Abstract: Objective:To determine the contents of rutin,and isoquercetin in mulberry leaves by HPLC. Methods:An external standard method was adopped by HPLC with Agilent TC-C18 column(250mm×4.6mm,5μm) as fixed phase,and CH3CN-CH3OH-H2O-H3PO4(100:10:340:0.3,V/V) as mobile phase. The detection wavelength was 365 nm and the flow rate was 1.0ml/ min. Results:Rutin and isoquercetin were well separated by this method. Linearities of rutin and isoquercetin were good in concentration ranges of 7.5～150μg/ml(R2=0.9995) and 7.1～142μg/ml(R2=0.9998) respectively. The average spiked recoveries are 98.79%(RSD 3.37%) and 99.01%(RSD 2.43%) and RSDs of repeatability experiments are 0.0133% and 0.0214% respectively. Conclusion:The method validation data indicate that the method is reliable and it can be used for quality control of crude drug mulberry leave and its preparation.

Key words: mulberry leaves, flavonoids, HPLC, rutin, isoquercetin