The present invention relates to a variety of Magainin derivatives andpharmaceuticallyacceptable salts produced thereof, with the derivatives having sequences asshown below:Gly-Ile-Gly-Lys-Phe-Leu-His-Ser-Ala-Lys-Lys-Phe-Gly-Lys-Ala-Phe-Val-Gly-Glu-Ile-X-Asn-Y-OHIn which:X is an amino acid residue selected from the group consisting of Met, Ile andLeu, Y is thecombination of two amino acid residues selected from the group consisting ofSer, Lys, Ile, Argand Leu. The derivatives of this invention have the same or higher anti-microbial activitiescompared to that of the naturally occurring Magainin. They are easily producedby solid-phasesynthesis, and more easily, by bioengineering techniques.
