Satoshi Sasaki

Publications (6)23.49 Total impact

• Article: Discovery of 1-{4-[1-(2,6-difluorobenzyl)-5-[(dimethylamino)methyl]-3-(6-methoxypyridazin-3-yl)-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidin-6-yl]phenyl}-3-methoxyurea (TAK-385) as a potent, orally active, non-peptide antagonist of the human gonadotropin-releasing hormone receptor.

  Kazuhiro Miwa, Takenori Hitaka, Takashi Imada, Satoshi Sasaki, Mie Yoshimatsu, Masami Kusaka, Akira Tanaka, Daisuke Nakata, Shuichi Furuya, Satoshi Endo, Kazumasa Hamamura, Tomoyuki Kitazaki
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  ABSTRACT: We previously discovered an orally active human gonadotropin-releasing hormone (GnRH) receptor antagonist, thieno[2,3-d]pyrimidine-2,4-dione derivative 1 (sufugolix). To reduce the cytochrome P450 (CYP) inhibitory activity and improve in vivo GnRH antagonistic activity, further optimization of this scaffold was carried out. We focused our synthetic efforts on chemical modification at the 5 and 3 positions of the thieno[2,3-d]pyrimidine-2,4-dione ring based on computational modeling, which resulted in the discovery of 1-{4-[1-(2,6-difluorobenzyl)-5-[(dimethylamino)methyl]-3-(6-methoxypyridazin-3-yl)-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidin-6-yl]phenyl}-3-methoxyurea (16b) as a highly potent and orally active GnRH antagonist. Compound 16b showed potent in vitro GnRH antagonistic activity in the presence of fetal bovine serum (FBS) without CYP inhibition. Oral administration of 16b maintained the suppressive effect of the plasma luteinizing hormone levels in castrated cynomolgus monkeys at a 3 mg/kg dose for more than 24 h. Compound 16b is currently under clinical development with the code name of TAK-385.
  Journal of Medicinal Chemistry 06/2011; 54(14):4998-5012. · 4.80 Impact Factor
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  Available from: earthwebz.com

  Article: 2-acylamino-4,6-diphenylpyridine derivatives as novel GPR54 antagonists with good brain exposure and in vivo efficacy for plasma LH level in male rats.

  Toshitake Kobayashi, Satoshi Sasaki, Naoki Tomita, Seiji Fukui, Masaharu Nakayama, Atsushi Kiba, Masami Kusaka, Shin-ichi Matsumoto, Masashi Yamaguchi, Fumio Itoh, Atsuo Baba
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  ABSTRACT: GPR54 is a G protein-coupled receptor (GPCR) which was formerly an orphan receptor. Recent functional study of GPR54 revealed that the receptor plays an essential role to modulate sex-hormones including GnRH. Thus, antagonists of GPR54 are expected to be novel drugs for sex-hormone dependent diseases such as prostate cancer or endometriosis. We recently reported 2-acylamino-4,6-diphenylpyridines as the first small molecule GPR54 antagonists with high potency. However, the representative compound 1 showed low brain exposure, where GPR54 acts as a modulator of gonadotropins by binding with its endogenous ligand, metastin. In order to discover compounds that have not only potent GPR54 antagonistic activity but also good brain permeability, we focused on converting the primary amine on the side chain to a secondary or tertiary amine, and finally we identified 15a containing a piperazine group. This compound exhibited high affinity to human and rat GPR54, apparent antagonistic activity, and high brain exposure. In addition, intravenous administration of 15a to castrated male rat suppressed plasma LH level, which indicates the possibility of a small molecule GPR54 antagonist as a novel drug for sex-hormone dependent diseases.
  Bioorganic & medicinal chemistry 07/2010; 18(14):5157-71. · 2.82 Impact Factor
• Article: Synthesis and structure-activity relationships of 2-acylamino-4,6-diphenylpyridine derivatives as novel antagonists of GPR54.

  Toshitake Kobayashi, Satoshi Sasaki, Naoki Tomita, Seiji Fukui, Noritaka Kuroda, Masaharu Nakayama, Atsushi Kiba, Yoshihiro Takatsu, Tetsuya Ohtaki, Fumio Itoh, Atsuo Baba
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  ABSTRACT: GPR54 is a G protein-coupled receptor (GPCR) which was formerly an orphan receptor. Recent functional study of GPR54 revealed that the receptor has an essential role to modulate sex-hormones including GnRH. Though antagonists of GPR54 are expected to be novel drugs for sex-hormone dependent diseases such as prostate cancer or endometriosis, small molecule GPR54 antagonists have not been reported. We have synthesized a series of 2-acylamino-4,6-diphenylpyridines to identify potent GPR54 antagonists. Detailed structure-activity relationship studies led to compound 9l with an IC(50) value of 3.7nM in a GPR54 binding assay, and apparent antagonistic activity in a cellular functional assay.
  Bioorganic & medicinal chemistry 06/2010; 18(11):3841-59. · 2.82 Impact Factor
• Article: Design, synthesis, and structure-activity relationships of thieno[2,3-b]pyridin-4-one derivatives as a novel class of potent, orally active, non-peptide luteinizing hormone-releasing hormone receptor antagonists.

  Takashi Imada, Nobuo Cho, Toshihiro Imaeda, Yoji Hayase, Satoshi Sasaki, Shizuo Kasai, Masataka Harada, Hirokazu Matsumoto, Satoshi Endo, Nobuhiro Suzuki, Shuichi Furuya
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  ABSTRACT: Design, synthesis, and structure-activity relationships of thieno[2,3-b]pyridin-4-one-based non-peptide luteinizing hormone-releasing hormone (LHRH) receptor antagonists are described. Starting with the thienopyridin-4-one derivative 26d (T-98475) an optimization study was performed, which resulted in the identification of a highly potent and orally bioavailable LHRH receptor antagonist, 3-(N-benzyl-N-methylaminomethyl)-7-(2,6-difluorobenzyl)-4,7-dihydro-2-[4-(1-hydroxy-1-cyclopropanecarboxamido)phenyl]-5-isobutyryl-4-oxothieno[2,3-b]pyridine (33c). Compound 33c displayed subnanomolar in vitro activities for the human receptor and its oral administration caused effective suppression of the plasma LH levels in castrated male cynomolgus monkeys. Furthermore, SAR studies revealed that a hydroxyalkylamido moiety on the 2-phenyl ring is virtually equivalent to an alkylureido moiety, at least in this series of compounds.
  Journal of Medicinal Chemistry 07/2006; 49(13):3809-25. · 5.25 Impact Factor
• Article: Discovery of a thieno[2,3-d]pyrimidine-2,4-dione bearing a p-methoxyureidophenyl moiety at the 6-position: a highly potent and orally bioavailable non-peptide antagonist for the human luteinizing hormone-releasing hormone receptor.

  Satoshi Sasaki, Nobuo Cho, Yoshi Nara, Masataka Harada, Satoshi Endo, Nobuhiro Suzuki, Shuichi Furuya, Masahiko Fujino
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  ABSTRACT: We have previously disclosed the first potent and orally effective non-peptide antagonist for the human luteinizing hormone-releasing hormone (LHRH) receptor, a thieno[2,3-b]pyridin-4-one derivative, T-98475 (1). Extensive research on developing non-peptide LHRH antagonists has been carried out by employing a strategy of replacing the thienopyridin-4-one nucleus with other heterocyclic surrogates. We describe herein the design and synthesis of a series of thieno[2,3-d]pyrimidine-2,4-dione derivatives containing a biaryl moiety, which led to the discovery of a highly potent and orally active non-peptide LHRH antagonist, 5-(N-benzyl-N-methylaminomethyl)-1-(2,6-difluorobenzyl)-6-[4-(3-methoxyureido)phenyl]-3-phenylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (9k: TAK-013). Compound 9k showed high binding affinity and potent in vitro antagonistic activity for the human receptor with half-maximal inhibition concentration (IC(50)) values of 0.1 and 0.06 nM, respectively. Oral administration of 9k caused almost complete suppression of the plasma LH levels in castrated male cynomolgus monkeys at a 30 mg/kg dose with sufficient duration of action (more than 24 h). The results demonstrated that the thienopyrimidine-2,4-dione core is an excellent surrogate for the thienopyridin-4-one and that thienopyrimidine-2,4-diones and thienopyridin-4-ones constitute a new class of potent and orally bioavailable LHRH receptor antagonists. Furthermore, molecular modeling studies indicate that the unique methoxyurea side chain of 9k preferentially forms an intramolecular hydrogen bond between the aniline NH and the methoxy oxygen atom. The hydrogen bond will shield the hydrogen bonding moieties from the solvent and reduce the desolvation energy cost. It is therefore speculated that the intramolecular hydrogen bond resulting from judicious incorporation of an oxygen atom into the terminal alkyl group of the urea may increase the apparent lipophilicity to allow increased membrane permeability and consequently to improve the oral absorption of 9k in monkeys. On the basis of its profile, compound 9k has been selected as a candidate for clinical trials and it is expected that it will provide a new class of potential therapeutic agents for the clinical treatment of a variety of sex-hormone-dependent diseases.
  Journal of Medicinal Chemistry 02/2003; 46(1):113-24. · 5.25 Impact Factor
• Article: A new class of potent nonpeptide luteinizing hormone-releasing hormone (LHRH) antagonists: design and synthesis of 2-phenylimidazo[1,2-a]pyrimidin-5-ones.

  Satoshi Sasaki, Toshihiro Imaeda, Yoji Hayase, Yoshiaki Shimizu, Shizuo Kasai, Nobuo Cho, Masataka Harada, Nobuhiro Suzuki, Shuichi Furuya, Masahiko Fujino
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  ABSTRACT: The design and synthesis of a new class of nonpeptide luteinizing hormone-releasing hormone (LHRH) receptor antagonists, the 2-phenylimidazo[1,2-a]pyrimidin-5-ones, is reported. Among compounds described in this study, we identified the potent antagonist 15b with nanomolar in vitro functional antagonism. The result might suggest that the heterocyclic 5-6-ring system possessing a pendant phenyl group attached to the five-membered ring is the important structural feature for a scaffold of small molecule LHRH antagonists.
  Bioorganic & Medicinal Chemistry Letters 09/2002; 12(16):2073-7. · 2.55 Impact Factor