Syntheses and biological evaluation of analogs of luteinizing hormone-releasing hormone (LH-RH) modified in position 2, 3, 4 or 5

N. Yanaihara, T. Hashimoto, C. Yanaihara, K. Tsuji, Y. Kenmochi, F. Ashizawa, T. Kaneko, H. Oka, S. Saito, A. Arimura, A. V. Schally

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39 Scopus citations


Syntheses by the conventional methods as well as the chemical, physical and biological properties are described of the following analogs of the LH-releasing hormone (LH-RH): [Leu3]-LH-RH, [Phe3]-LH-RH, [Trp2] [His3]-LH-RH, Des-Trp3-LH-RH, Des-His2-[Phe5]-LH-RH, [Ala4]-LH-RH, [Phe5]-LH-RH and [Ala4] [Phe5]-LH-RH. In vivo assays showed that [Leu3]-LH-RH did not release LH in doses as high as 5 - 25 μg, having less than 0.0008% of LH-RH activity, while [Phe3]-LH-RH had 0.43% of the LH-RH activity of natural LH-RH. The LH-RH activities of [Trp2] [His3]-LH-RH, Des-Trp3-LH-RH and Des-His2-[Phe5]-LH-RH were extremely low. On the other hand, [Ala4]-LH-RH, [Phe5]-LH-RH and [Ala4] [Phe5]-LH-RH had significant LH-RH activity. The structure-activity relationship of LH-RH is discussed on the basis of these findings.

Original languageEnglish (US)
Pages (from-to)64-73
Number of pages10
JournalBiochemical and biophysical research communications
Issue number1
StatePublished - May 1 1973
Externally publishedYes


ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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