Biological diversity from a structurally diverse library: Systematically scanning conformational space using a pyranose scaffold

Article abstract of DOI:10.1021/jm1002777

Success in discovering bioactive peptide mimetics is often limited by the difficulties in correctly transposing known binding elements of the active peptide onto a small and metabolically more stable scaffold while maintaining bioactivity. Here we describe a scanning approach using a library of pyranose-based peptidomimetics that is structurally diverse in a systematic manner, designed to cover all possible conformations of tripeptide motifs containing two aromatic groups and one positive charge. Structural diversity was achieved by efficient selection of various chemoforms, characterized by a choice of pyranose scaffold of defined chirality and substitution pattern. A systematic scanning library of 490 compounds was thus designed, produced, and screened in vitro for activity at the somatostatin (sst_1?5) and melanin-concentrating hormone (MCH₁) receptors. Bioactive compounds were found for each target, with specific chemoform preferences identified in each case, which can be used to guide follow-on drug discovery projects without the need for scaffold hopping.

Full text of DOI:10.1021/jm1002777

5576 J. Med. Chem. 2010, 53, 5576–5586
DOI: 10.1021/jm1002777
Biological Diversity from a Structurally Diverse Library: Systematically Scanning
Conformational Space Using a Pyranose Scaffold†
‡
Giovanni Abbenante, Bernd Becker, Sebastien Blanc, Chris Clark, Glenn Condie, Graeme Fraser,
‡
§
‡
‡
§
ꢀ
Matthias Grathwohl,‡ Judy Halliday,‡ Senka Henderson,‡ Ann Lam,‡ Ligong Liu,‡ Maretta Mann,‡ Craig Muldoon,‡
Andrew Pearson,‡ Rajaratnam Premraj,‡ Tracie Ramsdale,‡ Tony Rossetti,‡ Karl Schafer,‡ Giang Le Thanh,‡
‡
‡
‡
‡
‡
‡
ꢀ
Gerald Tometzki, Frank Vari, Geraldine Verquin, Jennifer Waanders, Michael West, Norbert Wimmer,
Annika Yau,‡ Johannes Zuegg,‡ and Wim Meutermans*,‡
‡
Alchemia Ltd, Eight Mile Plains, Queensland 4113, Australia, and §Euroscreen SA, Brussels 1070, Belgium
Received March 2, 2010
Success in discovering bioactive peptide mimetics is often limited by the difficulties in correctly
transposing known binding elements of the active peptide onto a small and metabolically more
stable scaffold while maintaining bioactivity. Here we describe a scanning approach using a library
of pyranose-based peptidomimetics that is structurally diverse in a systematic manner, designed to
cover all possible conformations of tripeptide motifs containing two aromatic groups and one
positive charge. Structural diversity was achieved by efficient selection of various chemoforms,
characterized by a choice of pyranose scaffold of defined chirality and substitution pattern. A
systematic scanning library of 490 compounds was thus designed, produced, and screened in vitro
for activity at the somatostatin (sst1-5) and melanin-concentrating hormone (MCH1) receptors.
Bioactive compounds were found for each target, with specific chemoform preferences identified in
each case, which can be used to guide follow-on drug discovery projects without the need for scaffold
hopping.
Introduction
However, despite success in the field, the design of bio-
active peptide mimetics remains a challenging task. Chemically
accessible scaffolds that deliver a seemingly high topographi-
cal overlay with the bioactive conformation(s) of the natu-
ral ligand do not necessarily deliver the desired activity. This
may be further complicated by an inability to accurately
predict the bioactive conformation of the peptide. Hence,
instead of trying to mimic only specific postulated bioactive
conformations, we have aimed to develop a more systematic
approach by designing libraries of molecules that, together,
comprehensively mimic the possible conformations of the
aminoacidmotifsinthe parentpeptide. The pyranosescaffold
is ideally suited for this purpose because of its unique versa-
tility in terms of positioning three substituents in three-
dimensional space (diverse presentations) and the significant
overlay of this accessible topographical space with tripeptide
conformational space.20
We have been interested in utilizing this unique character-
istic of the pyranose scaffold to develop a systematic drug
discovery approach toward bioactive peptidomimetics. Our
approach involves the production and in vitro testing of a
library of pyranose-based mimetics where the 3D presenta-
tion, defined by the order and positioning of the three high-
lighted vectors in Figure1, is systematically varied to cover the
range of topographies accessible to tripeptides, thereby effec-
tively scanning for peptidomimetics with the desired bioactivity
profile. To avoid misunderstandings of the word “presentation”
we have coined the term “chemoform” to specifically describe
the order and positioning of the three vectors. The premise of
our approach is that each receptor will have a chemoform
For over 20 years new concepts in peptidomimetic
chemistry have been developed with the aim of transpos-
ing structural and functional requirements for bioactivity
from a peptide onto metabolically more stable and drug-
like scaffolds.1
The functional requirements for bioactivity of a peptide
are dictated by the nature of the binding elements directly
involved in receptor binding (side chains of the amino acid
motif and, possibly, backbone elements), while the struc-
tural requirements are dictated by the relative orientation
of these binding elements (bioactive conformation). With
well-defined peptide conformations and motifs, small pepti-
domimetic molecules can be designed by appending substitu-
ents that mimick the binding elements onto a rigid organic
scaffold in a way that positions these elements in a similar
relative orientation to that in the bioactive peptide conforma-
tion. One such example scaffold is the pyranose ring system,
pioneered as a peptide mimetic scaffold by the Hirschmann
group in the early nineties to mimic a specific set of confor-
mations of the KWF loop of SST14, the somatostatin
hormone and endogenous ligand of the sst1-5 receptors.2-11
A significant body of work has accumulated since using a
monosaccharide scaffold in various peptidomimetic design
approaches.12-19
†In memory of our colleague, Gerry Tometzki.
*To whom correspondence should be addressed. Phone: 61-7 3340
0200. Fax: 61-7 3340 0222. E-mail: wmeutermans@alchemia.com.au.
Website: www.alchemia.com.au.
r
pubs.acs.org/jmc
Published on Web 07/14/2010
2010 American Chemical Society

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15 5577
Figure 1. Break down of a pyranose-based peptidomimetic in terms of chemoform and motif.
Figure 2. An example pyranose-based mimetic of the FKW tripeptide motif and the four distances that are determined from a calculated low
energy conformation to describe the presentation. F=phenylalanine mimetic; K=lysine mimetic; W=tryptophan mimetic; Sc=scaffold;
D1 = distance between F and K; D2 = distance between F and W; D3 = distance between W and K; D4 = distance from scaffold center
perpendicular to the FKW plane.
preference that, once defined, can be used as a basis in structure-
activity relationship (SARa) design to move from hit-to-lead
and beyond, without the need for scaffold hopping.
3 Minimal synthetic effort: All compounds in the library
should be accessed from common building blocks to sim-
plify the synthetic effort required for the library production.
Here we describe the design, production, and biological
evaluation of a systematic structurally diverse library around
a tripeptide motif containing two aromatics and one positive
charge. The molecular shape is varied by selecting chemo-
forms that are different from each other and synthetically
feasible through the same synthetic strategy. This systematic
scanning library was screened against the somatostatin recep-
tor subtypes (sst1-5) and the melanin-concentrating hormone
receptor 1 (MCH1), examples of class A G-protein coupled
receptors (GPCR) known to bind peptides containing this
tripeptidemotif, and actives analyzed to define unique chemo-
form and motif preferences for each selected receptor.
The design of the pyranose library and its comparison with
peptides was done using the three side chains from the FKW
tripeptide motif (phenylalanine, lysine, and tryptophan) as
the reference model. The set of pyranose presentations
selected for this FKW conformational scanning library were
then used for all motifs containing two aromatics and one
positive charge.
Distances between the key features of the compounds have
been used as descriptors of 3D shape for each compound
(Figure 2). The key features include the mass center of the
binding elements on each substituent, and the mass center of
the scaffold, as outlined in Figure 2. Four distances have
been included in the list of descriptors: three distances bet-
ween each of the three different substituents (between F-K,
K-W, and W-F) and one distance between the scaffold (Sc)
and the plane spanned by the three substituents (F, K, and
W). This latter descriptor defines the relative position of the
scaffold to the FKW plane, i.e., the sign (() of the distance,
calculated using a fixed order for the plane definition (F, K, W)
and the right-hand rule, defines the scaffold position as
either above or below the plane. This descriptor is thereby
able to describe the chirality of the molecule. Furthermore,
the same descriptors can easily be generated for a tripeptide,
using the mass center of the peptide backbone atoms as
scaffold (Sc). Compound or tripeptide conformations can
now be compared and similarity/dissimilarity calculated by
the Euclidian mean of the differences in their four distances.
For the design of our scanning library, we need to first
define the conformational tripeptide space that we wish to
cover. For this purpose, we extracted all tripeptide fragments
containing F, K, or W, in any order, from a set of NMR
and X-ray structures with less than 25% sequence identity
(Pdb_Select_25) to each other.21 A total of 259 FKW tripeptide
Results
Design of a Pyranose-Based FKW Scanning Library. Cen-
tral to the scanning concept is the selection of compounds to
be included in the library. The design of our scanning library
follows three basic principles:
1 Comprehensive: The library needs to include a range of
chemoforms in order to cover the tripeptide conforma-
tional space comprehensively.
2 Systematic-compound efficient: The compounds in-
cluded in the library need to cover that tripeptide
conformational space evenly.
a Abbreviations: C, chemoform; CG, chemoform group; Cpds, com-
pounds; DIPEA, N,N-diisopropylethylamine; DMPFN, 3,5-dimethyl-
1-pyrazolylformamidinium nitrate; DTT, dithiothreitol; EDTA, ethy-
lenediaminetetraacetic acid; GPCR, G-protein coupled receptor;
HBTU, O-Benzotriazole-N,N,N0,N0-tetramethyl-uronium-hexafluoro-
phosphate; MCH, melanin-concentrating hormone; PDB, Protein Data
Bank; Pip, piperidine; PSHF, proton sponge HF; QC, quality control;
RLB, radioligand binding; rmsd, root-mean-square deviation; SAR,
structure-activity relationship; Sc, scaffold; sst, somatostatin; TBDPS,
tert-butyldiphenylsilyl; TES, triethylsilane; TFA, trifluoroacetic acid.

5578 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15
Abbenante et al.
fragments were extracted and the corresponding four dis-
tance descriptors calculated from the coordinates as found in
their corresponding X-ray or NMR structure. Figure 3 shows
the 259 FKW tripeptide conformations in a two-diagram
plot, D1-D2 and D3-D4.
The results of the conformation analysis can be visualized
by plotting the four distances in a two diagram plot. The
single low energy conformation of the glucose-based FKW
mimetic 1 is marked in dark blue, and the remaining low
energy conformations in green. Figure 4 clearly shows two
clusters of conformations for the example FKW-mimetic.
In what follows, only one low energy conformation is plot-
ted out for each mimetic. The main purpose of this analysis is
to help define the area in the diagrams populated by the
FKW tripeptide motif and guide the design of our diversity
library.
In the design of a pyranose-based scanning library, con-
sideration must also be given to the synthetic feasibility and
implementation of the library assembly process. We have
previously described a solid phase synthetic approach using
allose- and glucose-based scaffolds for the parallel produc-
tion of pyranose-based mimetics.22 Having established this
versatile and regiospecific synthetic route, we wanted to
design a FKW-scanning library based on the glucose and
allose scaffolds A-D (Figure 5).
The distances between the side chain substituents range
˚
from 4 to 16 A for D1-D3, whereas the distance of the back-
˚
bone to the plane (D4) ranges from -5 to þ5 A.
To evaluate the level of rigidity of the pyranose-based
mimetics, a conformational analysis was carried out on the
example molecule 1 in Figure 1. This included systematic vari-
ation of the pyranose ring conformation and of the first
rotatable torsional angle of each substituent followed by energy
minimization. Conformations with energy greater than 5 kcal
from the lowest energy conformation were discarded. In addi-
tion, only low energy conformations with root-mean-square
˚
deviation (rmsd) of heavy atom positions greater than 1 A were
selected for the conformational flexibility analysis, resulting in a
diverse set of low energy conformations.
This synthetic route includes resin linkage at position 4 of
the scaffolds, leaving four positions available to attach the
three side-chain mimetics (from the FKW tripeptide), lead-
ing in principle to 24 possible chemoforms per scaffold, or a
total of 96 chemoforms. To simplify the library production,
only amine substituents were considered at position 2, which
brings the number of chemoforms to six per scaffold. On the
basis of a simple vector overlay analysis revealing similarities
between chemoforms, the number of chemoforms included
for the production of our scanning library was further
reduced to the 16 chemoforms listed in Table 1. For each
of these chemoforms, a combinatorial library of 6-9 com-
pounds was then created by combining up to three substit-
uents for each amino acid (3 lysine, 2-3 phenylalanine
(depending on the position of F), and 1 tryptophan mimetics,
see Table 2). This results in a scanning library of 114 com-
pounds, to mimic the FKW tripeptide motif in various
spatial orientations.
Figure 3. Distances D1-D4 (expressed in two diagrams, D1-D2
and D3-D4) for FKW tripeptide sequences found in crystal struc-
tures of proteins, obtained from the Protein Data Bank (PDB). All
˚
distances are in A.
To evaluate the extent of overlap of this library with the
FKW tripeptide conformational space described in Figure 3,
the four distance descriptors were calculated for each of the
114 mimetics using one low energy conformation per mime-
tic. The distance plots in Figure 6 show that the distances
˚
˚
D1-D3 ranged from 4 to 16 A and D4 ranged from -6toþ6A,
i.e., the D1-D4 values for the FKW tripeptide fragments
(Figure 3) fall within the range covered by the pyranose-
based mimetics. In addition, the plot illustrates that the
mimetics in this scanning library are spread across this range.
Thus far we have described the design of a FKW mimetic
library. For this study, we wanted to apply the concept of
structurally diverse pyranose-based peptide mimetics to the
general aromatic-aromatic-positive charge motif, including
Figure 4. Distances D1-D4 for low energy conformations of com-
pound 1. Dark-blue solid circles: A single calculated low energy
conformation used as starting point for the conformational ana-
lysis. Green solid circles: Multiple low energy conformations of
compound 1 within 5 kcal, obtained from conformational analysis.
˚
All distances are in A.
Figure 5. General structures for the four scaffolds (Sc) from which the scanning library was designed and built: (A) R-D-glucosamine, (B) β-
D-glucosamine, (C) R-D-allosamine, and (D) β-D-allosamine.

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15 5579
Table 1. Chemoforms Selected for the Scanning Library
position on scaffold
Ca
Sc (Figure 5)
1
2
3
6
no. of Cpds
1
A
A
B
F
W
K
K
K
K
K
K
K
K
K
K
K
K
K
K
K
K
W
OMe
OMe
OMe
OMe
OMe
OMe
OMe
OMe
W
9
6
9
6
9
6
9
6
9
6
9
6
6
6
6
6
2
F
W
3
F
W
4
B
F
W
5
C
C
D
D
A
A
B
F
W
6
F
W
7
F
W
8
F
9
F
W
OMe
OMe
OMe
OMe
F
Figure 6. Distances D1-D4 for 114 pyranose-based FKW mime-
tics in Table 1. All distances are in A.
˚
10
11
12
13
14
15
16
F
W
F
W
B
F
W
of the library will initially provide information on active
chemoform groups, and resynthesis and retesting of hits will
help define active chemoforms.
B
SMe
SMe
SMe
SMe
B
W
F
W
D
D
F
W
We used the synthetic route in Scheme 1 starting from R/β
mixtures of glycosides 2 (either allose or glucose configura-
tion), obtained from glycosylation of the corresponding thio-
methyl glycosides.23 Conditions of glycosylation were optimized
to obtain between 1/3 and 1/1 R/β anomeric ratio as deter-
mined by NMR analysis. The R/β glycoside mixtures and
β-thiomethyl-glycoside building blocks were loaded on the
resin and resins 3 carried through the synthetic process22
using Irori mini-Kan technology in a split-and-mix library
approach.24 In brief, the benzoate protecting group was re-
F
a Chemoforms (C) are defined as combinations of scaffold and sub-
stitution pattern; Scaffolds (Sc) are defined as depicted in Figure 5:
(A) R-D-glucosamine; (B) β-D-glucosamine; (C) R-D-allosamine, and
(D) β-D-allosamine.
Table 2. Definition of the Substituents Used in the Design of the
Scanning Library to Mimic Amino Acid Side Chainsa
ꢀ
moved using Zemplen conditions and alkylation performed
using LiOtBu and an alkyl bromide to generate intermediate 4.
Treatment with the HF salt of proton sponge removed the
tert-butyldiphenylsilyl (TBDPS) protecting group at 6, and
alkylation, performed as before, introduced the substituent
at position 6. Reduction of the azide 5 with dithiothreitol
(DTT), followed by acylation using O-benzotriazole-N,N,
N0,N0-tetramethyl-uronium-hexafluoro-phosphate (HBTU)
activation, afforded the protected amine 6. To afford the
amine-based mimetics 8,tBOC amino acids were used in the pre-
vious step, followed by TFA induced cleave-deprotection.
To produce the guanidine-based mimetics 9, the resin-loaded
free amine was guanylated using 3,5-dimethyl-1-pyrazolyl-
formamidinium nitrate (DMPFN) prior to cleavage from
resin.
a *Only used at position 1 of the scaffolds.
All products were isolated by HPLC to generate pure sam-
ples for in vitro testing (either R/β mixtures or pure anomers).
Table 3 summarizes the number of compounds designed and
successfully obtained per chemoform group, with an average
purity of 97% as measured by ELSD.
peptide motifs such as FKF and WKW, as well as extending
the motif with an arginine mimetic, FRW, FRF, and WRW.
For these additional motifs, the same list of chemoforms
in Table 1 and substituents described in Table 2 for F, W, K,
and R were included in the library design.
Screening for Activity at the sst1-5 Receptors. Somatosta-
tins are a family of cyclopeptides that bind to the G-protein-
coupled receptor subtypes sst1-5 and act as potent inhibitors
of various endocrine (growth hormone, insulin, glucagon,
gastrin, cholecystokinin, vasoactive intestinal polypeptide,
secretin) and exocrine (gastric acid, pancreatic enzymes) secre-
tory processes, as well as modulation of cell proliferation.25-30
Critical for receptor recognition are the β-turn amino acids
tryptophan and lysine, and this has formed the basis for the
design and development of several metabolically stable peptide
analogues as well as many glucose-based turn mimetics from
the Hirschmann laboratories in the past two decades.2,3,5,6,8
Our library, scanning the FKW motif, was initially scree-
ned for radioligand binding (RLB) activity at the sst1-5 recep-
tors using aequorin cell lines for each of human sst1-5 receptors.
The bias in the library design yielded a high hit rate. A num-
ber of top actives were selected based on the single point
The resulting designed library contains 540 compounds
and is effectively a combinatorial library of the aromatic-
aromatic-positive charge motif across eight chemoforms
(note that due to the symmetry in the aromatic-aromatic-
positive charge motif, the number of chemoforms in Table 1
is halved, as C1dC2, C3dC4, etc.).
Production of the Library. The general synthetic route has
been described elsewhere and is summarized in Scheme 1.
Although the synthetic route will deliver anomerically pure
single compounds from anomerically pure glycosides, the
preference in this library production was given to synthesize
R/β anomeric mixtures in order to reduce the production and
purification efforts and the in vitro screening costs. Once hits
are identified from screening this library, they are resynthe-
sized as individual anomers and retested. For this reason, in
our library description (Table 3), we have grouped chemo-
forms together in chemoform groups (CG I-V). Screening

5580 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15
Abbenante et al.
Scheme 1. Synthetic Route towards the Pyranose-Based Mimetics in the Designed Scanning Library
Table 3. Chemoform Groups (CG) Included in the Synthetic Library Scanning the Aromatic-Aromatic-Positive Charge Motif
position on scaffold
no. of Cpds
CG
C (Table1)
Sc (Figure 5)
1
2
3
6
designed
obtaineda
success rate (%)
no. of samplesb
I
1-4
5-8
9-12
13,14
15,16
A/B
C/D
A/B
B
Ar
Ar
Pos
Pos
Pos
Pos
Pos
Ar
Ar
OMe
OMe
Ar
144
144
144
54
124
144
138
30
92
100
96
62
72
II
III
IV
V
Ar
OMe
Ar
Ar
69
30
SMe
SMe
Ar
Ar
56
D
54
540
54
490
100
92
54
287
total
a Definition of synthetic success was based on LCMS analysis (correct MW and >80% purity of the combined R/β products by ELSD), and on weight
of material obtained after purification (>1 mg). b Number of samples (single compound and R/β mixtures) tested. The synthesis delivered 490 com-
pounds from 540 designed compounds in 287 samples (for group I-III all compounds are initially tested as R/β mixtures).
screening for each of the sst1-5 receptors for confirmatory
IC50 determination.
expected from the chemoform analysis in Table 4. The sst5
receptor does not appear to have a clear preference for one
anomer over the other. All compounds in the table have
agonist or partial agonist activity.
Table 4 lists the structures and IC50 of the five top hits for
the sst4 and sst5 receptors from this confirmatory screening.
The top sst4 hits share the same substitution pattern and
scaffold, indicating that the sst4 receptor binds preferentially
to molecules of this chemoform group (CG V) over the other
chemoform groups in the library. In addition, the sst4 recep-
tor tolerates guanidines and amines in the binding motif. The
sst5 top hits also share a common substitution pattern but
with no specific chiral center preference (CG I and II). These
sst4 and sst5 binding chemoforms are clearly distinct as visua-
lized in Table 4.
The top hits for the sst1-3 receptors were analyzed follow-
ing the same principles. Table 5 lists the affinity range and the
structural features of the top 5 confirmed hits for the sst1-5
receptors. Submicromolar hits were identified for the sst2-5
receptors.
Screening for MCH1 Receptor Antagonists. Melanin-
concentrating hormone is a 19 residue cyclic peptide that
binds with high affinity to two receptors, MCH1 and MCH2,
with pharmacological activity in body weight regulation.31-38
MCH1 antagonists have been demonstrated to reduce weight in
rodents39,40 and are being pursued for the development of
novel antiobesity therapies.41-45 Among the MCH residues
important for binding are arginine-6,11, tyrosine-13, and
tryptophan-17, and MCH1 small molecule antagonists typi-
cally contain aromatics and a basic amine.46 As our library is
designed to scan the aromatic-aromatic-positive charge
motif, we decided to screen this library for antagonist acti-
vity at the MCH1 receptor in a collaborative effort with
Euroscreen SA.
For selected sst5 hits from groups I and II, the individual
anomers were synthesized for confirmatory testing and
evaluation of subtype selectivity. Table 6 summarizes RLB
IC50 results across sst1-5 for single stereoisomers. The sst5 actives
show good selectivity over sst4 and vice versa, as would be
Primary screening identified 17 hits (>50% inhibition at
6.6 μM in MCH1 aequorin cell line) from 287 samples in the
library. These antagonists were further evaluated in RLB for
IC50 detemination, with seven samples showing binding IC50
more potent than 10 μM. All the confirmed hits, listed in

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15 5581
Table 4. Structures of the Five Top Hits for the sst4 and sst5 Receptor
Table 5. Structural Features of Confirmed sst1-5 Hits
mimetic in figure 6 to clarify two points: (i) the diagrams in
Figures 3 and 6 show good similarity, in terms of the range of
distances D1-D4 that are covered by the peptides and the
structural features
of top 5
no. of hits
<10 μM
IC50 (μM)
range of top 5
˚
˚
mimetics respectively (4-16A for D1-D3and -4 toþ4 A for
D4), (ii) the mimetics in Figure 6 are spread across this
D1-D4 accessible tripeptide space. Given that each point in
Figure 6 should be considered as covering a larger sphere due
to inherent conformational flexibility, we conclude that this
library of selected mimetics, although built from a single scaf-
fold, covers the range of accessible tripeptide conformations
in terms of positioning the amino acid side chains in space.
The selected motifs for the described library are binding
motifs for the sst1-5 and MCH1 receptors. The screening of
this library for activity at these receptors is therefore largely a
biological evaluation of the structural diversity in the library.
If the library is comprehensive in covering tripeptide confor-
mations, we expect to find active and inactive molecules in the
library. This is the case for sst1-5 and MCH1. In addition to
this, the results for both sst1-5 and for MCH1 screening show
that each receptor has a high degree of preference for specific
chemoforms or chemoform types in the library. In the case of
sst4, the top actives share a single chemoform, which is distinct
fromthe single chemoform shared by the MCH1 top actives or
the chemoforms recognized by sst5. For the sst5 receptor,
some chemoform degeneracy can be observed that relates
to chiral center inversion, however the general substitution
pattern is the same for all sst5 hits.
Affinity and selectivity are further dictated by the nature of
the substituents, as can be observed for the sst5 and MCH1
hits. The top hits for both receptors share the same chemo-
form (C1-2), but the MCH1 receptor has a preference for
guanidine over primary amine whereas the opposite is true for
the sst5 receptor.
This chemoform and motif preference can be visualized in a
heatmap (Figure 7), where the library is represented as a
matrix of chemoforms (eight for Ar-Ar-Pos motif) and type
of positive charge (amine or guanidine), creating 16 wells.
By coloring various wells in the heatmap, the top actives per
target
CG
Posa
sst1
sst2
sst3
sst4
sst5
16
18
15
17
20
1.70-3.30
0.65-1.46
0.14-0.22
0.18-0.72
0.07-0.2
II
K,R
K
II,V
II
K,R
K,R
K
V
I, II
a Pos = positive charge, amine (K) or guanidine (R).
Table 7, belong to the same chemoform group I with the
common feature of guanidine as the positive charge.
The top five R/β mixtures were resynthesized as individual
R or β products and retested. The RLB data demonstrated
a consistent preference for the R anomer products over the
β isomers, with the best IC50 from the initial hit finding library
at 120 nM. Similar to the sst4 receptor, the MCH1 receptor
preferentially binds to one chemoform, and, as is the case for
its peptide ligands, with a preference for guanidine over
amine in the binding motif (Table 8).
Discussion
Our interest is in developing a systematic approach toward
identifying suitable topographies, i.e., molecular shapes that
complement the binding site of the selected target. Our pre-
mise is that the pyranose scaffold is a versatile tool to generate
diverse molecular shapes that can simulate a broad spectrum
of tripeptide conformations. The molecular design principles
we have used (measuring four distances for one low-energy
conformation) to evaluate this are not sophisticated, as no
consideration of the molecular flexibility is made nor conside-
ration of the orientation of the substituent. Figure 4 illustrates
the level of flexibility of these types of mimetics, suggesting
that each single point (one for each mimetic) in Figure 6
should be seen as a larger sphere of conformations around
that point. We have opted to show single conformation per

5582 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15
Abbenante et al.
Table 6. sst1-5 Receptor Binding Affinities for Selected Anomerically Pure Compounds
position on scaffold
IC50 ( μM)
Cpd
1
2
3
6
CG
Sc
sst1
>10
sst2
>10
>10
6.10
sst3
sst4
>10
sst5
8d-R
8d-β
8 h-R
8 h-β
8e-β
8a
Nap
Nap
PhEt
PhEt
Nap
SMe
PrN
PrN
PrN
PrN
EtN
EtN
ClBn
ClBn
Nap
Nap
Nap
Nap
Me
Me
Me
Me
Me
ClBn
I
A
B
0.50
0.43
8.40
1.32
0.38
6.33
0.07
0.05
0.20
0.18
0.02
6.00
I
>10
>10
>10
>10
>10
>10
I
A
B
I
3.32
0.65
0.98
II
V
D
D
2.80
9.59
4.00
0.43
Table 7. Radioligand Binding Affinities for Selected Hits at the MCH1
Receptor
for challenging targets where traditional library screening
efforts have failed to deliver suitable hits.
position on scaffold
Experimental Section
Cpd
Sc
1
2
3
Ki (μM)
Radioligand Binding Assays on Somatostatin Receptors. Com-
petition binding assays were performed using membranes prepa-
red from CHO cells stably and selectively expressing the cloned,
human sst1, sst2, sst3, sst4, or sst5 receptors. Assays were carried
out in 96-well plates (Master Block, Greiner, 786201) following
successive addition of 50 μL of assay buffer (25 mM Hepes pH
7.4, 5 mM MgCl2, 1 mM CaCl2, 10 μg/mL Saponin, 0.5% pro-
tease free BSA), 10 μL of test compound or reference ligand
(Somatostatin-28, Peninsula, 8004), 20 μL of membrane ex-
tracts (sst1 =2, sst2 =0.2, sst3, sst4, sst5 =0.7 μg protein/well),
and 20 μL of radioligand (3-[125I] iodotyrosyl11Somatostatin-
14, Amersham, IM161). The final concentration of 3-[125I]
iodotyrosyl11Somatostatin-14 in the assay ranged from 0.07 to
0.42 nM across the receptor subtypes tested. The plate was
incubated 60 min at 25 °C in a water bath and then filtered over
GF/B filters (Perkin-Elmer, 6005177, presoaked in 0.5% PEI for
2 h at room temperature) with a Filtration unit (Perkin-Elmer).
The filters were washed six times with 0.5 mL of ice-cold wash
buffer (25 mM HEPES pH 7.4, 5 mM MgCl2, 1 mM CaCl2),
then 50 μL of Microscint 20 (Packard) was added and the plate
was incubated for 15 min on an orbital shaker and then counted
with a TopCount for 1 min/well. All values were corrected for
nonspecific binding determined by addition of an excess of
SST28 (1 μM). Ki values were calculated by nonlinear regression
analysis using a single-site model (XLfit, IDBS Software), and
the previously determined Kd value of SST28 for the radioligand
at each receptor subtype. Compounds were tested once in dupli-
cate samples.
SPA Binding Assays on MCH1 Receptors. Competition bind-
ing assays were performed using membranes prepared from
CHO cells stably and selectively expressing the cloned, human
MCH1 receptor. The assay was carried out in an Optiplate
(Perkin-Elmer, 60052) wherein test compound (50 μL, used at
increasing concentrations) was combined with successive addi-
tions of 25 μL of radioligand ([125I]-MCH, Perkin-Elmer, NEX
375, 2200 Ci/mMol) diluted in assay buffer (25 mM HEPES pH
7.4, 1 mM CaCl2, 5 mM MgCl2, 0.2% protease free BSA) and
25 μL of a premix of membrane/beads (PVT-WGA beads,
Amersham, RPNQ0001, 0.25 mg/well). Plates were incubated
at room temperature for 2 h before counting for 1 min/well in a
TopCount (Packard). Phe-(D)Tyr-MCH (Bachem, H-2218) was
used as the reference ligand. IC50 values were calculated by non-
linear regression analysis using a sigmoidal dose-response
model (XLfit, IDBS Software).
9c
9d
9e
9f
A/B
A/B
A/B
A/B
A/B
A/B
A/B
ClBn
Nap
ClBn
EtPh
Nap
Nap
Nap
PrG
PrG
PrG
PrG
PrG
EtG
MeG
ClBn
ClBn
Nap
1.2
1.8
2.6
3.5
5.1
6.3
6.6
ClBn
Nap
Nap
9g
9h
9i
ClBn
Table 8. Radioligand Binding Affinities of Single Anomers at the
MCH1 Receptor
position
MCH1
Cpd
1
2
3
6
CG
Sc
IC50 (μM)
9c-R
9c-β
9d-R
9d-β
9e-R
9e-β
9f-R
9g-R
ClBn
ClBn
Nap
PrG
PrG
PrG
PrG
PrG
PrG
PrG
PrG
ClBn
ClBn
ClBn
ClBn
Nap
Me
Me
Me
Me
Me
Me
Me
Me
I
I
I
I
I
I
I
I
A
B
A
B
A
B
A
A
0.12
1.66
0.92
1.75
0.45
>3a
Nap
ClBn
ClBn
PhEt
Nap
Nap
ClBn
Nap
0.54
1.16
a Compound showed <50% RLB displacement at 3 μM.
receptor can be easily visualized relative to the chemoform
selection in the library.
The screening of this “shape” scanning library delivered
submicromolar hits for five out of six receptors, from a single
library of 490 compounds. The same library was also screened
forotherreceptors recognizingthe Ar-Ar-Pos motif, such as
melanocortin (MC1, MC4) and nociceptin (NOP) receptors
(data not shown). Orthosteric hits were identified for all three
receptors, and a clear chemoform preference could be asso-
ciated with each receptor. This high success rate is a reflection
of the systematic nature of the library design. By being sys-
tematic, we avoid the need to predict bioactive conformation
for peptide mimetic design and empirically scan for the bio-
active peptide mimetic. As these hits are built on a rigid
small molecule scaffold, the consequent hit-to-lead and lead
optimization processes may only require alterations at the
substituent sites, such as incorporation of more drug-like
substituents, without a need to move away from the scaffold,
or indeed chemoform, and associated starting materials and
chemistries.
AequoScreen Functional Studies on Somatostatin and MCH1
Receptors. AequoScreen is an aequorin-based assay performed
by Euroscreen SA. Assays were performed in CHO cells stably
and selectively expressing the cloned, human sst1, sst2, sst3, sst4,
or sst5 receptors or CHO cells stably and selectively expressing
the MCH1 receptor. Cells in midlog phase, grown in media
without antibiotic 18 h prior to the test, were detached by gentle
flushing with PBS-EDTA (5 mM EDTA), recovered by centri-
fugation and resuspended in “BSA medium” (DMEM/HAM’s
F12 Gibco cat. no. 11039-021, with HEPES, without phenol red
Wehave biasedthe described library towardspecific motifs,
targeting selected receptors. We have now assembled a 14000
compound librarythatis systematically diverse in motif and in
chemoform, built on the pyranose scaffold. The screening
of this library across many classes of targets will provide fur-
ther evaluationof the broad applicability ofthis scanning app-
roach and may provide alternative drug discovery opportunities

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15 5583
Figure 7. Heatmap of the diversity library highlights the specific chemoform and charge preference for the selected GPCRs.
þ0.1% BSA). Cells were then counted, centrifuged, and resus-
pended in a 15 mL Falcon tube at a concentration of 1.7 ꢀ
106 cells/mL. Coelenterazine h (Promega, cat. no. X300X, stock
solution: 500 μM in methanol) was added to the cells in suspen-
sion at a final concentration of 5 μM. The Falcon tube, wrapped
in aluminum foil, was then placed on a vertical rotating wheel
(6 rpm) and incubated at room temperature (temperature should
be maintained below 22 °C) overnight in order to reconstitute
active aequorin. Cells were counted, diluted in “BSA-medium”,
and incubated for 60 min prior to experimentation. For sst recep-
tors, compounds to be tested and reference ligands were diluted
in “BSA-medium” and distributed in a 96-well plate (50 μL/well)
prior to injection of cells (5000 cells/50 μL). For MCH1 receptor,
test and reference compounds were similarly prepared and dis-
tributed in a 384-well plate (30 μL/well) prior to injection of cells
(5000 cells/30 μL). Cells were injected and agonist activity
was measured by recording the emission of light (FDSS 6000
Hamamatsu) for a period of 90 s. Antagonist activity was tested
on the same preparation: in the case of sst receptors, following
the addition and 15 min incubation with 100 μL of the reference
agonist (SST28, Bachem, H4955), and in the case of MCH1,
following the addition and 3 min incubation with 30 μL of the
reference agonist (MCH, Bachem, H1482). In both cases, the
reference agonist was used at a final concentration equivalent to
the EC80 determined for the same experimental day (using
the reader injection system). All values were normalized relative
to background (defined as 0%) and the maximal response to
SST28 or MCH (defined as 100%), respectively. EC50 values
were calculated by nonlinear regression analysis using a sigmoi-
dal dose-response model (XLfit, IDBS Software).
2-deoxy-R/β-D-allopyranoside 2e, (naphth-2-yl)methyl 2-azido-3-
O-benzoyl-6-O-(tert-butyldiphenylsilyl)-2-deoxy-R/β-D-allopyrano-
side 2f, 20-(phenyl)ethyl 2-azido-3-O-benzoyl-6-O-(tert-butyl-
diphenylsilyl)-2-deoxy-R/β-D-allo-pyranoside 2g, 40-chlorobenzyl
2-azido-3-O-benzoyl-6-O-(tert-butyldiphenylsilyl)-2-deoxy-R/β-D-
allopyranoside 2h) were prepared in solution as R/β mixtures
(details are provided in the Supporting Information). All glycoside
products as well as the Glc-SMe and All-SMe building blocks23
were then attached to the resin. Resin loading determination was
performed by subjecting a known amount of resin to cleavage and
diluting the filtrate to a known volume. The concentration of the
sugar was assessed by HPLC/UV comparison to a standard curve,
and the resulting resin loading value was derived.
The library synthesis was performed following the “split-and-
pool” technique, using the IRORI directed sorting process and
the Synthesis Manager software. Each individual resin was split
in the desired number of Kan microreactors. Around 80 mg of
resin was introduced in each Kan, using the IRORI dry resin
filler. Each microreactor contained a unique tag identifier (ceramic
2D-coded cap). By pooling microreactors into common build-
ing block groups, the directed sorting process made the synthesis
efficient while enabling the synthesis of one discrete compound
in each microreactor. Quality control (QC) Kans were added to
monitor evolution of each reaction along the library production
process.
When the synthetic process was completed, the Kans were
transferred into BOHDAN blocks for cleavage off-resin. The
discrete crude compounds were collected and purified by pre-
parative LC/MS. The purified samples were reanalyzed by LC/
MS with parallel ELSD detection and weighted after drying
to determine yield and purity. A sample synthesis was judged
successful if it demonstrated the correct MHþ value in MS and
was obtained with a yield greater than 1 mg and a purity by
ELSD greater than 85%. The list of the 287 successful samples
obtained in this way, along with the yield and C-18 HPLC
retention time, is provided as Supporting Information.
Resynthesis of Actives As Individual Anomers. Individual
anomer products were obtained using the same solid phase
synthetic route as described,22 but starting from a single anomer
glycoside, obtained after column chromatography of the R/β
glycosides.
Molecular Modeling Studies. All pyranose compounds were
created initially as 2D SLN strings using the Sybyl package from
Tripos. The three-dimensional structures of the compounds were
generated using an industry-standard 3D structure generator
(Concord) and further energy minimized, using the MMFF94s
force field, creating a single, low energy conformation for each
compound. The four descriptors were calculated using Sybyl
(Tripos) using in-house SPL scripting.
Selected compounds have undergone a systematic conforma-
tional analysis procedure, which included a systematic variation
of the ring conformation of the pyranose ring, followed by a
systematic variation of the first rotatable torsional angle of each
substituent. All feasible conformations were then energy mini-
mized, discarding all conformations with energy greater than
5 kcal from the lowest energy conformation. In addition, from
this set of low energy conformations only conformations were
selected which had an rmsd of heavy atom position greater than
Compounds 8 h-R, 8 h-β, and 8a were synthesized and char-
acterized in detail elsewhere.22
(Naphth-2-yl)methyl 2-(40-Aminobutyrylamido)-3-O-(40-chloro-
benzyl)-2-deoxy-6-O-methyl-r-D-glucopyranoside (8d-R). Resin
loaded glycoside 2b-R (80 mg resin, 0.35 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(6.7 mg, 44%). 1H NMR (500 MHz, DMSO-d6) δ 1.73 (m, 2 H,
NHCOCH2CH2CH2NH2), 2.23 (t, 2H, J = 7.2. Hz, NHCO-
CH2CH2CH2NH2), 2.79 (t, 2H, J = 7.5 Hz, NHCOCH2-
CH2CH2NH2), 3.30 (s, 3H, OCH3), 3.35-3.42 (m, 1H, H-4),
3.53 (dd, 1H, JH5,H6a =5.8 Hz, JH6a,H6b =10.7 Hz, H-6a), 3.61
(dd, 1 H, JH5,H6b = 0.5 Hz, H-6b), 3.63-3.69 (m, 1H, H-3),
3.70-3.76 (ddd, 1H, H-5), 3.88-3.95 (m, 1H, H-2), 4.63, (d, 1H,
˚
1 A from any other conformation. This procedure, which was
implemented within Sybyl using the built-in Systematic Search
method extended with in-house scripting, generated a set of low
energy and diverse conformers for the selected compounds.
Library Production Process. Practically, all glycosides 2 (benzyl
2-azido-3-O-benzoyl-6-O-(tert-butyldiphenylsilyl)-2-deoxy-R/β-D-
glucopyranoside 2a, (naphth-2-yl)methyl 2-azido-3-O-benzoyl-6-
O-(tert-butyldiphenylsilyl)-2-deoxy-R/β-D-glucopyranoside 2b,
20-(phenyl)ethyl 2-azido-3-O-benzoyl-6-O-(tert-butyldiphenylsilyl)-
2-deoxy-R/β-D-glucopyranoside 2c, 40-chlorobenzyl 2-azido-3-O-
benzoyl-6-O-(tert-butyldiphenylsilyl)-2-deoxy-R/β-D-glucopyranoside
2d, benzyl 2-azido-3-O-benzoyl-6-O-(tert-butyldiphenylsilyl)-
J
A,B = 11.6 Hz, OCH2(B)-Ar1), 4.64 (d, 1H, JA,B = 12.7 Hz,
OCH2(B)-Ar2), 4.82 (d, 1H, OCH2(A)-Ar1), 4.76 (d, 1H, JH1,H2
=
=
3.5 Hz, H-1), 4.85 (d, 1H, OCH2(A)-Ar2), 5.47 (d, 1H, JOH,H-4
7.0 Hz, OH-4), 7.31-7.40 (m, 4H, aromat H)), 7.50-7.58 (m, 3H,

5584 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15
Abbenante et al.
aromat H), 7.61-7.78 (bs, 3H, NH3), 7.88-7.97 (m, 4 H, aromat
H), 8.17 (d, 1 H, JNH,H-2 = 8.8 Hz, C-2NH). 13C NMR (125.7
MHz, DMSO-d6) δ 22.95 (CH2CH2CH2), 31.72 (COCH2),
40.34 (H2NCH2), 52.17 (C-2), 58.4 (OCH3), 68.25 (OCH2Ar2),
70.26 (C-4), 71.36 (C-6), 71.62 (C-5), 72.46 (OCH2Ar1), 79.63
(C-3), 96.1 (C-1), 125.79, 125.88, 126.14, 126.22, 127.46, 127.51,
127.76, 128.84, 128.94, 131.51, 132.37, 132.61, (all aromat C),
171.28 (NHCO). HRMS (ESI, pos mode) m/z [M þ H]þ calcd
for C29H36Cl1N2O6 543.2256; found 543.2254.
(s, 3H, OCH3), 3.36 (dd 1 H, H-4), 3.50 (dd, 1H, JH5,H6a = 5.7
Hz, JH6a,H6b= 10.7 Hz, H-6a), 3.58 (dd, 1H, JH5,H6a =0.5 Hz,
H-6b), 3.60-3.66 (m, 2 H, H-3, H-5), 3.89 (ddd, 1 H, H-2), 4.46
(d, 1H, JA,B =12.6 Hz, OCH2(B)-Ar2), 4.62 (d, 1H, JA,B =11.6
Hz, OCH2(B)-Ar1), 4.65 (d, 1H, OCH2(A)-Ar1), 4.70 (d, 1H,
J
J
H1,H2 =3.4 Hz, H-1), 4.81 (d, 1H, OCH2(A)-Ar2), 5.45 (d, 1H,
OH,H-4 = 6.9 Hz, OH-4), 7.29-7.46 (m, 8 H, aromat. H), 7.59
(m, 1 H, NH), 8.12 (d, 1 H, JNH,H-2=8.7 Hz, C-2NH). 13C NMR
(125.7 MHz, DMSO-d6) δ 24.55 (CH2CH2CH2), 31.68 (COCH2),
40.34 (H2NCH2), 52.13 (C-2), 58.37 (OCH3), 67.28 (OCH2Ar2),
70.22 (C-4), 71.32 (C-6), 71.60 (C-5), 72.50 (OCH2Ar1), 79.60
(C-3), 96.22 (C-1), 127.80, 128.08, 128.90, 129.34, 131.49, 132.04,
136.58, 138.22 (all aromat C), 156.65 (guanidine C), 171.73 (NH-
CO). HRMS (ESI, pos mode) m/z [M þ H]þ calcd for C26H35-
Cl2N4O6 569.1928; found 569.1917.
(Naphth-2-yl)methyl 2-(40-Aminobutyrylamido)-3-O-(40-chloro-
benzyl)-2-deoxy-6-O-methyl-β-D-glucopyranoside (8d-β). Resin
loaded glycoside 2b-β (80 mg resin, 0.37 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(4.6 mg, 29%). 1H NMR (600 MHz, DMSO-d6) δ 1.63-1.69 (m,
2H, NHCOCH2CH2CH2NH2(A,B), 2.03-2.22 (m, 2H, NH-
COCH2CH2CH2NH2), 2.76 (m, 1H, J = 7.6 Hz, NHCOCH2-
CH2CH2NH2 (A)), 3.10-3.17 (m, 1H, J=7.6 Hz, NHCOCH2-
CH2CH2NH2 (B)), 3.25 (s, 3H, OCH3), 3.27-3.59 (m, 4H, H-3,
H-4, H-5, H-6a), 3.67 (dd, 1H, JH5,H6b=0.5 Hz, JH6a,H6b=10.6
Hz, H-6b), 3.70-3.83 (m, 1H, H-2), 4.48 (d, 1H, JH1,H2=8.1 Hz,
H-1), 4.55 (d, 1H, JA,B = 11.7 Hz, OCH2(B)Ar1), 4.59 (d, 1H,
OCH2(B)Ar1), 4.70 (d, 1H, JA,B =12.7 Hz, OCH2(B)Ar2), 4.76
(d, 1H, JA,B = 11.7 Hz, OCH2(A)Ar1), 4.91 (d, 1H, OCH2-
(A)Ar2), 5.32 (d, 1H, JOH, H-4 = 6.7 Hz, OH-4(B)), 5.40-5.45
(m, 1H, OH-4(A)), 6.52 (bs,1H, NH2), 6.66 (m, 1H, NH2),
7.27-7.55 (m, 7H, aromat H), 7.79-7.95 (m, 4H, aromat H),
8.01 (d, 1H, JNH,H-2 = 9.1 Hz, C-2NH), 9.40 (bs, 1H, NH3).
HMBC (599.72 MHz/150.815 MHz, DMSO-d6) δ 23.73
(CH2CH2CH2)(A), 24.43 (CH2CH2CH2)(B), 32.28 (COCH2),
38.73 (H2NCH2), 52.32 (C-2), 58.42 (OCH3), 69.43 (OCH2-
Naph), 69.90 (C-4(B)), 70.49 (C-4(A)), 71.32 (C-6), 72.13
(OCH2Ar), 75.41 (C-5), 79.51 (C-3(B)), 82.21 (C-3(A)), 100.14
(H-1), 125.57, 125.69, 125.92, 127.56, 127.80, 128.85, 131.43,
131.55, 132.13, 132.37, 132.60, 135.30, 137.99 (all aromat C), 170.93
(NHCO)(A), 171.16 (NHCO)(B). HRMS (ESI, pos mode) m/z
[M þ H]þ calcd for C29H36Cl1N2O6 543.2256; found 543.2259.
(Naphth-2-yl)methyl 2-(30-Aminopropionylamido)-2-deoxy-
6-O-methyl-3-O-(naphth-2-yl)methyl-β-D-allopyranoside (8e-β).
Resin loaded glycoside 2f-β (80 mg resin, 0.3 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(2.1 mg, 16%). 1H NMR (500 MHz, DMSO-d6) δ 2.43-2.56 (m,
2H, NHCOCH2CH2NH2), 2.88 (t, 2H, J=6.8. Hz, NHCOCH2-
CH2NH2), 3.02-3.10 (dq, 2H, NHCOCH2CH2CH2NH2), 3.31
(s, 3H, OCH3), 3.54 (dd, 1H, JH5,H6 = 5.9 Hz, JH6a,H6b = 10.8
Hz, H-6a), 3.57-3.64 (m, 1H, H-4), 3.68 (d, 1H, JH5,H6b = 0.5
Hz, H-6b), 3.82 (m, 1H, H-2), 3..88-3.96 (m, 2 H, H-3, H-5),
(40-Chlorobenzyl) 3-O-(40-Chlorobenzyl)-2-deoxy-2-(40-guanidino-
butyrylamido)-6-O-methyl-β-D-glucopyranoside (9c-β). Resin
loaded glycoside 2d-β (80 mg resin, 0.34 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(8.8 mg, 57%). 1H NMR (600 MHz, DMSO-d6) δ 1.61-1.69 (m,
2H, NHCOCH2CH2CH2NH), 2.06-2.14 (m, 2H, NHCOCH2-
CH2CH2NH), 3.06 (q, 2H, NHCOCH2CH2CH2NH), 3.30 (s,
3H, OCH3), 3.20-3.30 (m, 2H, H-4, H-5), 3.43 (dd, 1H, H-3),
3.49 (dd, 1H, JH5,H6=4.2 Hz, JH6a,H6b=-10.7 Hz, H-6a), 3.64
(d, 1H, JH5,H6b =0.5 Hz, H-6b), 3.69 (m, 1H, H-2), 4.42 (d, 1H,
JH1,H2 =8.4 Hz, H-1), 4.51, (d, 1H, JA,B =12.7 Hz, OCH2(B)-
Ar1), 4.54 (d, 1H, JA,B = 11.8 Hz, OCH2(B)-Ar2), 4.73 (d, 1H,
OCH2(A)-Ar1), 4.77 (d, 1H, OCH2(A)-Ar2), 5.44 (d, 1H, JOH,H-4
=
4.3 Hz, OH-4), 7.28-7.46 (m, 8H, aromat H), 7.67 (bs, 1H, NH),
8.03 (d, 1H, JNH,H-2=9.1 Hz, C-2NH). HMBC (600 MHz/150.8
MHz, DMSO-d6) δ 24.55 (CH2CH2CH2), 32.05 (COCH2), 40.02
(H2NCH2), 53.73 (C-2), 58.42 (OCH3), 68.61 (OCH2Ar1), 69.78
(C-4), 71.31 (C-6), 72.13 (OCH2Ar2), 75.41 (C-5), 82.21 (C-3),
100.14 (C-1), 127.68, 128.03, 128.85, 131.43, 131.67, 131.78,
136.94, 137.88 (all aromat C), 156.63 (guanidino carbon), 171.40
(NH-CO). HRMS (ESI, pos mode) m/z [M þ H]þ calcd for
C26H35Cl2N4O6 569.1928; found 569.1935.
(Naphth-2-yl)methyl 3-O-(40-Chlorobenzyl)-2-deoxy-2-(40-guani-
dinobutyrylamido)-6-O-methyl-r-D-glucopyranoside (9d-R). Resin
loaded glycoside 2b-R (80 mg resin, 0.35 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(10.5 mg, 64%). 1H NMR (500 MHz, DMSO-d6) δ 1.59-1.68 (m,
2 H, NHCOCH2CH2CH2NH), 2.18 (t, 2H, J= 7.3. Hz, NHCO-
CH2CH2CH2NH2), 3.06 (q, 2H, NHCOCH2CH2CH2NH), 3.30
(s, 3H, OCH3), 3.38 (dd 1 H, H-4), 3.52 (dd, 1H, JH5,H6a=5.7 Hz,
JH6a,H6b =10.7 Hz, H-6a), 3.61 (dd, 1H, JH5,H6a =0.5 Hz, H-6b),
4.71, (d, 1H, JA,B=12.1 Hz, OCH2(B)-Ar1), 4.83 (d, 1H, JA,B
=
3.65 (dd, 1H, JH3,H4=8.8 Hz, JH2,H3=10.7 Hz, H-3), 3.72 (m, 1H,
H-5), 3.91 (ddd, 1 H, H-2), 4.63 (dd, 2H, OCH2(B)-Ar1,OCH2(B)-
Ar2), 4.76 (d, 1H, JH1,H2 = 3.4 Hz, H-1), 4.83 (t, 2H, OCH2(A)-
Ar1,OCH2(A)-Ar2), 5.46 (d, 1H, JOH,H-4 = 7.0 Hz, OH-4), 7.30-
7.38 (m, 4 H, aromat H), 7.49-7.57 (m, 3H, aromat H), 7.57-7.64
11.9 Hz, OCH2(B)-Ar2), 4.83 (d, 1H, JH1,H2=7.8 Hz, H-1), 4.92
(d, 1H, OCH2(A)-Ar1), 4.99 (d, 1H, OCH2(A)-Ar2), 5.32 (d, 1H,
JOH,H-4=5.5 Hz, OH-4), 7.46-7.55 (m, 5H, aromat H), 7.62 (d,
1 H, aromat. H), 7.66-7.78 (bs, 2H, NH2), 7.81-7.93 (m, 8 H,
aromat H), 8.28 (d, 1H, JNH,H-2 = 8.1 Hz, C-2NH). 13C NMR
(125.7 MHz, DMSO-d6) δ 31.78 (COCH2), 35.16 (H2NCH2),
52.65 (C-2), 58.53 (OCH3), 67.98 (OCH2Ar2), 70.02 (C-4), 71.89,
73.64, 74.41, 77.81, (3 sugar carbons, and (OCH2Ar1)), 98.42
(C-1), 125.67, 125.76, 125.80, 125.81, 125.94, 126.02, 126.18, 127.38,
127.40, 127.55, 127.59, 132.28, 132.60, 135.45, 136.42, (all
aromat. C), 156.61, 157.86 (TFAþ TFA-salt)), 169.00 (NHCO).
HRMS (ESI, pos mode) m/z [M þ H]þ calcd for C32H37N2O6
545.2646; found 545.2639.
(m, 1 H, NH), 7.86-7.95 (m, 4H, aromat H), 8.16 (d, 1 H, JNH,H-2
=
8.7 Hz, C-2NH). 13C NMR (125.7 MHz, DMSO-d6) δ 24.56
(CH2CH2CH2), 31.70 (COCH2), 40.34 (H2NCH2), 52.18 (C-2),
58.39 (OCH3), 68.22 (OCH2Ar2), 70.26 (C-4), 71.38 (C-6), 71.63
(C-5), 72.46 (OCH2Ar1), 79.64 (C-3), 96.11 (C-1), 125.83, 125.87,
126.13, 126.23, 127.44, 127.49, 127.73, 127.80, 128.92, 131.49,
132.36, 132.60, 135.05, 138.22 (all aromat C), 156.66 (guanidine
C), 171.71 (NH-CO). HRMS (ESI, pos mode) m/z [M þ H]þ calcd
for C30H38Cl1N4O6 585.2474; found 585.2466.
(40-Chlorobenzyl) 3-O-(40-Chlorobenzyl)-2-deoxy-2-(40-guanidino-
butyrylamido)-6-O-methyl-r-D-glucopyranoside (9c-R). Resin
loaded glycoside 2d-R (80 mg resin, 0.26 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(5.8 mg, 49%). 1H NMR (500 Hz, DMSO-d6) δ 1.60-1.70 (m,
2 H, NHCOCH2CH2CH2NH), 2.16 (t, 2H, J= 7.3. Hz, NHCO-
CH2CH2CH2NH2), 3.07 (q, 2H, NHCOCH2CH2CH2NH), 3.28
(Naphth-2-yl)methyl 3-O-(40-Chlorobenzyl)-2-deoxy-2-(40-guani-
dinobutyrylamido)-6-O-methyl-β-D-glucopyranoside (9d-β). Resin
loaded glycoside 2b-β (80 mg resin, 0.37 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(5.9 mg, 34%). 1H NMR (600 MHz, DMSO-d6) δ 1.61-1.72 (m,
2H, NHCOCH2CH2CH2NH), 2.06-2.16 (m, 2H, NHCOCH2-
CH2CH2NH), 3.07 (q, 2H, NHCOCH2CH2CH2NH), 3.32 (s, 3H,

Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15 5585
OCH3), 3.30-3.37 (m, 2H, H-4, H-5), 3.44 (dd, 1H, H-3), 3.51 (dd,
1H, JH5,H6 = 4.5 Hz, JH6a,H6b = 10.7 Hz, H-6a), 3.67 (d, 1H,
(15.7 mg, 749%). 1H NMR (500 MHz, DMSO-d6) δ 1.61-1.69
(m, 2 H, NHCOCH2CH2CH2NH), 2.15 (t, 2H, J=7.3. Hz, NH-
COCH2CH2CH2NH2), 2.86 (t, 2H, J= 6.9 Hz, NHCOCH2-
CH2CH2NH), 3.08 (q, 2 H, CH2-Ar1), 3.24 (s, 3H, OCH3), 3.32
(m, 1 H, H-4), 3.44 (dd, 1H, JH5,H6a = 5.8 Hz, JH6a,H6b = 10.7
Hz, H-6a), 3.47-3.57 (m, 3H, H-3, H-5, H-6b), 3.58-3.64 (m,
1H, OCH2CH2(A)), 3.73-3.80 (m, 1H, OCH2CH2(B)), 3.85
(ddd, 1 H, H-2), 4.61, (d, 1H, JA,B = 11.6 Hz, OCH2(B)-Ar2),
4.68 (d, 1H, JH1,H2 =3.5 Hz, H-1), 4.79 (d, 1H, OCH2(A)-Ar2),
5.41 (d, 1H, JOH,H-4=6.6 Hz, OH-4), 7.18-7.23 (t, 1 H, aromat
H),), 7.24-7.39 (m, 8H, aromat H), 7.62 (m, 1 H, NH), 7.90 (d,
1 H, JNH,H-2=8.8 Hz, C-2NH). 13C NMR (125.7 MHz, DMSO-
d6) δ 24.54 (CH2CH2CH2), 31.72 (COCH2), 35.02 (CH2Ar),
40.34 (H2NCH2), 52.13 (C-2), 58.30 (OCH3), 67.71 (OCH2Ar2),
70.18 (C-4), 71.27, 71.38, (C-5* C-6*), 72.41 (OCH2Ar1), 79.63
(C-3), 96.59 (C-1), 125.98, 127.79, 128.09, 128.70, 128.96,
131.49, 138.24, 138.65, (all aromat C), 156.69 (guanidine C),
171.66 (NH-CO). HRMS (ESI, pos mode) m/z [M þ H]þ calcd
for C27H38Cl1N4O6 549.2474; found 549.2473.
JH5,H6b =0.5 Hz, H-6b), 3.74 (m, 1H, H-2), 4.49 (d, 1H, JH1,H2 =
8.1 Hz, H-1), 4.51, (d, 1H, JA,B=11.8 Hz, OCH2(B)-Ar1), 4.69 (d,
1H, JA,B = 12.7 Hz, OCH2(B)-Ar2), 4.77 (d, 1H, OCH2(A)-Ar1),
4.91 (d, 1H, OCH2(A)-Ar2), 5.43 (d, 1H, JOH,H-4=5.5 Hz, OH-4),
7.27-7.44 (m, 5H, aromat H), 7.48-7.57 (m, 3H, aromat. H, NH-
CH2), 7.77-7.94 (m, 4H, aromat H), 8.03 (d, 1H, JNH,H-2=9.2Hz,
C-2NH). HMBC (600 MHz/150.8 MHz, DMSO-d6) δ 24.55
(CH2CH2CH2), 32.05 (COCH2), 40.02 (H2NCH2), 53.73 (C-2),
58.42 (OCH3), 69.43 (OCH2Ar1), 69.78 (C-4), 71.31 (C-6), 72.13
(OCH2Ar2), 75.29 (C-5), 82.21 (C-3), 100.02 (C-1), 125.45, 125.57,
125.69, 125.92, 127.33, 127.56, 127.68, 128.85, 131.43, 132.13,
132.60, 135.30, 137.99 (all aromat C), 156.51 (guanidino carbon),
171.40 (NH-CO). HRMS (ESI, pos mode) m/z [M þ H]þ calcd for
C30H38Cl1N4O6 585.2474; found 585.2469.
40-Chlorobenzyl 2-Deoxy-2-(40-guanidinobutyrylamido)-6-O-
methyl-3-O-(naphth-2-yl)methyl-r-D-glucopyranoside (9e-R). Resin
loaded glycoside 2d-R (80 mg resin, 0.26 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(7.9 mg, 65%). 1H NMR (600 MHz, DMSO-d6) δ 1.60-1.71 (m,
2 H, NHCOCH2CH2CH2NH), 2.15-2.24 (m, 2H, NHCOCH2-
CH2CH2NH2), 3.06 (q, 2H, NHCOCH2CH2CH2NH), 3.29 (s,
3H, OCH3), 3.41 (dd 1 H, H-4), 3.52 (dd, 1H, JH5,H6a = 5.8 Hz,
(Naphth-2-yl)methyl 2-Deoxy-2-(40-guanidinobutyrylamido)-
6-O-methyl-3-O-(naphth-2-yl)methyl)-r-D-glucopyranoside (9g-R).
Resin loaded glycoside 2b-R (80 mg resin, 0.35 mmol/g) was
carried through the solid phase synthetic process. The title pro-
duct was isolated by HPLC purification and MS detection as a
1
white solid (9.7 mg, 58%). H NMR (500 MHz, DMSO-d6) δ
J
H6a,H6b =10.7 Hz, H-6a), 3.60 (dd, 1H, JH5,H6a =0.5 Hz, H-6b),
3.64-3.72 (m, 2H, H-3, H-5), 3.94 (ddd, 1 H, H-2), 4.47 (d, 1H,
gem =12.6 Hz, OCH2(B)-Ar1), 4.67 (d, 1H, OCH2(A)-Ar1), 4.72
(d, 1H, JH1,H2 = 3.5 Hz, H-1), 4.81 (d, 1H, Jgem = 11.6 Hz,
OCH2(B)-Ar2), 4.99 (d, 1H, OCH2(A)-Ar2), 5.50 (d, 1H, JOH,H-4
1.59-1.70 (m, 2 H, NHCOCH2CH2CH2NH), 2.17-2.26 (m,
2H, NHCOCH2CH2CH2NH2), 3.05 (q, 2H, NHCOCH2CH2-
CH2NH), 3.32 (s, 3H, OCH3), 3.43 (dd 1 H, H-4), 3.54 (dd, 1H,
J
JH5,H6a=5.7Hz, JH6a,H6b=10.7 Hz, H-6a), 3.63 (dd, 1H, JH5,H6a=
=
0.5 Hz, H-6b), 3.69-3.79 (m, 2H, H-3, H-5), 3.96 (ddd, 1 H,
6.7 Hz, OH-4), 7.39-7.53 (m, 7H, aromat H), 7.56-7.64 (m, 1 H,
NH), 7.76-7.92 (m, 4H, aromat H), 8.20 (d, 1 H, JNH,H-2=8.5 Hz,
C-2NH). HMBC (600 MHz/150.8 MHz, DMSO-d6) δ 24.55
(CH2CH2CH2), 31.58 (COCH2), 40.13 (H2NCH2), 52.09 (C-2),
58.30 (OCH3), 67.21 (OCH2Ar1), 70.24 (C-4), 71.31 (C-6), 71.43
(C-5), 73.42 (OCH2Ar2), 79.51 (C-3), 96.15 (C-1), 124.63, 125.22,
125.57, 125.81, 127.33, 127.56, 129.20, 132.02, 132.13, 132.60, 132.72,
136.59, 136.82 (all aromat C), 156.516 (guanidine C), 171.75 (NH-
CO). HRMS (ESI, pos mode) m/z [M þ H]þ calcd for C30H38Cl1-
N4O6 585.2474; found 585.2466.
40-Chlorobenzyl 2-Deoxy-2-(40-guanidinobutyrylamido)-6-O-
methyl-3-O-(naphth-2-yl)methyl)-β-D-glucopyranoside (9e-β). Resin
loaded glycoside 2d-β (80 mg resin, 0.34 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid
(7.8 mg, 49%). 1H NMR (600 MHz, DMSO-d6) δ 1.61-1.69 (m,
2H, NHCOCH2CH2CH2NH), 2.10 (t, 2H, JA.B =7.1 Hz NHCO-
CH2CH2CH2NH), 3.04 (q, 2H, NHCOCH2CH2CH2NH), 3.32 (s,
3H, OCH3), 3.29-3.36 (m, 2H, H-4, H-5), 3.47-3.55 (m, 2H, H-3,
H-6a), 3.66 (d, 1H, JH6a,H6b=10.7 Hz, JH5,H6b=0.5 Hz, H-6b), 3.74
H-2), 4.65 (dd, 1H, Jgem=12.4 Hz, OCH2(B)-Ar1), 4.78 (d, 1H,
J
H1,H2 = 3.4 Hz, H-1), 4.82 (d, 1H, Jgem = 11.6 Hz, OCH2(B)-
Ar2), 4.86 (d, 1H OCH2(A)-Ar1), 5.00 (d, 1H, OCH2(A)-Ar2),
5.50 (d, 1H, JOH,H-4 = 7.0 Hz, OH-4), 7.44-7.64 (m, 7H, 6
aromat H, NH), 7.77-7.96 (m, 8H, aromat H), 8.22 (d, 1 H,
J
NH,H-2=8.7 Hz, C-2NH). 13C NMR (125.7 MHz, DMSO-d6) δ
24.58 (CH2CH2CH2), 31.74 (COCH2), 40.34 (H2NCH2), 52.27
(C-2), 58.41 (OCH3), 68.22 (OCH2Ar2), 70.35 (C-4), 71.43 (C-6),
71.68 (C-5), 72.45 (OCH2Ar1), 79.66 (C-3), 96.16 (C-1), 125.34,
125.80, 125.84, 125.865, 125.869, 125.91, 126.13, 126.229,
126.233, 127.32, 127.38, 127.44, 127.45, 127.50, 127.74, 132.21,
132.37, 132.61, 135.08, 136.86 (all aromat C), 156.66 (guanidine
C), 171.75 (NH-CO). HRMS (ESI, pos mode) m/z [M þ H]þ
calcd for C34H41N4O6 601.3021; found 601.3019.
Acknowledgment. The research described herein was in
part supported by a SmartFuturesFund fromthe Queensland
Government through a National and International Research
Alliances Program entitled: Application of Alchemia’s Drug
Discovery Platform (VAST) to discover new drug candidates
for selected G-Protein coupled receptors (GPCRs).
(m, 1H, H-2), 4.45 (d, 1H, JH1,H2=8.1Hz,H-1),4.52,(d,1H,JA,B
=
12.7 Hz, OCH2(B)-Ar1), 4.72-4.77 (m, 2H, OCH2(A)-Ar1, OCH2-
(B)-Ar2), 4.95 (d, 1H, JA,B =11.7 Hz, OCH2(A)-Ar2), 5.48 (d, 1H,
JOH,H-4=5.1 Hz, OH-4), 7.31 (d, 2 H, J=8.4 Hz, aromat. H), 7.39
(d, 2 H, J=8.4 Hz, aromat. H), 7.43-7.52 (m, 3H, aromat H), 7.67
(bs, 1H, NH-CH2), 7.78 (s, 1H, aromat H), 7.83-7.92 (m, 3H,
aromat H), 8.06 (d, 1H, JNH,H-2 = 9.1 Hz, C-2NH). HMBC (600
MHz/150.8 MHz, DMSO-d6) δ 24.55 (CH2CH2CH2), 32.05
(COCH2), 40.02 (H2NCH2), 53.73 (C-2), 58.42 (OCH3), 68.61
(OCH2Ar1), 69.90 (C-4), 71.31 (C-6), 73.18 (OCH2Ar2), 75.41 (C-
5), 82.21 (C-3), 100.26 (C-1), 125.34, 125.45, 125.69, 125.81, 127.45,
127.92, 128.85, 131.78, 132.13, 132.49, 132.60, 136.47, 136.71, 136.82
(all aromat C), 156.51 (guanidino carbon), 171.40 (NH-CO).
HRMS (ESI, pos mode) m/z [M þ H]þ calcd for C30H38Cl1N4O6
585.2474; found 585.2471.
Supporting Information Available: Experimental details for
the FKW tripeptide distance analysis, synthetic details of the
library synthesis, and NMR spectral data (1H, 13C or HMBC,
and COSY) for compounds 8d-R, 8d-β, 8e-β, 9c-R, 9c-β, 9d-R,
9d-β, 9e-R, 9e-β, 9f-R, and 9 g-r. This material is available free of
charge via the Internet at http://pubs.acs.org.
References
(1) Jones, R. M.; Boatman, P. D.; Semple, G.; Shin, Y. J.; Tamura,
S. Y. Clinically validated peptides as templates for de novo
peptidomimetic drug design at G-protein-coupled receptors. Curr.
Opin. Pharmacol. 2003, 3, 530–543.
(2) Hirschmann, R.; Nicalou, K. C.; Pietranico, S.; Salvino, J.; Leahy,
E. M.; Sprngeler, P. A.; Furst, G.; Amos B. Smith, I. Nonpeptidal
Peptidomimetics with a β-D-Glucose Scaffolding. A Partial Somatosta-
tin Agonist Bearing a Close Structural Relationship to a Potent, Selec-
tive Substance P Antagonist. J. Am. Chem. Soc. 1992, 114, 9217–9218.
(3) Hirschmann, R.; Yao, W.; Cascieri, M. A.; Strader, C. D.; Maechler,
L.; Cichy-Knight, M. A.; John Hynes, J.; van Rijn, R. D.; Sprengeler,
P. A.; Amos B. Smith, I. Synthesis of Potent Cyclic Hexapeptide
20-(Phenyl)ethyl 3-O-(40-Chlorobenzyl)-2-deoxy-2-(40-guanidino-
butyrylamido)-6-O-methyl-r-D-glucopyranoside (9f-R). Resin
loaded glycoside 2c-R (80 mg resin, 0.45 mmol/g) was carried
through the solid phase synthetic process. The title product was
isolated by HPLC purification and MS detection as a white solid

5586 Journal of Medicinal Chemistry, 2010, Vol. 53, No. 15
Abbenante et al.
NK-1 Antagonists. Use of a Minilibrary in Transforming a
Peptidal Somatostatin Receptor Ligand into an NK-1 Receptor
Ligand via a Polyvalent Peptidomimetic. J. Med. Chem. 1996,
39, 2441–2448.
Synthetic Approach towards Diversity Libraries using Monosac-
charide Scaffolds. J. Org. Chem. 2010, 75, 197–203.
(23) Rajaratnam, P. G., P.; Katavic, P.; Kuipers, K.; Huyh, N.; Ryan, S.;
Falzun, T.; Tometzki, G.; Bornaghi, L.; Thanh Le, G.; Abbenante, G.;
Liu, L.; Meutermans, W. W., N.; West, M. Orthogonally Protected
Monosaccharide Building Blocks for Solid Phase Production of Diver-
sity oriented Libraries. Aust. J. Chem. 2010, 63, 693–699.
(24) Xiao, X. Y.; Li, R.; Zhuang, H.; Ewing, B.; Karunaratne, K.; Lillig,
J.; Brown, R.; Nicolaou, K. C. Solid-phase combinatorial synthesis
using MicroKan reactors, Rf tagging, and directed sorting. Bio-
technol. Bioeng. 2000, 71, 44–50.
(4) Hirschmann, R.; , J. H., Jr.; Cichy-Knight, M. A.; van Rijn, R. D.;
Sprengeler, P. A.; Spoors, P. G.; Shakespeare, W. C.; Pietranico-
Cole, S.; Barbosa, J.; Liu, J.; Yao, W.; Rohrer, S.; Smith., A. B., III
Modulation of Receptor and Receptor Subtype Affinities Using
Diastereomeric and Enantiomeric Monosaccharide Scaffolds as a
Means to Structural and Biological Diversity. A New Route to
Ether Synthesis. J. Med. Chem. 1998, 41, 1382–1391.
(5) Liu, J.; Underwood, D. J.; Cascieri, M. A.; Rohrer, S. P.; Cantin,
L. D.; Chicchi, G.; Smith, A. B., III; Hirschmann, R. Synthesis of a
Substance P Antagonist with a Somatostatin Scaffold: Factors
Affecting Agonism/Antagonism at GPCRs and the Role of Pseudo-
symmetry. J. Med. Chem. 2000, 43, 3827–3831.
(6) Hirschmann, R.; Nicolaou, K.; Pietranico, S.; Leahy, E.; Salvino,
J. M.; Arison, B.; Cichy, M.; Spoors, P.; Shakespeare, W.; Sprengeler,
P.; Hamley, P.; Smith, A., III; Reisine, T.; Raynor, K.; Maechler, L.;
Donaldson, C.; Vale, W.; Freidinger, R. M.; Cascieri, M.; Strader,
C. D. De Novo Design and Synthesis of Somatostatin Non-Peptide
Peptidomometics Utilizing β-D-Glucose as a Novel Scaffolding.
J. Am. Chem. Soc. 1993, 115, 12550–12568.
(25) Dasgupta, P. Somatostatin analogues: multiple roles in cellular prolif-
eration, neoplasia, and angiogenesis. Pharmacol. Ther. 2004, 102, 61–85.
(26) Ferone, D.; Boschetti, M.; Resmini, E.; Giusti, M.; Albanese,
V.; Goglia, U.; Albertelli, M.; Vera, L.; Bianchi, F.; Minuto, F.
Neuroendocrine-immune interactions: the role of cortistatin/
somatostatin system. Ann. N.Y. Acad. Sci. 2006, 1069, 129–144.
(27) Tulipano, G.; Schulz, S. Novel insights in somatostatin receptor
physiology. Eur. J. Endocrinol. 2007, 156, S3–S11.
(28) Cervia, D.; Bagnoli, P. An update on somatostatin receptor
signaling in native systems and new insights on their pathophysiol-
ogy. Pharmacol. Ther. 2007, 116, 322–341.
(29) Guillermet-Guibert, J.; Lahlou, H.; Cordelier, P.; Bousquet, C.;
Pyronnet, S.; Susini, C. Physiology of somatostatin receptors.
J. Endocrinol. Invest. 2005, 28, 5–9.
(7) Hirschmann, R.; Sprengeler, P.; Kawasaki, T.; Leahy, J.; Shakespeare,
W.; Smith, A., III The versatile steroid nucleus: design and synthesis of
a peptidomimetic employing this novel scaffold. Tetrahedron 1993, 49,
3665–3676.
(30) Barnett, P. Somatostatin and somatostatin receptor physiology.
Endocrine 2003, 20, 255–264.
(8) Prasad, V.; Birzin, E. T.; McVaugh, C. T.; van Rijn, R. D.; Rohrer,
S. P.; Chicchi, G.; Underwood, D. J.; Thornton, E. R.; Smith, A.,
III; Hirschmann, R. Effects of Heterocyclic Aromatic Substituents
on Binding Affinities at Two Distinct Sites of Somatostatin Recep-
tors. Correlation with the Electrostatic Potential of the Substi-
tuents. J. Med. Chem. 2003, 46, 1858–1869.
(9) Abrous, L.; Hynes, J., Jr.; Friedrich, S. R.; Smith, A. B., III;
Hirschmann, R. Design and synthesis of novel scaffolds for drug
discovery: hybrids of beta-D-glucose with 1,2,3,4-tetrahydrobenzo-
[e][1,4]diazepin-5-one, the corresponding 1-oxazepine, and 2- and
4-pyridyldiazepines. Org. Lett. 2001, 3, 1089–1092.
(10) Hirschmann, R.; Ducry, L.; Smith, A. B., III Development of an
efficient, regio- and stereoselective route to libraries based on the
beta-D-glucose scaffold. J. Org. Chem. 2000, 65, 8307–8316.
(11) Angeles, A. R.; Neagu, I.; Birzin, E. T.; Thornton, E. R.; Smith,
A. B., III; Hirschmann, R. Synthesis and binding affinities of novel
SRIF-mimicking beta-D-glucosides satisfying the requirement for a
pi-cloud at C1. Org. Lett. 2005, 7, 1121–1124.
(31) Pissios, P.; Bradley, R. L.; Maratos-Flier, E. Expanding the scales:
The multiple roles of MCH in regulating energy balance and other
biological functions. Endocr. Rev. 2006, 27, 606–620.
(32) Wermter, A. K.; Reichwald, K.; Buch, T.; Geller, F.; Platzer, C.;
Huse, K.; Hess, C.; Remschmidt, H.; Gudermann, T.; Preibisch,
G.; Siegfried, W.; Goldschmidt, H. P.; Li, W. D.; Price, R. A.;
Biebermann, H.; Krude, H.; Vollmert, C.; Wichmann, H. E.; Illig,
T.; Sorensen, T. I.; Astrup, A.; Larsen, L. H.; Pedersen, O.; Eberle,
D.; Clement, K.; Blundell, J.; Wabitsch, M.; Schafer, H.; Platzer,
M.; Hinney, A.; Hebebrand, J. Mutation analysis of the MCHR1
gene in human obesity. Eur. J. Endocrinol. 2005, 152, 851–862.
(33) Guesdon, B.; Paradis, E.; Samson, P.; Richard, D. Effects of
intracerebroventricular and intra-accumbens melanin-concentrating
hormone agonism on food intake and energy expenditure. Am.
J. Physiol. Regul. Integr. Comp. Physiol. 2009, 296, R469–475.
(34) Gehlert, D. R.; Rasmussen, K.; Shaw, J.; Li, X.; Ardayfio, P.;
Craft, L.; Coskun, T.; Zhang, H. Y.; Chen, Y.; Witkin, J. M.
Preclinical evaluation of melanin-concentrating hormone receptor
1 antagonism for the treatment of obesity and depression. J. Phar-
macol. Exp. Ther. 2009, 329, 429–438.
(12) Meutermans, W.; Le, G. T.; Becker, B. Carbohydrates as scaffolds
in drug discovery. ChemMedChem 2006, 1, 1164–1194.
(35) Antal-Zimanyi, I.; Khawaja, X. The role of melanin-concentrating
hormone in energy homeostasis and mood disorders. J. Mol.
Neurosci. 2009, 39, 86–98.
(13) Becker, B.; Condie, G. C.; Le, G. T.; Meutermans, W. Carbohydrate-
based scaffolds in drug discovery. Mini Rev. Med. Chem. 2006, 6, 1299–
1309.
(36) Saito, Y.;Nagasaki, H. The melanin-concentrating hormone system and
its physiological functions. Results Probl. Cell Differ. 2008, 46, 159–179.
(37) Nahon, J. L. The melanocortins and melanin-concentrating hor-
mone in the central regulation of feeding behavior and energy
homeostasis. C. R. Biol. 2006, 329, 623-638; discussion 653-655.
(38) Harrold, J. A.; Halford, J. C. The hypothalamus and obesity.
Recent Pat. CNS Drug Discovery 2006, 1, 305–314.
(39) McBriar, M. D. Melanin Concentrating Hormone Receptor Anta-
gonists as Antiobesity Agents: From M2 to MCHR-1. Curr. Top.
Med. Chem. 2007, 7, 1440–1454.
(14) Jensen, K. J.; Brask, J. Carbohydrates as templates for control of
distance-geometry in de novo-designed proteins. Cell. Mol. Life
Sci. 2002, 59, 859–869.
(15) Opatz, T.; Kallus, C.; Wunberg, T.; Schmidt, W.; Henke, S.; Kunz,
H. D-Glucose as a multivalent chiral scaffold for combinatorial
chemistry. Carbohydr. Res. 2002, 337, 2089–2110.
(16) Cervi, G.; Peri, F.; Battistini, C.; Gennari, C.; Nicotra, F. Bicyclic
carbohydrate-derived scaffolds for combinatorial libraries. Bioorg.
Med. Chem. 2006, 14, 3349–3367.
(17) Hunger, U.; Ohnsmann, J.; Kunz, H. Carbohydrate scaffolds for
combinatorial syntheses that allow selective deprotection of all
four positions independent of the sequence. Angew. Chem., Int. Ed.
Engl. 2004, 43, 1104–1107.
(40) Luthin, D. R. Anti-obesity effects of small molecule melanin-
concentrating hormone receptor 1 (MCHR1) antagonists. Life
Sci. 2007, 81, 423–440.
(41) McBriar, M. D. Recent advances in the discovery of melanin-
concentrating hormone receptor antagonists. Curr. Opin. Drug
Discovery Dev. 2006, 9, 496–508.
(18) Gruner, S. A.; Locardi, E.; Lohof, E.; Kessler, H. Carbohydrate-
based mimetics in drug design: sugar amino acids and carbohydrate
scaffolds. Chem. Rev. 2002, 102, 491–514.
(42) Judd, A. S.; Souers, A. J.; Kym, P. R. Lead optimization of melanin
concentrating hormone receptor 1 antagonists with low hERG
channel activity. Curr. Top. Med. Chem. 2008, 8, 1152–1157.
(43) Rivera, G.;Bocanegra-Garcia, V.;Galiano, S.;Cirauqui, N.;Ceras, J.;
Perez, S.; Aldana, I.; Monge, A. Melanin-concentrating hormone
receptor 1 antagonists: a new perspective for the pharmacologic
treatment of obesity. Curr. Med. Chem. 2008, 15, 1025–1043.
(44) Kym, P. R.; Judd, A. S.; Lynch, J. K.; Iyengar, R.; Vasudevan, A.;
Souers, A. J. Lead optimization strategies and tactics applied to the
discovery of melanin concentrating hormone receptor 1 antago-
nists. Curr. Top. Med. Chem. 2007, 7, 1471–1488.
(45) Kowalski, T. J.; Sasikumar, T. Melanin-concentrating hormone
receptor-1 antagonists as antiobesity therapeutics: current status.
BioDrugs 2007, 21, 311–321.
(46) MacNeil, D. J.; Bednarek, M. A. MCH receptor peptide agonists
and antagonists. Peptides 2009, 30, 2008–2013.
(19) Murphy, P. V.; Bradley, H.; Tosin, M.; Pitt, N.; Fitzpatrick, G. M.;
Glass, W. K. Development of carbohydrate-based scaffolds for
restricted presentation of recognition groups. Extension to divalent
ligands and implications for the structure of dimerized receptors.
J. Org. Chem. 2003, 68, 5692–5704.
(20) Le, G. T.; Abbenante, G.; Becker, B.; Grathwohl, M.; Halliday, J.;
Tometzki, G.; Zuegg, J.; Meutermans, W. Molecular diversity
through sugar scaffolds. Drug Discovery Today 2003, 8, 701–709.
(21) Hobohm, U, S. C. Enlarged representative set of protein structures.
Protein Sci. 1994, 3, 522–524.
(22) Thanh, G. L.; Adamson, G.; Becker, B.; Clark, C.; Falzun,
G. C. T.; Grathwohl, M.; Gupta, P.; Hanson, M.; Huynh, N.;
Katavic, P.; Kuipers, K.; Lam, A.; Liu, L.; Mann, M.; Mason, J.;
McKeveney, D.; Muldoon, C.; Pearson, A.; Rajaratnam, P.; Ryan,
S.; Tometzki, G.; Verquin, G.; Waanders, J.; West, M.; Wilcox, N.;
Wimmer, N.; Yau, A.; Zuegg, J.; Meutermans., W. A Versatile