Nocardithiocin, a Novel Thiopeptide Antibiotic, Produced by Pathogenic Nocardia pseudobrasiliensis IFM 0757.

Nocardithiocin is a novel thiopeptide compound produced by the pathogenic Nocardia pseudobrasiliensis strain IFM 0757. It shows a strong activity against acid-fast bacilli such as the Mycobacterium and Gordonia species. Nocardithiocin was highly active against rifampicin-resistant as well as -sensitive Mycobacterium tuberculosis strains, and most of the resistant strains were inhibited at concentrations ranging from 0.025 to 1.56 microg ml(-1). The structure of the thiopeptide antibiotic containing thiazole, natural and unnatural amino acids was elucidated by MS and NMR spectral analyses.