PD 114,759 and PD 115,028, novel antitumor antibiotics with phenomenal potency. I. Isolation and characterization

The isolation of two new antibiotics, PD 114,759 and PD 115,028, exhibiting in vivo antitumor activity at extremely low doses is described. The physico-chemical properties of these sulfur-containing compounds show that they represent a novel class of antitumor agents.