1956 Volume 9 Issue 2 Pages 75-81
As shown in the previous paper, Takeuchi, Nitta, and Umezawa(1) obtained a crude powder of pluramycin and they studied the effect on Ehrlich carcinoma of mice. When it was daily injected to mice to which one million tumor cells had been intraperitoneally inoculated, and the daily injection was started 5 days after the inoculation, it inhibited the ascites increase and prolonged the survival period. When it was daily intraperitoneally injected to mice to which one million tumor cells had been subcutaneously inoculated, and the daily injection was started 5 days after the inoculation, it inhibited the growth of the subcutaneous mild tumor. The ratio of the minimum effective daily dose to the daily tolerable dose was observed to be 1/6, when the injection was started 5 days after the inoculation. Among known antitumor substances, pluramycin was considered to be the strongest in the antitumor activity to Ehrlich carcinoma.
The pluramycin-producing strain was isolated from the soil sample obtained at Nagano Prefecture and it was assigned to a new specieis, Streptomyces pluricolorescens. The antitumor activity the cultured liquid was first found by testing the effect on ascites type of Ehrlich carcinoma. The active agent was extracted by testing each extract on the antitumor effect and the anti-HeLa cell effect. Then, the active agent in the crude powder was found to exhibit the bacteriostatic effect. The existence of two antitumor agents was confirmed by the countercurrent distribution studies. The one which was the major part of the antitumor activity in the cultured liquid and which was considered to be stronger in the antitumor activity than another was named pluramycin A, and another was mimed pluramycin B. The existence of pluramycins A and B was confirmed also by the paper chromatography. Pluramycin A was further purified and obtained in the crystalline form.
In this paper, the isolation and characters of pluramycins are presented.
