Inhibition of experimental murine tumors by a new compound isolated from mutated Penicillium nigricans

A new compound, a sterol derivative of an unknown structure, has been isola ted from a mutant variety of Penicillium nigricans. The compound has shown a significant antitumor activity against Ehrlich ascites carcinoma and sarc oma 180 tumor growth in mice. Tumor regression was manifested by 81% and 83 % decrease in the tumor volume and the total tumor cell count, respectively , against Ehrlich ascites carcinoma and those by 80% and 90% against sarcom a 180. Intraperitoneal treatment with this agent also prolonged the life sp an of the tumor bearing mice remarkably. Thus, the new compound did not sho w any appreciable toxicity against blood and bone marrow cells. On the cont rary, it improved the hemoglobin and RBC values, thereby substantialy ameli orating the anemia that accompanied tumor growth. In addition, it reduced t he degree of tumor-associated hematological changes, such as peripheral blo od leukocytosis, bone marrow hypocellurarity, and splenomegaly.