Camptothecin derivatives are used clinically as anti-tumor alkaloids. Campt
othecin and its related compounds are at present obtained by extraction fro
m intact plants, but transformed plant cell cultures may be an alternative
source of production. We have established a hairy root culture of Ophiorriz
a pumila (Rubiaceae) transformed by Agrobacterium rhizogenes strain 15834.
This hairy root culture grew well, increasing by 16-fold during 5 weeks in
liquid culture, and it produced camptothecin as a main alkaloid up to 0.1%
per dry weight of the cells. Interestingly, not only the hairy root cells c
ontained camptothecin, but the culture medium also accumulated substantial
amounts. Camptothecin content in the medium was increased by the presence o
f a polystyrene resin (Diaion HP-20) that absorbed camptothecin. Camptothec
in was easily recovered from the resin. Our method is the most feasible and
commercially applicable way to produce camptothecin by in vitro cell cultu
re.