Essential structure of orexin 1 receptor antagonist YNT-707, Part IV: The role of D-ring in 4,5-epoxymorphinan on the orexin 1 receptor antagonistic activity

Tsuyoshi Saitoh, Kazunori Seki, Ryo Nakajima, Naoshi Yamamoto, Noriki Kutsumura, Yasuyuki Nagumo, Yoko Irukayama-Tomobe, Yasuhiro Ogawa, Yukiko Ishikawa, R. Tanimura, Masashi Yanagisawa, Hiroshi Nagase

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The orexin 1 receptor (OX1R) antagonists carrying a morphinan skeleton such as YNT-707 (2) and YNT-1310 (3) showed potent and extremely high selective antagonistic activity against OX1R. In the course of our study of the essential structure of YNT-707 for high binding affinity against OX1R, we prepared derivatives of 2 without the D- and 4,5-epoxy rings to clarify the roles of these structural determinants toward OX1R antagonistic activity. The D- and 4,5-epoxy rings played important roles for the active orientation of the 17-sulfonamide and 6-amide side chains. Finally, we identified the simple structure required for selective OX1R antagonistic activity in the complex morphinan skeleton, which is expected to be a useful scaffold for further design of OX1R ligands.

Original languageEnglish (US)
JournalBioorganic and Medicinal Chemistry Letters
StatePublished - Jan 1 2019



  • Morphinan
  • Nalfurafine
  • Orexin
  • Ring removal
  • YNT-707

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Medicine
  • Molecular Biology
  • Pharmaceutical Science
  • Drug Discovery
  • Clinical Biochemistry
  • Organic Chemistry

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