Structural development of liver X receptor (LXR) antagonists derived from thalidomide-related glucosidase inhibitors

Article abstract of DOI:10.1248/cpb.55.1750

Following our previous discovery of LXR antagonistic activity of 2′-substituted phenylphthalimides derived from thalidomide-related glucosidase inhibitors, structure-activity studies and further structural development led to 5-chloro-N-2′-n-pentylphenyl-1,3-dithiophthalimide (5CPPSS-50), with IC₅₀ values of about 10 and 13 μM for LXRα and LXR β, respectively.

Full text of DOI:10.1248/cpb.55.1750

1750
Notes
Chem. Pharm. Bull. 55(12) 1750—1754 (2007)
Vol. 55, No. 12
Structural Development of Liver X Receptor (LXR) Antagonists Derived
from Thalidomide-Related Glucosidase Inhibitors
Tomomi NOGUCHI-YACHIDE,a Hiroyuki MIYACHI,a Hiroshi AOYAMA,a Atsushi AOYAMA,a
Makoto MAKISHIMA,b and Yuichi HASHIMOTO*,a
a Institute of Molecular & Cellular Biosciences, The University of Tokyo; 1–1–1 Yayoi, Bunkyo-ku, Tokyo 113–0032,
Japan: and b Department of Biochemistry, Nihon University School of Medicine; 30–1 Oyaguchi-kamicho, Itabashi-ku,
Tokyo 173–8610, Japan. Received July 4, 2007; accepted September 25, 2007; published online September 26, 2007
Following our previous discovery of LXR antagonistic activity of 2ꢀ-substituted phenylphthalimides derived
from thalidomide-related glucosidase inhibitors, structure–activity studies and further structural development
led to 5-chloro-N-2ꢀ-n-pentylphenyl-1,3-dithiophthalimide (5CPPSS-50), with IC50 values of about 10 and 13 mM
for LXRa and LXRb, respectively.
Key words liver X receptor; thalidomide; phthalimide skeleton; antagonist; glucosidase inhibitor
Nuclear receptors (NRs) are ligand-dependent transcrip- regulate the expression of several genes involved in glucose
tion factors which regulate the expression of responsive metabolism.8,9) Thus, LXRs have been regarded as members
genes and thereby affect diverse processes, including cell of the metabolic subfamily of nuclear receptors, participating
growth, development, differentiation and metabolism.1) in the regulation of both lipid and sugar metabolism. Mitro et
Based on the elucidated human genome sequence, 48 NRs al. reported that LXRs act as glucose sensors, i.e., D-glucose
are thought to exist in humans.1) NRs are divided into four and D-glucose-6-phosphate act as ligands for LXRs and acti-
subfamilies, including (1) classical steroid hormone recep- vate their transcription activity with EC50 values of 3141 mM
tors, (2) retinoid/vitamin D3/thyroid hormone receptors, (3) for LXRa and 308 mM for LXRb.10) This finding indicates
metabolic receptors, and (4) orphan receptors. So far, the lig- that LXRs recognize both oxysterols and glucose derivatives
ands of only 20—25 of them have been identified, including as their physiological ligands.
(1) classical steroid hormone receptors [estrogen receptors
We have been engaged in structural development studies
(ERs)/estradiol, progesterone receptor (PR)/progesterone, an- of thalidomide, a drug first launched as a sedative/hypnotic
drogen receptor (AR)/testosterone, glucocorticoid receptor agent, but withdrawn from the market because of its severe
(GR)/cortisone, and mineral corticoid receptor (MR)/aldos- teratogenicity, focusing on its potential for the treatment of a
terone], (2) retinoid/vitamin D3/thyroid hormone receptors range of diseases, including cancers, diabetes, and rheuma-
[retinoic acid receptors (RARs)/all trans-retinoic acid and toid arthritis.11—15) We have developed a series of potent a-
retinoid X receptors (RXRs)/9-cis retinoic acid, thyroid glucosidase inhibitors, including CP0P (4), CP4P (5) and
hormone receptors (TRs)/thyroxine, vitamin D receptor PPS-33 (6) (Fig. 2).11—18) CP0P (4) is a non-competitive in-
(VDR)/1,25-dihydroxyvitamin D3], and (3) metabolic recep- hibitor of a-glucosidase, whereas CP4P (5) is a competitive
tors [peroxisome proliferator-activated receptors (PPARs)/ inhibitor.16—18) PPS-33 (6) is another competitive a-glucosi-
fatty acid, liver X receptor (LXRs)/oxysterol, farnesoid X re- dase inhibitor, but it also inhibits other enzymes, including
ceptor (FXR)/bile acid, and steroid xenobiotic receptor maltase and dipeptidylpeptidase type IV.19) The competitive
(SXR)/steroids].1) The LXRs are members of the metabolic inhibition of a-glucosidase by CP4P (5) and PPS-33 (6) indi-
receptor subfamily of the NR superfamily, and consist of two cated that these compounds might be structural mimics of
subtypes, LXRa and LXRb. The physiological ligands of glucose. On this basis, we found that CP4P (5) and PPS-33
LXRs are considered to be oxysterols, such as 24(S),25- (6) act as antagonists for LXRs.20) Our former structural de-
epoxycholesterol (1, EPC),1—3) and several synthetic ago- velopment studies based on CP4P (5) suggested that 2ꢀ-hy-
nists, including GW3965 (2) and T0901317 (3), have been drophobic substituents enhance the LXR antagonistic activity
reported (Fig. 1).4,5)
LXRs function as heterodimers with other nuclear recep- ported to be moderate LXR antagonists.20)
of the compounds, and PP2P (7) and PP-60 (8) have been re-
tors, the retinoid X receptors (RXRa, RXRb and RXRg), to
In this paper, we describe the structure–activity relation-
regulate important aspects of cholesterol homeostasis by ship of the 2ꢀ-alkyl group and further structural development
controlling expression of their target genes, including ATP of LXR antagonists based on the N-2ꢀ-alkylphenylphthalim-
binding cassette ABCA1 and CYP7A genes.6,7) LXRs also ide skeleton.
Fig. 1. Structures of Known LXR Agonists, EPC (1), GW3965 (2) and T0901317 (3)1—5)
∗ To whom correspondence should be addressed. e-mail: hashimot@iam.u-tokyo.ac.jp
© 2007 Pharmaceutical Society of Japan

December 2007
1751
Fig. 2. Structures of Thalidomide-Related a-Glucosidase Inhibitors with (5, 6) or without (4) LXR Antagonistic Activity10—12) and LXR Antagonists (7, 8)
Derived from These a-Glucosidase Inhibitors20)
Table 2. IC50 Values of PP-50 (14), 5CPP-50 (20), PPS-50 (21), PPSS-50
(22) and 5CPPSS-50 (23) for LXR Antagonistic Activity (mM)
Table 1. LXR Antagonistic Activities of 2ꢀ-Alkylated Phenylphthalimides
(8—15)
PP-50 (14) 5CPP-50 (20) PPS-50 (21) PPSS-50 (22) 5CPPSS-50 (23)
LXRa 42—45
LXRb 69—82
23—25
41—44
24—28
67—71
26—28
31—40
9.9—10
12—14
% Inhibition at 100 mM
substituent for LXR antagonistic activity. The substituent ef-
fect on antagonistic activity seemed to be greater for LXRa
than for LXRb. The IC50 values of PP-50 (14) were calcu-
lated to be 42—45 mM and 69—82 mM for LXRa and LXRb,
respectively (Fig. 4, Table 2).
Effects of 5-Chloro Substitution and Thiocarbonylation
Our previous and preliminary results, i.e., (i) 5CP4P (16)
possesses more potent antagonistic activity toward both
LXRa and LXRb than 56CP4P (17) or CP4P (18), and (ii)
PPS-33 (6) is a moderately potent LXR antagonist while PP-
33 (19) is not (Fig. 3), suggested that 5-chlorination and/or
thiocarbonylation of the phthalimide moiety enhance the ac-
n
LXRa
LXRb
PP-00 (9)
PP-10 (10)
PP-20 (11)
PP-30 (12)
PP-40 (13)
PP-50 (14)
PP-60 (8)
PP-70 (15)
—
0
1
2
3
4
5
6
29
26
42
50
64
89
88
88
33
31
29
44
52
81
75
77
Effect of the 2ꢀ-Alkyl Group As previously reported, tivity.20) Therefore, we examined the effects of 5-chlorination
PP-60 (8) shows moderate antagonistic activity toward and/or thiocarbonylation of PP-50 (14), i.e., 5CPP-50 (20),
LXRs, while the corresponding non-substituted phenylpthal- PPS-50 (21), PPSS-50 (22), and 5CPPSS-50 (23) (Fig. 3).
imide (PP-00: 9) has only very weak activity.20) To find the All of the compounds were prepared by usual organic syn-
optimum alkyl chain length of the 2ꢀ-alkyl substituent, we thetic methods, and their LXR antagonistic activity was eval-
prepared derivatives with different alkyl chain length, i.e., uated as described in Experimental. None of these com-
PP-10 (10), PP-20 (11), PP-30 (12), PP-40 (13), PP-50 (14) pounds showed LXR agonistic activity.
and PP-70 (15) (Table 1). All of the compounds were pre-
As expected, 5-chlorination enhanced the antagonistic ac-
pared by condensation of an appropriate o-alkylaniline with tivity toward both LXRa and LXRb (Fig. 4, Table 2): 5CPP-
phthalic anhydride. The LXR antagonistic activity of the pre- 50 (20) is a more potent LXR antagonist than PP-50 (14).
pared compounds was evaluated using a reporter gene assay Monothiocarbonylation of PP-50 (14) also resulted in en-
method with CMX-GAL4N-hLXR as the recombinant recep- hancement of the activity, as expected: PPS-50 (21) is more
tor gene, TK-MH100x4-LUC as the reporter gene and the active than PP-50 (14) (Table 2). Further thiocarbonylation of
CMX b-galactosidase gene for normalization, as previously PPS-50 (21), i.e., PPSS-50 (22), had little effect on LXRa
reported,21—23) and the results are shown in Table 1. None of antagonistic activity, but enhanced the LXRb antagonistic
the prepared compounds exhibited any LXR agonistic activ- activity. Based on these results, 5-chloro-N-2ꢀ-n-pentyl-
ity (data not shown).
phenyl-1,3-dithiophthalimide (5CPPSS-50: 23) was designed
As shown in Table 1, the effect of 2ꢀ-alkyl chain length on and prepared, and was found to be the most potent LXR an-
the LXR antagonistic activity of the compounds was clear. tagonist among the prepared compounds, with IC50 values of
The compounds with no alkyl group or an alkyl group 9.9—10 mM and 12—14 mM for LXRa and LXRb, respec-
shorter than an ethyl group, i.e., PP-00 (9) and PP-10 (10), tively (Table 2).
showed only very weak antagonistic activity toward both
LXRa and LXRb. The ethyl analog, PP-20 (11), showed also Conclusion
very weak antagonistic activity toward LXRb, but it had
In conclusion, LXR antagonists based on N-2ꢀ-
moderate antagonistic activity toward LXRa. The antagonis- alkylphenylphthalimide were structurally developed. As the
tic activity of compounds with a 2ꢀ-alkyl chain longer than a 2ꢀ-alkyl group, an n-pentyl group was determined to be the
methyl group increased in the order of: PP-20 (11)ꢁPP-30 best substituent. Further structural development resulted in
(12)ꢁPP-40 (13)ꢁPP-50 (14), for both LXRa and LXRb. 5CPPSS-50 (23), which has IC50 values of around 10 mM for
Further elongation of the 2ꢀ-alkyl chain, i.e., PP-60 (8) and antagonistic activity towards both LXRs. Further structural
PP-70 (15), scarcely affected (in the case of LXRa), or development and biological studies of 5CPPSS-50 (23) are in
seemed to slightly decrease (for LXRb) the activity. Thus, progress.
the 2ꢀ-n-pentyl group [PP-50 (14)] seemed to be the best

1752
Vol. 55, No. 12
Fig. 3. Effects of 5-Chlorination and Thiocarbonylation,20) and Design of Novel LXR Antagonists (20—23)
Fig. 4. LXR Antagonistic Activities of PP50 (14) and Its Derivatives (20—23) Measured by Means of Reporter Gene Assay
Various concentration of the test compounds were added in the presence of 0.1 mM T0901317 (3). The relative luciferase activity induced with 0.1 mM T0901317 (3) alone was
defined as 100%.

December 2007
1753
Experimental
PPS-50 (21) as a brown oil.
General Melting points were determined by using a Yanagimoto hot-
PPS-50 (21): 1H-NMR (500 MHz, CDCl3) d: 8.06—8.07 (1H, m), 7.87—
stage melting point apparatus and are uncorrected. 1H-NMR spectra were 7.89 (1H, m), 7.78 (1H, d, Jꢂ6.84 Hz), 7.41—7.76 (2H, m), 7.34 (1H, dt,
recorded on a JEOL JNM-GX500 (500 MHz) spectrometer. Chemical shifts Jꢂ7.69, 1.71 Hz), 7.16 (1H, d, Jꢂ8.10 Hz), 2.44 (1H, d, Jꢂ6.84 Hz), 2.42
are expressed in parts per million relative to tetramethylsilane. Mass spectra (1H, d, Jꢂ6.84 Hz), 1.51—1.54 (2H, m), 1.17—1.26 (4H, m), 0.78 (3H, t,
were recorded on a JEOL JMS-DX303 spectrometer. For silica gel chro- Jꢂ7.27 Hz). HR-FAB-MS: (MꢃH)ꢃ Calcd for C19H20NOS, 310.1266.
matography, Silica Gel 60 (Cica-Reagent Co. Ltd.) was used.
Found 310.1292.
N-2ꢀ-Methylphenylphthalimide (PP-10: 10) mp 180—181 °C. 1H-
PPSS-50 (22): 1H-NMR (500 MHz, CDCl3) d: 7.96 (2H, dd, Jꢂ5.55,
NMR (500 MHz, CDCl3) d: 7.99 (2H, m), 7.83 (2H, m), 7.40 (2H, m), 7.35 2.99 Hz), 7.77 (2H, dd, Jꢂ5.55, 2.99 Hz), 7.42—7.46 (2H, m), 7.35 (1H, dt,
(1H, m), 7.23 (1H, d, Jꢂ5.9 Hz), 2.24 (3H, s). Anal. Calcd for C15H11NO2: Jꢂ7.69, 1.71 Hz), 7.13 (1H, dd, Jꢂ7.69, 1.71 Hz), 2.36 (3H, t, Jꢂ8.12 Hz),
C, 75.94; H, 4.67; N, 5.90. Found: C, 76.03; H, 4.72; N, 5.86.
1.49—1.54 (2H, m), 1.15—1.20 (4H, m), 0.77 (3H, t, Jꢂ7.27 Hz). HR-FAB-
1
N-2ꢀ-Ethylphenylphthalimide (PP-20: 11) mp 132—133 °C. H-NMR
(60 MHz, CDCl3) d: 7.62—8.10 (4H, m), 6.96—7.50 (4H, m), 2.52 (2H, q,
Jꢂ7.5 Hz), 1.18 (3H, t, Jꢂ7.5 Hz). Anal. Calcd for C16H13NO2: C, 76.48; H, (5CPPSS-50: 23) A mixture of 5CPP-50 (20) (150 mg, 0.46 mmol), 2,4-
MS: (MꢃH)ꢃ Calcd for C19H20NS2, 326.1037. Found 326.1063.
5-Chloro-N-2ꢀ-n-pentylphenyl-2,3-dihydroisoindole-1,3-dithione
5.21; N, 5.57. Found: C, 76.65; H, 5.26; N, 5.54.
bis-(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane 2,4-disulfide (Lawes-
N-2ꢀ-n-Propylphenylphthalimide (PP-30: 12) Ethyl triphenyl phos- son reagent, Aldrich Co. Ltd.) (404 mg, 1.00 mmol) in dehydrated toluene
phonium bromide (1229 mg, 3.31 mmol) in THF (25 ml) was treated with
1 eq BuLi (1.6 M n-hexane solution, 2.04 ml) under ice cooling (stirred for
20 min). Then, 2-nitrobenzaldehylde (500 mg) in THF (1 ml) was added in
(30 ml) was refluxed for 8 h. The reaction mixture was concentrated and the
residue was purified by silica gel column chromatography (AcOEt : n-
hexaneꢂ1 : 15 v/v) and recrystallized from n-hexane–AcOEt to afford
aliquots, and stirred for 1 h. The resulted mixture was washed with water 90.5 mg (55%) of 5CPPSS-50 (23) as brown powder. mp 90—91 °C. 1H-
and separated by silica gel chromatography (AcOEt : n-hexaneꢂ1 : 1.15 v/v) NMR (500 MHz, CDCl3) d: 7.91 (1H, d, Jꢂ1.71 Hz), 7.89 (1H, d,
to give 271 mg pale yellow oil (crude yield: 50%). The oil was dissolved in Jꢂ8.12 Hz), 7.71 (1H, dd, Jꢂ8.12, 1.71 Hz), 7.43—7.49 (2H, m), 7.36 (1H,
10 ml EtOH and hydrogenated in the presence of 10% Pd/C (20 mg) under dt, Jꢂ7.69, 1.71 Hz), 7.12 (1H, d, Jꢂ7.69 Hz), 2.35 (2H, t, Jꢂ7.85 Hz),
an H2 atmosphere for 2 h to give 2-n-propylaniline quantitatively. The ob- 1.49—1.55 (2H, m), 1.13—1.34 (4H, m), 0.79 (3H, t, Jꢂ7.27 Hz). Anal.
tained 2-n-propylaniline was mixed with phthalic anhydride (121 mg) and Calcd for C19H18ClNS2: C, 63.40; H, 5.04: N, 3.89. Found: C, 63.22; H,
heated at 160 °C to melt under an Ar atmosphere for 1 h. The resulted mix-
ture was separated by silica gel chromatography (AcOEt : n-hexaneꢂ1 : 5
5.21: N, 3.91.
Reporter Gene Assay21—23) Human embryonic kidney (HEK) 293 cells
v/v) to give PP-30 (376 mg, y: 92%). The total yield was 46%. mp 94— were cultured in Dulbecco’s modified Eagle’s medium containing 5% fetal
95 °C. 1H-NMR (500 MHz, CDCl3) d: 7.95—7.99 (2H, m), 7.78—7.83 (2H, bovine serum at 37 °C in a humidified atmosphere of 5% CO2 in air. Trans-
m), 7.42 (1H, dt, Jꢂ7.33, 1.22 Hz), 7.39 (1H, dd, Jꢂ7.79, 2.14 Hz), 7.33 fections were performed by the calcium phosphate coprecipitation method.
(1H, dt, Jꢂ7.33, 2.14 Hz), 7.17 (1H, dd, Jꢂ7.79, 1.22 Hz), 2.47 (2H, t,
Test compounds with or without 0.1 mM T0901317 (3) (purchased from Cay-
Jꢂ7.79 Hz), 1.57 (2H, tq, Jꢂ7.79, 7.32 Hz), 0.86 (3H, t, Jꢂ7.32 Hz). Anal. man Co. Ltd.), were added 8 h after the transfection, and luciferase and b-
Calcd for C17H15NO2: C, 76.96; H, 5.70; N, 5.28. Found: C, 77.03; H, 5.56; galactosidase activities were assayed using a luminometer and microplate
N, 5.37.
reader (Wallac 1420 Multilabel Couner, Peerkin Elmer Co. Ltd.). The exper-
N-2ꢀ-n-Butylphenylphthalimide (PP-40: 13) PP-40 (13) was prepared iment was repeated three times, and the normalized average values are pre-
in the same manner as described for the synthesis of PP-30 (12) in a total sented in this paper.
yield of 38%. mp 75—76 °C. 1H-NMR (500 MHz, CDCl3) d: 7.94—7.99
(2H, m), 7.78—7.83 (2H, m), 7.42 (1H, dt, Jꢂ1.22, 7.86 Hz), 7.39 (1H, dd,
Acknowledgment The work described in this paper was partially sup-
Jꢂ7.25, 2.44 Hz), 7.33 (1H, dt, Jꢂ2.44, 7.25 Hz), 7.17 (1H, dd, Jꢂ1.22, ported by Grants-in-Aid for Scientific Research from The Ministry of Edu-
7.86 Hz), 2.49 (2H, t, Jꢂ7.78 Hz), 1.52—1.56 (2H, m), 1.19—1.23 (2H, m), cation, Culture, Sports, Science and Technology, Japan, and the Japan Soci-
0.79—0.81 (3H, t, Jꢂ7.02 Hz). Anal. Calcd for C18H17NO2: C, 77.40; H, ety for the Promotion of Science.
6.13; N, 5.01. Found: C, 77.51; H, 6.53; N, 4.99.
N-2ꢀ-n-Pentylphenylphthalimide (PP-50: 14) PP-50 (14) was prepared References
in the same manner as described for the synthesis of PP-30 (12) in a total
yield of 52%. mp 77—78 °C. 1H-NMR (500 MHz, CDCl3) d: 7.95—7.99
(2H, m), 7.78—7.83 (2H, m), 7.42 (1H, dt, Jꢂ1.22, 7.94 Hz), 7.39 (1H, dd,
Jꢂ7.25, 2.44 Hz), 7.33 (1H, dt, Jꢂ2.44, 7.25 Hz), 7.17 (1H, dd, Jꢂ7.94,
1.22 Hz), 2.48 (2H, t, Jꢂ7.94 Hz), 1.51—1.56 (2H, m), 1.19—1.23 (4H, m),
0.79—0.81 (3H, t, Jꢂ7.02 Hz). Anal. Calcd for C19H19NO2: C, 77.79; H,
6.53; N, 4.77. Found: C, 77.70; H, 6.55; N, 4.88.
1) Chawla A., Pepa J. J., Evans R., Mangelsdorf D. J., Science, 294,
1866—1870 (2001).
2) Janowski B. A., Willy P. J., Devi T. R., Falck J. R., Mangelsdorf D. J.,
Nature (London), 383, 728—731 (1996).
3) Lehmann J. M., Kliewer S. A., Moore L. B., Smith-Oliver T. A., Blan-
chard D. E., Spencer T. A., Willson T. M., J. Biol. Chem., 272, 3137—
3140 (1997).
N-2ꢀ-n-Hexylphenylphthalimide (PP-70: 15) PP-70 (15) was prepared
in the same manner as described for the synthesis of PP-30 (12) in a total
yield of 48%. mp 40 °C. 1H-NMR (500 MHz, CDCl3) d: 7.94—7.99 (2H,
m), 7.78—7.83 (2H, m), 7.41 (1H, dt, Jꢂ1.22, 7.21 Hz), 7.39 (1H, dd,
Jꢂ8.02, 2.14 Hz), 7.32 (1H, dt, Jꢂ2.14, 7.21 Hz), 7.16 (1H, dd, Jꢂ8.02,
1.22 Hz), 2.48 (2H, t, Jꢂ7.94 Hz), 1.49—1.58 (2H, m), 1.10—1.27 (8H, m),
0.79 (3H, t, Jꢂ7.02 Hz). Anal. Calcd for C21H23NO2: C, 78.47; H, 7.21; N,
4.35. Found: C, 78.77; H, 7.27; N, 4.21.
5-Chloro-N-2ꢀ-n-pentylphenylphthalimide (5CPP-50: 20) 5CPP-50
(20) was prepared in the same manner as described for the synthesis of PP-
30 (12) in a total yield of 83%. mp 88—89 °C. 1H-NMR (500 MHz, CDCl3)
d: 7.94 (1H, d, Jꢂ1.30 Hz), 7.90 (1H, d, Jꢂ8.12 Hz), 7.77 (1H, dd, Jꢂ8.12,
1.30 Hz), 7.39—7.42 (2H, m), 7.32—7.35 (1H, m), 7.15 (1H, d, Jꢂ7.27 Hz),
2.46 (2H, t, Jꢂ7.27 Hz), 1.53—1.56 (2H, m), 1.21—1.23 (4H, m), 0.80 (3H,
t, Jꢂ7.27 Hz). Anal. Calcd for C19H18ClNO2: C, 69.62; H, 5.53: N, 4.27.
Found: C, 69.69; H, 5.32; N, 4.26.
4) Collins J. L., Fivush A. M., Watson M. A., Galardi C. M., Lewis M.
C., Moore L. B., Parks D. J., Wilson J. G., Tippin T. K., Binz J. G.,
Plunket K. D., Morgan D. G., Beaudet E. G., Whitney K. D., Kliewer
S. A., Willson T. M., J. Med. Chem., 45, 1963—1966 (2002).
5) Schults J. R., Tu H., Luk A., Repa J. J., Medina J. C., Li L., Schwend-
ner S., Wang S., Thoolen M., Mangelsdorf D. J., Lustig K. D., Shan B.,
Genes Develop., 14, 2831—2838 (2000).
6) Repa J. J., Turley S. D., Lobaccaro J. M. A., Medina J., Li L., Lustig
K., Shan B., Heyman R. A., Dietschy J. M., Mangelsdorf D. J.,
Science, 289, 1524—1529 (2000).
7) Peet D. J., Turley S. D., Ma W., Janowski B. A., Lobaccaro J. M. A.,
Hammer R. E., Mangelsdorf D. J., Cell, 93, 693—704 (1998).
8) Laffitte B. A., Chao L. C., Li J., Walczak R., Hummasti S., Joseph S.
B., Castrillo A., Wilpitz D. C., Mangelsdorf D. J., Collins J. L., Saez
E., Tontonoz P., Proc. Natl. Acad. Sci. U.S.A., 100, 5419—5424
(2003).
N-2ꢀ-n-Pentylphenyl-3-thioxo-2,3-dihydroisoindol-1-one (PPS-50: 21)
and N-2ꢀ-n-Pentylphenyl-2,3-dihydroisoindole-1,3-dithione (PPSS-50:
22) A mixture of PP-50 (14) (650 mg, 2.22 mmol), 2,4-bis-(4-methoxy-
phenyl)-1,3-dithia-2,4-diphosphetane 2,4-disulfide (Lawesson reagent,
9) Cao G., Liang Y., Broderick C. L., Oldham B. A., Beyer T. P., Schmidt
R. J., Zhang Y., Stayrook K. R., Suen C., Otto K. A., Miller A. R., Dai
J., Foxworthy P., Gao H., Ryan T. P., Jiang X. C., Burris T. P., Eacho P.
I., Etgen G. J., J. Biol. Chem., 278, 1131—1136 (2003).
Aldrich Co. Ltd.) (900 mg, 2.23 mmol) in dehydrated toluene (40 ml) was re- 10) Mitro N., Mak P. A., Vatgas L., Godio C., Hampton E., Molteni V.,
fluxed for 8 h. The reaction mixture was concentrated and the residue was Kreusch A., Saez E., Nature (London), 445, 219—223 (2007).
purified by silica gel column chromatography (AcOEt : n-hexaneꢂ1 : 10 to 11) Hashimoto Y., Curr. Med. Chem., 5, 163—178 (1998).
1 : 5 v/v) to afford 430 mg (y: 59%) of PPSS-50 (22) and 100 mg (y: 15%) of 12) Hashimoto Y., Bioorg. Med. Chem., 10, 461—479 (2002).

1754
Vol. 55, No. 12
13) Hashimoto Y., Tanatani A., Nagasawa K., Miyachi H., Drugs Future, 19) Shimazawa R., Takayama H., Kato F., Kato M., Hashimoto Y., Bioorg.
29, 383—391 (2004).
Med. Chem. Lett., 9, 559—562 (1999).
14) Hashimoto Y., Mini-Rev. Med. Chem., 2, 543—551 (2002).
15) Shimazawa R., Takayama H., Fujimoto Y., Komoda M., Dodo K., Ya-
20) Noguchi-Yachide T., Aoyama A., Makishima M., Miyachi H.,
Hashimoto Y., Bioorg. Med. Chem. Lett., 17, 3957—3961 (2007).
masaki R., Shirai R., Koiso Y., Miyata K., Kato F., Kato M., Miyachi 21) Makishima M., Lu T. T., Xie W., Whitfield G. K., Domoto H., Evans
H., Hashimoto Y., J. Enzyme Inhibit., 14, 249—275 (1999).
16) Sou S., Mayumi S., Takahashi H., Yamasaki R., Kadoya S., Sodeoka
M., Hashimoto Y., Bioorg. Med. Chem. Lett., 10, 1081—1084 (2000).
17) Takahashi H,, Sou S., Yamasaki R., Sodeoka M., Hashimoto Y., Chem.
Pharm. Bull., 48, 1494—1499 (2000).
R. M., Haussler M. R., Mangelsdorf D. J., Science, 296, 1313—1316
(2002).
22) Makishima M., Okamoto A. Y., Repa J. J., Tu H., Learned R. M., Luk
A., Hull M. V., Lustig K. D., Mangelsdorf D. J., Shan B., Science, 284,
1362—1365 (1999).
18) Sou S., Takahashi H., Yamasaki R., Kagechika H., Endo Y.,
Hashimoto Y., Chem. Pharm. Bull., 49, 791—793 (2001).
23) Kasuga J., Makishima M., Hashimoto Y., Miyachi H., Bioorg. Med.
Chem. Lett., 16, 554—558 (2006).