Discovery of Lu AA33810: A highly selective and potent NPY5 antagonist with in vivo efficacy in a model of mood disorder

Article abstract of DOI:10.1016/j.bmcl.2011.06.124

The structure-activity relationship of a series of tricyclic-sulfonamide compounds 11-32 culminating in the discovery of N-[trans-4-(4,5-dihydro-3,6- dithia-1-aza-benzo[e]azulen-2-ylamino)-cyclohexylmethyl]-methanesulfonamide (15, Lu AA33810) is reported. Compound 15 was identified as a selective and high affinity NPY5 antagonist with good oral bioavailability in mice (42%) and rats (92%). Dose dependent inhibition of feeding was observed after i.c.v. injection of the selective NPY5 agonist ([cPP^1-7,NPY^19-23,Ala ³¹,Aib³²,Gln³⁴]-hPP). In addition, ip administration of Lu AA33810 (10 mg/kg) produced antidepressant-like effects in a rat model of chronic mild stress.

Full text of DOI:10.1016/j.bmcl.2011.06.124

Bioorganic & Medicinal Chemistry Letters 21 (2011) 5436–5441
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Discovery of Lu AA33810: A highly selective and potent NPY5 antagonist
with in vivo efficacy in a model of mood disorder
Mathivanan Packiarajan a, , Mohammad R. Marzabadi a, Mahesh Desai a, Yalei Lu a, Stewart A. Noble a,
⇑
Wai C. Wong a, Vrej Jubian a, Gamini Chandrasena a, Toni D. Wolinsky b, Hualing Zhong b, Mary W. Walker b,
Ove. Wiborg c, Kim Andersen d
a Department of Chemical & Pharmacokinetic Sciences, Lundbeck Research USA, 215 College Road, Paramus, NJ 07652, USA
b Synaptic Transmission, Disease Biology Unit, Lundbeck Research USA, 215 College Road, Paramus, NJ 07652, USA
c Center for Psychiatric Research, Aarhus University Hospital, Aarhus, Denmark
d Neuroscience Drug Discovery DK, H. Lundbeck A/S, Ottiliavej 9, Denmark 2500 Copenhagen Valby, Denmark
a r t i c l e i n f o
a b s t r a c t
Article history:
The structure–activity relationship of a series of tricyclic-sulfonamide compounds 11–32 culminating in
the discovery of N-[trans-4-(4,5-dihydro-3,6-dithia-1-aza-benzo[e]azulen-2-ylamino)-cyclohexylmeth-
yl]-methanesulfonamide (15, Lu AA33810) is reported. Compound 15 was identified as a selective and
high affinity NPY5 antagonist with good oral bioavailability in mice (42%) and rats (92%). Dose dependent
Received 25 May 2011
Revised 27 June 2011
Accepted 29 June 2011
Available online 2 July 2011
inhibition of feeding was observed after i.c.v. injection of the selective NPY5 agonist ([cPP1–7,NPY19–23
,
Ala31,Aib32,Gln34]-hPP). In addition, ip administration of Lu AA33810 (10 mg/kg) produced antidepres-
sant-like effects in a rat model of chronic mild stress.
Keywords:
Tricyclic NPY5 antagonists
Aminothiazoles
Ó 2011 Elsevier Ltd. All rights reserved.
Lu AA33810
Inhibition of NPY5 agonist ([cPP1–7
NPY19–23,Ala31,Aib32,Gln34]-hPP)
induced feeding
,
Chronic mild stress (CMS)
Neuropeptide Y (NPY) is a 36 amino acid neuropeptide belong-
ing to the pancreatic polypeptide family. NPY is widely distributed
throughout the central and peripheral nervous systems1 and has
been demonstrated to modulate numerous physiological processes
such as: appetite,2–4 metabolism, and mood.5 It exerts its biological
effects via interaction with a family of specific membrane bound
GPCR’s. A total of five receptor subtypes have been cloned and
pharmacologically characterized (NPY Y1, Y2, Y4, Y5, and Y6).
The stimulation of feeding behavior by NPY is thought to occur
in part through activation of the hypothalamic NPY5 receptors.6,7
Therefore, antagonists of the NPY5 receptor were considered to
be potentially useful in controlling appetite. The NPY5 receptor is
also expressed in limbic regions8 which raises the possibility that
it could play a role in mood disorders as well. Recently two NPY5
antagonists from Merck and Shionogi, MK-05779a and Velneperit,9b
respectively, have advanced to human clinical trials. Both com-
pounds decreased body weight relative to placebo.
Benextramine 1 displays non-selective micromolar binding to
the NPY1 (Ki = 1.8 M) and NPY5 receptors (Ki = 5 M). In early
lead discovery efforts (data not shown), it was found that clipping
l
l
the molecule in half, via disulfide disconnection and capping with
O
H
N
H
N
S
N
H
S
N
H
1
, Benextramine
NPY5 Ki = 5 µM
O
H2N
N
H
N
H
N
N
N
H
H
N
S
S
O
O
O
O
2
, SNAP6608
NPY5 Ki = 32 nM
3
, CGP71683
NPY5 Ki = 1.4 nM
l
.inker
HN
S
The starting point for the medicinal chemistry effort described
herein was the weakly potent NPY receptor antagonist lead
benextramine (compound 1,10a,b Fig. 1).
N
R2
N
H
R1
linker
.
HN
S
N
R2
N
H
SO2
R1
X
4
11-32
X
⇑
Corresponding author. Tel.: +1 201 350 0313; fax: +1 201 261 0623.
E-mail address: matp@lundbeck.com (M. Packiarajan).
Figure 1. The evolution of tricyclic NPY5 antagonists.
0960-894X/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2011.06.124

M. Packiarajan et al. / Bioorg. Med. Chem. Lett. 21 (2011) 5436–5441
5437
O
H2N
a-b
NH2
c
BOC
S
N
H
BOC NH
BOC NH
OH
N
H
6a
5
7a
H
NH2
N
NH2
c
HN
NH2
S
BOC
N
linker
linker
BOC
N
S
CBZ
7c
, linker=(CH2)5
HN
H
H
6b-6f
7b-7f
7g
6b
6c
7b
,
linker=(CH2)4,
,
linker=(CH2)5,
,
linker=(CH2)4,
6d, linker=(CH2)6, 6e, linker=Z-cyclohexyl 7d, linker=(CH2)6, 7e, linker=Z-cyclohexyl
6f, linker=(CH2)2O(CH2)2
7f, linker=(CH2)2O(CH2)2
O
5
Br
4
6
7
R2
8
R2
R2
d
e-f
OH
3
XH
X
8a-e
X
2
O
9
1
9a
9b
8a
8b
, X=S, R2=H; , X=O, R2=H
, X=S, R2=H; , X=O, R2=H
9c, X=O, R2=8-OCH
8c, X=O, R2=m-OCH
9d, X=O, R2=9-OCH3
8d, X=O, R2=o-OCH 3
3
3
9e
, X=S, R2=7-F
8e
, X=S, R2=p-F
O
O
Br
F
F
f
9f
Scheme 1. Reagents and conditions: (a) (PhO)2P(O)N3, NEt3, BnOH; (b) H2/Pd, EtOAc, EtOH, RT, overnight, 94% for two steps; (c) PhC(O)NCS, RT, overnight, 74% then K2CO3,
MeOH, RT, overnight, 95%; (d) dihydrofuran-2(3H)-one, NaOMe, MeOH, reflux, overnight; (e) PPA, 100 °C, overnight, 52%, and (f) Br2, HBr in AcOH, AcOH, three steps >80%.
H
an aryl group, retained micromolar receptor affinity. It was also
H
N
N
linker
HN
linker
HN
N
N
found that the length and the rigidity of the linker between the
amines greatly influenced NPY5 binding. Furthermore, replace-
ment of the amine with a sulfonamide significantly enhanced
NPY5 receptor binding. The initial optimization efforts resulted in
the discovery of the high affinity NPY5 receptor antagonists 2,
SNAP660810c (NPY5 Ki = 32 nM) and 3, CGP7168311 (NPY5
Ki = 3 nM). Compound 2 was found to be a subtype-selective
NPY5 antagonist and did not display cross-reactivity when tested
against a panel of 18 GPCR targets. However, several issues were
identified with the compound (high in vitro clearance, low solubil-
ity and potent CYP3A4 inhibition) likely due to the high lipophilic-
ity (c Log P = 6.7). Conversely, compound 3 was shown to be
selective among the NPY subtypes. However, 3 was not selective
against a panel of 24 GPCRs and ion channels (serotonin uptake
Ki = 6.2 nM and muscarinic receptor Ki = 2.7 nM) and was thus
unusable as an NPY5 antagonist tool compound.12 We attributed
the cross-reactivity issues to the aminoquinazoline group of
a
b, c
SO2
R1
7a-7f + 9a-9f
S
BOC/CBZ
S
R2
R2
X
X
11-32 X = CH2, O and S
10
Scheme 2. Reagents and conditions: (a) DIEA, EtOH, reflux, overnight, 84%; (b) TFA,
60% if BOC, or H2/Pd, EtOAc, EtOH, RT, overnight if CBZ and (c) RSO2Cl, DIEA, CH2Cl2,
4 h, RT, 60-85%.
compound and high lipophilicity (c Log P = 5.91). SAR studies re-
lated to chemotype 2 and 3 results tetracyclic compounds 4 with
high NPY5 affinity.13 Optimization of tetracyclic scaffold 4 led to
identification of dihydrobenzo[2,3]thiepine analogs (11–32). Here-
in we describe our efforts to optimize
a tricyclic dihydro-
benzo[2,3]thiepine sulfonamide series13,14 (Fig. 1, Scheme 2)
leading to the discovery of the selective NPY5 antagonist 15 suit-
able for use in behavioral models of mood disorders.
Table 1
The in vitro NPY5 affinity and selectivity profiles of compounds 11-16
H
N
N
O
S
HN
S
O
R1
S
Compound
R1
hNPY5 Ki (nM)11,12,14
hNPY5 IC50 (nM)11,12,14
hNPY1,2,4 IC50 (nM)11,12,14
O
11
4.9 1.1
34.6 2.7
43.6 3.7
>1000
12
13.9 2.9
ND
N
S
13
14
21.5 5.3
1.9 0.3
10.4 1.3
3.8 0.5
ND
N
>1000
15
16
CH3
CH2CH3
1.5 0.1
2.8 0.8
1.8 0.2
30.8 0.3
>1000
>1000
For a description of the pharmacological assays (Ki, IC50 and hNPY1,2,4 cross-reactivity assays) see Refs. 11,12,14 The Ki and IC50 values are reported as an average SEM of
n P3 determinations. hNPY5 = human cloned NPY5 receptor; ND = not determined.

5438
M. Packiarajan et al. / Bioorg. Med. Chem. Lett. 21 (2011) 5436–5441
Table 2
SAR of tricyclic aminothiazole with variations of R2, X and R1 groups
R2
5
6
4
O
S
O
3
N
Linker
7
8
2
R1
S
1
X
Compound
R2
X
-Linker-
R1
hNPY5 Ki (nM)11,12,14
hNPY5 IC50 (nM)11,12,14
17
18
19
20
21
22
23
24
5-F
5-F
5-F
5-F
5-F
H
C
C
C
C
C
S
–HN(CH2)5NH–
–HN(CH2)5NH–
–HN(CH2)5NH–
–HN(CH2)5NH–
–HN(CH2)5NH–
–HN(CH2)5NH–
–HN(CH2)5NH–
–HN(CH2)5NH–
CH3
i-Pr
CH3
CH2CF3
CH2CH3
CH3
5.5 0.6
46 19
2.3 0.7
98.7 13.8
0.9 0.2
9.9 1.4
1.3 0.3
5.0 0.8
1.3 0.3
0.6 0.1
1.4 0.3
7.5 0.7
0.9 0.4
8.8 1.5
2.5 0.8
0.8 0.2
H
H
S
S
CH2CH3
CH2CH3
HN
NH
25
5-F
C
CH3
27
3
8.8 1.5
26
27
5-F
5-F
C
C
–HN(CH2)4NH–
–HN(CH2)2O(CH2)2NH–
CH2CF3
i-Pr
3.4 0.5
2.4 0.5
1.9 0.4
ND
NH
HN
28
6-OCH3
O
CH3
6.7 2.1
ND
NH
HN
29
30
7-OCH3
5-F
O
S
CH3
CH3
1.1 0.3
1.7 0.4
ND
ND
–HN(CH2)5NH–
HN
31
32
5-F
H
C
CH3
CH3
1.1 0.3
ND
HN
HN
O
16.1 3.0
3.9 0.9
HN
The Ki and IC50 values are reported as average SEM of n P3 determinations. hNPY5 = human cloned NPY5 receptor; ND = not determined.
The synthesis of tricyclic sulfonamide analogs 11–32 and their
intermediates are outlined in Schemes 1 and 2. The thiourea inter-
mediates 7a–7f and the a-haloketone analogs 9a–9f were synthe-
nanomolar affinities were realized with substituted phenyl isoster-
es. The NPY cross-reactivities at NPY1, NPY2, and NPY4 receptors
were periodically checked, and in general, excellent NPY subtype
selectivity was observed (Table 1). Compounds 11–32 were also
found to behave as antagonists in a FLIPR based calcium mobiliza-
tion assay (Tables 1 and 2). The R1 substituent was limited to small
alkyl groups as we examined the rest of the SAR including: differ-
ent linkers; X substitution; and the R2 group. This work is summa-
rized in Table 2.
It was shown that optimal affinity could be achieved with com-
pounds having a four to six carbon linker, in combination with a set
of small R1 (CH3, Et, i-Pr, CH2CF3) and R2 (H, F, OCH3) groups (com-
pounds 17–32). Reversal of the attachment points of the cyclo-
hexyl linker in compound 28 and placement of an O-heteroatom
in the linker, compound 27, was also well tolerated. All isosteres
where X = S, C or O were essentially equipotent at the NPY5 recep-
tor. The SAR of analogs 11–32 is summarized in Figure 2.
sized from either commercially available or custom-synthesized
starting materials as shown in Scheme 1. Curtius rearrangement15
of an N-protected amino acid 5 followed by hydrogenolysis gave
mono-protected diamine 6a. This was readily transformed to the
thiourea 7a via the reaction with benzoylisothiocyanate and
subsequent methanolysis. Reversing the sequence of the deprotec-
tion of the Curtius rearrangement product from N-protected
amino acid 5 using trifluoroacetic acid gave benzyl (trans 4-
(aminomethyl)cyclohexyl)carbamate which reacted with benzoy-
lisothiocyanate followed by methanolysis to afford compound 7g.
Similarly, commercially available mono N-Boc protected diamines
6b–6f were readily manipulated to give the analogous N-Boc
protected thiourea intermediates 7b–7f.
The
a-haloketone analogs 9a–9f were synthesized in a se-
quence of three steps in >80% yields. The reaction between a
substituted phenol or a substituted thiophenol with dihydrofu-
ran-2(3)-one gave the carboxylic acid intermediates 8a–8e. Acid
catalyzed intramolecular cyclization of compounds 8a–8e afforded
the fused cyclic ketones which were brominated to produce the
In order to triage compounds for the next tier of experiments,
several compounds that displayed reasonable NPY5 affinities were
screened in human and rat microsomal preparations and in single
dose pharmacokinetic experiments to determine brain and plasma
levels (10 mg/kg, po). Compound 15 displayed the best overall pro-
file, with moderate rat in vitro clearance and reasonable brain/
plasma levels at 4 h (Table 3) and was chosen for detailed analysis.
corresponding
a
-bromoketone compounds 9a–9e.14 Similarly the
compound 9f was prepared by bromination of the commercially
available 8-fluoro benzosuberone.
The compounds 11–32 were prepared as outlined in Scheme 2.
A condensation reaction between a-haloketone compounds 9a–9f
4-6 carbon linker is optimal
and N-BOC- or N-CBZ-protected thiourea linker analogs 7a–7f pro-
duced aminothiazole intermediates 10.14 Deprotection of the ami-
no group followed by reaction with an appropriate sulfonyl
chloride generated compounds 11–32 in moderate to good yields.
The SAR of the sulfonamide R1-group, depicted in Table 1, was
investigated keeping the tricyclic template and cyclohexyl linker
constant. Simple aliphatic substituents (15–16) were well toler-
ated. The naphthyl group (12) and polar imidazole (13) analogs
yielded compounds with reduced NPY5 affinities. However, low
R1 = alkyl and aryl groups are tolerated
5
6
R2
7
4
3
O
S
N
8
R1
Linker
X
S
O
1
8-X = O,C,S are tolerated
R2 = H, 5-F, 5-OCH3, 6-OCH3 groups are tolerated
Figure 2. SAR summary.

M. Packiarajan et al. / Bioorg. Med. Chem. Lett. 21 (2011) 5436–5441
5439
Table 3
Selected compounds in vitro metabolic clearance and rat plasma and brain exposure data with calculated properties
a
a
Compound
hClint (L/min)
rClint (mL/min)
[Plasma]b (ng/mL)
[Brain]c (ng/g)
MW (g/mole)
c Log P
14
15
23
24
30
6.9
2.5
ND
ND
6.8
120
40
ND
ND
89
8
10
460
0
2
140
491.7
423.6
425.6
411.6
415.6
6.0
4.3
5.0
3.9
4.0
320
14
2
61
a
The hClint and rClint are human (L/min) and rat (mL/min) intrinsic clearances, respectively, and the clearances were determined according Obach et al.,16 The rat and
human maximum liver blood flow corresponds to 20 mL/min and 1.5 L/min, respectively.
b
The single dose plasma PK was assessed at 10 mg/kg po in two animals at 4 h with averaged values are shown. Compound limit of quantification (LOQ) is 2 ng/mL.
The brain exposures were determined at the conclusion of the experiment at 4 h and the compound limit of quantification (LOQ) in the brain homogenate was 2 ng/g..
c
CYP2C19 and CYP2D6 (IC50 >10 l
M). Caco-217 permeability studies
Table 4
In vivo PK properties of Lu AA3381019
with compound 15 show good intrinsic permeability (Papp[A–B]
=
36.7 cm/s à 10À6) and low potential for Pgp substrate liability
Species
%F
CLp (L/h/kg)
Cmax
Tmax (h)
Vss (L/kg)
T1/2 (h)
(Papp[B–A] = 40.4 cm/s à 10À6
, B–A/A–B efflux ratio = 1.1). Com-
Rat
Mouse
92
42
1.1
0.3
288
126
1.9
1.3
3.3
3.6
6.3
8.2
pound 15 exhibited acceptable PK properties in rats and mice
(Table 4). The optimal rodent pharmacokinetic profile, selectivity
and good brain penetration, rendered Lu AA33810 a suitable tool
compound for further in vivo studies. Lu AA33810 did not inhibit
food intake in rats following a 24 h starvation period, consistent
with similar reports for other NPY5 antagonists. However, it
produced a dose dependent inhibition of centrally induced feeding
caused by the intracerebrovascular (i.c.v.) injection of the NPY5
selective agonist ([cPP1–7,NPY19–23,Ala31,Aib32,Gln34]-hPP) or (cPP)
(0.75 nmole in 0.9% saline) with an MED of 3 mg/kg po (Fig. 3).
These initial findings prompted a more extensive in vivo screening
of Lu AA33810. A summary of in vivo experiments that culminated
in the finding of efficacy with implications for mood disorders is
described elsewhere.18
%F = absolute oral bioavailability; CLp = plasma clearance (L/h/kg); Cmax = maximum
plasma concentration; Tmax = time to reach maximum plasma concentration (h);
Vss = volume of distribution at steady state (L/kg); T1/2 = plasma half-life (h).
vehicle
3 mg/kg
** p < .01
10 mg/kg
30 mg/kg
# p < .001
100
80
60
40
20
0
#
**
#
**
#
**
#
#
#
#
Significant inhibition of cPP-induced feeding by Lu AA33180 oc-
curred with pretreatment intervals of 1, 2, 4, and 6 h, but not at
24 h. The brain and plasma levels at each dose and time point
are shown in Table 5. No detectable brain and plasma levels were
observed at the 24 h time point consistent with the behavior. The
lowest estimated free brain levels (ꢀ0.4 nM, rat PPB = 99.4%) corre-
sponding with efficacy are consistent with the rat Y5 potency
(Ki = 1.4 nM).
#
#
1
2
4
6
24
hours post-treatment with Lu AA33810
Figure 3. Effects of Lu AA33810 on 1 h food intake in response to cPP.20 Results are
presented as mean 1-h food intake (g) SEM from 16–20 animals per group. Data
for each time point were expressed as percent of food intake relative to the
vehicle + cPP group and analyzed with one-way analysis of variance. The Newman–
Keuls test was used for post-hoc analysis.
The effect of Lu AA33810 in the chronic mild stress (CMS) test
of sucrose drinking was examined (Fig. 4). CMS model is consid-
ered to be a model of reward deficit or anhedonia and may also
capture motivational deficit or apathy. In this model, rats are ex-
posed to chronic stress (or non-stressful conditions) over a 5 week
period and sucrose consumption is measured at weekly intervals.
Stress-sensitive animals show a reduction in sucrose consumption
compared to nonstressed animals. Drug administration is then ini-
tiated and chronic stress is continued, with weekly sucrose con-
sumption measurements for a total of four weeks. Chronic stress
is associated with a robust decrease in sucrose drinking in approx-
imately 60% of animals, which are then selected for drug testing
throughout the remaining portion of the study. Drug-responders
are defined as stress-sensitive animals for which drug treatment
is associated with an increase sucrose drinking greater >10%.
Compound 15 (Lu AA33810) displayed high selectivity when
tested against a panel of 70 GPCR, transporter, channel and enzyme
targets, having closest cross-reactivity for h5HT2B (Ki = 245 nM)
and h5HT1A (Ki = 478 nM). The hERG IC50 of compound 15 was
determined to be >10 lM in a patch clamp cellular assay. Plasma
protein binding (PPB) data showed compound 15 was highly
bound, 99.4% and 98.2% in rat and human, respectively.
Lu AA33810 exhibited moderate inhibition of Cytochrome P450
CYP3A4 (IC50 = 4.1 lM) and was inactive against CYP1A2, CYP2C9,
Table 5
Rat plasma and brain exposure data of Lu AA33810 from dose dependent food intake study
Dose
3 mg/kg
[Plasma] (ng/mL)
10 mg/kg
[Plasma] (ng/mL)
159
260 58
141
46 38
30 mg/kg
[Plasma] (ng/mL)
Time (h)
[Brain] (ng/g)
[Brain] (ng/g)
[Brain] (ng/g)
1
2
4
6
54 24
87 38
52 22
30 36
0
54 24
87 38
52 22
30 36
0
3
179 32
244 54
172 32
124 46
0
267 42
337 178
519 185
181 305
0
288 24
319 81
643 312
401 181
0
8
24
0
Plasma (ng/ml)) and brain (ng/g tissue) concentration (mean SD) after 3, 10 and 30 mg/kg po dosing in 20% HP-b cyclodextrin suspension.

5440
M. Packiarajan et al. / Bioorg. Med. Chem. Lett. 21 (2011) 5436–5441
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**
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**
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6
4
Stress/Vehicle (n = 11)
Stress/Esc Responders (n = 10)
Stress/Lu Responders (n = 13)
2
Control/Vehicle (n = 12)
0
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W.; Dhanoa, D.; Islam, I.; Zhang, J.; Gluchowski, C. Bioorg. Med. Chem. Lett. 2000,
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0
1
2
3
4
Weeks of Treatment
Figure 4. Effect of Lu AA33810 in the chronic mild stress study in rats.21 Effects of
chronic treatment with vehicle (1 ml/kg), escitalopram (Esc, 5 mg/kg), or Lu
AA33810 (Lu, 10 mg/kg) on the consumption of 1% sucrose solution in rats exposed
to chronic mild stress.
12. Della Zuana, O.; Sadlo, M.; Germain, M.; Feletou, M.; Chamorro, S.; Tisserand,
F.; de Montrion, C.; Boivin, J. F.; Duhault, J.; Boutin, J. A.; Levens, N. Int. J. Obesity
2001, 25, 84.
13. Rueeger, H.; Gerspacher, M.; Buehlmayer, P.; Rigollier, P.; Yamaguchi, Y.;
Schmidlin, T.; Whitebread, S.; Nusslein-Hildesheim, B.; Nick, H.; Cricione, L.
Bioorg. Med. Chem. Lett. 2004, 14, 2451.
14. (a) Marzabadi, M.R.; Wong, W.C.; Noble, S.A. Patent US 6124331, 2000.; (b)
Marzabadi, M. R.; Wong, W. C.; Noble, S.A.; Desai, M.N. Patent WO
2000064880, 2000.; (c) Marzabadi, M.R.; Wong, W.C.; Noble, S.A.;
Buhlmayer, P.; Rueger, H.; Yamaguchi, Y.; Schilling, W. Patent WO
2001002379, 2001.
15. Shioiri, T.; Ninomiya, K.; Yamada, S. J. Am. Chem. Soc. 1972, 94, 6203; Ninomiya,
K.; Shioiri, T.; Yamada, S. Tetrahedron 1974, 30, 2151.
16. Obach, R. S.; Baxter, J. G.; Liston, T. E.; Silber, B. M.; Jones, B. C.; Macintyre, F.;
Rance, D. J.; Wastall, P. J. Pharmacol. Exp. Ther. 1997, 283, 46.
17. Yazdanian, M.; Glynn, S. L.; Wright, J. L.; Hawi, A. Pharm. Res. 1998, 15, 1490.
18. Walker, M. W.; Marzabadi, M. R.; Jubian, V.; Zhong, H.; Huang, X.; Wolinsky, T.
D.; Chandrasena, G.; Ping, X. L.; Edwards, T.; Patel, J. P. G.; Marsteller, D. M.;
Papp, M.; Overstreet, D.; Moore, N.; Zhang, X.; Gerald, C. P. G.; Craig, D. A. J.
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19. The animals (n = 2) were dosed at 1 and 2 mg/kg iv and po, respectively, in a
crossover manner following a 24 h washout. Both jugular and carotid artery
cannulated Sprague–Dawley male rats with averaged body weight of 200–
250 g were dosed with compound 15 dissolved in 20% beta cyclodextrin, pH
adjusted with methane sulfonic acid to afford a solution. The serial blood
samples consist of 12 time points were collected using an automated blood
sampling device (Dilab, Lund, Sweden) over a 24 h post dose period. The
plasma samples were collected by centrifugation of blood samples and the
plasma concentrations were determined using a tandom, Agilent 1100 HPLC
(Agilent Technologies, Palo Alto, CA) and a TSQ Quantum MS (ThermoFinnigan,
San Jose, CA) with Xcalibur software. The PK parameters were determined
performing noncompartmental analysis of plasma concentration-time profile
using WinNonlin 5.2 Software (Pharsight, Cary, NC)
Peripheral administration of escitalopram (Esc, 5 mg/kg ip twice a
day) significantly increased sucrose consumption in drug-respond-
ers after 1 week of dosing (Fig. 4) with a sustained effect though
week 4. Similarly, peripheral administration of Lu AA33810 (Lu,
10 mg/kg ip twice a day) significantly increased sucrose drinking
in drug responders with a significant effect after 2 weeks and a sus-
tained effect through week 4 (Fig. 4). These results for Lu AA33810
are in good agreement with results from an earlier chronic mild
stress study performed using a different experimental paradigm18
and further implicate a potential role for Y5 in modulation of stress
sensitivity.
In summary, template hopping and optimization of the known
NPY5 leads resulted in the discovery of compound 15, Lu
AA33180, (methanesulfonamide,-[[trans-4-[(4,5-dihydro[1] ben-
zothiepino[5,4-d]thiazol-2-yl)amino]cyclohexyl]methyl]-sulfon-
amide). Lu AA33180 has a good PK profile in rats and mice with
acceptable CNS exposure. Lu AA33180 showed an oral dose depen-
dent inhibition of a centrally induced cPP feeding effect but no
significant inhibition of feeding in a 24 h rat starvation model. In
the CMS study, Lu AA33810 normalized stress-induced deficits in
a manner resembling that of established antidepressants. Lu
AA33180 represents a good tool for exploring the role of the
NPY5 receptor in disease-relevant preclinical models.
20. Rats were obtained from Charles River Labs (Kingston, NY) with cannulae
implanted into the lateral cerebral ventricle. In order to achieve the number of
animals for statistical power, experiments were performed using two different
shipments of rats. Animals were dosed with either 20% cyclodextrin vehicle or
Lu AA33810 (3, 10, and 30 mg/kg) at 1, 2, 4, 6, or 24 h prior to i.c.v.
administration of cPP (0.6 nmol) and monitoring of food intake over the
following 1 h time period. Each of these 20 conditions (4 doses  5 time points;
n = 2/condition) was tested weekly on the same day, with 6–7 days intervening
between tests. The drug treatment received by a given animal was randomized
from week to week, as was the pretreatment time. Each animal was tested 4–5
times. Each week, brain and plasma samples were obtained from a parallel
satellite group of animals (n = 2/dose). Results are presented as mean 1-h food
intake (g) SEM from 16–20 animals per group. Data for each time point were
expressed as percent of food intake relative to the vehicle + cPP group and
analyzed with one-way analysis of variance. The Newman–Keuls test was used
for post-hoc analysis.
Acknowledgments
We thank Dahai Dong and Manual Cajina for providing the
DMPK bio-analytical support. We acknowledge Kiho Han and Noel
Boyle for the binding and the functional assays and Natalia Betan-
court for the preparation of the NPY cells. We also thank Dr. John
M. Peterson and Dr. Andrew D. White for their helpful discussions.
References and notes
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21. The stress protocol was performed as described previously by Jayatissa et al.22
Male SD rats, 200–250 g (at start of study) were acclimatized (singly housed)
for 1 week before the start of the stress period. Animals were not handled
during the acclimatization period (except for cage maintenance). During the
drug administration period, drugs were injected intraperitoneally twice a day,
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using an injection volume of 1.0 ml/kg and
hydroxypropylmethylcellulose (HPMC). The
a
vehicle of 0.25%
reference compound,
escitalopram (5 mg/kg) was dissolved by vortexing in vehicle. Lu AA33810
(10 mg/kg) was added to vehicle, sonicated for 30 min until a fine suspension
was formed and then injected as a suspension. Drug treatment groups were
composed of n = 25; drug responders (those showing increase in sucrose
consumption >10% after drug administration) were differentiated from
nonresponders. Only drug responders were included in the analysis. Values
7. Gerald, C.; Walker, M. W.; Criscione, L.; Gustafson, E. L.; Batzl-Hartmann, C.;
Smith, K. E.; Vaysse, P.; Durkin, M. M.; Laz, T. M.; Linemeyer, D. L.; Schaffhauser,

M. Packiarajan et al. / Bioorg. Med. Chem. Lett. 21 (2011) 5436–5441
5441
are the means SEM of n = 10–13 animals per group. All data were analyzed
using a one-way ANOVA followed by post hoc Fischer LSD tests for pairwise
comparisons of groups. Significant effect with escitalopram is evident after 1, 2,
3 and 4 weeks of treatment. For Lu AA33810 there is a significant effect after
4 weeks of treatment, after 2 and 3 weeks there is an obvious tendency to a
significant group effect. ⁄P <0.05; ⁄⁄P <0.01.
22. Jayatissa, M. N.; Bisgaard, C.; Tingstrom, A.; Papp, M.; Wiborg, O.
Neuropsychopharmacology 2006, 31, 2395.