Structural dependence of HPLC separation pattern of anthocyanins from Bilberry (Vaccinium myrtillus L.)

An HPLC method using isocratic elution was established for the analysis of fifteen anthocyanins contained in bilberry (Vaccinium myrtillus L.). Separation was attained by using an aqueous solution of 20% methanol containing 0.5% TFA as the mobile phase with a flow rate of 2 ml/min. The detection limit was 0.3 pmol for delphinidin 3-O-beta-D-glucopyranoside, which is a major anthocyanin in bilberry extract. The reproducibility was 0.19-3.85% (S.E.M) for peak area and 0.64-0.77% (S.E.M) for relative mobility normalized by the elution position of the solvent peak. When the relative elution volumes of each anthocyanins were correlated to their corresponding anthocyanin structures, a characteristic pattern was observed. From this pattern, the structures of unknown anthocyanins could be predicted from their elution times. Therefore, the present method is useful for the study of anthocyanins from various biological sources.