-azidocyclohexylamine 12, which was obtained
Received: April 15, 2011
Accepted: May 18, 2011
Published: May 18, 2011
r
2011 American Chemical Society
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LETTER
Scheme 1. Synthesis of Diaminocyclitol 1a
Figure 1. Chemical structures of cyclitol derivatives (1ꢀ6) and other
reported potential GCase pharmacological chaperones.
from azido alcohol 714 by a procedure described previ-
ously for racemic 12,13 followed by catalytic hydrogenation
(Scheme 1).
The synthesis of compounds 2ꢀ5 started from (þ)-condur-
itol B 1414 (Scheme 2), which was benzylated and dihydroxylated
to give myo-inositol derivative 16.15 Dimesylation of 16 followed
by substitution with NaN3 afforded diazide 17.16 In our hands,
the reported17 conversion of 17 to 19 using catalytic hydrogena-
tion in the presence of Boc2O was unsuccessful. However,
LiAlH4 reduction of diazide 17 to 18 followed by conventional
N-Boc protection gave dicarbamate 19.
Unfortunately, we were unable to effectively dialkylate 19 with
nonyl iodide to produce 20. This reaction afforded a 1:1 mixture
of the desired Boc-protected diamine 20 and imidazolidinone 21.
On one hand, compound 20 was transformed into diaminocy-
clitol 2 after removing protecting groups by conventional
methods. On the other hand, the hydrogenolysis of 21 with
Pd/C provided the 1,3-di-N-nonylimidazolidinone 3.
The intermediates 16 and 18 were used to synthesize com-
pounds 4ꢀ6 (Scheme 2). The free diamine 4 was obtained after
BCl3 O-debenzylation of cis-diamine 18. The imidazolidinone 5
was prepared by reaction of cis-diamine 18 with N,N0-carbonyldii-
midazole to give the corresponding imidazolidinone 23, which was
transformed into the final compound 5 after O-debenzylation.
Finally, 1,2-di-O-nonyl-myo-inositol 6 was obtained by alkylation
of diol 16 with nonyl iodide, followed by O-benzyl removal.
Compounds 1ꢀ6 were evaluated as inhibitors of recombinant
GCase (imiglucerase, Cerezyme) at the pH values 5.2 and 7.0.
For comparative purposes, the iminosugar NN-DNJ (Figure 1)
was also tested at pH 7.0. As shown in Table 1, compounds 1ꢀ3
were found to be potent imiglucerase inhibitors. On the other
hand, the free diamine 4, imidazolidinone 5, and 1,2-di-O-nonyl-
myo-inositol 6 were weak imiglucerase inhibitors.
a Reagents and conditions: (a) LiAlH4, THF, rt, 91%. (b) Boc2O, Et3N,
CH2Cl2, rt, 82%. (c) MsCl, Et3N, THF, rt, 63%. (d) NaN3, DMF, 90 °C,
65%. (e) CF3CO2H, CH2Cl2, rt, 86%. (f) C8H17CHO, NaBH3CN, AcOH
(cat.), MeOH, rt, 75%. (g) Pd/C, MeOH, HCl, H2 (2 atm), rt, 77%.
agreement with the correlation between lipophilicity and inhibi-
tory activity that was observed in other glycomimetic inhibitors of
this enzyme.9ꢀ12,18ꢀ21 Similarly, the 1,3-di-N-nonylimidazolidin-
one 3 was significantly more active than the imidazolidinone 5,
which shows only marginal inhibition of the enzyme. It is
remarkable that the inhibitory potency of compound 3 is in the
nanomolar range in spite of the differences in structure and
protonation state compared with related 1,2-diaminocyclohexanes
or guanidines (see Figure 1). Inhibition constants (Ki) for the
most active compounds were determined, and in all cases, a
competitive inhibition mode was found (see Figures S1ꢀS3 of
the Supporting Information). The N,N0-dinonyl diaminocyclitol 2
is the most potent inhibitor found in this work, having a remark-
able Ki value of 26 nM, which is 7-fold more potent than N-nonyl
diaminocyclitol 1 and 27-fold more potent than 1,3-di-N-non-
ylimidazolidinone 3. This is the most potent aminocyclitol deri-
vative found in our series and compared favorably with other
cyclitol compounds, including the bicyclic derivatives.12
A pharmacological chaperone is expected to bind to the enzyme
active site at the neutral pH of the ER to assist folding, but it should
dissociate at the lysosome low-pH to facilitate glucosylceramide
binding and the subsequent enzymatic reaction. Therefore, com-
pounds that exhibit higher inhibitory activity at lumenal ER pH
(7.0) than at lysosomal pH (5.2) would be better pharmacological
chaperones. Interestingly, compounds 1ꢀ4 and 6 showed lower
IC50 values at neutral pH, which denote an advantageous property
for pharmacological chaperone candidate molecules. A similar pH
dependence of the inhibitory activity has been previously reported
for other compounds which showed enzyme enhancement in cells
with various GCase mutations.23,24
The N-alkylated diamines 1 and 2 were found to be better
inhibitors than the free diamine 4, indicating that the presence
of an N-alkyl chain is favorable for imiglucerase inhibition, in
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Scheme 2. Synthesis of Compounds 2ꢀ6 from (þ)-Conduritol B 14a
a Reagents and conditions: (a) NaH, BnBr, DMF, 30 °C, 75%. (b) OsO4, acetoneꢀH2O, N-methylmorpholine N-oxide, rt, 83%. (c) (1) MsCl, pyridine,
rt; (2) NaN3, DMF, 85 °C, 77% for two steps. (d) LiAlH4, THF, rt, 93%. (e) Boc2O, Et3N, CH2Cl2, rt, 53%. (f) NaH, C9H19I, DMF, 80 °C, 21% (20),
24% (21). (g) CF3CO2H, CH2Cl2, rt, 86%. (h) N,N0-carbonyldiimidazole, CH2Cl2, reflux, 83%. (i) NaH, C9H19I, DMF, 0 °C, 78%. (j) Pd/C, MeOH,
HCl, H2 (2 atm), rt, 85%. (k) Pd/C, MeOH, H2 (2 atm), rt, 88ꢀ93%. (l) BCl3, CH2Cl2, ꢀ78 °C, 87%.
Table 1. GCase Inhibitory Activity and Maximum Observed Increase in GCase Activity Using Pharmacological Chaperones and
NN-DNJ
imiglucerase
IC50 (μM)
compd
pH 7.0
pH 5.2
Kia (μM)
% GCase inhibitionb
N370S GCase activity increasec
L444P GCase activity increasec
1
0.081
0.056
1.21
44.4
n.d.
0.64
0.09
1.61
53.4
46%e
144.0
0.66f
0.17
0.026
0.70
n.d.d
n.d.
50
1.6 ( 0.1 (1 μM)
1.6 ( 0.2 (0.1 μM)
2.0 ( 0.1 (10 μM)
1.2 ( 0.1 (10 μM)
n.d.
1.3 ( 0.2 (1 μM)
1.3 ( 0.1 (1 nM)
no activity
n.d.
2
96
3
36
4
17
5
n.d
n.d.
56g
n.d.
6
49.3
n.d.
0.30f
n.d.
n.d.
NN-DNJ
0.30
1.4 ( 0.1 (5 μM)
no activity
a Competitive inhibitor (pH 5.2). b Incubation for 24 h at 5 μM inhibitor and 5 mM substrate in wild-type (wt) human fibroblast. c N370S and L444P
lymphoblasts from Gaucher patients were incubated with test compounds for 3 days before being used for enzyme assay. Data in parentheses correspond
to the concentration of the tested compound. Experiments were performed in triplicate, and the mean ( SD is shown. The relative activity was obtained
by normalizing the activity corresponding to each compound concentration tested to the activity of untreated cells. d n.d.: not determined. e % inhibition
at 1 mM inhibitor. f See ref 22. g Incubation for 24 h at 50 μM inhibitor and 5 mM substrate.
Candidate compounds for PCT should display high selectivity
for GCase enzyme without inhibiting other glycosidases. To ad-
dress this subject, the cyclitol derivatives were assayed as inhibitors
of commercial R- and β-glycosidases, showing negligible effects at
100 μM (see Table S1 of the Supporting Information).25 In
addition, none of the compounds displayed significant inhibition
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Figure 2. (A) Stabilization ratios of compounds 1ꢀ4 and NN-DNJ after thermal denaturation (48 °C) for 20 min (green bar), 40 min (red bar), and 60 min
(blue bar) at the indicated inhibitor concentrations (μM). (B) Intact cell GCase inhibition in wt human fibroblasts. Compounds 1ꢀ4 and NN-DNJ were
incubated for a 24 h period at the indicated inhibitor concentrations. Experiments were performed in triplicate, and bars represent the mean ( SD.
Figure 3. Effects of compounds 1ꢀ3 on GCase activity in N370S (A) and L444P (B) lymphoblasts from Gaucher patients. Cells were cultured for
3 days in the absence or presence of increasing concentrations (μM) of compounds before GCase activity was measured. Experiments were performed in
triplicate, and each bar represents the mean ( SD. Enzyme activity is normalized to untreated cells, assigned a relative activity of 1.
on glucosylceramide synthase at 250 μM, thus indicating a good
selectivity toward GCase.26
for 1 and 4, well below the CC50 determined for these com-
pounds (see Table S3 of the Supporting Information). The high
potency of compounds 1ꢀ4 required analysis at lower concen-
trations (see Figure 2B and Table 1). A good correlation between
the Ki values against imiglucerase and GCase inhibition in cell
culture was observed, except for compound 4, which showed a
noticeable inhibition in cellular assays, higher than could be
expected from data obtained in isolated enzyme inhibition ex-
periments. The reasons for this behavior are at present unclear
and could be related to a favorable permeability and stability or a
synergistic effect in cells.
Interestingly, compounds 1ꢀ3 also behaved as potent GCase
inhibitors in these cells at low-micromolar concentrations. As shown
in Figure 2B, diaminocyclitol 2 was the most potent inhibitor with
74% and 21% of GCase inhibition at 500 and 50 nM, respectively.
These results show that these compounds are powerful GCase
inhibitors in live cells, reflecting good membrane permeability and
cellular stability to inhibit the cellular enzyme.
The resistance to thermal denaturation in the presence of a
potential pharmacological chaperone is a method used to assess
the enzyme stabilization effects due to compound binding.6,9ꢀ12,24
In this context, the effect of compounds 1ꢀ4 and NN-DNJ on the
stabilization of recombinant GCase activity during thermal dena-
turation at 48 °C was determined. The stabilization ratio27 values
found for each compound at different concentrations and incuba-
tion times are plotted in Figure 2A (see also Table S2 of the
Supporting Information). Diaminocyclitols 1 and 2 exhibited
stabilization ratios of 5.5 and 34.7, respectively, at 10 μM after 1 h
of incubation time at 48 °C, comparing favorably with NN-DNJ,
which showed a 9.2 stabilization ratio at 100 μM. The enzyme
stabilization effects of compounds 3 and 4 were much weaker.
The cellular GCase inhibition by compounds 1ꢀ4 and NN-
DNJ was initially studied in wt human fibroblasts after 24 h of
incubation at nontoxic concentrations: 5 μM for 2ꢀ3 and 50 μM
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The potential for pharmacological chaperone activity of
compounds 1ꢀ4 was further evaluated in human lymphoblasts
derived from Gaucher patients homozygous for N370S or L444P
mutations. The iminosugar NN-DNJ, an activator for N370S
GCase but not for the L444P variant, was used as a control.6 The
compounds were incubated at different concentrations for 3 days
with the Gaucher cells, and the GCase activity was measured to
determine the increase or reduction of the enzyme activity in
compound treated cells compared with untreated cells. The
results obtained are summarized in Table 1 (see also Figure 3).
In the analysis of N370S GCase activation, diaminocyclitol 1
showed a 60% activity increase at 1 μM and 1,3-di-N-nonylimi-
dazolidinone 3 caused a 2.0-fold increase at 10 μM. Similarly,
NN-DNJ showed a 40% activity increase at 5 μM. Remarkably,
the treatment of N370S lymphoblasts with diaminocyclitol 2 led
to a 1.6-fold maximal increase in N370S GCase activity at the
very low concentration of 100 nM (see Figure 3A). Compound 4
showed a nonsignificant enzyme activity enhancement on N370S
lymphoblasts, and it was not tested in the L444P variant cells.
The effects of compounds 1ꢀ3 and NN-DNJ on L444P GCase
activity, which characterize a more severe disease phenotype than
N370S, were measured using the type 2 GD lymphoblast cell line.
After a 3-day incubation, NN-DNJ and imidazolidinone 3 showed
no GCase activation at low concentrations and inhibition at high
concentrations. In contrast, diaminocyclitols 1 and 2 maximally
increased the L444P GCase activity by about 30% at 1 μM and
1 nM, respectively (see Table 1 and Figure 3B).
Funding Sources
This work was supported by MICINN (CTQ2008-01426/
BQU), CSIC, and Generalitat de Catalunya (2009-SGR-1072).
A.T. thanks MICINN for a predoctoral fellowship.
’ ACKNOWLEDGMENT
The authors thank Drs. J. Casas and A. Delgado for helpful
discussions, Dr. M. Egido-Gabꢁas, E. Dalmau, and N. Guillem for
experimental contributions, and Genzyme Corp. for a generous
imiglucerase supply.
’ ABBREVIATIONS
GD, Gaucher disease; GCase, β-glucocerebrosidase; ER, endo-
plasmic reticulum; PCT, pharmacological chaperone therapy;
NN-DNJ, N-nonyldeoxynojirimycin; CO-DNJ, R-1-C-octyl-1-
deoxynojirimycin; wt, wild-type; CC50, compound concentra-
tion required to induce 50% cytotoxicity
’ REFERENCES
(1) Zhao, H.; Grabowski, G. A. Gaucher disease: Perspectives on a
prototype lysosomal disease. Cell. Mol. Life Sci. 2002, 59, 694–707.
(2) Futerman, A. H.; van Meer, G. The cell biology of lysosomal
storage disorders. Nat. Rev. Mol. Cell Biol. 2004, 5, 554–565.
(3) Platt, F. M.; Lachmann, R. H. Treating lysosomal storage
disorders: Current practice and future prospects. Biochim. Biophys. Acta,
Mol. Cell Res. 2009, 1793, 737–745.
In summary, different diaminocyclitol derivatives with myo-
configuration have been synthesized as potential GCase phar-
macological chaperones. These compounds have been tested as
GCase inhibitors in imiglucerase and wt human fibroblasts.
Among them, diaminocyclitols 1ꢀ2 and imidazolidinone 3 were
found to be potent inhibitors of recombinant GCase with Ki
values in the nanomolar range and also behaved as strong
inhibitors of GCase in wt fibroblasts. Furthermore, cyclitol
derivatives 1ꢀ3 are able to increase the activity of N370S GCase
between 1.6- and 2-fold at low micromolar or even nanomolar
concentrations, and diaminocyclitols 1ꢀ2 maximally increase
the GCase activity of the L444P cell line by about 30%. It is worth
noting the unusual potency of N,N0-dinonyl diaminocyclitol 2,
which increased GCase activity in L444P and N370S lympho-
blasts at 1 nM. In spite of the reduced number of compounds
tested, the results described establish that the myo-1,2-diamino-
cyclitol structure characterizes a promising family in the search
for optimal compounds for the potential treatment of GD.
(4) Parenti, G. Treating lysosomal storage diseases with pharmaco-
logical chaperones: from concept to clinics. EMBO Mol. Med. 2009,
1, 268–279.
(5) Yu, Z.; Sawkar, A. R.; Kelly, J. W. Pharmacologic chaperoning as
a strategy to treat Gaucher disease. FEBS J. 2007, 274, 4944–4950.
(6) Sawkar, A. R.; Cheng, W.-C.; Beutler, E.; Wong, C.-H.; Balch,
W. E.; Kelly, J. W. Chemical chaperones increase the cellular activity of
N370S β-glucosidase: A therapeutic strategy for Gaucher disease. Proc.
Natl. Acad. Sci. U. S. A. 2002, 99, 15428–15433.
(7) Khanna, R.; Benjamin, E. R.; Pellegrino, L.; Schilling, A.; Rigat,
B. A.; Soska, R.; Nafar, H.; Ranes, B. E.; Feng, J.; Lun, Y.; Powe, A. C.;
Palling, D. J.; Wustman, B. A.; Schiffmann, R.; Mahuran, D. J.; Lockhart,
D. J.; Valenzano, K. J. The Pharmacological Chaperone Isofagomine
Increases Activity of the Gaucher Disease L444P Mutant Form of
β-Glucosidase. FEBS J. 2010, 277, 1618–1638.
(8) Yu, L.; Ikeda, K.; Kato, A.; Adachi, I.; Godin, G.; Compain, P.;
Martin, O.; Asano, N. R-1-C-octyl-1-deoxynojirimycin as a pharmaco-
logical chaperone for Gaucher disease. Bioorg. Med. Chem. 2006,
14, 7736–7744.
(9) Egido-Gabꢁas, M.; Canals, D.; Casas, J.; Llebaria, A.; Delgado, A.
Aminocyclitols as Pharmacological Chaperones for Glucocerebrosidase,
a Defective Enzyme in Gaucher Disease. ChemMedChem 2007,
2, 992–994.
’ ASSOCIATED CONTENT
(10) Díaz, L.; Bujons, J.; Casas, J.; Llebaria, A.; Delgado, A. Click
Chemistry Approach to New N-Substituted Aminocyclitols as Potential
Pharmacological Chaperones for Gaucher Disease. J. Med. Chem. 2010,
53, 5248–5255.
(11) Díaz, L.; Casas, J.; Bujons, J.; Llebaria, A.; Delgado, A. New
Glucocerebrosidase Inhibitors by Exploration of Chemical Diversity of
N-Substituted Aminocyclitols Using Click Chemistry and in Situ Screen-
ing. J. Med. Chem. 2011, 54, 2069–2079.
S
Supporting Information. Experimental details, charac-
b
terization data for all new compounds, and biological assay
protocols. This material is available free of charge via the Internet
at http://pubs.acs.org.
’ AUTHOR INFORMATION
Corresponding Author
*Fax int: þ34-932045904. E-mail: amadeu.llebaria@cid.csic.es.
Author Contributions
Ana Trapero performed chemistry and biology experiments,
analyzed data and wrote the paper. Amadeu Llebaria designed
research, analyzed data and wrote the paper.
(12) Trapero, A.; Alfonso, I.; Butters, T. D.; Llebaria, A. Polyhy-
droxylated Bicyclic Isoureas and Guanidines Are Potent Glucocerebro-
sidase Inhibitors and Nanomolar Enzyme Activity Enhancers in Gaucher
Cells. J. Am. Chem. Soc. 2011, 133, 5474–5484.
(13) Serrano, P.; Llebaria, A.; Delgado, A. Regio- and Stereoselective
Synthesis of Aminoinositols and 1,2-Diaminoinositols from Conduritol
B Epoxide. J. Org. Chem. 2005, 70, 7829–7840.
618
dx.doi.org/10.1021/ml200098j |ACS Med. Chem. Lett. 2011, 2, 614–619

ACS Medicinal Chemistry Letters
LETTER
(14) Gonzꢁalez-Bulnes, P.; Casas, J.; Delgado, A.; Llebaria, A. Prac-
tical synthesis of (ꢀ)-1-amino-1-deoxy-myo-inositol from achiral pre-
cursors. Carbohydr. Res. 2007, 342, 1947–1952.
(15) Luchetti, G.; Ding, K.; d’Alarcao, M.; Kornienko, A. Enantio-
and Diastereodivergent Synthetic Route to Multifarious Cyclitols from
D-Xylose via Ring-Closing Metathesis. Synthesis 2008, 19, 3142–3147.
(16) Guꢁedat, P.; Spiess, B.; Schlewer, G. Synthesis of (()-1,2-
Dideoxy-1,2-Diamino-myo-Inositol. Tetrahedron Lett. 1994, 35, 7375–
7378.
(17) Azev, V. N.; d’Alarcao, M. Synthesis of 1,2-Diamino-1,2-
dideoxy-myo-inositol-Derived Ligands for the Investigation of Metal
Complex Reactivity. J. Org. Chem. 2004, 69, 4839–4842.
(18) Overkleeft, H. S.; Renkema, G. H.; Neele, J.; Vianello, P.; Hung,
I. O.; Strijland, A.; van der Burg, A. M.; Koomen, G.-J.; Pandit, U. K.;
Aerts, J. M. Generation of Specific Deoxynojirimycin-type Inhibitors of
the Non-lysosomal Glucosylceramidase. J. Biol. Chem. 1998, 273, 26522
26527.
(19) Zhu, X.; Sheth, K. A.; Li, S.; Chang, H.-H.; Fan, J.-Q. Rational
Design and Synthesis of Highly Potent β-Glucocerebrosidase Inhibitors.
Angew. Chem., Int. Ed. 2005, 117, 7616–7619.
(20) Aguilar, M.; Gloster, T. M.; García-Moreno, M. I.; Ortiz Mellet,
C.; Davies, G. J.; Llebaria, A.; Casas, J.; Egido-Gabꢁas, M.; García Fernꢁandez,
J. M. Molecular Basis for β-Glucosidase Inhibition by Ring-Modified
Calystegine Analogues. ChemBioChem 2008, 9, 2612–2618.
(21) Ogawa, S.; Kobayashi, Y.; Kabayama, K.; Jimbo, M.; Inokuchi, J.
Chemical Modification of β-Glucocerebrosidase Inhibitor N-Octyl-β-
valienamine: Synthesis and Biological Evaluation of N-Alkanoyl and
N-Alkyl Derivatives. Bioorg. Med. Chem. 1998, 6, 1955–1962.
(22) Compain, P.; Martin, O. R.; Boucheron, C.; Godin, G.; Yu, L.;
Ikeda, K.; Asano, N. Design and Synthesis of Highly Potent and Selective
Pharmacological Chaperones for the Treatment of Gaucher’s Disease.
ChemBioChem 2006, 7, 1356–1359.
(23) Bendikov-Bar, I.; Ron, I.; Filocamo, M.; Horowitz, M. Char-
acterization of the ERAD process of the L444P mutant glucocerebro-
sidase variant. Blood Cells Mol. Dis. 2011, 46, 4–10.
(24) Maegawa, G. H.; Tropak, M. B.; Buttner, J. D.; Rigat, B. A.;
Fuller, M.; Pandit, D.; Tang, L.; Kornhaber, G. J.; Hamuro, Y.; Clarke,
J. T.; Mahuran, D. J. Identification and Characterization of Ambroxol as
an Enzyme Enhancement Agent for Gaucher Disease. J. Biol. Chem.
2009, 284, 23502–23516.
(25) Compounds were screened against the following glycosidases:
sweet almond β-glucosidase, yeast R-glucosidase, rice R-glucosidase,
green coffee beans R-galactosidase, and bovine liver β-galactosidase.
Cyclitols 1ꢀ3 showed between 44 and 92% inhibition of β-galactosidase
at 100 μM. For further details, see the Supporting Information.
(26) Only diaminocyclitol 2 showed a significant inhibition (73%)
on glucosylceramide synthase at 250 μM, but was inactive when tested at
50 μM. For further details, see the Supporting Information.
(27) This parameter is defined as the ratio of the relative enzymatic
activities (inhibitor vs control) at a given inhibitor concentration and
incubation time.
619
dx.doi.org/10.1021/ml200098j |ACS Med. Chem. Lett. 2011, 2, 614–619