Abstract: A flavonoid was isolated from Desmodium caudatum (Thunb.) DC by silica gel column chromatography. The structure of the isolated compound was elucidated on the basis of spectral characteristics and identified as yukovanol. The content of yukovanol in D.caudatum was determined by HPLC.The chromatographic separation were carried out using the following condition:Agilent ZORBAX SB-C18 column (250 mm × 4.6 mm,5 μm) was used with methanol-0.2% phosphoric acid (70:30) as mobile phases.The flow rate was 1.0 mL/min.The UV detection wavelength was 270 nm and the column temperature was 35 ^oC.The results showed that the linear range of yukovanol were 0.011-0.242 μg,the yukovanol average recovery as 99.76%,RSD = 1.42% (n=6).Distinct differences were found among D.caudatum samples produced in different places.

Key words: Desmodium caudatum (Thunb.) DC, yukovanol, isolation and purification, HPLC