Antioxidant phenolic compounds from the leaves of Erica Arborea (Ericaceae)

Reversed-phase HPLC analyses of the methanol extract of the leaves of Erica arborea afforded a novel phenylpropanoid glucoside, named ericarborin, together with five flavonoids, dihydromyricetin 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-beta-D-glucopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, apigenin 7-O-beta-D-glucopyranoside and apigenin 7-O-beta-D-(6-O-acetyl-glucopyranoside). While the structure of ericarborin was determined by extensive 1D and 2D NMR analyses, the structures of all known flavonoids were determined by direct comparison of their spectroscopic data with respective literature data. The antioxidant properties of these compounds were assessed by the DPPH assay. The chemotaxonomic significance of these phenolic compounds has been discussed.