Serratiomycin, a new antibacterial peptolide from an eubacterium culture, MB 5691

Abstract A novel peptolide antibiotic, serratiomycin, 1 , was isolated from the culture broth of a eubacterium by solvent extraction and column chromatography. The structure of 1 was determined to be cyclo( d -β-hydroxydecanoyl- l -leucyl- l -seryl- l - allo threonyl- d -phenylalanyl- d -isoleucyl). 1 exhibited a weak and mostly Gram-positive antibacterial spectrum in vitro .