Production, purification, and characterization of chandramycin, a polypeptide antibiotic from Streptomyces lydicus

A plant pathogenic actinomycete identified as Streptomyces lydicus was isolated from the deep-pitted scab lesions of potato tubers. This strain produces a new polypeptide antibiotic named chandramycin. The antibiotic was isolated from culture broth by extraction with organic solvents and purified by chromatography. The purified antibiotic is a light-yellow crystalline compound soluble in water and in most organic solvents. Amino acid analysis of the acid hydrolysates of chandramycin revealed the presence of glycine, cis-methyl proline, valine, beta, beta-dimethylaminobutyric acid, beta-methyl-phenylalanine, and beta-2-thioazolyl-beta-alanine. The amino acid composition of chandramycin is qualitatively similar to that of a known antibiotic, bottromycin A2. Chandramycin showed activity against several gram-positive and a few gram-negative species of bacteria. It showed a strong activity against anaerobic microorganisms. Oral doses of antibiotic when administered up to 466 mg/kg of body weight failed to produce any observable toxic effect in mice.