Identification of two Gossypetin Monomethyl Ethers as Yellow Flower Pigments in the Rutaceae

Abstract

Gossypetin 7-methyl ether 3-rutinoside has been characterized as a yellow flower pigment in Ruta graveolens and in five other Ruta species. By contrast, in four Haplophyllum species, the 7-glucoside of gossypetin 3′-methyl ether provides the yellow coloration in the flower. Although carotenoid accompanies the yellow flavonol in R. graveolens, there is no evidence of UV patterning and the petals are uniformly UV absorbing.