In the first report¹⁾ the effect of pluramycin crude powder on Ehrlich carcinoma of mice was described, and in the second report²⁾ process of isolation and properties of pluramycin A were described. Pluramycin was produced by a streptomyces assigned to S. pluricolorescens, n. sp., and it was extracted from the cultured broth with ethyl acetate at pH 7.0, and after the evaporation of the solvent it was purified by the countercurrent distribution between ethyl acetate and phosphate buffer of pH 5.3. Then, existences of pluramycins A and B were found. Pluramycin A had basic characters, and its free base was obtained as orange needle or plate crystals²⁾. The free base was soluble in methanol, ethanol, acetone, chloroform, ethyl acetate, butyl acetate, benzene and ethyl cellosolve. It was slightly soluble in ether and hexane, and insoluble in petroleum ether and water. It was soluble in acid water and rapidly decreased the activity. It was differentiated from known antibiotics by analytical results and the infrared spectra. The acid hydrolysis did not give ninhydrin positive spots.

Acute and chronic toxicities and effect of pluramycin A on Ehrlich carcinoma were studied and the results are presented in this paper.