Phenolics of Arbutus unedo L. (Ericaceae) Fruits: Identification of Anthocyanins and Gallic acid Derivatives

Arbutus unedo L., the strawberry tree (Ericaceae family), is an evergreen shrub or small tree, typical of the Mediterranean fringe and climate. The aim of the present study was to evaluate the profile of the phenolic constituents of A. unedo fruits. Seven compds. were purified by Sephadex LH-20 column chromatog. of the MeOH ext. followed by HPLC and were characterized as arbutin, β-D-glucogalline, gallic acid 4-O-β-D-glucopyranoside, 3-O-galloylquinic acid, 5-O-galloylquinic acid, 3-O-galloylshikimic acid, and 5-O-galloylshikimic acid, by NMR and ESI-MS analyses. Moreover, LC-PDA-MS anal. of the red pigment of A. unedo fruits revealed the presence of 3 anthocyanins recognized as cyanidin 3-O-β-D-galactopyranoside, delphinidin 3-O-β-D-glucopyranoside, and cyanidin 3-O-β-D-arabinopyranoside. These pigments were also quantified.