Steroidal C-21 mercapto derivatives as dissociated steroids: Discovery of an inhaled dissociated steroid

Article abstract of DOI:10.1016/j.bmcl.2011.08.108

A series of C-21 mercapto derivatives of hydrocortisone have been synthesized and evaluated in cell based transrepression and transactivation assays. The benzothiazole derivative, compound 6 not only showed a dissociated profile in vitro functional assays but also a pharmacological profile in a Brown-Norway rat therapeutic index model of asthma that dissociated side effects (thymolysis) while maintaining efficacy against pulmonary inflammation and lung function.

Full text of DOI:10.1016/j.bmcl.2011.08.108

Bioorganic & Medicinal Chemistry Letters 21 (2011) 6343–6347
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Steroidal C-21 mercapto derivatives as dissociated steroids: Discovery
of an inhaled dissociated steroid
⇑
Purakkattle Biju , Kevin McCormick, Robert Aslanian, Michael Berlin, Daniel Solomon, Richard Chapman,
Robbie McLeod, Daniel Prelusky, Stephen Eckel, George Kelly, Michelle Natiello, Aileen House,
Xiomara Fernandez, Rema Bitar, Jonathan Phillips, John Anthes
Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of C-21 mercapto derivatives of hydrocortisone have been synthesized and evaluated in cell
based transrepression and transactivation assays. The benzothiazole derivative, compound 6 not only
showed a dissociated profile in vitro functional assays but also a pharmacological profile in a Brown-
Norway rat therapeutic index model of asthma that dissociated side effects (thymolysis) while maintain-
ing efficacy against pulmonary inflammation and lung function.
Received 20 July 2011
Revised 19 August 2011
Accepted 25 August 2011
Available online 31 August 2011
Ó 2011 Elsevier Ltd. All rights reserved.
Keywords:
Inhaled asthma
Hydrocortisone
C-21 mercapto derivatives
Dissociated Steroid
Transactivation and transrepression
Glucocorticoids (anti-inflammatory steroids) have been on the
market for more than 60 years and represent the most effective
therapy for both acute and chronic inflammatory conditions
including allergic and non allergic diseases such as asthma, COPD,
rheumatoid arthritis and many more. The discovery of cortisone in
2 significantly helped allergy and asthma patients to manage exac-
erbations and provided higher quality of life.
1
Mechanistically, glucocorticoids are involved in two major gene
5
transcription pathways, transrepression and transactivation.
Broadly speaking, transrepression is the interaction of the
glucocorticoid receptor-steroid monomer complex with the
1
948 and the endogenous glucocorticoid hydrocortisone 1 in 1951
and its use for the treatment of rheumatoid arthritis generated
enormous interest in the use of glucocorticoids for the treatment
of various inflammatory diseases that triggered an explosive devel-
opment in the discovery of synthetic glucocorticoids. The earlier
research in this area generated compounds with improved gluco-
corticoid receptor affinity and selectivity to other nuclear receptors
such as progestrone and mineralocorticoid. The most commonly
used synthetic glucocorticoids are prednisolone, dexamethasone,
budesonide, mometasone furoate 2 and fluticasone propionate 3.
Although currently marketed glucocorticoids are very effective
for the treatment of inflammatory conditions, their long term use
is limited by a number of serious side effects2 such as skin
thinning, decreased bone density, HPA axis suppression and
glucose intolerance. The therapeutic index of classical steroids
has been further improved3 by both route of administration and
by adjusting the pharmacokinetic profile of the compound. The
transcription factors such as AP-1 and NFj-B, which is believed
to be the major contributor of the antiinflammatory activity of
glucocorticoids. However, most of the systemic side effects are
due to the interaction of glucocorticoid receptor-steroid dimer
complex with DNA, which brings increased transcription called
transactivation. The transactivation of genes by GR is suggested
to be key in determining the metabolic side effects of glucocorti-
coids. The transactivation mechanism involves glucocorticoid
receptor dimerization and DNA binding to DNA palindromes,
referred to as glucocorticoid response elements (GRE), and subse-
quent recruitment of coactivators to transcriptionally activate
(transactivate) target genes, such as tyrosine amino transferase
(TAT). The major side effects such as decreased bone density skin
thinning, HPA axis suppression and diabetes are hypothesized to
be due to the genomic events as a result of the interaction of
glucocorticoid receptor-steroid dimer complex with DNA. Hence,
a glucocorticoid that can separate transactivation from transre-
pression may display an improved safety profile and is called a
4
development of topical steroids such as mometasone furoate
6
dissociated steroid or selective glucocorticoid receptor modulator.
⇑
Corresponding author.
E-mail address: julianbiju@yahoo.com (P. Biju).
A number of pharmaceutical companies are actively pursuing
research towards the discovery and development of both steroidal7
0
960-894X/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2011.08.108

6
344
P. Biju et al. / Bioorg. Med. Chem. Lett. 21 (2011) 6343–6347
F
towards IL-6 cytokine synthesis (EC50 = 36 nM) and a weak induc-
Cl
OH
tion of tyrosine amino transferase in both human HEPG2 liver cells
(Emax = 5%) and rat H4II-E cells (Emax = 0%) (Table 1). Compound 4
was further evaluated in a number of in vivo assays. In an allergen
challenge model using Brown-Norway rats (Table 2), compound 4
delivered by intratracheal insufflation showed significant inhibi-
tion of inflammatory cell influx (ED50 = 0.42 mg/kg) comparable
to the standard fluticasone propionate 3 (ED50 = 0.14 mg/kg),
which is a full agonist for transactivation. Compound 4 further
demonstrated safer profile in rats compared to the standard 3 with
less of a decreased in body weight, adrenal weight and thymus
weight (Table 3) in an intraperitoneal dosing study. Since com-
O
O
S
O
O
O
OH
O
HO
HO
HO
O
O
Cl
F
F
O
S
O
O
1
2
3
N
S
O
O
HO
R1
4; R & R1 = H
; R =F, R = H
; R = H, R = -CO-2furyl
5
6
1
pound 4 showed significant antiinflammatory activity and a better
R
10,11
1
O
safety profile, it was further evaluated
by dosing via nose-only
dry powder inhalation in the allergen challenged Brown-Norway
rat model. In this critical inhalation model, compound 4 demon-
strated only moderate efficacy of 27% inhibition of total BAL cells
Figure 1. C-21 mercapto derivatives as dissociated steroids.
8
with a lung concentration of 85 lg/kg. It therefore warranted addi-
tional SAR optimization of transrepression potency and physico-
chemical properties for an inhaled candidate.
and non steroidal dissociated glucocorticoids for the treatment of
various inflammatory diseases. Herein, we report our efforts to-
wards the discovery of compound 6, a C-21 mercapto-benzothia-
zole readily prepared from hydrocortisone, that demonstrated a
dissociated profile both in vitro and in vivo.
Generally inhaled steroids achieve their anti-inflammatory and
1
2
improved safety profile through a combination of high affinity for
the glucocorticoid receptor, antiinflammatory potency, long lung
retention and an extensive hepatic first pass metabolism of sys-
temically absorbed fraction of the drug. The long lung retention
is often the result of optimum lipophilicity and high receptor affin-
ity of the drug molecule. Compound 4 is derived from the endoge-
nous glucocorticoid hydrocortisone, which is not only a weaker
steroid but also displays poor selectivity to other nuclear receptors.
In recent years, a number of very potent synthetic steroids have
been developed, particularly with improved selectivity and antiin-
flammatory efficacy. Table 4 summarizes various steroidal core
modifications with C-21 mercaptobenzothiazole motif. Although
introduction of a 9-fluoro analog 5 (Fig. 1) showed a slight
improvement in IL-6 inhibition, the compound demonstrated mod-
erate activity in the transactivation assay. On the other hand, the
prednisolone analog 7 showed a significant dissociated profile with
Initial screening of an internal compound library identified var-
ious C-21 mercapto hydrocortisone derivatives as initial hits. These
compounds were evaluated in transrepression and transactivation
in vitro cell based assays. Transrepression was measured in a TNF
stimulated IL-6 cytokine synthesis assay in human bronchial epi-
thelial cells (H292 cells). Functional transactivation was measured
by the induction of tyrosine amino transferase (TAT), an enzyme
with well characterized endogenous glucocorticoid response ele-
ments that catalyzes the degradation of tyrosine to p-hydroxy phe-
nyl pyruvate. Human HepG2 liver cells and rat H4II-E cell lines
have been used for TAT functional assays. A recombinant human
Hela-GRE-luciferase assay has been used for measuring transacti-
vation in addition to TAT assays.9
One of the initial lead compounds, a hydrocortisone C-21 mer-
captobenzothiazole 4 (Fig. 1) showed moderate inhibitory activity
Table 1
Transactivation and transrepression in cell based assays
a
a
a
Compd
IL-6 inhibition IC50 (nM) Emax (%)
Rat TAT EC50 (nM) Emax (%)
hTAT EC50 (nM) Emax (%)
4
36 (97)
(0)
(5)
Fluticasone propionate 3
0.075 (99)
0.76 (110)
0.7 (113)
Note: The top concentration for the Emax when there are no EC50 available is 1
lM.
a
Values are means of two experiments.
Table 2
Antiinflammatory efficacy: allergic Brown-Norway rat model (intratracheal dosing study)
Compd
Inhibition of inflammatory
cell influx (single dose, i.t,
ED50 (mg/kg)
Fluticasone propionate 3
4
0.14
0.42
Table 3
Three day intraperitoneal dose: effect on body, adrenal and thymus wt
Compd
Body wt change ED50 (mg/kg)
Adrenal wt change ED50 (mg/kg)
Thymus wt change ED50 (mg/kg)
Fluticasone propionate 3
0.34
0.52
0.14
4
>100
>100
>100

P. Biju et al. / Bioorg. Med. Chem. Lett. 21 (2011) 6343–6347
6345
Table 4
Effect of C-21 mercaptobenzothiazole modification on various steroid cores
N
S
S
O
HO
OH
R3
R1
R2
O
Compd
R
1
R
2
R
3
hGR IC50 (nMa)
IL-6 inhibition IC50 (nM)a (Emax%)
hGRE EC50 (nM)a (Emax%)
rTAT EC50, nMa (Emax%)
4
5
7
8
9
4.8
4.6
3.8
18
13
17
18
36 (97)
18.8 (95)
35 (78)
4.4 (98)
1.9 (100)
4.95 (88)
39.1 (95)
(30)
535 (63)
(29)
45.5 (68)
17 (66)
50 (60)
295 (55)
(0)
(21)
(19)
(33)
27 (79)
(29)
(34)
H
F
F
Cl
H
H
H
F
H
H
Me
Me
Me
H
1
1
0
1
Me
Note: Compounds 4 and 5 is derived from hydrocortisone with one double bond and compounds from 7-11 has two double bonds. The top concentration for the Emax when
there are no EC50 available is 1 M.
Values are means of two experiments.
l
a
Table 5
Transactivation and transrepression data for C-17 furoates
R
S
O
O
O
HO
O
O
Compd
IL-6 inhibition IC50 (nM)a (Emax%)
Rat TAT EC50 (nM)a (Emax%)
hu.TAT EC50 (nM)a (Emax%)
12
13
14
N
15.9 (86)
(4)
(33)
2.85 (96)
1.4 (98)
(11)
(9)
(22)
(41)
N
N
N
Me
N
1
5
3.7 (98)
(17)
(39)
N
O
1
1
1
1
2
6
7
8
9
0
2.2 (97)
2 (100)
(9)
(2)
(2)
(7)
(12)
55.6 (53)
(5)
N
S
N
S
14.3 (94)
9.7 (94)
0.9 (100)
(15)
N
N
N
N
(35)
S
N
22.4 (57)
Note: The top concentration for the Emax when there are no EC50 available is 1 lM.
a
Values are means of two experiments.
a transrepression potency similar to the hydrocortisone analog 4.
The dexamethasone and fluticasone analogs 8 and 9 demonstrated
remarkable improvement in the IL-6 inhibitory activity. The
mometasone analog 10 with a 9-chloro substitution also demon-
strated excellent antiinflammatory activity. Interestingly, most of
the 9-halo derivatives (5, 8, 9 and 10) showed slightly higher trans-
activation to the corresponding deshalogenated analogs.
The promising dissociated profile of the hydrocortisone and
prednisolone series of compounds 4 and 7 encouraged us to further
optimize SAR, particularly to improve transrepression potency and

6
346
P. Biju et al. / Bioorg. Med. Chem. Lett. 21 (2011) 6343–6347
Table 6
Prednisolone C-17 furoate series: transactivation and transrepression in cell based assays
R
S
O
O
O
HO
O
O
Compd
IL-6 inhibition IC50 (nM)a (Emax%)
hGRE EC50 (nM)a (Emax%)
rTAT EC50 (nM)a (Emax%)
rTAT EC50 (nM)a (Emax%)
S
N
2
0
1
20
0.75 (99)
14.1 (93)
18.7 (62)
50.8 (43)
2
2
1
2
2
N
2.1 (96)
2.1 (98)
17.3 (73)
13.3 (97)
(32)
(24)
(24)
(43)
N
2
2
N
Me
Note: The top concentration for the Emax when there are no EC50 available is 1
lM.
a
Values are means of two experiments.
lipophilicity. We have shown in the past with the discovery of
1
1
mometasone furoate that C-17 esters, especially furoates are
known to improve receptor affinity and transrepression potency.
We therefore prepared a series of C-17 furyl esters of different
C-21 mercapto compounds in the hydrocortisone (Table 5) and
prednisolone series (Table 6). As we expected, most of the
compounds demonstrated single digit nanomolar potency towards
IL-6 inhibition, a several fold improvement from the corresponding
desfuroate compound. For example compound 6 showed an IL-6
inhibition IC50 of 2 nM compared to the desfuroate compound 4
1
1
20
00
Fluticasone Propionate
Compound
3
6
8
0
60
4
2
0
0
0
(
IC50 = 36 nM). Most of the compounds listed in Table 5 demon-
strated an excellent dissociated profile except compounds 16 and
9 which incorporate a benzoxazole and 3,4-dimethylthiazole mo-
1
tifs respectively. Each showed moderate activity in the human TAT
transactivation assay.
1
10
100
1000
10000
Estimated Pulmonary Deposition (µg/kg)
Table 6 summarizes a list of C-17 furoates prepared from the
parent steroid prednisolone. Most of the compounds listed in Ta-
ble 6 showed higher transactivation in the recombinant human
GRE luciferase assay. However, this series of compounds demon-
strated excellent transrepression potency, for example, compound
Figure 2. Therapeutics index model: compound 6 versus Fluticasone propionate 3
towards lung function and thymolysis.
2
0 showed an IC50 of 0.75 nM with full efficacy (Emax = 99%) to-
In the nose-only inhalation experiment, micronized compound
6 at concentrations of 10% drug admixed with micronized lactose
and 100% drug delivered by nose only inhalation once a day for
3 days. The results with inhaled compound 6 demonstrated dose-
dependent improvement in lung function with an ED70 of 47 lg/
kg daily estimated pulmonary deposition. Importantly, compound
wards IL-6 inhibition.
After identifying hydrocortisone based C-17 furoates with an
excellent dissociated profile and potent anti-inflammatory activity
in cell based assays, selective analogs were evaluated in a dry pow-
der nose only inhalation model. The benzothiazole compound 6
demonstrated full antiinflammatory efficacy and an improved
6 failed to induce thymolysis P20% at any dose tested up to
safety profile compared to the standard fluticasone propionate 3 (
730 lg/kg. The TI of compound 6 was greater than 15 compared
Fig. 2). Studies were performed in ovalbumin-challenged1
0,11
rats
to the positive control fluticasone propionate. This further demon-
strated that compound 6 has exceeded our primary goal of achiev-
ing a TI 10 fold greater than that of fluticasone propionate which
that were sensitized to ovalbumin by intraperitoneal injection of
ovalbumin and aluminum hydroxide, then challenged with aero-
solized ovalbumin (1% for 30 min). Twenty four hours after the
ovalbumin challenge, a bronchoalveolar lavage sample was ob-
tained and inflammatory cell numbers were enumerated. Addi-
tionally, the rats were surgically prepared for the measurement
of lung functions and changes in the forced vital capacity (FVC)
were measured. The safety profile of compound 6 was assessed
from changes in thymus weight13, which is a sensitive measure
of steroid side effect liability. The nose-only inhalation system
was used to conduct dose/response experiments and calculate a
therapeutic index (TI). The TI was calculated from the dose at
which there was a 20% reduction in thymus weight (ED20[thymol-
ysis]) and a 70% reversal of the ovalbumin induced reduction in
lung function as measured by forced vital capacity (ED70[FVC])
and expressed in as the ratio (TI = ED20(thymolysis)/ED70(FVC)).
has a TI of 1.1 (ED70(FVC) = 21
lg/kg and ED20(thymolysis) =
23 g/kg). Data in the Brown-Norway rat model with other clini-
l
cally effective inhaled corticosteroids such as beclomethasone
dipropionate and budesonide also showed a non-dissociated
profile similar to fluticasone propionate with a TI ꢀ1. Moreover,
compound 6 showed negligible plasma exposure (AUC = 7h ng/
ml; 10 mpk dose) in a rapid rat oral pharmacokinetic study. The
development of compound 6, a glucocorticoid with reduced side
effects, will allow safer treatments for patients who require long-
term suppression of inflammation.
A general procedure for the preparation of the above mentioned
compounds is outlined in the Scheme 1. The commercially
available hydrocortisone 1, was converted to the mesylate 23 by
using the standard procedure. Treatment of the mesylate 23 with

P. Biju et al. / Bioorg. Med. Chem. Lett. 21 (2011) 6343–6347
6347
OH
4. (a) Shapiro, E. L.; Gentles, M. J.; Tiberi, R. L.; Popper, T. L.; Berkenkopf, J.; Lutsky,
B.; Watnick, A. S. J. Med. Chem. 1987, 30, 1581; (b) Popper, T. L.; Gentles, M. J.;
Kung, T. T.; Berkenkopf, J.; Lutsky, B. N.; Watnick, A. S.; Shapiro, E. L. J. Steroid
Biochem. 1987, 27, 837.
OMs
O
OH
O
HO
HO
OH
5.
(a) Barnes, P. Clin. Sci. (London, England: 1979) 1998, 94, 557; (b) Rhen, T.;
Cidlowski, J. A. N. Engl. J. Med. 2005, 353, 1711; (c) Ito, K.; Getting, S.; Charron, C.
Scientific World J. 2006, 6, 1750.
i)
ii)
O
O
1
6. (a) Catley, M. C. The Scientific World 2007, 7 (MAR.), 421; Rosen, J.; Miner, J. N.
Curr. Med. Chem: Immunol., Endocrine & Metabolic Agents 2002, 2, 11; (b)
Schacke, H.; Rehwinkel, H.; Asadullah, K. Expert Opin. Ther. Patent 2008, 18, 339;
Miner, J. N.; Hong, M. H.; Negro-Vilar, A. Expert Opin. Investig. Drugs 2005, 14,
1527; (c) Rehwinkel, H.; Schäcke, H. ChemMedChem 2006, 1, 803.
2
3
N
N
S
S
O
OH
S
S
O
O
7. Belvisi, G.; Wicks, S. L.; Battram, C. H.; Bottoms, S. E. W.; Redford, J. E.;
Woodman, P.; Brown, T. J.; Webber, S. E.; Foster, M. L. J. Immunol. 2001, 166,
HO
O
HO
1975.
iii)
O
8. (a) Schaecke, H.; Asadullah, K.; Berger, M.; Rehwinkel, H. Methods and Principles
in Medicinal Chemistry 2008, 39, 305 (Nuclear Receptors as Drug Targets); (b)
Schacke, H.; Zollner, T. M.; Docke, W. D.; Rehwinkel, H.; Jaroch, S.; Skuballa, W.;
Neuhaus, R.; May, E.; Zugel, U.; Asadullah, K. Br. J. Pharmacol. 2009, 158, 1088;
O
O
4
6
(
2
c) Schäcke, H.; Berger, M.; Rehwinkel, H.; Asadullah, K. Mol. Cell Endocrinol.
007, 275, 109; (d) Mohler, M. L.; He, Y.; Wu, Z.; Hong, S. S.; Miller, D. D. Expert
Scheme 1. Reagents and conditions: (i) CH
3 2 2 2
SO Cl, Hunig’s Base, CH Cl , 0 °C to rt,
9
2%; (ii) 2-mercaptobenzothiazole, K CO , acetone, reflux, 85%; (iii) furoyl chloride,
2
3
Opin. Ther. Pat. 2007, 17, 37; (e) Hudson, A. R.; Roach, S. L.; Higuchi, R. I.;
Phillips, D. P.; Bissonnette, R. P.; Lamph, W. W.; Yen, J.; Li, Y.; Adams, M. E.;
Valdez, L. J.; Vassar, A.; Cuervo, C.; Kallel, E. A.; Gharbaoui, C. J.; Mais, D. E.;
Miner, J. N.; Marschke, K. B.; Rungta, D.; Negro-Vilar, A.; Zhi, L. J. Med. Chem.
°
2 2
DMAP, CH Cl , 0 C to rt, 81%.
2
007, 50, 4699; (f) Morgan, B. P.; Swick, A. G.; Hargrove, D. M.; LaFlamme, J. A.;
2
-mercaptobenzothiazole in acetone afforded compound 4, which
Moynihan, M. S.; Carroll, R. S.; Martin, K. A.; Lee, E.; Decosta, D.; Bordner, J. J.
Med. Chem. 2002, 45, 2417; (g) Robinson, R. P.; Buckbinder, L.; Haugeto, A. I.;
McNiff, P. A.; Millham, M. L.; Reese, M. R.; Schaefer, J. F.; Abramov, Y. A.;
Bordner, J.; Chantigny, Y. A.; Kleinman, E. F.; Laird, E. R.; Morgan, B. P.; Murray,
J. C.; Salter, E. D.; Wessel, M. D.; Yocum, S. A. J. Med. Chem. 2009, 52, 1731. and
references cited therein; (h) Takahashi, H.; Bekkali, Y.; Capolino, A. J.; Gilmore,
T.; Goldrick, S. E.; Nelson, R. M.; Terenzio, D.; Wang, J.; Zuvela-Jelaska, L.;
Proudfoot, J.; Nabozny, G.; Thomson, D. Bioorg. Med. Chem. Lett. 2006, 16, 1549;
was treated with furoyl chloride to afford the final compound 6.
In summary, compound 6 represents a novel inhaled steroid
with a pharmacological profile in the Brown-Norway rat therapeu-
tic index model of asthma that ‘dissociates’ the side-effect
(
thymolysis) while maintaining efficacy against pulmonary inflam-
mation and lung function. Thus C-21 mercapto derivatives of
hydrocortisone offers a new class of steroids with an improved
safety profile.
(
i) Regan, J.; Lee, T. W.; Zindell, T. R. M.; Bekkali, Y.; Bentzien, J.; Gilmore, T.;
Hammach, A.; Kirrane, T. M.; Kukulka, A. J.; Kuzmich, D.; Nelson, R. M.;
Proudfoot, J. R.; Ralph, M.; Pelletier, J.; Souza, D.; Zuvela-Jelaska, L.; Nabozny,
G.; Thomson, D. S. J. Med. Chem. 2006, 49, 7887; (j) Biggadike, K.; Boudjelal, M.;
Clackers, M.; Coe, D. M.; Demaine, D. A.; Hardy, G. W.; Humphreys, D.; Inglis, G.
A.; Johnston, M. J.; Jones, H. T.; House, D.; Loiseau, R.; Needham, D.; Skone, P. A.;
Uings, I.; Veitch, G.; Weingarten, G. G.; McLay, I. M.; Macdonald, S. J. F. J. Med.
Chem. 2007, 50, 6519; (k) Thompson, C. F.; Quraishi, N.; Ali, A.; Tata, J. R.;
Hammond, M. L.; Balkovec, J. M.; Einstein, M.; Ge, L.; Harris, G.; Kelly, T. M.;
Mazur, P.; Pandit, S.; Santoro, J.; Sitlani, A.; Wang, C.; Williamson, J.; Miller, D.
K.; Yamin, T. D.; Thompson, C. M.; O’Neill, E. A.; Zaller, D.; Forrest, M. J.;
Carballo-Jane, E.; Luell, S. Bioorg. Med. Chem. Lett. 2005, 15, 2163.
Acknowledgments
We thank Dr. John C. Hunter, Dr. Malcom Maccoss, Dr. John
Piwinski and Dr. William Greenlee from the Merck Research
Laboratory.
9
.
For Biological assay details, refer WO 2009085879.
References and notes
10. Celly, C. S.; House, A.; Sehring, S. J.; Zhang, X. Y.; Jones, H.; Hey, J. A.; Egan, R.
W.; Chapman, R. W. Eur. J. Pharmacol. 2006, 540, 147.
1
.
(a) Barnes, P. J. N. Eng. J. Med. 1995, 332, 868; (b) Townsend, H. B.; Saag, K. G.
Clin. Exp. Rheum. 2004, 22, S77; (c) Greaves, M. W.; Gatti, S. J. Dermat. Treat.
11. Chapman, R. W.; House, A.; Jones, H.; Richard, J.; Celly, C.; Prelusky, D.; Ting, P.;
Hunter, J. C.; Lamca, J.; Phillips, J. E. Eur. J. Pharmcol. 2007, 571, 215.
12. (a) Hoegger, P. Curr Med. Chem. Anti-Inflammatory & Anti-Allergy Agents 2003, 2,
395; (b) Kelly, H. W. Ann. Allergy, Asthma Immunol. 2003, 91, 326; (c) Derendorf,
H.; Nave, R.; Drollmann, A.; Cerasoli, F.; Wurst, W. Eur. Respir. J. 2006, 28, 1042;
(d) Bodor, N.; Buchwald, P. Curr. Pharm. Des. 2006, 12, 3241; (e) Johnson, M. J.
Allergy Clin. Immunol. 1996, 97, 169.
1
999, 10, 83.
2
3
.
.
Schacke, H.; Docke, W.-D.; Asadullah, K. Pharmacol. Ther. 2002, 96, 23.
(a) Brattsand, R.; Axelsson, B. I. New Drugs Asthma 1992, 2, 193; (b) Axelsson, B.;
Brattsand, R. Progress in Respiratory Research 2001, 31, 94 (New Drugs for
Asthma, Allergy and COPD); (c) Thalen, A.; Andersson, P. H.; Andersson, P. T.;
Axelsson, B.; Edsbacker, S.; Brattsand, R. Lung Biology in Health and Disease
13. Reichardt, H. M.; Kaestner, K. H.; Tuckermann, J.; Kretz, O.; Wessely, O.; Bock,
R.; Gass, P.; Schmid, W.; Herrlich, P.; Angel, P.; Schutz, G. Cell 1998, 93, 531.
2
002, 163, 521 (Inhaled Steroids in Asthma).