Enduracidin, a New Antibiotic. VII. Primary Structure of the Peptide Moiety

The primary structure of enduracidin, a cyclodepsipeptide antibiotic, was estimated by the determination of the amino acid sequence, optical isomers of each amino acid, and lactone structure. The result is that the enduracidin has a macro-ring lactone structure which is composed of 16 amino acids, and has a side chain aspartic acid which is connected to a fatty acid by an amide bond. The tentative structure is shown in Fig. 7.