Coniferin dimerisation in lignan biosynthesis in flax cells

The use of [8,9- 13C 2]-coniferin coupled with mass spectrometry and nuclear magnetic resonance showed the ability of a flax cell suspension to biosynthesise differently linked (neo)lignans: 8–8′, 8–5′ and 8- O-4′. The continuous synthesis and subsequent metabolisation of these coniferin-derived dimers were established all over the culture period. [ 13C 2]-Coniferin was provided to a flax ( Linum usitatissimum L.) cell suspension to monitor subsequent dimerisation by MS and NMR. The label was mainly incorporated into a 8–8′-linked lignan, lariciresinol diglucoside, a 8–5′-linked neolignan, dehydrodiconiferyl alcohol glucoside and a diastereoisomeric mixture of a 8- O-4′-linked neolignan, guaiacylglycerol-β-coniferyl alcohol ether glucoside. This latter compound is reported for the first time in flax. The strong and transient increase in these compounds in fed cells was concomitant with the observed peak in coniferin content. These results suggest (i) a rapid metabolisation of coniferin into lignans and neolignans and indicate the capacity of flax cells to operate different types of couplings, and (ii) a continuous synthesis and subsequent metabolisation of coniferin-derived dimers all over the culture period.