ANTIBIOTIC GROUPS 181 



See also group A, p. 178 for exfoliatin. 



III. Containing nitrogen; activity against gram-negative organisms 

 limited to members of all or one of the genera Neisseria, Hemoph- 

 ilus, and Brucella. 



1. See group A, pp. 178-179, for luteomycin, carbomycin, erythro- 

 mycin, leucomycin. 



IV. Containing nitrogen and sulfur. 



1. YelloAV crystals, insoluble in water, neutral. 

 Thioaurin 

 Antibiotic HA-9 

 V. Containing nitrogen, active against rickettsiae; soluble in organic 

 solvents. 



1. White, neutral, containing nonionic chlorine. 



Chloramphenicol 



2. Yellow. 



a. Containing nonionic chlorine. 



Chlortetracycline 



b. Containing no chlorine. 



Oxytetracycline 

 Griseolutein 



c. Incompletely described. 



Flaveolin 

 VI. Containing nitrogen; not active against rickettsiae; basic; water- 

 soluble. 



1. Limited activity against gram-negative bacteria. See group A, 

 p. 178, for viomycin and vinactin. 



2. Nearly as active against gram-negative as against gram-positive 

 bacteria. 



a. Pigmented. 



a 1 . Yellow compounds. 

 Flaveolin 

 b 1 . Red Rhodocidin 



b. Nonpigmented. 



a 1 . Activity against gram-positive and gram-negative bac- 

 teria on nutrient agar relatively limited (3-40 mcg/ml). 

 Maximum light absorption at 236 and 296 van. 

 Netropsin 



b 1 . Inhibition of gram-negative and gram-positive bacteria on 

 nutrient agar often requires less than 1 mcg/ml. No 

 typical ultraviolet absorption spectra. 

 a 2 . Inactivated by cysteine. 



