Pfizer Handbook of Microbial Metabolites 



336 



CH3 CH3 



Actinomycin C3 



The dual nature of the actinomycin molecules makes it rather 

 obvious that they must be formed by condensation of two similar 

 halves. Butenandt showed that xanthommatin was derived 

 from tryptophan by feeding experiments with the labeled amino 

 acid. Similarly Katz has shown® that actinocinin is derived 

 from tryptophan. Thus the entire actinomycin molecule is 

 composed of amino acid derivatives. In the case of xanthom- 

 matin the intermediate is kynurenine, a known degradation 

 product of tryptophan. Kynurenine may also be an intermedi- 

 ate in actinocinin biosynthesis, although the assumed inter- 

 mediate, 3-oxy-4-methyl-anthranilic acid might equally well 

 arise through a variation in the biosynthetic route to tryptophan. 



^ Edward Katz, N. Y. Acad. Sci. Conference on Actinomycins, 

 March 31 to April 1, 1960. (Unpublished) 



