Tetrocarcins, novel antitumor antibiotics. II. Isolation, characterization and antitumor activity

Novel antitumor antibiotics, tetrocarcin complex composed of three components (A, B and C) were isolated from the culture broth of Micromonospora chalcea KY11091 through various procedures. Tetrocarcins showed marked activity against experimental tumors such as mouse sarcoma 180 and mouse leukemia P388. Multiple injections showed better therapeutic effect against tumors. Mode of action of tetrocarcin A against Bacillus subtilis was found to be through the inhibition of RNA synthesis.