Keys to Antibiotics 



KEY NO. 1 



Antibiotics Which Are Active Mainly against Gram-positive Bacteria 



I. Antibiotics active mainly against mycobacteria and/or actinomycetes 



A. Antibiotics for which one maximum of light asborption has been reported 

 (Each number indicates the maximum, expressed in m/x.) 



1. 208 in 0.1 A^ HCl; 218 in 0.1 N NaOH 



2. 226 in water at pH G.O 



3. 235 in ethanol 



4. 237. o in methanol 



5. 260 



6. 260 in methanol over a wide pH range 



7. 268 in 0.1 A^ HCl; 280 to 282.5 in 0.1 N XaOH 



all)()vei'ticillin 



cycloserine 



hygroscopin A 



elaiomycin 



mycomycetin 



august my cin A 



phthiomycin 



viomycin 



bo\iii()cidin 



pyridomycin 



B 



8. 270 at pH 8.4 



9. 303 in alcohol 

 10. 306 in 50 per cent aqueous ethanol; 31() in 



0.1 A^ HCl 

 Antibiotics for which more than one maximum of light absorption has been re- 

 ported 



1. 227 and 270 in acidic solutions 



2. 230 and 285, with end-absorption, in water 



3. 240, 410, and 425 in cyclohexane 



4. 244 and 295 to 300; ninhydrin-positive 



5. 251 and 364 in methanol 



6. 255 and 320 in water 



7. 256 and 365 in methanol 



8. 260 and 270, with weak maxima at 290, 307, 

 327, and 348 



C. Antibiotics with no light absorption or for which light al)sorption has not been re- 

 ported 

 1. Neutral, white antibiotics 



amicetin 



tubercidin 

 (|uestiomycin B 

 (juestiomycin A 

 phleomycin (base) 

 tubermycin B 

 grisaminc 

 tubermycin A 



isomycomycin 



2. Acidic, colorless substance, essentially insol- 

 uble in water and chloroform 



3. Heat-stable substances, probably basic and 

 water-soluble 



4. Reddish substance 



5. Lytic agent 



acetomycni 

 longisporin 



actithiazic acid 



antiphlei antibiotics 



antismegmatis antibiotic 



nocardin 



nocardamin 



actinolysin 



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