Figure 8.

The production of podophyllotoxin in plants takes place in 33 steps where coniferyl alcohol acts as the precursor. The pathway is called phenylpropanoid pathway. In the early steps of podophyllotoxin biosynthesis coniferyl alcohol in formed in nine steps from phenylalanine. Coniferyl alcohol then undergoes a site-selective and unusual enantio-dimerization to form (+)-pinoresinol. Pinoresinol is then reduced to (−)-secoisolariciresinol, which is catalyzed by a dehydrogenase to (−)-matairesinol. The next intermediate formed is (−)-pluviatolide, which is methylated to (−)-5′-desmethoxy-yatein that is converted to the yatein. Yatein is the intermediate that gets converted to the end product; podophyllotoxin [109].