[4,4'-D-diaminopropionic acid]gramicidin S: a synthetic gramicidin S analog with antimicrobial activity against Gram-negative bacteria.

Gramicidin S is especially active against Gram-positive bacteria; e.g., Staphylococcus aureus. An analog, [4,4'-D-diaminopropionic acid]gramicidin S, which contains D-diaminopropionic acid residues instead of D-phenylalanine residues, has been synthesized. This analog is active against some of the Gram-negative bacteria; e.g., Escherichia coli and Salmonella typhosa. Activities of several related analogs are discussed.