220 THE ANTIBIOTICS 



Toxicity: LD (mice), intraperitoneal, about 200 mg/kg. 

 Utilization: None. 



Reference: Maeda, K., Okami, Y., Taya, O., and Umezawa, H., J. Antibio- 

 tics (Japan) 5, 1952, 465; Japan. J. Med. Sci. Biol., 5, 1952, 327-329. 



Phagolessin 



Produced by: Streptomyces sp. 



Method of extraction: Precipitation by phosphotungstic acid; extraction with 

 80 per cent ethanol at pH 3.0 and chromatography over alumina. 



Chemical and physical properties: Soluble in acidified water (pH 3.8) and 

 methanol; less soluble in ethanol; insoluble in acetone, ether, benzene, 

 chloroform, and petroleum ether. Maximum stability at pH 3, at 100°C 

 for 15 minutes. At pH 9.0, immediate irreversible inactivation occurs. 



Biological activity: Inhibition of Klebsiella pneumoniae (3 mcg/ml); other 

 organisms are more resistant, requiring >12.5 mcg/ml, but some 

 bacteria and mycobacteria are moderately sensitive. Has marked 

 antiphage action. 



Toxicity: ~LD m (mice), intraperitoneal, <31 mg/kg. 



Utilization: None. 



Reference: Asheshov, I. N., Strelitz, F., and Hall, E. A., Antibiotics & 

 Chemotherapy, 2, 1952, 361-362. 



Phalamycin 



Produced by: Streptomyces noursei variant. 



Method of extraction: Culture filtrate frozen and thawed. The first ^f of 

 the melt contains most of the antibiotic. Extraction from the concen- 

 trate at pH 7.5-8.0 with ethyl acetate which is removed by vacuum 

 distillation. The residue is taken up in methanol, the solution is chilled, 

 and the inactive precipitate formed is discarded. The solution is again 

 concentrated in vacuo, and the residue is picked up in chloroform. The 

 chloroform solution is washed with water and concentrated in vacuo. 

 The residue is washed with ether and extracted with ethyl acetate. 

 Removal of the ethyl acetate leaves phalamycin. 



Chemical and physical properties: Yellow powder. Contains nitrogen. Solu- 

 ble in lower alcohols, esters, chloroform, acetone. Slightly soluble in 

 benzene, ether, and water. Relatively stable from pH 2.5 to 7.0. 

 Probably neutral. Negative biuret, ninhydrin, Sakaguchi, and Molisch 

 tests. Ultraviolet absorption curve shows a slight inflection between 

 293 and 316 m/x. 



Biological activity: Active against gram-positive bacteria including myco- 

 bacteria and nocardia. Inactive against gram-negative bacteria and 

 fungi. Active in mice against Streptococcus hemolyticus. 



