Abstract: Isolation of cinnamon proanthocyanidins was performed on AB-8 resin.1000 mg procyanidins raw materials were dissolved in small amount of 60% ethanol,then the concentrated solution was added to adsorption column in a constant rate.Ethanol solutions with volume fraction of 10%,50%,70%,100% were selected in gradient eluting by AB-8 resin.The mass of F₁₀ that could be obtained from the ethanol 10% eluent was 290 mg;that of F₅₀ obtained from the ethanol 50% eluent was 150 mg; that of F₇₀ was 410 mg; that of F₁₀₀ was 80 mg.The sample with the highest purity in the four parts was F₁₀, and its purity was 90.03%.The F₁₀₀ had the lowest purity in the four parts,and its purity was 42.11%.The eluting recovery achieved 93%.According to the analysis of polymerization degree and antioxidant activity,10%~50% ethanol eluent contained mainly oligomeric proanthocyanidins (OPC),70%~100% ethanol eluent contained polymeric proanthocyanidins (PPC).The antioxidative activity of 10% ethanol eluent was the highest.

Key words: proanthocyanidins, fractionation, antioxidative activity