1260
C. L. Cioffi et al. / Bioorg. Med. Chem. Lett. 23 (2013) 1257–1261
Table 2
In vitro profile of 40
a
b
CYP inhibition IC50 (3A4, 2D6, 2C19, 2C9)
hERG IC50
>100
Selectivity panel IC50 (1
All <50% inhibition
lM)
CLint
(l
L/min/mg)
% PPBc
Mini-amesd
Negative
All >10
l
M
l
M
Human = 13, rat = 5.5
Human = 87, rat = 84
a
b
c
‘Patch-Xpress’ patch-clamp assay; compound was tested (n = 3) in a 5-point concentration–response on HEK293 cells stably expressing the hERG channel.
Compound concentration at 1
Plasma protein binding.
lM.
d
TA98 and TA100 strains tested in the presence and absence of rat S9 fraction.
Table 3
PK properties of 40 in rat (2 mg/kg IV and 10 mg/kg POa)
sults indicated both CNS penetration of inhibitor 40 and in vivo
engagement with the target, which justified further optimization
and development of our series.
CLb (mL/h/kg)
Vss (mL/kg)
1321
3258
486
1995
2.9
In summary, we have rationally designed and developed a ser-
ies of potent and selective non-sarcosine-derived N-((1-(4-(propyl-
sulfonyl)piperazin-1-yl)cycloalkyl)methyl)benzamide inhibitors of
GlyT-1. Poor HLM stability was identified as a key deficiency
requiring improvement for the series. Installation of a gem-difluoro
cyclohexyl central ring provided a competent strategy for greatly
improving this issue while maintaining an excellent in vitro profile
and favorable CNS drug-like characteristics. This modification pro-
vided compound 40, which demonstrated in vivo activity in the rat
CSF glycine biomarker model and provided proof-of-concept that
our series could generate a GlyT-1 inhibitor capable of in vivo
engagement with the target. Additional refinements to the series
that have led to advanced analogues demonstrating exquisite
in vitro potency and in vivo activity will be reported in due course.
Cmax (ng/mL)
AUC0 ? 1 (h ng/mL)c
Terminal T1/2 (h)
Tmax (h)
1.5
25.7
%Fd
a
IV and PO formulation: 10% EtOH, 40% PEG400, 50% H2O.
Total plasma clearance.
Area under the curve extrapolated to infinity.
Oral bioavailability.
b
c
d
250
225
*
200
*
Acknowledgments
175
150
125
100
75
The authors would like to thank Drs. Robert E. Davis, Jeffery S.
Sprouse, and Bryan L. Roth for helpful discussions.
References and notes
1. Andreasen, N. C. Brain Res. Rev. 2000, 31, 106.
2. (a) Seeman, P.; Lee, T. Science 1975, 188, 1217; (b) Sawa, A.; Snyder, S. H. Science
2002, 296, 692; (c) Howes, O.; Shitj, K. Schizophr. Bull. 2009, 1.
3. Tamminga, C. A.; Davis, J. M. Schizophr. Bull. 2007, 33, 937.
4. Javitt, D. C.; Zukin, S. R. Am. J. Psychiatry 1991, 148, 1301.
5. Millan, M. J. Psychopharmacology 2005, 179, 30.
1
10
100
Compound 40 (mg/kg PO)
6. Javitt, D. C. Int. Rev. Neurobiol. 2007, 78, 69.
7. Neill, J. C.; Barnes, S.; Cook, S.; Grayson, B.; Idris, N. F.; McLean, S. L.; Snigdha, S.;
Rajagopal, L.; Harte, M. K. Pharmacol. Ther. 2010, 128, 419.
8. Field, J. R.; Walker, A. G.; Conn, J. P. Cell 2011, 17, 689.
9. Gomeza, J.; Armsen, W.; Betz, H.; Eulenburg, V. Neurotransmitter Transporters
2006, 457.
n = 5/group. Error bars represent SEM. p < 0.05 vs. respective control,
Tukey HDS analysis.
Figure 6. Dose dependent elevation of rat CSF glycine induced by 40.
10. Eulenburg, V.; Armsen, W.; Betz, H.; Gomeza, J. Trends Biochem. Sci. 2005, 30,
325.
11. Javitt, D. C. Curr. Opin. Psychiatry 2006, 19, 151.
12. Moehler, H.; Boison, D.; Singer, P.; Feldon, J.; Pauly-Evers, M.; Yee, B. K.
Biochem. Pharmacol. 2011, 81, 1065.
13. Lane, H.; Liu, Y.; Huang, C.; Chang, Y.; Jiau, C.; Perng, C.; Tsai, G. E. Biol.
Psychiatry 2008, 63, 9.
14. Javitt, D. C. Curr. Opin. Drug Discov. Devel. 2009, 12, 468.
15. Buchanan, R. W.; Javitt, D. C.; Marder, S. R.; Scooler, N. R.; Gold, J. M.; McMahon,
R. P.; Heresco-Levy, U.; Carpenter, W. T. Am. J. Psychiatry 2007, 164, 1593.
17. Pinard, E.; Alanine, A.; Alberti, D.; Bender, M.; Borroni, E.; Bourdeaux, P.; Brom,
V.; Burner, S.; Fischer, H.; Hainzl, D.; Hauser, N.; Jolidon, S.; Lemgyel, J.;
Nocross, R. D.; Peullmann, G.; Schmid, P.; Schmitt, S.; Stadler, H.; Wermuth, R.;
Wettstin, J. G.; Zimmerli, D. J. Med. Chem. 2010, 53, 4603.
18. (a) Cioffi, C. L.; Liu, S.; Wolf, M. A. Annu. Rep. Med. Chem. 2010, 45, 19; (b)
Gilfillan, R.; Kerr, J.; Walker, G.; Wishart, G. Top. Med. Chem. 2009, 4, 223; (c)
Wolkenburg, S.; Sur, C. Curr. Top. Med. Chem. 2010, 10, 170; (d) Bridges, T.;
Williams, R.; Lindsley, C. Curr. Opin. Mol. Ther. 2008, 10, 591; (e) Lechner, S.
Curr. Opin. Pharmacol. 2006, 6, 75; (f) Thomsen, C. Drug Discov. Today: Ther.
Strateg. 2006, 3, 539.
19. Cioffi, C. L.; Wolf, M. A.; Guzzo, P. R.; Shuang, L.; Sadalapure, K.; Parthasarathy,
V.; Maeng, J.-H. Patent Application WO 2011/153359-A1, 2011.
20. Lindsley, C. W.; Zhao, Z.; Leister, W. H.; O’Brien, J.; Lemaire, W.; Williams, D. L.;
Chen, T.-B.; Chang, R. S. L.; Burno, M.; Jacobson, M. A.; Sur, C.; Kinney, G. G.;
Pettibone, D. J.; Tiller, P. R.; Smith, S.; Tsou, N. N.; Duggan, M. E.; Conn, P. J.;
Hartman, G. D. ChemMedChem 2006, 1, 807.
150
125
100
75
50
25
0
1
10
100
Compound 40 (mg/kg PO)
n = 5/group. Error bars represent SEM.
Figure 7. Dose dependent elevation of 40 in rat CSF.