132 FUNGI AS ANTAGONISTS 



Bush and Goth (lOO) isolated from A. flavus a second substance 

 designated as flavicin. They grew the organism for 6 to 8 days on a 

 nitrate-glucose medium containing 2 per cent corn steep. The filtrate 

 was acidified to fH 2.5 to 3.0 with 5 |j phosphoric acid and extracted 

 with purified isopropyl ether. The ether was treated with a slight ex- 

 cess of o.2A^ NaHC03 (5 to 10 cc. per liter of culture), giving a yield 

 of 75 to 100 per cent of active material obtained. Purification was ob- 

 tained by acidification of the NaHCOg extract with 5 [i H3PO4 to fH 

 2 to 3 and removal of the precipitate, the latter containing most of the 

 toxicity (due no doubt to aspergillic acid) and the filtrate most of the 

 activity. The filtrate was treated with ice-cold isopropyl ether, satu- 

 rated with CO2, washed with cold distilled water, and reextracted. The 

 combined extracts were distilled at 0° C. to dryness under CO2. A yel- 

 low-orange glassy residue was obtained. It had a low toxicity and was 

 active in vivo. In its properties it resembled penicillin. 



McKee and MacPhillamy (56s, 56^) further established, by chemi- 

 cal isolation and composition, solubility and stability, biological behav- 

 ior, low toxicity to animals, and therapeutic activity, that the second anti- 

 biotic substance produced by A . flavus is similar to penicillin. A sodium 

 salt, assaying 240 O.U./mg. was obtained chromatographically and 

 gave the following composition : 45.36 per cent C, 4. 1 6 per cent H, 3.02 

 per cent N, and 13.36 per cent Na, [ajo = + 108° C. (in water). 



Waksman and Bugie (929) have shown by means of the bacterio- 

 static spectrum that, under submerged conditions, diflFerent strains of 

 A. flavus produced two substances, one comparable to aspergillic acid 

 and the other to penicillin. Some strains produced little or no activity 

 in submerged cultures, and most strains produced very little activity in 

 stationary cultures. No activity was produced in synthetic media. The 

 production of gigantic acid by a species of A . giganteus and parasiticin 

 hy A. -parasiticus (142) appears to be comparable to that of flavicin. 



Aspergillus jumigatus Group 



Four antibacterial substances were isolated from strains of A . jumi- 

 gatus: the two pigments, spinulosin and fumigatin {66"^), which are 

 not selective in their action against bacteria, the colorless fumigacin 



