N-Arylsulfonyl-α-amino carboxamides are potent and selective inhibitors of the chemokine receptor CCR10 that show efficacy in the murine DNFB model of contact hypersensitivity

Article abstract of DOI:10.1016/j.bmcl.2016.09.047

Compound 1 ((4-amino-3,5-dichlorophenyl)-1-(4-methylpiperidin-1-yl)-4-(2-nitroimidazol-1-yl)-1-oxobutane-2-sulfonamido) was discovered to be a 690 nM antagonist of human CCR10 Ca²⁺flux. Optimization delivered (2R)-4-(2-cyanopyrrol-1-yl)-S-(1H-indol-4-yl)-1-(4-methylpiperidin-1-yl)-1-oxobutane-2-sulfonamido (eut-22) that is 300 fold more potent a CCR10 antagonist than 1 and eliminates potential toxicity, mutagenicity, and drug–drug-interaction liabilities often associated with nitroaryls and anilines. eut-22 is highly selective over other GPCR's, including a number of other chemokine receptors. Finally, eut-22 is efficacious in the murine DNFB model of contact hypersensitivity. The efficacy of this compound provides further evidence for the role of CCR10 in dermatological inflammatory conditions.

Full text of DOI:10.1016/j.bmcl.2016.09.047

Bioorganic & Medicinal Chemistry Letters xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
N-Arylsulfonyl-
a-amino carboxamides are potent and selective
inhibitors of the chemokine receptor CCR10 that show efficacy in the
murine DNFB model of contact hypersensitivity
⇑
Asitha Abeywardane, Gary Caviness, Younggi Choi, Derek Cogan , Amy Gao, Daniel Goldberg,
Alexander Heim-Riether, Debra Jeanfavre, Elliott Klein, Jennifer A. Kowalski, Wang Mao, Craig Miller,
Neil Moss, Philip Ramsden, Ernest Raymond, Donna Skow, Lana Smith-Keenan, Roger J. Snow, Frank Wu,
Jiang-Ping Wu, Yang Yu
Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, CT 06877, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
Compound
1
((4-amino-3,5-dichlorophenyl)-1-(4-methylpiperidin-1-yl)-4-(2-nitroimidazol-1-yl)-1-
oxobutane-2-sulfonamido) was discovered to be a 690 nM antagonist of human CCR10 Ca2+ flux.
Optimization delivered (2R)-4-(2-cyanopyrrol-1-yl)-S-(1H-indol-4-yl)-1-(4-methylpiperidin-1-yl)-1-
oxobutane-2-sulfonamido (eut-22) that is 300 fold more potent a CCR10 antagonist than 1 and elimi-
nates potential toxicity, mutagenicity, and drug–drug-interaction liabilities often associated with nitroar-
yls and anilines. eut-22 is highly selective over other GPCR’s, including a number of other chemokine
receptors. Finally, eut-22 is efficacious in the murine DNFB model of contact hypersensitivity. The effi-
cacy of this compound provides further evidence for the role of CCR10 in dermatological inflammatory
conditions.
Received 29 June 2016
Revised 15 September 2016
Accepted 16 September 2016
Available online xxxx
Keywords:
CCR10
CCL27
Psoriasis
Ó 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://
creativecommons.org/licenses/by/4.0/).
Contact hypersensitivity
Structural alerts
The control of T cell homing to different tissues during inflam-
mation is the result of the interplay of selectins, integrins and che-
mokine receptors (CCRs), resulting in the direction of distinct T cell
subsets to specific inflammatory sites1,2 The chemokine receptor
CCR10 plays an important role in the migration of skin-homing
memory T-cells to the skin3,4 through activation by the chemokine
CCL27/CTACK or to mucosal epithelia through activation of CCL28.5
Both CCR10 and CCL27 are associated with inflammatory skin dis-
eases such as allergic contact dermatitis and psoriasis.6–8 Notably,
interruption of the CCL27–CCR10 interaction with anti-CCL27 anti-
bodies suppresses allergen-induced skin inflammation.6 These
reports suggest disruption of the CCL27–CCR10 interaction may
be a promising treatment for inflammatory skin diseases. However,
the impact of blocking CCR10 directly on inflammation in the skin
has not been reported. Indeed, there are contradictory reports of
whether CCR10 antagonism is sufficient for a robust anti-inflam-
matory response, or whether intervention at other signaling path-
ways is also required.9–12 We embarked on a program to discover
and optimize selective small molecule antagonists of CCR10 and
to elucidate the role of CCR10 in inflammatory skin diseases.
Herein we describe the discovery and optimization of potent
CCR10 antagonists that further demonstrate efficacy in a murine
model of contact hypersensitivity.
We began by screening for inhibitors of the CCL27 dependent
Ca2+ flux in CHO-K cells stably transfected with both human
CCR10 and aequorin.13 Our screen identified compound 1 with a
CCR10 IC50 of 690 nM. Compound 1 (Fig. 1) also demonstrated fur-
ther functional CCR10 antagonism by inhibiting the CCL27 depen-
dent chemotaxis of Ba/F3 cells stably transfected with human
CCR10 with an IC50 of 53 nM. However, 20 lM of 1 exhibited no
N
NO2
N
O O
S
Cl
N
N
H
O
H2N
Cl
1
⇑
Corresponding author. Tel.: +1 203 791 6187.
E-mail address: derek.cogan@boehringer-ingelheim.com (D. Cogan).
Figure 1.
http://dx.doi.org/10.1016/j.bmcl.2016.09.047
0960-894X/Ó 2016 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Please cite this article in press as: Abeywardane, A.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.09.047

2
A. Abeywardane et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
antagonism of murine CCL27 dependent Ca2+ flux in CHO-K cells
stably transfected with murine CCR10 despite 88% sequence iden-
tity (90% homology) between human and murine CCR10.
Compound 1 also contains at least two structural alerts associ-
ated with toxicity in the nitro group and the aniline.14 We began
optimization efforts by establishing SAR trends that could avoid
the nitro and aniline. Meanwhile, we tracked our progress against
the murine receptor to establish whether functional probes for
murine models of skin inflammation would emerge.
N
O
N
a
R
R
O
S
Br
Cl
42 a R = H; 6-substituted
43a-f
b
c
d
e
R = H; 4-substituted
R = Me; 4-substituted
R = Boc; 7-substituted
R = H; 5-substituted
The synthesis of compounds 1–38 are summarized in Schemes
f R = Boc; 5-substituted
1–3, and have been described elsewhere.15 Bromide 39 was pre-
pared from c
-aminobutyrolactone via the published procedure.16
Scheme 2. Reagents and conditions: (a) NaH (R = H only), -tBuLi, saturated SO2 in
THF, then NCS (23–78%).
Imidazole, 2-nitroimidazole, 2-chloroimidazole, pyrazole, 1,2,3-tri-
azole, 1,2,4-triazole, 2-cyanopyrrole, and pyrrole were alkylated
with 39 to provide 40a–i, with 1,2,3-triazole generating a separa-
ble mixture of 40e and 40f in a 2:1 ratio. The final products were
prepared from N-Boc-amino acids 41a–o via amide coupling with
4-methylpiperidine, followed by Boc removal, and treatment of
the resulting amine with the appropriate sulfonyl chloride in the
presence of an acid scavenger. The homophenylalanine compounds
R-10 and S-10 were respectively prepared from commercially
available (R)- and (S)-Boc-homophenylalanine. 41l, 41m, and 41n
were prepared via Strecker chemistry as described previously.17
The sulfonyl chlorides used to prepare 15, 16, 17, 23, and 24
were obtained from commercial vendors. 4-Amino-3,5-
dichlorobenzene-sulfonyl chloride and 3-amino-2,4-dimethylben-
zenesulfonyl chloride were prepared by chlorosulfonylation of
2,6-dichloroaniline and 2,6-dimethylanline respectively. The
indolesulfonyl chlorides (43a–f) were prepared from the corre-
sponding bromoindole via bromine-halogen exchange with t-
butyllithium followed by quenching with saturated SO2 in THF
(Scheme 2). The resulting lithium sulfinate was then oxidized to
N
N
N
O
N
O
O
a, b, c
O O
S
O
OH
O
N
H
R2
N
H
Cl
*
*
45 R2 =
46 R2 =
44
H2N
HN
Cl
Br
R1
a, b
c, d
O
O
O
OH
N
N
O
N
H
O
N
H
O
O
O O
d
40 a-i
S
R3
39
R2
N
H
O
R1
R1
45:
46:
25, 27, 30, 32, 34, 36, 37
26, 28, 29, 31, 33, 35, 38
e
O O
S
N
N
H2N
R2
N
Scheme 3. Reagents and conditions: (a) HCl (66–100%); (b) R2-SO2Cl, base (45: 67%,
46: 66%); (c) NaOH; (d) HATU, base, R3-amine; or EDC, HOBt, R3-amine (23–51%).
H
O
O
41 a R1 = 2-nitroimidazol-1-yl
1-24
b
c
d
e
R1 = imidazol-1-yl
R1 = 2-cyanoimidazol-1-yl
R1 = 2-chloroimidazol-1-yl
R1 = 1,2,3-triazol-1-yl
the sulfonyl chloride with NCS. In some cases, the indole was pro-
tected as a Boc carbamate. In these cases, the final sulfonamide
product was treated with HCl in dioxane to provide the product.
The synthesis of amide analogues is illustrated in Scheme 3. The
Boc group of 44 is removed under acidic conditions, and reaction
with sulfonyl chlorides followed by saponification delivered 45
and 46. Amide coupling with HATU or EDC/HOBt then delivered
amide analogues 25–38.
f R1 = 1,2,3-triazol-2-yl
g
R1 = 1,2,4-triazol-1-yl
R1 = pyrazol-1-yl
h
i
R1 = pyrrol-1-yl
j
k
l
m
n
o
R1 = R-phenyl
R1 = S-phenyl
R1 = 2-chlorophenyl
R1 = 5-cyanopyrazol-1-yl
R1 = 5-chloropyrazol-2-yl
R1 = 2-cyanopyrrol-1-yl
We began to find replacements for the nitroimidazole by
assessing whether the nitro group was necessary for CCR10
potency (Table 1). While the nitro group improves potency over
the unsubstituted imidazole 2, it can be replaced with either cyano
or chloro (cf. 3 and 4 to 1). By exploring replacements to the imi-
dazole, we also discovered that the imidazole is not ideal. In the
absence of a 2-subtituent, a distally disposed aza group (analogous
to the imidazole 3-position as with 2, 5 and 7) is detrimental to
Scheme 1. Reagents and conditions: (a) R1-H, NaH (40–100%); (b) NaOH, water,
MeOH/dioxane (48–100%); (c) 4-methylpiperidine, EDC, HOBt, or 4-methylpiper-
idine, HATU, trialkylamine (30–100%); (d) HCl or TFA (73–100%); (e) R2SO2Cl,
trialkylamine (20–100%).
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A. Abeywardane et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
3
Table 1
Structure–activity relationships for modifications at R1
R1
O
O
Cl
S
N
N
H
O
H2N
Cl
a
a
a
Compound
R1
Human CCR10 pIC50
6.2 0.2
Chemotaxis CCL27 pIC50
7.3 [7.0, 7.5]
Murine CCR10 pIC50
N
N
N
N
N
NO2
1
<4.7
N
*
2
3
4
<4.7b
N
*
6.3 [6.0, 6.5]
6.3 [6.2, 6.5]
N
N
*
Cl
6.6 (n = 1)
<4.7
N
*
N
5
6
7
<4.7
N
*
N
N
N
5.5 [5.4, 5.5]
<4.7
5.9 (n = 1)
*
N
N
N
N
*
N
*
8
9
5.8 [5.8, 5.9]
5.9 [5.7, 6.0]
N
5.4 (n = 1)
*
*
*
R-10
S-10
6.2 [6.2, 6.2]
<5.0
6.3 (n = 1)
<5.0
5.0 [4.9, 5.0]
11
6.9 [6.8, 7.1]
Cl
N
N
N
N
12
13
14
7.2 [7.1, 7.3]
6.6 [6.6, 6.7]
7.7 0.2
5.5 [5.4, 5.6]
*
Cl
N
*
N
N
7.8 0.3
5.8 0.2
*
a
Average SD when P3 replicates, a range is shown when 2 replicates.
pIC50 from fluorescence imaging assay under the same conditions and in the same CHO-K cell line as the chemiluminescent assay.
b
potency. Compounds lacking the 3-aza substituent (e.g. 6, 8, 9 and
phenyl (11), pyrazole (12, 13), and pyrrole (14) improved poten-
cies to levels comparable to or greater than the imidazoles 1, 3
and 4.
10) have potency in the range of 0.6–4
lM. As with the imidazole,
the presence of a chloro or cyano adjacent to the chain linkage on
Please cite this article in press as: Abeywardane, A.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.09.047

4
A. Abeywardane et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
The enantiomerically pure homophenyalanine analogs R-10 and
sulfonamides with a cyanopyrrole at R1, but none were more
potent than 14. However, anilines were disproportionately repre-
sented among the most potent compounds. While only four exam-
ples in the array contained anilines,19 14 and three additional
anilines were among the ten compounds pIC50’s of P7 (Table 2;
16, 17, and 18; see Fig. S-1 in the Supplementary Material). More-
over, because anilines were among the only polar functional
groups tolerated in this region, these same anilines were among
the compounds with the highest lipophilic efficiencies
(LiPE = LLE = pIC50 ꢀ logD). Higher LiPE’s are associated with
S-10 demonstrate a strong stereospecificity for CCR10 antagonism
that was also observed for the enantiomer pairs of 1 (pIC50’s of 6.3
vs <4.7) and 14 (pIC50’s of 8.1 vs 4.8).
We discovered chlorophenyl 11, chloropyrazole 13 and
cyanopyrrole 14 that effectively bypass the concerns of the
nitroimidazole while significantly improving potency over 1. While
modifications in this region did not improve the murine/human
selectivity factor, murine potencies improved as the potencies for
the human receptor improved.
Similar to R1, the sulfonamide substituent (R2) of 1 presented a
need to establish SAR, optimize potency, and contend with an
undesirable structural feature. In this case, the structural feature
is an aniline that could be associated with hepatotoxicity, carcino-
genicity, and drug–drug interactions.18 We prepared >100 diverse
improved drug-likeness and
activity.20,21
a lower potential for off-target
In order to capitalize on the apparent potency contribution of
the anilines while mitigating their potential liabilities, we hypoth-
esized that indoles would have similar hydrogen-bond donating
Table 2
Structure–activity relationships for modification of the sulfonamide (R2)
N
N
O
O
S
N
R2
N
H
O
a
a
a
Compound
R2
Cl
Human CCR10 pIC50
7.7 0.2
Chemotaxis CCL27 pIC50
7.8 0.3
Murine CCR10 pIC50
5.8 0.2
*
14
H2N
Cl
*
15
16
5.9 0.2
<4.7 (n = 1)
NH2
*
7.4 [7.4, 7.5]
Cl
Cl
Cl
*
17
18
19
7.2 [7.1, 7.3]
7.0 [6.8, 7.2]
6.7 [6.7, 6.8]
H2N
H2N
Cl
*
7.1 [7.0, 7.1]
7.9 0.1
*
N
H
H
N
20
21
6.6 (n = 1)
5.1 (n = 1)
*
H
N
*
*
8.1 0.1
7.8 0.1
9.0 0.3
6.0 0.2
rac-22
eut-22
dis-22
8.7 0.2
9.0 [8.9, 9.1]
5.5 0.1
7.2 0.2
7.6 [7.4, 7.9]
4.8 [4.7, 4.8]
HN
N
*
23
6.9 [6.6, 7.1]
5.2 0.1
*
24
7.3 0.1
a
Average SD when P3 replicates, a range is shown when 2 replicates.
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A. Abeywardane et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
5
and electron-donating properties to the anilines without the
propensity for bioactivation to reactive species. As there did not
appear to be a strongly favored aniline geometry, a variety of
indole sulfonamides were prepared (Table 2). Two 5-yl and 7-yl
indole analogues (19 and 20) are less potent than the most similar
anilines. In contrast, 21 and 22 are more potent than the most clo-
sely related aniline (18). The NH of 22 seems to play a significant
role in its potency as the N-methyl indole 23 is ꢁ70-fold less
potent than rac-22 but is similarly potent to its isostere naphthyle-
nesulfonamide 24.
The combination of the indole with the cyanopyrrole in 22 sub-
stantially improved potency compared to compound 1 and elimi-
nated the risks associated with both the nitroimidazole and the
aniline found in 1. The resolved enantiomers of 22 demonstrate
stereospecificity for CCR10 antagonism consistent with the
homophenylalanine analogue 10. While the shift in potency
between the human and murine receptors persists, the potency
gains achieved in eut-22 translate to murine receptor antagonism
as well, bringing murine potency to a level sufficient for testing
in vivo.
potent. Examples in Table 3 illustrate the general observation that
the 4-methyl substituent imparts potency not observed with larger
(27 and 28) or more polar (29) piperidine 4-substituents. The
placement of the methyl substituent on the piperidine ring is also
important (30–33). In addition, the piperidine amide is superior to
the homologated ring (34 and 35) and truncated ring amides (eg.
36).
We characterized key compounds for further evidence that the
functional effects on Ca2+ flux and chemotaxis are a consequence of
direct interaction with CCR10 (Table 4). Compound 14 competi-
tively and reversibly binds CCR10 with an IC50 of 3.4 nM, as
detected in an immunochemical binding assays with Fc-CCL27
fusion. These compounds also inhibit the Ca2+ flux stimulated from
the other known chemokine ligand of CCR10, CCL28/MEC as deter-
mined from both fluorescent (FLIPRTM) and chemiluminescent read-
outs. Both 14 and 22 affect CCR100s coupling with G-protein as
detected in a GTP-binding assay (GTP-Eu).22 Compounds 14 and
22 also inhibit CCL27 dependent cAMP production in CCR10 trans-
fected HEK cells. No meaningful binding or activity was observed
against 29 GPCR’s, including six chemokine receptors (Table 5 in
the Supplementary Material). The consistency of the various func-
tional readouts (Ca2+ flux, cAMP production, GTP binding,
and chemotaxis) across three cell backgrounds (CHO-K, HEK, and
New opportunities were not revealed with modification of the
methylpiperidine amide. Among the R3 amide analogues of 14
and 22 we explored, the 4-methylpiperidine remained the most
Table 3
Structure–activity relationships for modification of the amide (R3)
Cl
*
N
N
O
A R2 =
H2N
Cl
O
O
S
R3
R2
N
HN
*
H
B R2 =
R3
R2 = ACompound
Human CCR10 pIC50
7.7 0.2
R2 = BCompound
Human CCR10 pIC50
8.7 0.2
a
a
14
rac-22
N
N
*
*
25
27
6.8 [6.6, 6.9]
6.4 [6.3, 6.5]
26
28
8.0 [8.0, 8.0]
8.0 0.2
CF3
OH
N
*
29
6.9 [6.9, 7.0]
N
N
N
*
*
*
30
32
34
6.1 [6.0, 6.1]
6.2 [6.1, 6.3]
6.6 [6.6, 6.6]
31
33
35
7.7 [7.7, 7.7]
7.2 [7.1, 7.2]
7.6 [7.5, 7.7]
N
*
36
37
<5.0 (n = 1)
<5.0 (n = 3)
N
N
*
*
38
5.4 0.1
a
Average SD when P3 replicates, a range is shown when 2 replicates.
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6
A. Abeywardane et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
Table 4
Summary of CCR10 antagonism data for select compounds
Assay
Cell line
Agonist/probe
Compound
1
14
rac-22
Competition binding pIC50
FLIPR Ca2+ flux pIC50
FLIPR Ca2+ flux pIC50
Aequorin Ca2+ flux pIC50
Aequorin Ca2+ flux pIC50
cAMP pIC50
HEK membrane prep
hCCL27-Fc
hCCL27
hCCL28
hCCL27
hCCL28
hCCL27
hCCL27
hCCL27
8.5
CHO-K (Aequorin, G
CHO-K (Aequorin, G
CHO-K (Aequorin, G
CHO-K (Aequorin, G
HEK
a
q)
q)
q)
q)
6.6 0.3
6.1 0.1
6.2 0.2
6.1 0.1
8.7 0.2
7.9 0.3
7.7 0.2
7.9 0.1
6.8
9.4 0.2
8.9 0.2
8.7 0.2
9.0 [8.9, 9.1]
7.6
a
a
a
GTP-Eu pIC50
Chemotaxis pIC50
HEK membrane prep
Ba/F3
7.7
7.9 0.3
8.0
9.0 0.3
7.3 [7.1, 7.4]
pIC50s are average SD when P3 replicates, a range is shown when 2 replicates, otherwise data from a single test occasion.
potential toxicity, mutagenicity, and drug–drug-interaction liabili-
ties that can be associated with nitroaryls and anilines. Compound
eut-22 is highly selective for CCR10 over other GPCR’s, including a
number of other chemokine receptors. Finally, eut-22 is efficacious
in a murine model of DNFB contact hypersensitivity. The efficacy of
this compound provides further evidence for the role of CCR10 in
dermatological inflammatory conditions. These small molecule
inhibitors may also be valuable in interrogating the role of CCR10
in mucosal inflammation (e.g. asthma)26 and cancer.5
Supplementary data
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.bmcl.2016.09.
047.
References and notes
1. Butcher, E. C.; Picker, L. J. Science 1996, 272, 60.
2. Kupper, T. S.; Fuhlbrigge, R. C. Nat. Rev. Immunol. 2004, 4, 211.
3. Williams, I. R. Immunol. Res. 2004, 29, 283.
4. Fu, Y.; Yang, J.; Xiong, N. J. Immunol. 2016, 196, 4859.
5. Xiong, N.; Fu, Y.; Hu, S.; Xia, M.; Yang, J. Protein Cell 2012, 3, 571.
6. Homey, B.; Alenius, H.; Muller, A.; Soto, H.; Bowman, E. P.; Yuan, W.; McEvoy,
L.; Lauerma, A. I.; Assmann, T.; Bunemann, E.; Lehto, M.; Wolff, H.; Yen, D.;
Marxhausen, H.; To, W.; Sedgwick, J.; Ruzicka, T.; Lehmann, P.; Zlotnik, A. Nat.
Med. 2002, 8, 157.
Figure 2. eut-22 but not dis-22 is efficacious in the DNFB model of murine contact
hypersensitivity when dosed at 100 mg/kg ip bid. Inhibition of the DNFB stimulated
inflammatory response in sensitized Balb-C mice. The readout is ear swelling 24 h
after stimulation with DNFB solution. aVehicle control. bBackground. cCsA:
cyclosporine A⁄⁄q < 0.05.
7. Campanati, A.; Goteri, G.; Simonetti, O.; Ganzetti, G.; Giuliodori, K.;
Stramazzotti, D.; Morichetti, D.; Bernardini, M. L.; Mannello, B.; Fabris, G.;
Offidani, A. Br. J. Dermatol. 2007, 157, 1155.
8. Hijnen, D.; De Bruin-Weller, M.; Oosting, B.; Lebre, C.; De Jong, E.; Bruijnzeel-
Koomen, C.; Knol, E. J. Allerg. Clin. Immunol. 2004, 113, 334.
9. Fujimoto, S.; Uratsuji, H.; Saeki, H.; Kagami, S.; Tsunemi, Y.; Komine, M.;
Tamaki, K. Cytokine 2008, 44, 172.
10. Mirshahpanah, P.; Li, Y. Y.; Burkhardt, N.; Asadullah, K.; Zollner, T. M. Exp.
Dermatol. 2008, 17, 30.
11. Reiss, Y.; Proudfoot, A. E.; Power, C. A.; Campbell, J. J.; Butcher, E. C. J. Exp. Med.
2001, 194, 1541.
12. Soler, D.; Humphreys, T. L.; Spinola, S. M.; Campbell, J. J. Blood 2003, 101, 1677.
13. Le, P. E.; Hisada, S.; Mizuguchi, Y.; Dupriez, V. J.; Burgeon, E.; Detheux, M. J.
Biomol. Screen. 2002, 7, 57.
14. Boelsterli, U. A.; Ho, H. K.; Zhou, S.; Leow, K. Y. Curr. Drug Metab. 2006, 7, 715.
15. Abeywardane,A.; Cogan, D.; Choi, Y.; Gao, D.A.; Goldberg, D.R.; Heim-Riether,
A.; Miller, C.; Ramsden, P.D.; Smith Keenan, L.L.; Snow, R.J.; Yang, Y. U.S. Patent
8,586,748, 2011.
16. Thompson, M. J.; Mekhalfia, A.; Hornby, D. P.; Blackburn, G. M. J. Org. Chem.
1999, 64, 7467.
17. Heim-Riether, A. Synthesis 2008, 883.
18. Kalgutkar, A. S.; Dalvie, D. K.; O’Donnell, J. P.; Taylor, T. J.; Sahakian, D. C. Curr.
Drug Metab. 2002, 3, 379.
19. Compounds were prepared from sulfonyl chlorides with unreactive anilines.
Due to aniline reactivity toward the sulfonyl chlorides, less substituted
analogues were not prepared.
20. Shultz, M. D. Bioorg. Med. Chem. Lett. 2013, 23, 5980.
21. Ryckmans, T.; Edwards, M. P.; Horne, V. A.; Correia, A. M.; Owen, D. R.;
Thompson, L. R.; Tran, I.; Tutt, M. F.; Young, T. Bioorg. Med. Chem. Lett. 2009, 19,
4406.
22. Frang, H.; Mukkala, V. M.; Syysto, R.; Ollikka, P.; Hurskainen, P.; Scheinin, M.;
Hemmila, I. Assay Drug Dev. Technol. 2003, 1, 275.
Ba/F3), along with the observed specificity of these compounds for
CCR10 all support these compounds’ activity proceeding through
direct interaction with CCR10.
The murine cellular potency and apparent specificity of 22 qual-
ified it as a suitable tool to test the impact of CCR10 antagonism on
dermal inflammation. Therefore, eut-22 was investigated for
efficacy against DNFB (2,4-dinitrofluorobenzene) murine contact
hypersensitivity (Fig. 2), with dis-22 serving as a structurally
related negative control. The model captures a predominantly T-
cell dependent inflammatory response of sensitized mice to topical
DNFB challenge on the ear.23 Due to high clearance of 22 in mice
(murine liver microsome t1/2 <3 min; >88% Qh), a 100 mg/kg dose
delivered intraperitoneally at 0 and 8 h was required to maintain
plasma exposure near or above the murine IC50 of eut-22 over
the majority of the experiment.24 Nonetheless, eut-22 exhibited
a dose-dependent anti-inflammatory response against DNFB stim-
ulated ear swelling in sensitized mice. While the eutomer eut-22
showed efficacy, the distomer dis-22 demonstrated no activity,
consistent with the stereospecificity of CCR10 antagonism. The
level of efficacy observed for eut-22 was similar to that observed
with anti-CCL27 antibody in the same model (60–85%).6
We report the first small molecule antagonists of CCR10.25,26
The initial hit from screening, a 690 nM antagonist of CCR10
dependent Ca2+ flux, contained both a nitroimidazole and an ani-
line. Optimization delivered eut-22 that is not only 300 times more
potent a CCR10 antagonist than the initial hit, but eliminated
23. Saint-Mezard, P.; Berard, F.; Dubois, B.; Kaiserlian, D.; Nicolas, J. F. Eur. J.
Dermatol. 2004, 14, 131.
Please cite this article in press as: Abeywardane, A.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.09.047

A. Abeywardane et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
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24. Satellite exposures of compound in 30% cremophore dosed in Balb-C mice:
eut-22, 100 mg/kg ip, 1 h: 7.6 4.5 M, 7 h: 0.2 0.2 M; 30 mg/kg ip, 1 h:
3.7 0.4 M, 7 h: not detected. dis-22, 100 mg/kg ip, 1 h: 18 M; 7 h: not
M, 7 h: not detected; 99% plasma protein
25. Jung, F.; Gombert, F.O.; Obrecht, D.; Bisang, C.; Bayly, C.I.; Bayly, C.I.;
Barthélémy, S.; Lederer, A.; Chevalier, E. U.S. Patent 8,754,038, 2014.
26. Daubeuf, F.; Jung, F.; Douglas, G. J.; Chevalier, E.; Frossard, N. Respir. Res. 2015,
16, 1.
l
l
l
2 l
detected; 30 mg/kg ip, 1 h: 3.2 0.8
binding for both compounds.
l
Please cite this article in press as: Abeywardane, A.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.09.047