Terpenoid and flavonoid spectrum of in vitro cultures of Glycyrrhiza glabra revealed high chemical heterogeneity: platform to understand biosynthesis

Simultaneous qualitative and quantitative assessment of eight flavonoids and two terpenoids were performed in fourteen in vitro raised morphogenic cultures of Glycyrrhiza glabra. Our study revealed that the spectrum and production of ten compounds, under investigation, were higher in organized tissue than the undifferentiated mass, however, aerial portions of the in vitro raised plants (leaf and stem) were found to be devoid of therapeutically relevant triterpenoid, glycyrrhizin. A correlation was observed between cell maturation, morphological differentiation and glycyrrhizin accumulation. Mature stolons (4 months) were characterized by the maximum accumulation of glycyrrhizin (8.60 µg/mg) in in vitro plantlets. The cytotoxic effect of the extracts evaluated against a panel of human cancer cell lines (in vitro) indicated that the pancreatic cell line (MIA-PaCa-2) were sensitive to all the fourteen extracts investigated. To the best of our knowledge this is the first comprehensive report relating plant growth regulators to metabolite spectrum and cytotoxic assessment in in vitro raised G. glabra cultures. Overall, our findings demonstrated that the metabolite spectrum of in vitro raised morphogenetic lines, under different stages of maturation, might offer a platform to understand the regulatory aspects of the concerned metabolite pathway and their consequent role in differentiation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11240-015-0910-4) contains supplementary material, which is available to authorized users.