Objective: To establish a method for the determination of C-25 epimers of ruscogenin1-O-[β-D-glucopyranosyl (1 → 2)] [β-D-xylopyranosyl (1 →3)]-β-D-fucopyranoside in the tuberous roots of Liriope muscari at different harvest time. Method: A Waters XBridge C18 column(4.6 mm× 250 mm

3.5 μm)was used for separation at 40 ℃ with a flow rate of 1.0 mL · min-1. The wavelength of detector was set at 203 nm and the mobile phase consisted of acetonitrile-water (42: 58). Result: The linear ranges of 25R-and 25S-epimer were 20.40-408.00 mg · L-1(R2=0.999 9) and 20.09-401.80 mg · L-1 (R2=0.999 9). The average recoveries were 99.85% and 101.40%

and RSD were 2.1% and 1.8%

respectively. 8 batches of L. muscari at different harvest time were analyzed by HPLC

the contents of 25R-

25S-epimer and were 0.081%-0.136%

0.012%-0.150%. Conclusion: The method is simple

sensitive and accurate

it can be used for determination of C-25 epimers of ruscogenin1-O-[β-D-glucopyranosyl (1 → 2)] [β-D-xylopyranosyl (1 →3)]-β-D-fucopyranoside. The contents of 25R-and 25S-epimer in the tuberous roots of L.muscari at different harvest time were significantly different

especially 25S-epimer

which indicate that the harvest time of L. muscari should be controlled strictly.