Edward A. Kaczka

The human tumor-egg host system. II. Discovery and properties of a new antitumor agent, hadacidin.

Summary A new crystalline antitumor agent, hadacidin, has been discovered in fermentation broths of Penicillium frequentans Westling. The human tumor-embryonated egg system was used to guide fermentation and isolation studies. Against HAD #1 the tumor ID50 of hadacidin is about 3 mg per egg. Hadacidin is active also against HEP #3 and A-42 in the embryonated egg. On a weight basis, hadacidin has about the same range of activity as azaserine and 6-mercaptopurine but has only one per cent the activity of the alkylating agent, triethylene melamine.