Modifications of the peptide pyrrhocoricin permit the production of
a variety of anti-bacterial or anti-fungal peptides having general formula R1-Asp-Lys-Gly-X-Y-Leu-Pro-Arg-Pro-Thr-Pro-Pro-Arg-Pro-Ile-Tyr-X-Y-R2
SEQ ID NO: 1 or multimeric compositions containing more than a single peptide
of that formula. These peptides may be straight chain or cyclic peptides, and may
contain one or more non-cleavable bonds. These peptides are characterized by anti-bacterial
or anti-fungal activity and metabolic stability in mammalian serum. These peptides
are useful in anti-bacterial or anti-fungal pharmaceutical compositions and for
further drug development or identification of other antibiotic or anti-fungal compounds.