[Identification and biological activity of peptides containing a partially benzyloxycarbonylated L-arginine on their amino terminus (author's transl)].

Nomega-Z-L-Arg-L-Phe-L-Phe was shown to be the antibiotically active compound in a peptide mixture which was obtained by treating Z3-L-Arg-L-Phe-L-Phe with hydrogen bromide/trifluoroacetic acid or 4N HBr/glacial acetic acid, respectively. Identification of this compound was achieved by thin-layer chromatography, enzymatic digestion and autobiograms with fungi. The pure Nomega-Z-L-Arg-L-Phe-L-Phe was not the only compound with antibiotic qualities; generally it could be said that all peptides with the sequence Nomega-Z-L-Arg-X-L-Phe (X might be any amino acid) are antibiotically active. All of them are antagonized by L-aspartic acid and asparagine in the crossstrip test (on fungi). The antibiotical activity of all these peptides must be due to the Nomega-Z-L-Arg-residue provided that it is coupled to a dipeptide X-L-Phe, or to an aromatic system (e.g. L-Phe or benzyl amine).