PHENOLIC SUBSTANCES 



201 



ISOFLAVONES 



HQ 



l^r\ 



HO O 



CHALKONES 



■0H^_/~\ 



HO O 

 AURONES (BENZALCOUMARANONES) 



This group is distinguished by the presence of a five- 

 membered heterocychc ring. 



HO. ^ ,0^ 



HO 



CATECHINS 



O^ 



OH 



LEUCO-ANTHOCYANINS 



HO 



BIFLAVONYLS 

 HO 



o-^^ / 



OH 



HO HO 



In addition to the many types of flavonoids already described 

 there are a few flavonoids substituted with isoprene units. The 

 substances artocarpin and isoartocarpin, found in the wood of Arto- 

 carpus integrifolia, are particularly interesting representatives since 



