Pfizer Handbook of Microbial Metabolites 148 



302 Frequentin, C14H20O4, colorless needles, m.p. 128°, [aln^^ +68° 



(0.5 in chloroform). 



Probably similar to palitantin in structure. 



Penicillium freqiientans Westling, P. cyclopium 



P. J. Curtis, H. G. Hemming and W. K. Smith, Nature 167 



557(1951). 



303 Palitantin, C14H22O4, colorless needles, m.p. 163°, [a]546i"^ +4.4° 



(c 0.8 in chloroform). 



O 



CH2 



/ \ 



CH3 CH2 



Penicillium palitans Westling, P. frequentans, P. cy- 

 clopium 



John Howard Birkinshaw and Harold Raistrick, Biochem. J. 

 30 801 (1936). 



P. J. Curtis, H. G. Hemming and W. K. Smith, Nature 167 

 557 (1951). 



A. Bracken, Anna Pocker and H. Raistrick, Biochem. J. 57 

 587 (1954). 



K. Bawden, B. Lythgoe and D. J. S. Marsden, /. Chem. Soc, 

 1162 (1959). (Structure) 



304 B-73, CigHieOoNo, colorless plates, m.p. 275°, [aln"' +3.43° (c 



0.4 in dimethylformamide). 



Negative ferric chloride test, non-fluorescent under U.V. 

 light, soluble in aqueous sodium hydroxide. 



Streptomyces albulus 



Non-antibiotic compound isolated from a broth contain- 

 ing cyclpheximide, 4-acetoxycycloheximide, C-73, and 

 fungicidin. 



K. Rao, Abstracts, 134th Meeting of the American Chemical 

 Society, Chicago, September 1958. 



305 C-73, C15H1-O4N, pale yellow needles, m.p. 199°, [a]i,^^ +5.06° 



(c 0.4 in dimethylformamide). 



Green ferric chloride test, bright yellow fluorescence in 

 U.V. light, soluble in sodium hydroxide solution. 



Streptomyces albulus 



This antibiotically inert compound was isolated from a 

 culture containing cycloheximide and stereoisomers, 4- 

 acetoxycycloheximide, fungicidin, E-73 and B-73. 



