Stimulation of Indole Alkaloid Content in Vanadium-Treated Catharanthus roseus Suspension Cultures.

Addition of vanadyl sulphate to cell suspensions of CATHARANTHUS ROSEUS was found to increase ajmalicine, catharanthine, and tryptamine levels. Up to 500 microg/g dry weight catharanthine and 131.0 microg/g dry weight ajmalicine were detected in vanadyl sulphate-treated cells. This represents an approximate increase of 50% over control levels. This stimulation was found to be dependent upon the concentration of vanadyl sulphate administered and upon the cell age. High tryptamine levels were not correlated with increased tryptophan decarboxylase activity. Vanadium content of the cells was found to reach a maximum within 1 min following vanadyl sulphate treatment as measured by Instrumental Neutron Activation Analysis.

Increased synthesis of ajmalicine and catharanthine by cell suspension cultures of Catharanthus roseus in response to fungal culture-filtrates.

The ammonium sulfate-precipitated fraction from mycelia and culture-filtrates and the crude, cell-free culture filtrates from the growth medium of the fungi Chrysosporium palmorum, Eurotium rubrum, Micromucor isabellina, and Pythium aphanidermatum when aseptically added to cell suspensions of Cantharanthus roseus caused a rapid and dramatic increase in indole alkaloid biosynthesis. Up to 400 micrograms/L ajmalicine and 600 micrograms/L catharanthine were detected in C. roseus cell suspension grown in the presence of the M. isabellina fungal culture filtrate for 3 d. Untreated cells produced only trace levels of ajmalicine and catharanthine per liter of cell suspension after 15 d of culture.

Increased accumulation of indole alkaloids by some cell lines of Catharanthus roseus in response to addition of vanadyl sulphate.

Vanadyl sulphate (10-500 mg/l), when added to cell suspension cultures of Catharanthus roseus stimulated increased intracellular accumulation of catharanthine and ajmalicine. This response was demonstrated in both flask and fermenter (30 litre) systems. The response varied, and depended upon cell line, concentration of vanadyl sulphate and the stage of the growth phase at which the cells were treated. This process has the potential to increase the yield and reduce the production time for commercially useful secondary plant metabolites.