Synthesis and biological activity of tripeptide FR113680 analogues containing unconventional amino acids.

Abstract

In order to further develop structure-activity relationships and to get information about the biological active conformations we synthetized analogues tripeptide to the FR 113680 [Ac-Thr-D-Trp(CHO)-PheNMeBzl; Ac: acethyl], in which the phenylalanine residue was replaced by unconventional amino acids [1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic); (3aS, 7aS)-octahydroindole-2-carboxylic acid (Oic); (S,S,S)-2-azabiciclo[3.3.0]octane-3-carboxylic acid (Aoc); 3-(1'-naphthyl)alanine (Nap); phenylglicine (Phg); thienylalanine (Thi)]. The biological activity of the peptides was performed on guinea pig ileum for neurokinin 1 (NK-1) and on rat colon for neurokinin 2 (NK-2). In particular, the replacement of the Phe3 by the Oic (8a) gave an higher antagonist activity in both NK-1 and NK-2 receptors, but no improvement in selectivity with respect to reference tripeptide (FR113680). The compound (8a) represent the first example of highly potent peptides that do not contain an aromatic amino acid of the third position as had been previously considered essential.

• Authors: G Caliendo, A Calignano, P Grieco, F Mancuso, E Perissutti, A Santini, V Santagada
• Journal: Biopolymers (Biopolymers) Vol. 36 Issue 4 Pg. 409-14 (Oct 1995) ISSN: 0006-3525 [Print] United States
• PMID: 7578938 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amino Acids
• Indicators and Reagents
• Neurokinin-1 Receptor Antagonists
• Oligopeptides
• Receptors, Neurokinin-1
• Receptors, Neurokinin-2
• FR 113680

Topics

• Amino Acid Sequence
• Amino Acids
• Animals
• Colon (physiology)
• Guinea Pigs
• Ileum (physiology)
• In Vitro Techniques
• Indicators and Reagents
• Male
• Molecular Sequence Data
• Muscle Contraction (drug effects)
• Muscle, Smooth (drug effects, physiology)
• Neurokinin-1 Receptor Antagonists
• Oligopeptides (chemical synthesis, chemistry, pharmacology)
• Rats
• Rats, Wistar
• Receptors, Neurokinin-1 (physiology)
• Receptors, Neurokinin-2 (antagonists & inhibitors, physiology)
• Sequence Homology, Amino Acid
• Structure-Activity Relationship