Steroidal alkaloids in tissue cultures and regenerated plants of Solanum dulcamara

Callus and cell suspension cultures were established with shoots of the soladulcidine variety of the bittersweet Solanum dulcamara L. Plantlets were regenerated from undifferentiated callus. From mixotrophic callus as well as mixotrophic suspension cultures soladulicidine, solasodine and the corresponding neutral spirostanes tigogenin and diosgenin were isolated and identified by thin layer chromatography and mass spectrometry. Total alkaloid concentrations were about 0.2 mg/g dry weight (callus) and 0.1 mg/g dry weight (green suspension cultures). In the heterotrophic cell line only the neutral sapogenins could be detected. Alkaloid accumulation in callus of Solanum dulcamara could be enhanced by the induction of organogenesis. The shoots of the regenerated plants from the mixotrophic callus contained soladulcidine (1.6 mg/g dry weight) and tigogenin. Thus, in concentration and composition the regenerated plants equalled the source plant.