ANTIBIOTICS OF ACTINOMYCETE8 191 



Antibiotic 136 



Produced by: Streptomyces lavendulae. 



Synonym: Closely related to streptothricin. 



Method of extraction: Adsorption at pH 7.5 on Folin Decalso, elution with 

 10 per cent NH 4 C1; adsorption at pH 7.4 on Darco G-60, elution with 

 acid methanol. Precipitation of methanol solution with acetone. 



Chemical and physical properties: Basic substance, soluble in methanol and 

 water, insoluble in acetone. Most stable at acid reaction. Not inacti- 

 vated by cysteine. 



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

 teria, mycobacteria, and fungi. Most active at alkaline reaction. Glu- 

 cose decreases activity. 



Toxicity: LD 6 o (mice), intravenous and subcutaneous, 10 mg/kg. 



Utilization: None. 



Reference: Bohonos, N., Emerson, R. L., Whiffen, A. J., Nash, M. P., and 

 DeBoer, C, Arch. Biochem., 15, 1947, 215-225. 



Antibiotic SKCC 1377 



Produced by: Streptomyces sp. 



Method of extraction: Extraction of culture nitrate with benzene. Concen- 

 tration in vacuo, back extraction with 0.05 N HC1, lyophilization. 



Chemical and physical properties: Red-brown powder. Soluble in water, 

 ethanol, and acetone. Insoluble in ether or benzene. In aqueous solu- 

 tion, yellow at acid or neutral reaction and purple at alkaline pH. 

 Unstable at alkaline reaction. Can stand 10 minutes at 100°C at 

 pH 3.5. Picrate crystals melt with decomposition at 165-168°. Maxi- 

 mum light absorption of the picrate at 245 mju and 255 m/x. 



Biological activity: Active against gram-positive bacteria. Not active against 

 Escherichia coli and fungi. 



Toxicity: LD 60 (mice), intraperitoneal, 5 mg/kg. 



Utilization: None. 



Reference: Reilly, H. C, Bact. Proc, 1952, 26. 



Antibiotic EI 5 



Produced by: Streptomyces sp. (closely related to S. griseus). 



Synonym: Closely related to actinorubin. 



Method of extraction: Adsorption on charcoal, elution with acid methanol, 



precipitation with acetone. 

 Chemical and physical properties: Stable. Soluble in water. Insoluble in 



ether and acetone. 

 Biological activity: Antimicrobial spectrum similar to actinorubin. 

 Toxicity: Nearly equal to actinorubin. 



