PhD defence C.L.C. (Christina) Seegers

Production routes toward podophyllotoxin

Most drugs are based on plant compounds. Nowadays, most of these are synthetically imitated, but a large part is still extracted directly from the plant. In her thesis, Christina Seegers looked at podophyllotoxin, which is used as basis for two very important anticancer drugs.

Seegers: 'Currently, podophyllotoxin is mainly extracted from a plant that grows only in the Himalayas (Himalayan mayapple), which is threatened with extinction. In the Netherlands, the common plant wild chervil contains a compound (deoxypodophyllotoxin) that is similar, but where a 'hook' is missing (OH group). We have developed a green extraction method to extract this compound from the roots of wild chervil. In addition, we developed a laboratory scale method to quickly determine deoxypodophyllotoxin content in wild chervil roots, that can be used in the future for plant breeding programs aimed at increasing the deoxypodophyllotoxin production in wild chervil. Alternatively, we have created root cultures of wild chervil that produce deoxypodophyllotoxin and show that we can grow it in the dark in a new type of disposable bioreactor. Then, we show conversion of deoxypodophyllotoxin into (epi)podophyllotoxin in a bacterial system. For this we used an enzyme from the Himalayan mayapple. In addition to wild chervil, we have also investigated the Himalayan mayapple. We have shown that we can grow this plant in a glasshouse in the Netherlands and that the root growth and/or podophyllotoxin production can be increased in various manners, for example by varying the soil type, temperature and by treatment with a natural plant hormone.'

Promotores: Prof. dr. W.J. Quax