This compound is a synthetic peptide with the sequence L-Tyr-D-Ala-Gly-L-Phe-L-Leu-N~5~-(diaminomethylidene)-L-Orn-N~5~-(diaminomethylidene)-L-Orn-L-Ile-N~5~-(diaminomethylidene)-L-Orn-L-Pro-L-Lys. It is a derivative of the natural antimicrobial peptide nisin, specifically a fragment or analog designed to study its structure-activity relationship. The presence of multiple N~5~-(diaminomethylidene)-L-ornithine residues (a modified amino acid) is a key structural feature aimed at enhancing stability or altering biological activity. Its primary application is in biochemical and microbiological research as a tool compound for investigating the mechanisms of action of lantibiotics, a class of peptide antibiotics to which nisin belongs. It is used to understand how specific sequences and post-translational modifications contribute to antimicrobial potency, particularly against Gram-positive bacteria like *Listeria* and *Staphylococcus*. This research is crucial for developing novel anti-infective agents. As a research-grade synthetic peptide, it is not used directly as a therapeutic API but serves as a critical intermediate in the development of potential new antimicrobial drugs. Handling requires standard precautions for laboratory peptides, including storage at low temperatures and avoidance of repeated freeze-thaw cycles to maintain stability.