192 



FLAVONOIDS AND RELATED COMPOUNDS 



Karanjin also has a furo ring fused to the flavonol structure: 



In fukugetin from Garcinia spicata bark an additional Cg - C3 group is attached to 

 the A ring of an otherwise typical flavone: 



fukugetin 



The dyes of Brazil wood and logwood are also similar in structure to the flavonoids. 

 Their chemistry has been reviewed by Robinson (33). It seems possible that both of their 

 aromatic rings could be derived from shikimic acid. If so, they do not really belong with 

 the flavonoids. 



hematoxylin 



brazilin 



Other substances are known with a 4-phenyl coumarin nucleus, such as calophyl- 

 lolide from Calophylluni inophylluni (34) and dalbergin. 



