Tetrocarcins, new antitumor antibiotics. 3. Antitumor activity of tetrocarcin A.

Tetrocarcin A, isolated from a Micromonospora culture showed activity against experimental i.p. inoculated tumors such as Ehrlich carcinoma, MH134 hepatoma, B16 melanoma. But it was not active against solid tumors such as sarcoma 180 and Ehrlich carcinoma. It was marginally active against the growth of solid Lewis lung carcinoma without prolonging the life span of the tumor-bearing mice. It was active against P388 leukemia (i.v.-i.v. system). It did not show myelosuppression and nephrotoxicity in mice. DNA and protein synthesis of P388 cells in culture were more significantly suppressed than RNA synthesis by tetrocarcin A.