6416
T. Fujimoto et al. / Bioorg. Med. Chem. Lett. 21 (2011) 6414–6416
Bergman, J. P.; Brashear, K. M.; McGaughey, G. G.; Bednar, R. A.; Lemaire, W.;
P<0.01 vs Veh
12000
9000
6000
3000
0
Doran, S. M.; Fox, S. V.; Garson, S. L.; Harrell, C. M.; Kraus, R. L.; Murphy, K.;
Reiss, D. R.; Cui, D.; Li, C.; Prueksaritanont, T.; Roller, S.; Tang, C.; Stevens, J.;
Tannenbaum, P.; Young, S. D.; Koblan, K. S.; Hartman, G. D.; Renger, J. J. (MEDI-
P<0.025 vs OXA
P<0.025 vs OXA
37) 239th ACS National Meeting
& Exposition March 21–25, San Francisco,
California 2010.; (e) Cox, C. D.; Breslin, M. J.; Whitman, D. B.; Schreier, J. D.;
McGaughey, G. B.; Bogusky, M. J.; Roecker, A. J.; Mercer, S. P.; Bednar, R. A.;
Lemaire, W.; Bruno, J. G.; Reiss, D. R.; Harrell, C. M.; Murphy, K. L.; Garson, S. L.;
Doran, S. M.; Prueksaritanont, T.; Anderson, W. B.; Tang, C.; Roller, S.; Cabalu, T.
D.; Cui, D.; Hartman, G. D.; Young, S. D.; Koblan, K. S.; Winrow, C. J.; Renger, J. J.;
Coleman, P. J. J. Med. Chem. 2010, 53, 5320; (f) Winrow, C. J.; Gotter, A. L.; Cox, C.
D.; Doran, S. M.; Tannernbaum, P. L.; Breslin, M. J.; Garson, S. L.; Fox, S. V.;
Harrell, C. M.; Stevens, J.; Reiss, D. R.; Cui, D.; Coleman, P. J.; Renger, J. . J. J.
Neurogenet. 2011, 25, 52.
4. Metabolic stabilities were determined by the described method below.
Liver metabolic stability assay conditions
Vehicle
0
10
30 (mpk)
Condition
Orexin-A (1 nmol)
Substrate concentration
Microsomal protein concentration
Co-enzyme
Temperature
Quench Solvent
Incubation time points
Detection
Calculations
1 lM
0.2 mg/mL
NADPH-regenerating systems
37 °C
Acetonitrile (1:1)
0, 15, 30 min
Figure 2. Effect of Compound 1m on orexin-A induced locomotion. ⁄p <0.01 versus
Vehicle/Vehicle (Dunnetts test), #p <0.025 versus Vehicle/OX-A (Williams test),
n = 8 for each groups.
In summary, we have described SAR study of benzoxazepine
scaffold leading to a novel, potent, selective, and orally available
human OX2R antagonist. In attempts to improve potency and met-
5-in-One analysis using LC/MS/MS
CL (l
L/min/mg) = 1000⁄(1-exp(k⁄t))/
t/m t; time, 20 (min) m; microsomal
protein, 0.2 (mg/mL) k; Rate constant
(1/min) calculated from exponential
fit of parent remaining vs. time
abolic stability, we utilized Hammett
rp and Hansch-Fujita p value
as aromatic substituent constants. These efforts led to compound
1m, which showed good in vitro potency (27 nM) with high LE
as 0.40 and over 100–fold selectivity against OX1R, good metabolic
stability in human and rat liver microsome, and good oral bioavail-
ability in rats.12 We further demonstrated the ability of compound
1m to inhibit orexin-A mediated locomotion, when administered
orally, in a dose dependent manner. Further in vivo evaluation will
be reported in due course.
curve, assuming first order kinetics
Criteria
Stable: <50
50–100 L/min/mg, Unstable:
>100 L/min/mg
lL/min/mg, Moderate:
l
l
5. One of examples for quinoid bioactivation is troglitazone as PPAR gamma
agonist. See references: (a) Blagg, J. Ann. Rep. Med. Chem. 2006, 41, 353; (b)
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Drug Discovery Des. 2008, 11, 43.
Supplementary data
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and references cited therein..
Supplementary data associated with this article can be found, in
8. Craig, P. N. Guidlines for drug and analogue design. In The Basis of Medicinal
Chemistry, vol. 1; Wolff, M. E., Ed.; Wiley-Interscience: New York, 1980. p. 165.
9. The Japanese Pharmacopoeia Fourteenth Edition.
References and notes
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11. Passive permeability as over 20 nm/s means high permeability. MDR1
directional transport ratio (B to A/A to B) as below 3.0 means low
susceptibility of P-gp.
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Zapatero, C. Expert Opin. Drug Discov. 2007, 2, 469. Ligand efficiency (LE) is the
binding energy per heavy atom (kcal molÀ1) =
D G/number of heavy
atoms = À1.36 log (OX2R IC50)/number of heavy atoms..
13. Bergman, J. M.; Roecker, A. J.; Mercer, S. P.; Bednar, R. A.; Reiss, D. R.; Ransom,
R. W.; Harrell, C. M.; Pettibone, D. J.; Lemaire, W.; Murphy, K. L.; Li, C.;
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