HPLC and NMR quantification of bioactive compounds in flowers and leaves of Brassica rapa : the influence of aging.

Several members of the Brassicaeae family are known to possess beneficial properties which positively impact human diet, thanks to the presence of antioxidants, bioactive polyphenols and amino acids. B. rapa , one of the most widespread and economically relevant species, represents an outstanding example. The aim of this study is to investigate, at the molecular level, the effect of plant aging on the concentration of some biologically relevant compounds in different parts of the plant. Using HPLC and NMR techniques, the quantification of polyphenolic species (caffeic acid, quercetin and rutin), succinic acid and alanine was performed in flowers and leaves of young and mature B. rapa plants.