PRODUCTION OF PLUMBAGIN BY CELL-SUSPENSION CULTURES OF DROSOPHYLLUM-LUSITANICUM LINK

The callus culture of Drosophyllum lusitanicum Link. derived from and kept on a Murashige and Skoog (1962) medium accumulated plumbagin {0.0 8% of fresh biomass wt. (FW)}, a naphthoquinone derivative of commerci al interest for its pharmacological and insecticide properties. The ca llus culture underwent a strong plasmolysis after being transferred in to a liquid medium. Nevertheless, the production of plumbagin rose mar kedly. After adaptation to a suspension, the culture growth turned dar k to black and contained ca. 40% of the plasmolyzed cells and ca. 0.8% FW of the accumulated plumbagin. The influence of different basic med ia and various concentrations of exogenous phytohormones in the cultur e on the growth and the production of plumbagin has been tested. II wa s found that, at optimal conditions, the plant suspension culture of D rosophyllum lusitanicum contained 3.5% FW of plumbagin corresponding t o production of 1.5 g l(-1) per fortnight. This overproduction (10 tim es higher than in the mother plant) indicates that the plant cell susp ension culture of Drosophyllum lusitanicum might be an excellent sourc e of plumbagin and will lead to greater commercial interest in this qu inone.