Elucidation of the Structure of Hormaomycin

Hormaomycin is an intercellular signal substance , whose sequence and constitution could be elucidated by a combination of degradation reactions and mass spectrometric and NMR spectroscopic investigations. Hormaomycin is a peptide lactone, which, in addition to containing three known amino acids, allo ‐threonine, isoleucine and (3‐methyl)phenylalanine, also contains two new amino acids: 4‐[( Z )‐propenyl]proline and 3‐(2‐nitrocyclopropylalanine). Signal substances such as 1 are gaining increasing importance for insights into microbial secondary metabolism.