Large-Scale Isolation of Three O-Methyl Anthocyanins from Bilberry (Vaccinium myrtillus L.) Extract

Abstract

Three O–methyl anthocyanidin 3–O–β–D–glucopyranosides were isolated from bilberry extract on a large-scale basis together with two non O–methyl analogues. Anthocyanidin 3–O–β–D–galactopyranosides were removed from bilberry extract together with parts of anthocyanidin 3–O–α–L–arabinopyranosides after treatment with β–galactosidase. The remaining arabinopyranosides were removed by applying acid catalytic hydrolysis. The amounts of anthocyanins recovered as flavylium trifluoroacetic acid salt were as follows: 630 mg for petunidin 3–O–β–D–glucopyranoside, 423 mg for peonidin 3–O–β–D–glucopyranoside, 588 mg for malvidin 3–O–β–D–glucopyranoside, 877 mg for delphinidin 3–O–β–D–glucopyranoside, and 742 mg for cyanidin 3–O–β–D–glucopyranoside.