Polyphenols in Chinese Kushui rose (Rosa sertata × Rosa rugosa) leaves

Polyphenols in Chinese Kushui rose ( Rosa sertata × Rosa rugosa ) leaves were first extracted and analysed in this study. Among four fractions (ethyl ether, ethyl acetate, n -butanol, and water layer) of crude extracts, the ethyl acetate fraction showed the highest ABTS •+ scavenging activity, and the n-butanol fraction exhibited the maximum components in composition. On-line HPLC-ABTS •+ analysis indicated that there were more than 30 antioxidant compounds from Chinese Kushui rose leaves. The identified polyphenols could be classified into quercetin derivatives, gallic acid derivatives, and proanthocyanidins. Gallic acid was the most antioxidative compound.