Metabolic Profiling of Lignans and Other Secondary Metabolites from Rapeseed (Brassica napus L.)

A metabolic profiling study was carried out on rapeseed (Brassica napus L.). Eleven glucosinolates were identified by high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD) and mass spectrometry (MS). Additionally, 18 phenolic compounds were profiled from an ethanol extract of rapeseed. Besides two major phenols, sinapine and methyl sinapate, 16 minor phenolic compounds were isolated and identified. Seven of them are new lignans including three (+/-)-thomasidioic acid derivatives and four (E,E)-dienolignan derivatives. The structures of novel phenolic compounds were elucidated by ID and 2D nuclear magnetic resonance (NMR) spectroscopy and MS. The analytical data of secondary metabolites in rapeseed winter cultivar Emerald and information about purification on a microscale are useful for upcoming studies on tissue-specific localization of these compounds.