... Drosera [21] Naphthoquinone Droserone Hydroxydroserone Biramentaceonea Droserone-5-glucoside Rossoliside Hydroxydroserone-5-glucoside 2-Methylnaphtazarin-5-O- ... Hydroxydroserone [5] H H CH3 OH OGlc Droserone-5-glucoside [6] OH H CH3 OH OGlc Hydroxydroserone-5-gluside R6 R7 [7] CH3 H Rossoliside [8] H CH3 2-Methyl-hydrojuglone -4 - glucoside ... hhthoquinone-Drosera [21]. R1 R2 R3 R 4 R5 [1] CH3 H H H OH 7-Methyljuglone [2] H H CH3 H OH Plumbagin [3] H H CH3 OH OH Droserone [4] OH...