Studies on a tumor-retarding agent produced by Aspergillus fumigatus.

For nearly 4 years a search has been conducted in our laboratories among materials of natural origin for agents having the ability to retard the growth of tumors. Early in the course of this in vestigation crude culture filtrates of the fungus Aspergillus fumigatus were found to retard the growth of the Crocker mouse sarcoma 180 and of the mammary adenocarcinoma E 0771 in mice (4). Meanwhile, Kidd (1) reported that this fungus produced a substance capable of destroying the viability of animal tumor cells in vitro. Chemical evidenceindicatedthatthisagentwasidenticalwith or similar to gliotoxin. Preliminary investigations of the in vivo activity of our preparations had mdi cated that gliotoxin was not the active principle. Thus, studies on the production, extraction, puri fication, and chemical nature of this new agent were undertaken.