Hentriakontapeptides of the sequence I wherein R1 is Ile or Val; R2 is His or Tyr and R3 is Gln or Glu, with opiate agonist activity and process for the preparation thereof bya) isolating such a compound from natural sources using procedures well known in the art orb) synthesizing such a compound using conventional solid phase peptide synthesis.
UNTRIAKONTAPEPTIDE WITH OPIATE ACTIVITY