Isolation and characterization of the lignans, isolariciresinol and pinoresinol, in flaxseed meal

The isolation and characterization of the lignans, isolariciresinol, pinore sinol, secoisolariciresinol, and matairesinol, potent phytoestrogens, from flaxseed meal are described. This is the first report of isolariciresinol a nd pinoresinol being detected in a food. The extraction method selected com bined the removal of the lignan glycosides from the plant matrix with an al coholic solvent system, followed by acid hydrolysis to release the aglycons . A reversed-phase high-performance liquid chromatography with diode array detection system was used for initial separation and detection of the ligna ns at 280 nm in the acid-hydrolyzed methanolic extract. Lignan trimethylsil yl ether derivatives were characterized by gas chromatography/mass spectrom etry. Secoisolariciresinol is the major lignan in flaxseed; isolariciresino l, pinoresinol, and matairesinol were identified as minor lignan components .