Metabolome Classification of Brassica napus L. Organs via UPLC-QTOF-PDA-MS and Their Anti-oxidant Potential

Introduction Brassica napus L. is a crop widely grown for its oil production and other nutritional components in the seed. In addition to the seed, other organs contain a wide range of phenolic metabolites although they have not been investigated to the same extent as in seeds. Objective To define and compare the phytochemical composition of B. napus L. organs, namely the root, stem, leaf, inflorescence and seeds. Method Non-targeted metabolomic analysis via UPLCQTOFMS was utilised in order to localise compounds belonging to various chemical classes (i.e. oxygenated fatty acids, flavonols, phenolic acids and sinapoyl choline derivatives). Results The vast majority of identified metabolites were flavonol glycosides that accumulated in most of the plant organs. Whereas other classes were detected predominantly in specific organs, i.e. sinapoyl cholines were present uniquely in seeds. Furthermore, variation in the accumulation pattern of metabolites from the same class was observed, particularly in the case of quercetin, kaempferol and isorhamnetin flavonols. Anti-oxidant activity, based on 2,2-diphenyl-1-picrylhdrazyl analysis was observed for all extracts, and correlated to some extent with total flavonoid content. Conclusion This study provides the most complete map for polyphenol composition in B. napus L. organs. By describing the metabolites profile in B. napus L., this study provides the basis for future investigations of seeds for potential health and/or medicinal use. Copyright (c) 2012 John Wiley & Sons, Ltd.