Pepthiomycin, a new peptide antibiotic mixture

Nosiheptide, a sulfur-containing peptide antibiotic isolated from Streptomyces actuosus 40037

Nosiheptide (9671 R.P.) isolated from Streptomyces actuosus 40037 (NRRL 2954) is a sulfur-containing polypeptidic antibiotic, quite different from all the other members of this family. Very active in vitro against gram-positive bacteria, it is inactive in vivo in experimentally infected mice. Not toxic, even at high dose, it may be used as a feed additive for chickens and pigs and it shows a favourable effect on the growth and conversion index.

Thiopeptin, a new feed additive antibiotic: microbiological and chemical studies

The thiopeptins are a new group of sulfur-containing peptide antibiotics produced by Streptomyces tateyamensis. The antibiotic consists of a major component (designated as thiopeptin B) and four minor ones (thiopeptins A(1) to A(4)). These components were isolated by solvent extraction from mycelium followed by chromatography on silica gel with various ratios of chloroform and methanol as elution solvents. Acid hydrolysis of each of the thiopeptin components yielded 1 mole of valine, 1 of threonine, 1 of cysteine, and 2 of alanine as amino acids. Each component of the thiopeptin A group has chemical and biological properties closely similar to those of thiopeptin B, but detailed characterization has established that thiopeptins A(1), A(3), and A(4) are new antibiotics. We could not obtain accurate data for determination of the uniqueness of A(2) because of insufficient sample. Thiopeptin has strong antibacterial activity against gram-positive bacteria and Mycoplasma, and exhibits no cross-resistance to major human-use antibiotics.