(582cl) Metabolic Profiling of Terpenoid Indole Alkaloids in Transgenic Catharanthus Roseus Hairy Roots

Plant-derived natural products play an important role in the pharmaceutical industry. The terpenoid indole alkaloids (TIAs) are prime examples and some of them have been developed as leading antineoplastic pharmaceuticals, such as vincristine and vinblastine. The natural yield of those valuable drugs is very low and chemical synthesis of those compounds is not very successful because of complex structure, which makes them extremely expensive. Despite significant progress in recent years, much remains unknown in these pathways, including uncharacterized enzymes or transcriptional regulation.   Therefore, manipulation of the TIA pathways and analysis of transcription and metabolite profiles in transgenic Catharanthus roseushairy root lines will improve the understanding of the network fluxes and regulation in TIAs pathways.

The bottleneck in developing the metabolic profiling methods of TIA pathways is that there are few commercialized available metabolite standards to be used to identify and quantify the metabolites in hairy root lines, which leads to an incomplete metabolic profile and a metabolic flux map that cannot reflect the real situation in the hairy root lines. Therefore, it is essential to get more identified metabolite standards to complete the metabolic profiling. In metabolomics study, LC-tandem MS technique has been applied in separation, detection, potential identification and quantification of low-concentrated metabolites with the advantages of high sensitivity and selectivity. Along with LC-tandem MS, NMR is also a leading analytical tool to investigate metabolism.

In this study, several metabolites were extracted and purified from either C. roseus hairy roots or an engineered yeast strain, NMR and LC-tandem MS were applied to identify the structure and MS fragment patterns of each metabolite. The newly identified metabolites were used as standards to develop the metabolic profiling of TIAs in hairy root lines.