Isolation and structural identification of the main anthocyanin monomer in Vitis amurensis Rupr

Many types of anthocyanins are present in Vitis amurensis Rupr of ‘Beibinghong’, which is grown in North-east China and has high antioxidant activity. However, the anthocyanin with the highest content in V. amurensis Rupr has not yet been identified. In this study, pulsed electric field extraction and semi-preparative liquid phase separation were used to isolate the anthocyanin monomer from ‘Beibinghong’. UV–vis spectroscopy, FTIR spectroscopy, mass spectra and nuclear magnetic resonance were used to identify the anthocyanin monomer. The antioxidant activities of the anthocyanin monomer were also analysed. Malvidin-3,5-O-diglucoside was identified as the main anthocyanin in V. amurensis Rupr, which could be used as a raw material for its extraction. Furthermore, malvidin-3,5-O-diglucoside can be potentially used as a functional food, and a novel therapeutic and preventive agent for oxidative stress-related diseases. This study provides technical information for the future purification and structural identification of anthocyanins.