194 THE ANTIBIOTICS 



Antimycin A 



Produced by: Streptomyces sp. 



Method of extraction: Adsorption on celite at pH 2.5. Elution with 0.5 

 per cent alcohol. Concentration in vacuo, extraction with ether. 



Chemical and physical properties: Acidic nitrogenous phenol, m.p. 139- 

 140°C; [a]^ -f 64.8° in chloroform. Very soluble in ether, alcohol, 

 acetone, and chloroform. Slightly soluble in petroleum ether, benzene, 

 and carbon tetrachloride. Insoluble in water. Very stable at room 

 temperature. Maximum ultraviolet light absorption at 233 and 320 

 m/i. C28EU0N2O9. Mild alkaline degradation yields, among other prod- 

 ucts, antimycic acid C11H14N2O5 [N-(3-aminosalicyloyl)L-threonine]. 



Biological activity: Active against many yeasts and filamentous fungi. 

 Very little activity against bacteria. Some protective action against 

 apple scab and tomato early blight. 



Toxicity: LD (rats), oral, 12 mg/kg; LD100, 30 mg/kg. Toxic to certain 

 insects and spiders. 



Utilization: None so far. 



Reference: Leben, C, and Keitt, G. W., Phytopathology, 88, 1948, 899; 

 J. Am. Chem. Soc, 71, 1949, 2436-2437; 75, 1953, 1100-1104, 3623- 

 3625; Science, 112, 1950, 172-173; Arch. Biochem., 28, 1950, 281-294. 



Antimycoin 



Produced by: Streptomyces aureus. 



Synonym: Fungicidin RAW (closely related to nystatin). 



Method of extraction: Extraction of broth with butanol, concentration 

 in vacuo; extraction of residue with ethanol and precipitation of active 

 material with ether. 



Chemical and physical properties: Insoluble in ether, chloroform, and ace- 

 tone. Soluble in ethyl alcohol and water. Most stable at slightly alka- 

 line pH. Can stand 100°C for 10 minutes at pH 7.0. Maximum light 

 absorption at 290, 305, and 316 m/x. 



Biological activity: Not active against bacteria, mycobacteria, and acti- 

 nomycetes. Active against fungi. 



Toxicity: LD 6 o (mice), intraperitoneal, 204 mg/kg. 



Utilization: Not known. 



Reference: Raubitschek, F., Acker, R. F., and Waksman, S. A., Antibiotics 

 & Chemotherapy, 2, 1952, 179-183. 



Antiphlei Factor 



Produced by: Streptomyces sp., closely related to S. aureus. 

 Method of extraction: Concentration of filtrate to dryness in vacuo, extrac- 

 tion with methanol and precipitation with acetone. 



