Studies of Peptide Antibiotics. XVIII. The Synthesis of Tyrocidine E

Abstract

Abstract The synthesis of cyclic decapeptide, cyclo-l-phenylalanyl-d-phenylalanyl-l-asparaginyl-l-glutaminyl-l-phenylalanyl-l-valyl-l-ornithyl-l-leucyl-d-phenylalanyl-l-prolyl, which has the amino acid sequence designated as tyrocidine E by Kurahashi, and the chemical and biological properties of the synthetic product, have been described. The degree of the activity of the synthetic product toward the Gram positive microorganisms is nearly the same as that of tyrocidine A. The results indicate that the l-tyrosine residue in the molecule of tyrocidine A can be replaced by l-phenylalanine without influencing activity.