Abstract: Objective: To analyze the compositions of flavonoids from reed leaves. Methods: The crude extract was prepared during the condensation of reed leaf extract. The primarily purified flavonoids were prepared by macro-porous resin. The hydrolysis conditions of flavonoids were optimized. Two samples were hydrolyzed to obtain two hydrolysis products. The compositions of flavonoids were determined by HPLC. Results: The contents of total flavonoids in crude extract and primary purified flavonoids samples were 57.1% and 18.5%, respectively. The optimal hydrolysis conditions for reed leaf flavonoids were hydrolysis temperature of 80－90 ℃, HCl concentration of 1.4 mol/L and hydrolysis time of 4 h. Totally 33 components were separated by HPLC from the crude extract and 8 components were identified based on their retention time. A total of 22 components were separated by HPLC from the primarily purified sample and 5 components were identified. A total of 28 components were separated from the hydrolysates and 7 components were identified. Similarly, 25 components were separated from the hydrolyzed primarily purified samples and 7 components were identified. Conclusion: Reed leaves contained rutin, scutellarin, hesperidin, luteolin, quercetin, apigenin, kaempferol, isorhamnetin or hesperetin, isoliquiritigenin, baicalein, and other unknown flavonoids. The content of apigenin among these components was the highest.

Key words: reed leaf, flavonoids, hydrolysis, HPLC