Figure 2.

Schematic representation of podophyllotoxin biosynthetic pathway. Dashed arrows represent unknown multiple reactions. Enzyme abbreviations: PAL– Phenylalanine ammonia lyase, C4H– Cinnamate 4-hydroxylyase, C3H– p-coumarate 3-hydroxylyase, CAOMT– caffeic acid–O-methyltransferase, 4CL– 4coumarate: CoA ligase, CCOMT– caffeoyl CoA o-methyltransferase, CCR– cinnamoyl CoA reductase, CAD- cinnamyl alcohol dehydrogenase, DP oxidase– dirigent protein oxidase, PLR– pinoresinol lariciresinol reductase, SDG– Secoisolariciresinol dehydrogenase.