OTHER METABOLIC PRODUCTS 81 



peutic action against Streptococcus, Staphylococcus, and Clostri- 

 dium septique in laboratory animals. From the same laboratory 

 Abraham et al. (1941) purified penicillin and determined its action 

 against body cells and against bacteria, indicating its therapeutic 

 potentialities to replace sulfonamides. In fact, it was found to 

 operate when sulfonamides are ineffective and to be without toxic 

 effect against body tissues. It is bacteriostatic to Staphylococcus 

 and Streptococcus in vitro in dilutions of one to a million. Its 

 chemical formula, according to Meyer et al. (1942), is Ci 4 Hi 9 NO«. 



In a series of reports additional important findings by Raistrick 

 and Smith (1941), Oxford, Raistrick, and Smith (1942), Oxford 

 and Raistrick (1942), and Oxford (1942) were announced on the 

 production by fungi of substances that inhibit the growth of 

 pathogenic bacteria. From Penicillium citrinnm these workers ob- 

 tained penicillin, and from P. cyclopium penicillic acid. Both 

 substances are bacteriostatic to Staphylococcus aureus, and peni- 

 cillic acid is inhibitory also to the typhoid and paratyphoid bac- 

 teria. They isolated spinulosin from Penicillium spinulosum and 

 fumigatin from Aspergillus fumigatiis. Fumigatin is especially 

 potent against Bacillus anthracis, Staphylococcus aureus, and 

 Vibrio cholerae. The same workers synthesized both spinulosin 

 and fumigatin. 



Waksman and Schatz (1943) found that Aspergillus clavatus 

 produces a potent bacteriostatic substance designated clavacin; 

 differing amounts are produced by different strains. 



Kochalaty ( 1943) purified an antibacterial substance called pena- 

 tin, produced by Penicillium notatum, to the extent that it in- 

 hibited growth of 50 species of pathogenic and non-pathogenic 

 bacteria in dilutions of one to ten millions or more. 



Waksman and Bugie (1943) concluded that the antibiotic activ- 

 ity of Aspergillus flavus is due to two substances: (1) aspergillic 

 acid, which is active against both Gram-positive and Gram-nega- 

 tive bacteria, and (2) flavacin, which is active against Gram-nega- 

 tive bacteria and may be identical with penicillin. In the produc- 

 tion of these antibacterial substances three factors are involved: 

 (1) differences in strains of A. flavus, (2) the composition of the 

 substrate, and (3) the conditions of growth, especially aeration. 



Bergel et al. (1943) isolated clavatin (identical with clavacin) 

 from solutions in which Aspergillus clavatus had been grown. 

 Their analyses indicated for clavatin the empirical formula 



