Pfizer Handbook of Microbial Metabolites 272 



593 Rifomycin B, C39H51O14N, m.p. 160-164° (dec). 



A dibasic acid (pKs 2.8, 6.7). Probably a quinone 

 (U.V. peaks at 400-460, also at 223, 234). 



Streptomyces mediterranean 



P. Sensi, A. Greco and R. Ballotta, 7th Annual Symposium 

 on Antibiotics, Washington, 1959. 



594 Vinacetin, yellow platelets, m.p. 157°. 



Apparently quinoid. Positive FeClg, violet color in 

 alkali, positive Molisch, Liebermann, Fehling. Negative 

 ninhydrin, Millon, Sakaguchi. 



Streptomyces sp. 



Kyuzo Omachi, J. Antibiotics (Japan) 6A 73 (1953). 



595 Rhodophyscin, red leaflets, m.p. 260° (dec). 



A quinone-like substance. 



Physica endococcina 



Wilhelm Zopf, Ann. 340 276 (1905). 



