SUBSTANCES PRODUCED BY ACTINOMYCETES 199 



NH-X 



A 



OH 



HO— *v i-NH-X 



OH 



Streptamine X = H 

 Streptidine X= — C^ ^tt 



When streptomycin chloride is hydrolyzed with i.o N sodium hy- 

 droxide, for three minutes at ioo° C. or for eighteen hours at 40° C, a 

 weakly acidic substance, m.p. 161° -162° C. is obtained. It has been 

 characterized as maltol, namely, 



The maltol gives a brilliant violet color with ferric chloride and a 

 positive iodoform testj it reacts rapidly with nitric acid, and sublimes 

 readily, even at 100° C. The benzoate melts at 114°-! 15° C. It has 

 been isolated from hydrolyzates of streptomycin salts ranging in purity 

 from 280 to 800 Mg/mg. The yields of maltol were about 30 per cent if 

 one mole was derived from one mole of streptomycin. 



It was suggested that the formation of maltol by alkaline hydrolysis 

 of streptomycin, measuring the ultraviolet absorption in acid solution, 

 be used as an assay procedure, for the absorption produced is propor- 

 tional to the initial antibiotic activity in preparations having a potency 

 of 50 to 800 Mg/mg. The ferric chloride color reaction also appeared 

 to be useful for this purpose. 



Streptomycin can be distinguished from streptothricin by inactiva- 

 tion with cysteine. This property is not due to the sulfhydryl group 

 alone. On oxidation of the cysteine, the substance is reactivated (179). 

 In view of the specific sensitivity of different bacteria to streptothricin 



