The Synthesis of [1-Deamino,4-L-leucine]-oxytocin and [1-Deamino,4-L-isoleucine]-oxytocin and Some of Their Pharmacological Properties

Herbert Takashima, Victor J. Hruby, Vincent du Vigneaud

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


[1-Deamino,4-L-leucine]-oxytocin and [1-deamino,4-L-isoleucine]-oxytocin have been synthesized by the solid phase method, and some of their pharmacological properties have been determined. [1-Deamino,4-L-leucine]-oxytocin was also synthesized by the p-nitrophenyl ester stepwise procedure and compared to that synthesized by the solid phase method. The two preparations were found to be identical. The oxytocic and avian vasodepressor potencies of [1-deamino,4-L-leucine]-oxytocin and [1-deamino,4-L-isoleucine]-oxytocin are two- to threefold higher than those of [4-L-leucine]-oxytocin and [4-L-isoleucine]-oxytocin respectively. The two deamino analogs also exhibit milk-ejecting activities of approximately 150 units/mg. Neither analog possesses appreciable pressor or antidiuretic activity. A similar enhancement of oxytocic and avian vasodepressor activities had been observed when the free amino group of [4-L-valine]-oxytocin was replaced by hydrogen.

Original languageEnglish (US)
Pages (from-to)677-680
Number of pages4
JournalJournal of the American Chemical Society
Issue number3
StatePublished - Feb 1 1970
Externally publishedYes

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry


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