Pfizer Handbook of Microbial Metabolites 410 



870 Aureothin, C20H23O6N, yellow crystals, m.p. 158°. 



CH3 O 



OzH—^y-QH^C—CH^C CH2' ' 



OCH3 



Streptomyces thioluteus 



Aureothin occurs as a by-product in the aureothricin 

 fermentation. 



Kenji Maeda, /. Antibiotics (Japan) 6A 137 (1953). (Iso- 

 lation) 



Y. Hirata, H. Nakata and K. Yamada, /. Chem. Soc. Japan 

 79 1390 (1958) and preceding papers. (Structure) 



QuiNONOiD Compounds. 



This section includes a group of colored compounds, 

 many of which have chromophores resembling those of 

 quinones. These unusual substances presented some 

 interesting structural problems. In many cases there 

 was a long time interval between isolation and complete 

 structure determination. 



The relationship between fulvic acid and citromycetin 

 is obvious. The relationship of both of these compounds 

 to fusarubin has been pointed out recently.^ This is less 

 obvious, but a precursor such as (I) was envisaged for all 

 three compounds, the formation of fusarubin involving 

 ring closure at the dotted line. 



Penicillium griseofulvum, which is one of the producers 



^ F. M. Dean, R. A. Eade, R. A. Moubasher and A. Robertson, Na- 

 ture 179 366 (1957). 



