TWO NEW FROG SKIN PEPTIDES, PHYLLOLITORINS, OF THE BOMBESIN-RANATENSIN FAMILY FROM Phyllomedusa sauvagei

Two novel peptides, phyllolitorins, of the bombesin-ranatensin family having litorin-like activity were isolated from the skin of Phyllomedusa sauvagei, the South American hylid frog.Both peptides were characterized as nonapeptide amides which differ each other only in the penultimate amino acid residue: Pyr-Leu-Trp-Ala-Val-Gly-Ser-X-Met-NH2, X=Leu or Phe.The presence of Ser residue, instead of His, in the third position from the C-terminus is a specific feature of the phyllolitorins.Chemical synthesis of the Leu8-and Phes-nonapeptide amides confirmed the proposed structures of the new peptides.