ANTIBIOTICS OF ACTINOMYCETES 223 



teus vulgaris (200-400 mcg/ml), and Mycobacterium 607 (40 mcg/ml). 

 Active in mice against Trypanosoma equiperdum. 



Toxicity: LD 6 o (mice), intravenous, 350 mg/kg; intraperitoneal, 525 

 mg/kg; oral, 675 mg/kg. 



Utilization: Might be used on an antiprotozoal agent. 



Reference: Porter, J. N., Hewitt, R. I., Hesseltine, C. W., Krupka, G., 

 Lowery, J. A., Wallace, W. S., Bohonos, N., and Williams, J. H., Anti- 

 biotics & Chemotherapy, 2, 1952, 409^10; Waller, C. W., Fryth, 

 P. W., Hutchings, B. L., and Williams, J. H., Am. Chem. Soc. 75, 

 1953, 2025; Baker, B. R., and Schaub, R. E., ibid., 3864. 



Resistomycin 



Produced by: Streptomyces resistomycificus. 



Method of extraction: Mycelium extracted with petroleum ether, then with 

 ether, the latter giving an active yellow extract. Chromatographic 

 separation yields dioxane-soluble, saffron-yellow, needle-shaped crys- 

 tals. 



Chemical and physical properties: Soluble in water with difficulty. Soluble 

 in ether, ethanol, and other organic solvents. Weak acid. Resistant to 

 action of alkali, acid, and heat (250°C). It contains no N or S. It de- 

 composes, without melting, at 315°C. C 2 3Hi 8 06. 



Biological activity: Active against Micrococcus pyogenes var. aureus and Bacil- 

 lus subtilis in dilution of 1:20,000,000, and against Myocobacterium 

 tuberculosis in dilution of 1:500,000 to 1:1,000,000. 



Toxicity: No information. 



Utilization: No information. 



Reference: Brockmann, H., and Schmidt-Kastner, G., Naturwiss., 88, 1951, 

 479-480. 



Rhodocidin 



Produced by: Streptomyces phoenix (no description available). 



Method of extraction: Addition of 0.03 per cent H 2 2 to broth. Filtration of 

 the mycelium. Addition of 15 per cent NaCl, extraction with ethyl 

 acetate. Concentration, addition of petroleum ether, extraction with 

 water. Addition of 2 per cent NaHS0 3 , washing with ethyl acetate. 

 After addition of 2 per cent acetone, extraction with ethyl acetate. 

 Addition of petroleum ether, extraction with water, concentration, 

 lyophilization. 



Chemical and physical properties: Red powder, showing a broad peak of 

 absorption at 500-530 m/z. Soluble in water and in many organic 

 solvents. Inactivated rapidly by dilute acids and alkalies. Inactivated 



