Azinomycins A and B, new antitumor antibiotics. III. Antitumor activity.

Azinomycins A and B, isolated from the culture broth of Streptomyces griseofuscus S 42227, were examined for antitumor activities against P388 leukemia, P815 mastocytoma, B-16 melanoma, Ehrlich carcinoma, Lewis lung carcinoma and Meth A fibrosarcoma.Azinomycin B was markedly effective against the intraperitoneally inoculated tumors such as P388 leukemia, B-16 melanoma and Ehrlich carcinoma.The intraperitoneal administration of azinomycin B showed 57% survivors for 45 days and 193 % ILS against P388 leukemia.For Ehrlich carcinoma, azinomycin B gave 161 % ILS and 63% survivors for 45 days, but solid tumors such as Lewis lung carcinoma and Meth A fibrosarcoma were not susceptible to repeated injection of this substance.AzinomycinA was somewhatless effective than azinomycin B for the tumor systems tested.In the course of screening for new antitumor substances, azinomycins A (1) and B (2) were discovered in the culture broth of strain S 42227.In the previous paper1}, the taxonomy of the producing organism, fermentation, isolation, physico-chemical properties, antimicrobial activity and in vitro cytotoxicity of azinomycins were reported.This paper describes the antitumor activity of these substances against various murine tumors.