Structure and accumulation of phenolics in elicited Echinacea purpurea cell cultures

Echinacea purpurea cell cultures have been established for the production of secondary and possibly bioactive compounds using elicitation techniques. Different elicitors including yeast elicitor, methyl jasmonate, glutathione, and manganese ions were used and compared for their effects on the formation of phenolics in the cell cultures. The accumulation of phenolics in the medium after elicitation with glutathione and manganese ions showed similar patterns as detected by HPLC in control medium. However, in yeast elicitor- and methyl jasmonate-treated cell suspension cultures, other phenolics were formed and accumulated in the medium. In contrast, both control and elicited cells contained the same pattern of phenolics. The main phenolics both in the medium and cells, 19 in total, were isolated and identified on the basis of chromatographic, chemical (derivatisation), enzymatic and spectroscopic techniques. The medium contained lignans, neolignans and acetophenone derivatives as main elicitor-enhanced products. The cells mainly contained phenolic glycosides including a new compound, alpha- O-beta-D-glucopyranosylacetovanillone. Detailed collision-induced dissociation electrospray ionisation mass spectrometric fragmentation pathways for 8,4'-oxyneolignan glycosides are discussed.