Isolation of Dimethylallylpyrophosphate:Umbelliferone Dimethylallyltransferase from Ruta graveolens

The enzyme catalyzing the first reaction specifically directed to furanocoumarin synthesis has been isolated from suspension cultures and young leaves of Ruta graveolens. With umbelliferone, Mn 2+ , and dimethylallylpyrophosphate as substrates the enzyme converts umbelliferone to 6-dimethylallylumbelliferone (demethylsuberosin), an established intermediate in the biosynthesis of linear furanocoumarins, but not to 8-dimethylallylumbelliferone (osthenol), the analogous intermediate in angular furanocoumarin biosynthesis. Herniarin does not substitute for umbelliferone, nor geranylpyrophosphate for dimethylallylpyrophosphate. The enzyme activity is associated with particles that sediment readily at high centrifugal force.