Discovery and characterization of [(cyclopentyl)ethyl]benzoic acid inhibitors of microsomal prostaglandin E synthase-1

Article abstract of DOI:10.1016/j.bmcl.2016.11.011

We describe a novel class of acidic mPGES-1 inhibitors with nanomolar enzymatic and human whole blood (HWB) potency. Rational design in conjunction with structure-based design led initially to the identification of anthranilic acid 5, an mPGES-1 inhibitor with micromolar HWB potency. Structural modifications of 5 improved HWB potency by over 1000×, reduced CYP2C9 single point inhibition, and improved rat clearance, which led to the selection of [(cyclopentyl)ethyl]benzoic acid compound 16 for clinical studies. Compound 16 showed an IC₈₀of 24 nM for inhibition of PGE₂formation in vitro in LPS-stimulated HWB. A single oral dose resulted in plasma concentrations of 16 that exceeded its HWB IC₈₀in both rat (5 mg/kg) and dog (3 mg/kg) for over twelve hours.

Full text of DOI:10.1016/j.bmcl.2016.11.011

Accepted Manuscript
Discovery and characterization of [(cyclopentyl)ethyl]benzoic acid inhibitors of
microsomal prostaglandin E synthase-1
Katherine M. Partridge, Stephen Antonysamy, Shobha N. Bhattachar,
Srinivasan Chandrasekhar, Matthew J. Fisher, Adrian Fretland, Karen Gooding,
Anita Harvey, Norman E. Hughes, Steven L. Kuklish, John G. Luz, Peter R.
Manninen, James E. McGee, Daniel R. Mudra, Antonio Navarro, Bryan H.
Norman, Steven J. Quimby, Matthew A. Schiffler, Ashley V. Sloan, Alan M.
Warshawsky, Jennifer M. Weller, Jeremy S. York, Xiao-Peng Yu
PII:
S0960-894X(16)31151-9
DOI:
http://dx.doi.org/10.1016/j.bmcl.2016.11.011
BMCL 24406
Reference:
To appear in:
Bioorganic & Medicinal Chemistry Letters
Received Date:
Revised Date:
Accepted Date:
9 September 2016
3 November 2016
4 November 2016
Please cite this article as: Partridge, K.M., Antonysamy, S., Bhattachar, S.N., Chandrasekhar, S., Fisher, M.J.,
Fretland, A., Gooding, K., Harvey, A., Hughes, N.E., Kuklish, S.L., Luz, J.G., Manninen, P.R., McGee, J.E., Mudra,
D.R., Navarro, A., Norman, B.H., Quimby, S.J., Schiffler, M.A., Sloan, A.V., Warshawsky, A.M., Weller, J.M.,
York, J.S., Yu, X-P., Discovery and characterization of [(cyclopentyl)ethyl]benzoic acid inhibitors of microsomal
prostaglandin E synthase-1, Bioorganic & Medicinal Chemistry Letters (2016), doi: http://dx.doi.org/10.1016/
j.bmcl.2016.11.011
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Discovery and characterization of [(cyclopentyl)ethyl]benzoic acid inhibitors of microsomal
prostaglandin E synthase-1
a,
b
a
Katherine M. Partridge, * Stephen Antonysamy, Shobha N. Bhattachar, Srinivasan
a,c
a
a,d
a,c
a,c
Chandrasekhar, Matthew J. Fisher, Adrian Fretland, Karen Gooding, Anita Harvey,
a
a
b
a
a
Norman E. Hughes, Steven L. Kuklish, John G. Luz, Peter R. Manninen, James E. McGee,
a
a
a
a
Daniel R. Mudra, Antonio Navarro, Bryan H. Norman, Steven J. Quimby, Matthew A.
a
a
a
a
a
Schiffler, Ashley V. Sloan, Alan M. Warshawsky, Jennifer M. Weller, Jeremy S. York, Xiao-
a
Peng Yu,
a
Lilly Research Laboratories, A Division of Eli Lilly and Company, Indianapolis, Indiana 46285,
USA
b
Eli Lilly Biotechnology Center, San Diego, CA 92121, USA
Present/Permanent address:
c
Retired
d
Discovery Sciences, Oncology Innovative Medicines Unit, AstraZeneca R&D Boston, 35
Gatehouse Drive, Waltham, MA 02451, USA
Abstract
We describe a novel class of acidic mPGES-1 inhibitors with nanomolar enzymatic and human
whole blood (HWB) potency. Rational design in conjunction with structure-based design led
initially to the identification of anthranilic acid 5, an mPGES-1 inhibitor with micromolar HWB
potency. Structural modifications of 5 improved HWB potency by over 1000×, reduced
CYP2C9 single point inhibition, and improved rat clearance, which led to the selection of
[
(cyclopentyl)ethyl]benzoic acid compound 16 for clinical studies. Compound 16 showed an

IC of 24 nM for inhibition of PGE formation in vitro in LPS-stimulated HWB. A single oral
8
0
2
dose resulted in plasma concentrations of 16 that exceeded its HWB IC in both rat (5 mg/kg)
8
0
and dog (3 mg/kg) for over twelve hours.
Graphical Abstract
1
6
1
nM mPGES-1 IC50
nM HWB IC50
4 nM HWB IC80
6
2
Plasma Exposure of 16 in Rat after a 5 mg/kg oral dose
1000
100
IC =24 nM
8
0
10
1
0
4
8
12
Time (h)
Corresponding Author:
(K.M.P.) E-Mail: Partridge_Katherine@lilly.com Tel: +1-317-433-0465.
*
Keywords: mPGES-1, Prostaglandin pathway, bioavailability, Biomarker
1
Arthritic pain is a leading cause of disability in the United States. Common treatments for the
initial stages of arthritis rely heavily on NSAIDs (non-steroidal anti-inflammatory drugs) and

2
cyclooxygenase-2 (COX-2) inhibitors to provide analgesia. Both classes of pharmaceuticals
block the cyclooxygenase (COX)-catalyzed conversion of arachidonic acid (AA) to
prostaglandin H (PGH ), which is rapidly converted to an array of bioactive prostanoids;
2
2
including TXA , PGE PGD , PGI , and PGF (Figure 1). Prostaglandin E (PGE ) is thought to
2
2,
2
2
2α
2
2
be the main mediator of pain and inflammation, and the resulting downstream suppression of
3
PGE gives NSAIDs and COX-2 inhibitors their analgesic properties.
2
Figure 1. Primary biosynthetic pathways of select prostanoids
NSAIDs non-selectively inhibit two isoforms of cyclooxygenase, COX-1 and COX-2. COX-1
is constitutively expressed in most tissues and is important for regulating homeostatic
4
physiologic tasks, including gastric cytoprotection and kidney function. COX-2 expression is
inducible and upregulated under inflammatory conditions, allowing increased production of
5
prostaglandins. The coincidental COX-1 inhibition found with traditional NSAIDs is thought to
give rise to the increased risk of gastric bleeding and ulcerations found with this class of
6
analgesics. COX-2 selective inhibitors were developed as a means to target inflammatory pain
7
while providing the potential for reduced risk of GI complications. Selective COX-2 inhibitors
are efficacious and appear to have a more tolerable GI profile than NSAIDs, however they have
been found to carry an increased cardiovascular risk, which is thought to arise from COX-2
8
derived suppression of PGI2. A more selective inhibitor of inducible PGE formation is an
2
attractive strategy for mediation of nociception with a lower risk of the side effects that result
9
from the indiscriminate suppression of other prostanoids.

Of the prostaglandin E synthases (PGES) known to convert PGH to PGE only microsomal
2
2,
10
PGES-1 (mPGES-1) expression is upregulated under inflammatory conditions. Additionally,
1
1
the expression of mPGES-1 and COX-2 has been shown to be coupled. Evidence for the key
role of mPGES-1 in inflammatory pain comes from murine knockouts, which demonstrated
reduced response in inflammatory pain models and resistance towards disease development in
12
collagen-induced arthritis models.
These observations suggest that a selective inhibitor of
mPGES-1 may offer the analgesic properties of traditional NSAIDs with a reduced side effect
profile. Work in this area has produced a wide range of chemotypes, including compounds with
1
3
both neutral and acidic moieties, for example 1–4 (Figure 2).
1
2
0
.007 M mPGES-1 IC50
0.016 M mPGES-1 IC50
>30 M HWB IC50
5 M HWB IC50
3
4
0
.003 M mPGES-1 IC50
0.241 M mPGES-1 IC50
0
.109 M HWB IC50
0.744 M HWB IC50
Figure 2. Representative mPGES-1 Inhibitors
To support the discovery of new molecules, enzymatic and native tissues assays have
been developed to assess the potency of mPGES-1 inhibitors. A cell-free assay using a
microsomal preparation assay of human mPGES-1 from HEK-293 cells was used to provide a
14
direct measure of enzyme inhibition. It is also known that mPGES-1 inhibitors impede the
1
3a
formation of PGE in in vitro LPS-stimulated human whole blood (HWB). Historically, this
2
assay has been a critical component of both NSAID and COX-2 inhibitor development. Pasqua
has shown that the inhibition of PGE production in HWB at the IC level for a variety of
2
80
NSAIDs and COX-2 analgesics correlated with plasma drug concentrations of the clinically
1
5
efficatious dose. The reduction of PGE in HWB provides a seamless biomarker linking in
2
1
6
vitro preclinical and the in vivo clinical observations.

The high-resolution X-ray crystal structure of mPGES-1, a homotrimeric protein, has recently
1
7
been published and has facilitated the development of new inhibitors through rational design.
In our laboratories, this led to the discovery and development of compound 4 (Figure 2).
Building on our understanding of the mPGES-1 binding site, we used structure-based drug
design to create a new class of mPGES-1 inhibitors. In this manuscript, we describe the
discovery and characterization of a series of potent, orally bioavailable cyclopentylethylbenzoic
acid inhibitors of mPGES-1.
1
3e
In the X-ray co-crystal of mPGES-1 and compound 4 (Figure 3), the central hydrophobic
core of 4 rests directly above the sulfur of the glutathione cofactor, and its substituents project
down the left and right shallow flanking grooves. This binding mode takes advantage of the
dense arrangement of hydrogen bond donors surrounding the opening to the glutathione binding
pocket. In addition to a direct hydrogen bond with His53, compound 4 interacts with both Arg52
and Thr131 through ordered water molecules. We hypothesized that a similarly shaped molecule,
with a properly oriented carboxylic acid, could form a direct salt bridge with Arg52, effectively
replacing the imidazole. In order to retain the orientation of the tert-butyl amide in the right
hand groove, we adjusted the central constraint by replacing the aromatic core with a five-
membered aliphatic moiety. We designed and synthesized compound 5, which was found to
inhibit mPGES-1 with an IC of 43 nM and a HWB IC of 8.9 M. The X-ray co-crystal
5
0
50
structure of 5 and mPGES-1 showed that the inhibitor adopts a similar binding mode to 4,
maintaining the five membered hydrophobic ring over the glutathione, as predicted. The central
ring allowed the critical pivaloyl amide moiety to correctly project into the right hand groove.
As designed, the carboxylate of compound 5 formed a hydrogen bond with His53 and also made
a direct hydrogen bond to Arg52 and a van der Waals contact with Thr131.

a.
b.
Figure 3. X-ray co-crystal structure of mPGES-1 with 4 and rac-5
A. mPGES-1 bound to compound 4 (represented as sticks and colored by atom: C, yellow;
N, blue; O, red; Cl, green). Glutathione is presented as sticks and colored by atom as
above except C is magenta and S is tan. Chain 1 is orange and represented by cartoon.
Side chains of chain 1 are represented as sticks and colored as above except C is orange.
Chain 2 is cyan and represented by cartoon. Side chains of chain 1 are represented as
sticks and colored as above except C is cyan.
B. mPGES-1 bound to rac-5. Representations and color assignments same as in (A)

5
0
.043 M mPGES-1 IC50
8
.91 M HWB IC50
While compound 5 displayed good enzymatic inhibitory activity, most of the potency did not
translate to the more physiologically relevant whole blood environment. Replacing the pivaloyl
amide of compound 5 with larger substituents, such as N-aryl piperidines (Table 1, compounds 6
and 7) improved the potency in enzymatic and HWB assays. Although compounds 6 and 7 had
similar IC values in the enzymatic assay (2 and 4 nM), compound 7 was 30 times more potent
5
0
in HWB. To support the notion that the suppression of PGE in HWB was due to inhibition of
2
mPGES-1 and not COX-1 or COX-2, compounds 6 and 7 were tested in an A549 cellular assay
which tested the production of multiple prostanoids. In this assay, 6 and 7 inhibited the
formation of PGE (IC = 0.021 M and 0.0035 M, respectively) but not PGI . Additionally,
2
50
2
in LPS stimulated HWB, 6 and 7 disrupted neither TXB nor PGF production. These data
2
2α
suggest that the observed inhibition of PGE formation in HWB was due to inhibition of
2
mPGES-1and not COX-1 or COX-2. While the IC was a useful metric early in the SAR
5
0
1
5
studies, the HWB IC is a more clinically relevant value. Therefore, we chose to benchmark
8
0
all future potency against the latter standard.
Compound 7 had single-digit nanomolar potency in HWB, but we identified at least two
characteristics that needed improvement. First, this compound had moderate clearance in the rat
(Cl = 40 mL/(min*kg)). Second, 7 inhibited CYP2C9 in a single-point microsomal preparation
assay (71% inhibition at 10 M). Therefore, further work aimed to identify compounds with
HWB activity similar to 7, while simultaneously reducing both the rat clearance and CYP
inhibition liabilities.

We continued our SAR studies by examining the linker between the cyclopentane and the
aromatic ring. The oxygen linked salicylic acid 8 demonstrated a modestly increased in HWB
IC , a decreased in CYP2C9 single point inhibition, and a slightly increased rat clearance
8
0
relative to anthranilic acid 7. Compound 9, an alkyl substituted benzoic acid, had similar HWB
potency and CYP2C9 single point inhibition to 7, but had lower clearance. The observed
decrease in clearance without an associated attenuation of CYP2C9 single-point inhibition
suggested that rat clearance was not driven solely by the apparent CYP2C9 interaction.
The improved clearance of compound 9 focused our attention on other 2-alkylbenzoic
acid derivatives. Replacement of the chloro- substituent of compound 9 yielded analogs 10–12,
which had similarly low rat clearance. Toluic acid 10 was 2× less potent in HWB than analog 9,
while fluoro- and hydrogen substitutions (11-12) resulted in approximately an order of
magnitude loss in potency. Unsubstituted benzoic acid 12 showed minimal inhibition of
CYP2C9. Within the confines of the single point changes between compounds 9–12, decreased
CYP2C9 inhibition appeared to correlate with decreased lipophilicity as characterized by the
calcuclated logD at pH 7.4. Nicotinic acid 13 was 4× less potent than parent benzoic acid 12 and
had higher clearance in the rat.
Table 1. SAR of mPGES-1 Inhibitors 6−16
HWB
PGE2
IC50
HWB
IC80
mPGES-1
Rat Clearance,
IV
c
% inhibition
of CYP2C9
@ 10 M
cLogD,
Cmpd R1
R2
R3
R4
a
IC50
nM)
7.4
b
(
b
b
(mL/(min*kg))
(
nM)
(nM)
d
6
NH
NH
Cl CH
Cl CH
2.07
2.95
2
81
1371
81 (34)
46
71
7
4
3
8
40 (14)

8
9
O
Cl CH
2.08
3.25
3.27
2.88
2.65
1.44
2.11
3.24
2
1
1
1
2
6
2
1
8
1
25
5
57 (22)
16 (11)
9 (3)
39
51
56
40
5
CH2 Cl CH
CH2 Me CH
1
0
1
2
3
4
5
3
10
41
40
146
267
43
1
1
1
1
1
CH2
CH2
CH2
CH2
CH2
F
CH
CH
N
6
12 (2)
5 (0.6)
38 (1)
6(3)
H
H
H
H
5
21
34
10
ND
22
32
CH
CH
17(5)
16
CH2
H
CH
3.15
1
6
24
31 (4)
14
a
b
Values are reported as geometric means of a minimum of three samples Calculated using Marvin and
c
calculator plugin freeware (www.chemaxon.com, ChemAxon Kft, Budapest, Hungary) a 1 mg/kg IV dose. Data is
a mean of three animals, standard deviation in parentheses. Pharmacokinetic calculations were performed using
d
Watson Version 7.4 Compound is a racemic mixture; all other compounds are single enantiomers
Because of the HWB potency, low clearance, and low CYP2C9 single point inhibition
associated with compound 12, the cyclopentylethyl benzoic acid core was held constant while
other N-aryl piperidine carboxamides were examined (compounds 14–16). These analogs had
similar apparent CYP2C9 single point inhibition and rat clearance but exhibited different
potencies. Replacing the trifluoromethyl substituent of 12 with a trifluoromethoxy group had a
negligible impact on potency. The 5-trifluoropyridyl analog 14 was less potent than 12 in HWB,
and 8-methylquinoline analogue 16 was slightly more potent. With high in vitro potency, low

CYP2C9 inhibition, moderate rat clearance, compound 16 was selected for further
characterization.
The X-ray co-crystal of 16 with mPGES-1 shows that the benzoic acid of 16 forms a
bidentate salt bridge to Arg52 and coordinates to His53 through a water bridge. The central
hydrophobic cyclopentane ring rests above glutathione, projecting the amide substituent down
the hydrophobic groove. The N-aryl piperidine rests in the hydrophobic cleft with interactions
dominated by van der Waals contacts with Tyr28, Ile32, Tyr130, and Gln134. The methyl
1
8
substituent of the quinoline projects deeply into a cleft behind Ile32.
Figure 4. X-ray co-crystal structure of mPGES-1 with 16
mPGES-1 bound to compound 16 (represented as sticks and colored by atom: C, yellow; N, blue;
O, red; Cl, green). Glutathione is presented as sticks and colored by atom as above except C is
magenta and S is tan. Chain 1 is orange and represented by cartoon. Side chains of chain 1 are
represented as sticks and colored as above except C is orange. Chain 2 is cyan and represented
by cartoon. Side chains of chain 1 are represented as sticks and colored as above except C is
cyan.
In contrast to celecoxib, compound 16 suppressed neither PGI formation in the A549 assay
2
nor TXB or PGF production in HWB at concentrations up to 10 µM. Furthermore, no
2
2α
inhibition of either COX-1 or COX-2 was observed with 10 μM, thus 16 is at least 10,000-fold

selective against those enzymes. Upon testing against a DiscoverX panel of 35 receptors and ion
channels, 16 did not display any activity that we deemed to present an undue risk. No activity
was detected against hERG at 10 M 16 in a CEREP assay. Taken together, these biochemical
data supported the characterization of 16 as a selective inhibitor of mPGES-1.
The pharmacokinetic profiles of 16 were determined in both rat and dog. The volume of
distribution at steady state was 4.8 L in the rat and 1.2 L in the dog. Clearances of less than
hepatic blood flow were observed in both species at an IV administered dose of 1 mg/kg. The
oral bioavailability exceeded 50% in both species.
a
Table 2. Pharmacokinetic Properties of 16
Volume of
Maximum oral
concentration
Oral
Bioavailability
(%)
Dose
Clearance, IV
(mL/min/kg)
Distribution at
Steady State,
IV (L/kg)
Species
IV/Oral (mg)
(
M)
Rat
1/5
1/3
31 (4)
4.8(1.8)
1.2(0.6)
0.53 (0.14)
4.0 (1.3)
52 (12)
68 (26)
Dog
6.5 (1.7)
a
Data is a mean of three animals. Standard deviation reported in parentheses. Pharmacokinetic calculations were
performed using Watson Version 7.4
As shown in Figure 5, with a 5 mg/kg oral dose of 16, plasma concentrations exceeded the
HWB IC of 24 nM for greater than 12 hours in the rat. With a 3 mg/kg oral dose in dog,
8
0
plasma concentrations exceeded the IC for 24 hours (Figure 6). The prolonged exposure above
8
0
levels corresponding to the HWB IC in both species were seen as an indicator that 16 was a
8
0
viable molecule to test for efficacy in the clinic.

1000
100
IC =24 nM
80
10
1
0
4
8
12
Time (h)
Figure 5. Plasma exposure of 16 in rat after a 5 mg/kg oral dose
10000
1000
100
IC =24 nM
80
10
1
0
4
8
12
16
20
24
Time (h)
Figure 6. Plasma exposure of 16 in dog after a 3 mg/kg oral dose
Compound 16 was readily synthesized from accessible precursors (Scheme 1). Dess–Martin
Periodinane-mediated oxidation of alcohol 17 generated aldehyde 18 in quantitative yield.
Wittig reaction between 18 and the in situ-generated ylide derived from phosphonium salt 19
furnished intermediate 20 in 59 % yield as an inconsequential 5:1 mixture of the E and Z
isomers. Hydrogenation of the olefin followed by removal of the Boc protecting group gave
amine hydrochloride intermediate 21 in quantitative yield over two steps. Nucleophilic aromatic
substitution of piperidine 22 with 2-chloro-8-methyl quinolone 23 and subsequent ester
hydrolysis yielded carboxylic acid 25. Finally, propylphosphonic anhydride-promoted coupling

between amine 21 and carboxylic acid 25 yielded intermediate 26 in 84% yield. Subsequent
hydrolysis with sodium hydroxide afforded 16 in 96% yield and >99% purity.
Scheme 1. Synthesis of compound 16
1
7
a
b
c
d,e
1
8
2
0
21
1
9
f
g
2
2
23
24
25
h
i
2
1
25
26
16
a
b
c
PPh , Toluene, reflux, 76% yield Dess-Martin Periodinane, CH Cl , –5 °C, 100% yield KOtBu, THF, 59%
3
2
2
d
e
f
yield Pt/C, H , 30 psig, EtOAc 4.0 M HCl in Dioxane, CH Cl , 100% yield over 2 steps K CO , DMSO, 130 °C,
6% yield NaOH, H O, MeOH, THF, 94% yield 50% propylphosphonic anhydride in EtOAc, DIPEA, CH Cl 0
C →r.t., 84% yield NaOH, THF, MeOH, H O, 94% yield
2
2
2
2
3
g
h
9
°
2
2
2
,
i
2
In summary, we have described a novel class of acidic mPGES-1 inhibitors with nanomolar
enzymatic and HWB potency. Rational design led initially to the identification of anthranilic
acid 5, a nanomolar inhibitor of mPGES-1 inhibitor with micromolar HWB potency. Structural
modifications improved the HWB affinity, reduced rat clearance and reduced the CYP2C9
liability. Because it exemplified these desirable qualities, compound 16 was characterized further

and found to exhibit, among other parameters, sufficient exposure relative to its potency to
render it suitable for clinical development.
Experimental Details
Atomic coordinates and structure factors for compound 4, 5, and 16 with mPGES-1 are available
from the RSCB Protein Data Bank with accession codes 5T37, 5T36 and 5TL9. Synthesis
1
9
protocols, compound characterization, and assay protocols have been published.
Acknowledgements
Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S.
Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported
by the U.S. DOE under Contract No. DE-AC02-06CH11357. The beamline staff, Stephen
Wasserman, John W. Koss, and Laura Morisco are gratefully acknowledged.
References
1
2
3
4
7
5
6
. Dancevic, C. M.; McCulloch, D. R., Arthritis Res. Ther. 2014, 16, 429.
. Kean, W. F.; Buchanan, W. W., Inflammopharmacology 2005, 13, 343
. Ricciotti, E.; FitzGerald, G. A., Arterioscler. Thromb. Vasc. Biol. 2011, 31, 986.
. Prusakiewicz, J. J.; Duggan, K. C.; Rouzer, C. A.; Marnett, L. J., Biochemistry 2009, 48,
353.
. Seibert, K.; Masferrer, J. L., Receptor 1994, 4, 17.
. Matsui, H.; Shimokawa, O.; Kaneko, T.; Nagano, Y.; Rai, K.; Hyodo, I., J. Clin. Biochem.
Nutr. 2011, 48, 107.
. (a) Chen, Y. F.; Jobanputra, P.; Barton, P.; Bryan, S.; Fry-Smith, A.; Harris, G.; Taylor, R. S.,
Health Technol. Assess. 2008, 12, 1; (b) Hawkey, C. J., Lancet 1999, 353, 307.
. (a) Yu, Y.; Ricciotti, E.; Scalia, R.; Tang, S. Y.; Grant, G.; Yu, Z.; Landesberg, G.; Crichton,
7
8
I.; Wu, W.; Pure, E.; Funk, C. D.; FitzGerald, G. A., Sci. Transl. Med. 2012, 4, 132; (b) Sun, S.
X.; Lee, K. Y.; Bertram, C. T.; Goldstein, J. L., Curr. Med. Res. Opin. 2007, 23, 1859.
9
1
1
1
. Chen, Y.; Liu, H.; Xu, S.; Wang, T.; Li, W., Med. Chem. Comm. 2015, 6, 2081.
0. Jakobsson, P. J.; Thoren, S.; Morgenstern, R.; Samuelsson, B., Proc. Natl. Acad. Sc.i U S A
999, 96, 7220.
1. Murakami, M.; Naraba, H.; Tanioka, T.; Semmyo, N.; Nakatani, Y.; Kojima, F.; Ikeda, T.;
Fueki, M.; Ueno, A.; Oh, S.; Kudo, I., J. Biol. Chem. 2000, 275, 32783.
2. Kamei, D.; Yamakawa, K.; Takegoshi, Y.; Mikami-Nakanishi, M.; Nakatani, Y.; Oh-Ishi,
1
S.; Yasui, H.; Azuma, Y.; Hirasawa, N.; Ohuchi, K.; Kawaguchi, H.; Ishikawa, Y.; Ishii, T.;
Uematsu, S.; Akira, S.; Murakami, M.; Kudo, I., J. Biol. Chem 2004, 279, 33684.
1
3. (a) Chang, H. H.; Meuillet, E. J., Fut. Med. Chem. 2011, 3, 1909; (b) Wang, J. L.; Limburg,
D.; Graneto, M. J.; Springer, J.; Hamper, J. R.; Liao, S.; Pawlitz, J. L.; Kurumbail, R. G.;
Maziasz, T.; Talley, J. J.; Kiefer, J. R.; Carter, J., Bioorg. Med. Chem. Let. 2010, 20, 7159; (c)
Riendeau, D.; Aspiotis, R.; Ethier, D.; Gareau, Y.; Grimm, E. L.; Guay, J.; Guiral, S.; Juteau, H.;
Mancini, J. A.; Methot, N.; Rubin, J.; Friesen, R. W., Bioorg. Med. Chem. Lett. 2005, 15, 3352;

(d) Arhancet, G. B.; Walker, D. P.; Metz, S.; Fobian, Y. M.; Heasley, S. E.; Carter, J. S.;
Springer, J. R.; Jones, D. E.; Hayes, M. J.; Shaffer, A. F.; Jerome, G. M.; Baratta, M. T.; Zweifel,
B.; Moore, W. M.; Masferrer, J. L.; Vazquez, M. L., Bioorg. Med. Chem. Lett.2013, 23, 1114;
(e) Schiffler, M. A.; Antonysamy, S.; Bhattachar, S. N.; Campanale, K. M.; Chandrasekhar, S.;
Condon, B.; Desai, P. V.; Fisher, M. J.; Groshong, C.; Harvey, A.; Hickey, M. J.; Hughes, N. E.;
Jones, S. A.; Kim, E. J.; Kuklish, S. L.; Luz, J. G.; Norman, B. H.; Rathmell, R. E.; Rizzo, J. R.;
Seng, T. W.; Thibodeaux, S. J.; Woods, T. A.; York, J. S.; Yu, X. P., J. Med. Chem. 2016, 59,
1
1
94.
4. Chandrasekhar, S.; Harvey, A. K.; Yu, X. P.; Chambers, M. G.; Oskins, J. L.; Lin, C.; Seng,
T. W.; Thibodeaux, S. J.; Norman, B. H.; Hughes, N. E.; Schiffler, M. A.; Fisher, M. J., J.
Pharm. Exp. Ther. 2016, 356, 635.
1
1
1
5. Huntjens, D. R.; Danhof, M.; Della Pasqua, O. E., Rheumatology (Oxford) 2005, 44, 846.
6. Durham, T. B.; Blanco, M. J., Bioorg. Med. Chem. Lett 2015, 25, 998.
7. (a) Sjogren, T.; Nord, J.; Ek, M.; Johansson, P.; Liu, G.; Geschwindner, S., Proc. Natl. Acad.
Sci U S A 2013, 110 (10), 3806; (b) Luz, J. G.; Antonysamy, S.; Kuklish, S. L.; Condon, B.; Lee,
M. R.; Allison, D.; Yu, X. P.; Chandrasekhar, S.; Backer, R.; Zhang, A.; Russell, M.; Chang, S.
S.; Harvey, A.; Sloan, A. V.; Fisher, M. J., J. Med. Chem. 2015, 58, 4727.
1
8: For another example of an 8-methyl quinoline containing ligand of mPGES-1 see Kuklish,
S.L.; Antonysamy, S.; Bhattachar, S.N.; Chandrasekhar, S.; Fisher, M.J.; Fretland, A.J.;
Gooding, K.; Harvey, A.; Hughes, N.E.; Luz, J.G.; Manninen, P.R.; McGee, J.E.; Navarro, A.;
Norman, B.H.; Partridge, K.M.; Quimby, S.J.; Schiffler, M.A.; Sloan, A.V.; Warshawsky, A.M.;
York, J.S.; Yu, X.-P.; Bioorg. Med. Chem. Lett. 2016, 26, 4824
1
9. Fisher, M.J.; Kuklish, S.L.; Partridge, K.M.; York, J. S. Patent Number WO 2016069374
A1, 2016

Graphical Abstract
Plasma Exposure of 16 in Rat after a 5 mg/kg oral
1000
dose
100
IC =24 nM
8
0
10
1
6
1
nM mPGES-1 IC50
nM HWB IC50
4 nM HWB IC80
6
2
1
0
4
8
12
Time (h)