Y. Xie et al. / Bioorg. Med. Chem. Lett. 19 (2009) 2354–2359
2359
Table 2 (continued)
a
Compound
R0
Inhibition (%) at 200 nm
49
IC50 (nM)
ND
Compound
R0
Inhibition (%) at 200 nm
88
IC50 (nM)
8-19
8-44
11.0b
Boc N
N
Cl
8-20
8-21
8-22
8-23
8-24
62
67
33.6
43.3
ND
8-45
8-46
8-47
8-48
8-49
8-50
79
86
92
75
14
15
20.1
39.6b
12.6b
37.3b
ND
NH
NH
Ph
16
NO2
ꢀ25
9
ND
Cl
F
ND
O
N
NH
8-25
ꢀ6
ND
ND
HN
O
a
IC50 values are determined from a single experiment performed in triplicate.
IC50 values are determined from two independent experiments performed in triplicate.
ND, not determined.
b
c
bridge with the catalytic nucleophile Asp333 in the active site of
sEH, is absolutely required for the activity.9 Hypothesizing that
the amide in our hit corresponded to the urea functionality serving
as the primary pharmacophore, we selected a variety of primary
amines to replace 2,4-dichloride benzylamine moiety, including
those frequently found in urea-based inhibitors. As shown in Table
2, the primary amide was quite tolerant to modification and nano-
molar potency was retained with various substitutions. N-Benzyla-
mide 8-9 (IC50 = 42.0 nM) and N-cyclohexylamide 8-14
(IC50 = 16.4 nM) were selected for further optimization. Extensive
modification of the benzyl group led to 8-37 with a significant
improvement of potency (IC50 = 12.7 nM). The most noticeable
SAR illustrated by this modification is that halides such as chloride
and fluoride seem favored for the substitution on the benzyl group.
The modification of cyclohexylamide 8-14 yielded the most potent
compounds 8-42 (IC50 = 7.9 nM) and 8-47 (IC50 = 12.6 nM). As
demonstrated by this result, adding an extra methylene to the
cyclohexyl ring significantly enhanced the activities. In contrast,
analogs with polar atoms (N and O) in the ring decreased the inhib-
itory potency to micromolar range (8-49 and 8-50). These SARs are
consistent with previous results obtained for urea derivatives.10
In summary, we have successfully identified a series of potent
non-urea sEH inhibitors via high throughput screens. Improved po-
tency was sought through SAR-guided modification. Compound 8-
42 with an IC50 of 7.9 nm represents the most potent non-urea sEH
inhibitor identified in this study. Physical and pharmacokinetic
properties of these promising compounds are under investigation.
Acknowledgment
This work was supported by the NIH MLSCN Grant.
References and notes
1. Smith, K. R.; Pinkerton, K. E.; Watanabe, T.; Pedersen, T. L.; Ma, S. J.; Hammock,
B. D. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 2186.
2. Schmelzer, K. R.; Kubala, L.; Newman, J. W.; Kim, I. H.; Eiserich, J. P.; Hammock,
B. D. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 9772.
3. Chiamvimonvat, N.; Ho, C. M.; Tsai, H. J.; Hammock, B. D. J. Cardiovasc.
Pharmacol. 2007, 50, 225.
4. Kim, I. H.; Tsai, H. J.; Nishi, K.; Kasagami, T.; Morisseau, C.; Hammock, B. D.
J. Med. Chem. 2007, 502, 5217.
5. Wolf, N. M.; Morisseau, C.; Jones, P. D.; Hock, B.; Hammock, B. D. Anal. Biochem.
2006, 335, 71.
6. See the screen results published in Pubchem (AID:1026).
7. Jones, P. D.; Tsai, H. J.; Do, Z. N.; Morisseau, C.; Hammock, B. D. Bioorg. Med.
Chem. Lett. 2006, 16, 5212.
8. Analytical data for the representative compounds: 8-42: 1H NMR (300 MHz,
CDCl3) d 6.94 (s, 2H), 5.38 (br, 1H), 3.92–3.89 (m, 1H), 3.62–3.57(m, 2H), 2.83–
2.63 (t, 2H), 2.61 (s, 6H), 2.30 (s, 3H), 2.17–2.10 (m, 1H), 1.87–1.83 (m, 4H),
1.74–1.35 (m, 12H); 13C NMR (75 MHz, CD3 OD) d 172.9, 142.9, 140.6, 132.1,
131.6, 50.6, 44.0,43.1, 35.4, 28.5, 28.3, 24.5, 23.1, 21.3; ESI-MS(M++H): 407.2. 8-
47: 1H NMR (300 MHz, CDCl3) d 6.94 (s, 2H), 5.48 (br, 1H), 3.60 (d, 2H), 3.07 (t,
2H), 2.81 (t, 2H), 2.61 (s, 6H), 2.30 (s, 3H), 2.20–2.05 (m, 1H), 1.88–1.84 (m, 2H),
1.77–1.64 (m, 6H); 1.50–1.38 (m, 1H); 1.35–1.05 (m, 4H); 0.95–0.82 (m, 2H);
13C NMR (75 MHz, CD3OD) d 174.2, 142.9, 140.7, 132.1, 131.5, 45.9, 44.0, 43.2,
38.2, 31.1, 28.6, 26.7, 26.1, 23.2, 21.3; ESI-MS(M++H): 407.3.
9. Argiriadi, M. A.; Morisseau, C.; Goodrow, M. H.; Dowdy, D. L.; Hammock, B. D.;
Christianson, D. W. J. Biol. Chem. 2000, 275, 15265.
10. Kim, I. H.; Heirtzler, F. R.; Morisseau, C.; Nishi, K.; Tsai, H. J.; Hammock, B. D.
J. Med. Chem. 2005, 48, 3621.