Novel antibiotic NCS-C and preparation method of the same

摘要

The specification describes novel antibiotic NCS-C and its free acid salts. Their antimicrobial effects are at least comparative with neocarzinostatin, and, against some microorganisms, superior. The novel antibiotic NCS-C or its free acid salt is prepared either by culturing an NCS-C yielding microorganism belonging to the Streptomyces family in a culture medium, separating the culture medium into bacterial bodies and culture filtrate, and extracting the culture filtrate with a water-immiscible polar organic solvent under acidic conditions, or by decomposing neocarzinostatin under acidic conditions and extracting resultant free acid salt with a polar organic solvent.