The production of 7-methyljuglone, quercetin and kaempferol by Drosera anglica and D-rotundifolia

The naphthoquinone 7-methyljuglone, flavonols quercetin and kaempferol are the main secondary metabolites of Drosera anglica and D. rotundifolia. The content of 7-methyljuglone was evaluated in four leaf ontogenetic phases, i n stem and flower of both species studied. The highest content (1.0 to 2.7% in dry matter) was found in young and in mature green leaves. High content of quercetin was estimated in all aboveground organs of both species (3.4 to 5.7%). In comparison with other plant organs the highest amount of kaemp ferol accumulates in the flower (0.41% and 0.58% respectively).