PHENOLIC SUBSTANCES 



197 



H,C 



Grisebach and Ollis (1961) have noted a high frequency of 

 co-occurrence of isoflavonoids and rotenoids (see Table 11-1), and 

 furthermore there is a rather close correlation in their group sub- 

 stitution patterns. 



It appears that a single pathway, in reality one that is possibly 

 as phylogenetically old as the first cellular organisms, leads to the 

 phenolic amino acids and hence to other phenolics. Secondly, another 

 pathway, originating also from an important basic metabolite (acetate), 

 cooperates to yield the complex flavonoids. 



Table 11-1. Distribution of flavonoids, isoflavonoids and rotenoids in selected 

 species (Experientia 17: by permission of Grisebach and Ollis, 1961). 



