We established a practical method for rapid and large-scale production of Valeriana fauriei var. dasycarpa Hara roots by bioreactor culture and confirmed valerenic acids and valepotriates production. We also compared valerenic acids and valepotriates production patterns according to various media conditions. Among the media tested, B5 medium gave the maximum biomass production of 101 g fresh weight, which was a 5.03-fold multiplication rate obtained 4 weeks after inoculation of 20 g of fresh weight. The best production of total valerenic acids (7.86 mg/l) and valepotriates (8.96 mg/l) was B5 medium.
Plants have been known to accumulate a very diverse range of triterpene saponins. We have investigated the regulation of saponin biosynthesis in higher plants using Centella asiatica (L.) Urban as a model plant. Effects of a feeding precursor on asiaticoside production from leaves and on the level of two-type OSCs mRNA were investigated. As a feeding precursor, squalene negatively affected the levels of CYS and bAS mRNA, but it also decreased the production of asiaticoside from whole plants. Plant hormones regulate secondary metabolism, and in plant tissue cultures they could affect both culture growth and secondary metabolite production. Although enhancement of asiaticoside production from whole plant cultures by addition of TDZ (thidiazuron) has been reported, the positive effect of TDZ on the levels of OSCs transcripts was not observed.