A process for preparing a synthetic peptide analog of a pharmaceutically acceptable growth hormone releasing factor or a non-toxic salt thereof

摘要

The invention provides synthetic peptides which are extremely potent in stimulating the release of pituitary GH in animals, including humans and also resist enzymatic degradation in the body. The peptides have the sequence: (B)R1-R2-R3-Ala-(Q1)R5-Phe-Thr-R8-Ser(Q2)R10-Arg-R12-(Q3)R13-Leu-R15-G ln-(Q4)Leu-R18-(Q5)Ala-Arg-R21-(Q6)R22-(Q7)Leu-R24-R25-(Q8)R26-(Q9)R27 -R28-Arg-Gln-Gln-Gly-Glu-R34-Asn-Gln-Glu-R38-R39-R40-Arg-R42-R43-R44 wherein R1 is Tyr, D-Tyr, Met, Phe, D-Phe, pCl-Phe, Leu, His or D-His; B is H, CaMe, NaMe, desamino, Ac or For; R2 is Ala, D-Ala, NMA or D-NMA; R3 is Asp or D-Asp; R5 is Ile or Leu; R8 is Ser, Asn, Lys, Arg, Asp or Glu; R10 is Tyr, D-Tyr or Phe; R12 is Arg or Lys; R13 is Ile, Val, Leu or Ala; R15 is Gly or Ala; R18 is Ser or Tyr; R21 is Lys, D-Lys, Arg or D-Arg; R22 is Leu, Ile, Ala or Val; R24 is Gln or His; R25 is Asp or Glu; R26 is Ile or Leu; R27 is Met, D-Met, Ala, Nle, Ile, Leu, Nva or Val; R28 is Asn or Ser; R34 is Ser or Arg; R38 is Arg or Gln; R39 is Gly or Arg; R40 is Ala or Ser; R42 is Phe, Ala or Val; R43 is Asn or Arg; R44 is a natural amino acid; Q1-Q9 are either H or CaMe, provided however that one of Q1-Q9 is CaMe. These peptides may also be used diagnostically, and the C-terminus can be shortened to residue-29.