192 THE ANTIBIOTICS 



Utilization: None. 



Reference: Weiser, R. S., Gardner, G. M., Lefler, J. S., and St. Vincent, 

 L., Proc. Soc. Exptl. Biol. Med., 72, 1949, 283-287. 



Antibiotic HA-9 



Produced by: Streptomyces sp. related to S. lipmanii. 



Synonym: Similar to thioaurin. 



Method of extraction: Addition to filtered broth of 1.25 pounds of ammonium 

 sulfate per liter and adjustment of pH to 6.5. Extraction with ethyl 

 acetate, concentration in vacuo. Further purification by chroma- 

 tography on silica gel. Development of the column with ethyl acetate. 

 Crystallization from ethyl acetate. 



Chemical and physical properties: Yellow needle-like crystals, m.p. 178- 

 180°C. Neutral substance. Maximum light absorption at 370 nux in 

 methanol, [a\l 5 = in glacial acetic acid. Relatively insoluble in water 

 and chloroform. Slightly soluble in ethyl acetate. Soluble in methanol. 

 C 7 H 6 N20 2 S2. 



Biological activity: Active against gram-positive and gram-negative bac- 

 teria. Slight activity against fungi. Not inactivated by serum. 



Toxicity: LD 6 o (mice), subcutaneous, 20 mg/kg; intravenous, 15 mg/kg. 



Utilization: Little promise, due to toxic nature. 



Reference: Eiserman, W., Minieri, P. P., Abbey, A., Charlebors, J., Mono- 

 rieff-Yeates, M., and Rigler, N. E., Antibiotics & Chemotherapy, 3, 

 1953, 385-392. 



Antibiotic X-206 



Produced by: Streptomyces sp. 



Method of extraction: Can be extracted from both the mycelium and the 

 broth filtrate. Broth extraction: extraction with butyl acetate, con- 

 centration in vacuo, back extraction with phosphate buffer (pH 8.9). 

 Mycelium extraction: extraction with ethanol and methanol, con- 

 centration in vacuo, extraction with butyl acetate, back extraction 

 with phosphate buffer (pH. 8.9). Further purification of both extracts 

 by chromatography on alumina. 



Chemical and physical properties: Colorless organic acid. m.p. 126-128°C. 

 [a]f + 15.0° in methanol. No characteristic absorption in the ultra- 

 violet. Unstable at acid and alkaline reactions. Soluble in alcohols, 

 esters, acetone, ether, and petroleum ether. Insoluble in water and 

 alkali. C46-47H80-82O13. 



Biological activity: Active in vitro against gram-positive bacteria and myco- 

 bacteria. Not active in vivo against bacterial and protozoal infections. 



Toxicity: LD50 (mice), subcutaneous, 11 mg/kg. 



