Pfizer Handbook of Microbial Metabolites 418 



892 Sterigmatocystin, CigHioOg, pale yellow needles, m.p. 246° 

 (dec), [aln"-^ -387° (c 0.424 in chloroform). 

 Probable structure: 



Aspergillus versicolor (Vuillemin) Tiraboschi 



J. E. Davies, D. Kirkaldy and John C. Roberts, J. Chem. Soc, 



2169 (1960). (Structure) 



Abou-Zeid, Dissertation, London, 1953. (Isolation) 



J. E. Davies, John C. Roberts and S. C. Wallwork, Chem. 



and Ind., 178 (1956). (Isolation) 



J. H. Birkinshaw and I. M. M. Hammady, Biochem. J. 65 



162 (1957). (Isolation) 



Yuichi Hatsuda and Shimpei Kuyama, /. Agr. Chem. Soc. 



Japan 28 989 (1954). (Chem. Abstr. 50 15,522) (Isolation) 



e. COMPOUNDS RELATED TO THIOPHENE, 

 IMIDAZOLE, THIAZOLE 

 AND ISOXAZOLE. 



Some of the commercially important compounds in this 

 section are the antibiotics cycloserine and the penicillins 

 and the vitamins, thiamine and biotin. 



Penicillin was discovered by Fleming in 1929, and com- 

 mercial fermentation techniques were developed during 

 the second World War. Penicillins with several different 

 side-chains were found to be produced by various penicil- 

 lia and aspergilli, and hundreds of unnatural penicillins 

 were prepared by the addition of side-chain precursors 

 to fermentations. 



It was not until 1959, however, that the nucleus com- 

 mon to all penicillins, 6-aminopenicillanic acid, was iso- 

 lated from fermentations.^ This discovery has made pos- 

 sible the preparation of a new series of penicilUns through 



iRoichi Kato, /. Antibiotics (Japan) 6A 130, 184 (1953); F. R. 

 Batchelor, F. P. Doyle, J. H. C. Nayler and G. N. Rolinson, Nature 

 183 257 (1959). 



