Investigation of Mammalian Lignan Precursors in Flaxseed: First Evidence of Secoisolariciresinol Diglucoside in Two Isomeric Forms by LC-MS

A strong research effort has been devoted in recent years to the mammalian lignans enterolactone and enterodiol because of their claimed protective effects against breast and colon cancer. Some plant lignans appear to be precursors of these molecules. This paper reports a novel identification procedure for one of these precursors, the secoisolariciresinol diglucoside, in the extracts of defatted flax-seed meal. The procedure is based on highperformance liquid chromatography coupled with either ionspray or continuous-flow fast-atom bombardment mass spectrometry. The application of these techniques allowed the identification in flax seed of two isomeric forms of this precursor for the first time. The isomers are reasonably the two diastereoisomers, due to the two equivalent stereogenic centers present in the molecule