Cyanidin and peodinin were separated using a C18 column (Waters NovaPac C18, 100 4.6 mm; Water corporation, Milford, MA, USA). The mobile phase consisted of 0.4% trifluoroacetic acid (TFA) in water and 0.4% TFA in acetonitrile at ratio of 18:82 and flow rate at 0.9 ml/min.