The isolation and characterization of narasin, a new polyether antibiotic.

Abstract
Narasin is a new polyether antibiotic produced by a strain of Streptomyces aureofaciens. It is purified by organic solvent extraction and silica gel chromatography. Narasin is active in vitro against gram-positive bacteria, anaerobic bacteria and fungi and is effective in protecting chickens from coccidial infections.