The growth and droserone content of callus cultures of Triphyophyllum peltatum grown in liquid 1/5 Linsmaier and Skoog medium was studied. During a lag phase in growth, droserone concentrations in the medium reached a value of 2.1 mg g−1 fr. wt. After this maximum value the concentration decreased slightly to 1.8 mg g−1 fr. wt., while the growth of the calli was enhanced (25% increase in fr. wt. within 7 days). Plumbagin and isoshinanolone were likewise present in the medium. By feeding 13C2-labelled acetate to the cultures the biosynthesis of droserone was elucidated. The incorporation of whole C2-units unambiguously shows its acetogenic origin and fits well in the biosynthetic scheme suggested for the structurally — and biogenetically — related naphthylisoquinoline alkaloids.
Bringmann, G., Rischer, H., Wohlfarth, M., Schlauer, J., & Aké Assi, L. (2000). Droserone from cell cultures of Triphyophyllum peltatum (Dioncophyllaceae) and its biosynthetic origin. Phytochemistry, 53(3), 339-343. https://doi.org/10.1016/S0031-9422(99)00543-9