Flavonoids from Trollius europaeus flowers and evaluation of their biological activity.

OBJECTIVES

This article describes the flavonoid composition of the flowers of Trollius europaeus and the method of isolation thereof and provides an attempt at investigating the antioxidant activity of the isolated flavonoids and the antityrosinase activity of the extracts from the investigated material.

METHODS

The compositional data were acquired by combining results of nuclear magnetic resonance, ultraviolet spectroscopy, electrospray ionisation-tandem mass spectrometry (ESI-MS/MS) analyses and those of an analysis of the products of acid hydrolysis of the compounds. The antioxidant activity of the extracts was studied using the 2,2'-diphenyl-1-picrylhydrazyl assay and the tyrosinase inhibitory activity - with the use of mushroom tyrosinase.

KEY FINDINGS

Ten flavonoid derivatives of luteolin and apigenin were isolated from the flowers of T. europaeus and identified. The investigation into the antioxidant activity revealed that orientin 2″-O-α-arabinopyranoside (4) and orientin 2″-O-β glucopyranoside (5) had a significant antioxidant effect.

CONCLUSIONS

The studies conducted led to the development of a method of isolating flavonoid, potentially antioxidant, compounds from T. europaeus. They allowed to determine which of the investigated flavonoids demonstrated significant antioxidant activity and could be used as natural antioxidants.