Quantitative variation of flavonoids among individuals of a Cistus ladanifer population

The flavonoids in the exudate from a group of 30 individuals of a Cistus ladanifer population were analysed. The exudate contained eight aglycone flavonoids (apigenin and kaempferol derivates), with differences in the secretion of dimethylated kaempferol from one individual to another. In most (24 individuals) the principal dimethylated kaempferol was kaempferol-3,7-dimethyl ether, with kaempferol-3,4'-dimethyl ether contributing at only a very low percentage. However, the other six individuals presented kaempferol-3,4'-dimethyl ether as the principal component. There is thus a different quantitative pattern between the two sets of individuals, pointing to the existence of two chemotypes of this species. (C) 1997 Elsevier Science Ltd.