[Sequence variation on an antibiotically active tripeptide (author's transl)].

Seven tripeptides with the sequence L-Arg-D,L-X-L-Phe were synthesised. Three of these peptides showed antibiotical activity on fungi. The amino- and the carboxylic terminus of the peptide L-Arg-D,L-Phe-L-Phe, which showed antibiotical activity, were changed to give the sequences L-X-D,L-Phe-L-Phe or L-Arg-D,L-Phe-L-X respectively. The resulting tripeptides showed no antibiotical activity.