Novel Compounds from the Farinose Exudate of Primula

In botany textbooks the farinose coating on leaves and inflorescences of many Primula species is still often said to "consist of flavone". We have shown earlier [1, 2] that it is in fact formed by varying amounts of unsubstituted flavone (at least 50%), 5-hydroxy flavone and 2'-hydroxy flavone, accompanied in many species by 5,8-dihydroxy flavone (primetin) and 5,2'-dihydroxyflavone. Further components with scattered distribution are 5,8,2'-trihydroxy flavone and 3',4'-dihydroxy flavone, the latter always occurring only as a trace constituent [3]. Recently we identified 2'-methoxyflavone, 5-hydroxy2'-methoxyflavone and 2',4'-dihydroxy chalcone as new constituents of Primula exudate and mentioned the existence of further compounds [4]. Now we wish to report on the identification of a novel flavone and its natural acetate from this material as well as on the synthesis of this flavone.