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 {0.08% of fresh biomass wt. (FW)}, a naphthoquinone derivative of commercial interest for its pharmacological and insecticide properties. The callus culture underwent a strong plasmolysis after being transferred into a liquid medium. Nevertheless, the production of plumbagin rose markedly. After adaptation to a suspension, the culture growth turned dark to black and contained ca. 40% of the plasmolyzed cells and ca. 0.8% FW of the accumulated plumbagin. The influence of different basic media and various concentrations of exogenous phytohormones in the culture on the growth and the production of plumbagin has been tested. II was found that, at optimal conditions, the plant suspension culture of Drosophyllum lusitanicum contained 3.5% FW of plumbagin corresponding to production of 1.5 g l(-1) per fortnight. This overproduction (10 times higher than in the mother plant) indicates that the plant cell suspension culture of Drosophyllum lusitanicum might be an excellent source of plumbagin and will lead to greater commercial interest in this quinone.