Griseorubins, a new family of antibiotics with antimicrobial and antitumor activity. II. Biological properties and antitumor activity of the antibiotic complex griseorubin.

The antibiotic complex griseorubin has antimicrobial activity against Gram-positive as well as -negative bacteria, mycobacteria, mycoplasma and protozoa in vitro but it is not active against yeast and fungi. Tests with transplantable rodent tumors indicate that griseorubin is inhibitory to the growth of lymphatic leukemia L1210 in mice and Zajdela ascites hepatoma in rats. The acute LD50 of griseorubin in mice is 50 mg/kg of body weight when given intraperitoneally. Attempts to potentiate the antitumor activity by complexing with DNA proved to be unsuccessful.