Identification of complex, naturally occurring flavonoid glycosides in Vicia faba and Pisum sativum leaves by HPLC-DAD-ESI-MSn and the genotypic effect on their flavonoid profile

Abstract

Vicia faba and Pisum sativum are legumes belonging to the plant family Fabaceae. As their flavonoid profile is highly diverse with quite complex structures, the aim of this study was to identify the flavonol glycosides in the leaves of different cultivars of V. faba and P. sativum. In V. faba the main flavonol aglycon is kaempferol, whereas in P. sativum the main flavonol aglycon is quercetin. Furthermore, V. faba leaves contain mono-, di-, tri- and tetraglycosides of quercetin and kaempferol with primarily glucose, rhamnose, and galactose as sugar moieties. Two of these structures have been identified to be acylated with acetic acid. In contrast, in P. sativum leaves only triglycosides were identified being sophotriosides. Nine of the 11 quercetin and kaempferol glycosides were acylated with selected hydroxycinnamic acids. Depending on cultivar, V. faba and P. sativum provided different flavonol profiles. Here, shown for the first time in legume leaves. For example, the summer cultivars of V. faba showed a high concentration of kaempferol-3-O-rhamnoarabinoside-7-O-rhamnoside. However, P. sativum with especially the cv Salamanca, had the most desired flavonoid glycoside profile referring to high concentrations of quercetin glycosides and exemplarily the acylation with p-coumaric acid.