ANTIBIOTICS OF ACTINOMYCETES 219 



Method of extraction: Extraction of mycelium with methanol, precipitation 



by ethyl acetate, re-solution in methanol and precipitation with ether. 

 Chemical and physical properties: Slightly soluble in methanol and ethanol 



and relatively insoluble in most organic solvents and water. Maximum 



light absorption at 290, 305, and 316 mju. C, 58.1 per cent; H, 8.7 per 



cent; N, 1.8 per cent. 

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



nomycetes. Active against fungi. Active in vivo in mice against C. 



neoformans, H. capsulatam and C. immitis. 

 Toxicity: LD 6 o (mice), intraperitoneal, 23 mg/kg. 

 Utilization: Not known. 

 Reference: Hazen, E. L., and Brown, R., Proc. Soc. Exptl. Biol. Med., 76, 



1951, 93-97. 



Oxytetracycline 



Produced by: Streptomyces rimosus. 



Synonym: Terramycin. 



Method of extraction: Adsorption on charcoal at neutrality, elution with 

 acid, eluate adjusted to pH 9 and extracted with butanol. 



Chemical and physical properties: Amphoteric substance. Soluble in eth- 

 anol, methanol, butanol, and in water mainly at high and low pH. 

 Maximum stability at pH 2.5, half-life of 134 hours at 37°C. Max- 

 imum absorption of ultraviolet light at 265 and 367 nnx. Bright yellow 

 fluorescence under ultraviolet light. C22N24N2O9. 



Biological properties: Active against gram-positive, gram-negative, and 

 acid-fast bacteria. Active against rickettsiae. Not active against fungi. 



Toxicity: LD 50 (mice) hydrochloride, intravenous, 178 mg/kg; subcutan- 

 eous, 830 mg/kg; oral, 6696 mg/kg. 



Utilization: Treatment of numerous bacterial and rickettsial infections. 



Reference: Ann. N. Y. Acad. Sci., 58, 1950, 223-460; Sobin, B. A., Finlay, 

 A. C, Kane, I. H., U. S. Patent 2,516,080, 1950; Stephens, C. R., and 

 Woodward, R. B., J. Am. Chem. Soc, 74, 1952, 4976-4977. 



Phaeofacin 



Produced by: Streptomyces phaeofaciens. 



Method of extraction: Extraction of the broth or mycelium with ethyl ace- 

 tate, concentration in vacuo to a syrup. Syrup dissolved in acetone and 

 cooled with formation of a precipitate. 



Chemical and physical properties: Soluble in ethyl acetate, ethanol, acetone, 

 and benzene. Slightly soluble in ether and petroleum ether. Insoluble 

 in water. 



Biological activity: Active against Trichophyton, Histoplasma capsulatum, 

 and Cryptococcus neoformans. 



