Pfizer Handbook of Microbial Metabolites 



1 60 



19 17 



COOH 



O^ 



o 



CH3— CH=CH— coo 



Rosenonolactone 



Rosololactone 



Trichothedn 



The carbon skeleton of rosenonolactone'' is apparently derived 

 from the same kind of precursor as gibberellic acid, but in a 

 simpler way. All that is required is the migration of a methyl 

 group from C-12 to C-13 in the same manner as in the biosyn- 

 thesis of steroids. 



The carbon skeleton of trichothecin^" can be derived from a 

 sesquiterpenoid intermediate by way of two 1,2-methyl group 

 shifts : 



-O 



2-C'^-Me- 

 valonate 



Proposed sesquiter- 

 penoid intermediate 



CH— COO 



Trichothecin 



319 



When labeled acetate was used in this study, 95% of the 

 activity appeared in the crotonic acid moiety. These results, 

 considered together, are another confirmation of the irreversibil- 

 ity of the acetate-mevalonate process. 



A symposium has been published thoroughly reviewing cur- 

 rent research on the biosynthesis of terpenes and sterols.^^ 

 Lactaroviolin, C15H14O, red-violet crystals, m.p. 53°. 



OHC 



-=G. E. W. Wolstenholme and Maeve O'Conner (Eds.), "CIBA 

 Foundation Symposium on the Biosynthesis of Terpenes and Sterols," 

 Little, Brown and Co., Boston, 1959. 



