Radamycin, a novel thiopeptide produced by streptomyces sp. RSP9. II. Physico-chemical properties and structure determination.

The new cyclic peptide antibiotic, radamycin (1) and the known thiopeptide methylsulfomycin I (2) have been isolated from the fermentation broth of a Streptomyces sp. RSP9. The structure of radamycin was elucidated by NMR, LC-MS and FAB-MS and was established as a thiopeptide with oxazole and thiazole moieties, and several unusual amino acids.

Radamycin, a novel thiopeptide produced by streptomyces sp. RSP9. I. Taxonomy, fermentation, isolation and biological activities.

The newly isolated strain Streptomyces sp. RSP9 produces two thiopeptides; one of them is methylsulfomycin I, which shows potent antibiotic activity against several gram-positive bacteria such as Micrococcus luteus and Staphylococcus aureus. The other is a new thiopeptide named radamycin.