NMR characterizationof induced accumulation of aromatic bioactive compounds in flax cell cultures

Flax is one of the oldest and highly cultivated oil seed crop in Europe and is regarded as a functional food due to the presence of high quality omega-3 fatty acids (?-linolenic acid), proteins, lignin, dietary fibers and phenolic derivatives (lignans) [1]. In particular, lignans exhibit antioxidant, cytotoxic, antifungal, antiviral and phytoestrogenic and cancer chemopreventive properties [2,3]. In this work, two different flax species have been exploited to obtain in vitro cell cultures for the improvement of lignans production. The species have been selected considering that lignan profile correlate with the genus systematic division of flax. Moreover, several elicitors such as methyl jasmonate (Me-JA) were used to increase metabolites production. NMR based metabolomics was performed to evaluate the metabolic profiling of selected flax extracts. Stable cell lines were established from leaf explants of Linum usitatissimum (cv Valoal) and Linum austriacum. The extracts (control and the 4 days Me-JA treatment) of the cell suspensions obtained from the two flax species were investigated by 1H NMR to evaluate differences in their total phenolic content. The same samples were analyzed by Folin-ciocalteu method to evaluate the total phenolic content. The metabolite profiles of flax cell suspensions were obtained by recording 1H-NMR spectra at 14.09 T. The aromatic regions of proton spectra highlighted different profiles between the two species showing that L. austriacum samples were more rich of aromatic compounds most likely belonging to the lignan class and that the two species are able to synthesize different molecules. The results suggest that the cell suspension technology combined with the elicitation could represent a promising technology for industrial production of bioactive compounds.