ANTIBIOTIC GROUPS 171 



a 1 . Red peptide, allo-isoleucine absent, active largely against 

 gram-positive bacteria. 



Actinomycin 



(Actinomycin A, B, X) 

 b 1 . Red peptide, contains D-allo-isoleucine. 



Actinomycin C 



(Ci, C2, C3) 

 c 1 . Closely related and incompletely described members of 

 the actinomycin group. 



Actinomycin Ji 



(Actinofiavin) 



b. Yellowish orange bases, highly toxic. 



Xanthomycin A, B 



c. Saffron-yellow, weakly acidic, stable. 



Resistomycin 



d. Yellowish basic substances, active only against mycobacteria. 



Antiphlei factor 



e. Reddish, acidic substance, active against mycobacteria. 



Nocardamin 



f. Violet pigment, soluble in water, alcohol, and ether. 



Rhodocidin 



g. Yellow substance, very slightly soluble in ether. 



Phalamycin 



2. Acid-base indicators, changing from red or yellow to blue, guinones 

 or anthocyanins. 



a. Amphoteric substituted quinones, crystalline perchlorate. 



Rhodomycin A, B 



b. Red pigmented, low nitrogen-containing compound. 



Rhodomycetin 



c. Non-nitrogen-containing quinone, alkali-soluble, ether-insol- 

 uble Actinorhodin 



d. Anthocyanin-like pigment, soluble in water. 



Litmocidin 



e. Reddish violet pigment. 



Coelicolorin 



f. Red-brown compound, yellow in acid (stable) and purple in 

 alkali (unstable) solution. 



SKCC 1377 



3. Nonpigmented substances. 



a. High molecular weight acids, not containing nitrogen. 

 a 1 . Also active against fungi. 

 a 2 . C 39 H 69 0u 



Nigericin 



