Abstract: To investigate the pharmacokinetics of ligustilide in Angelica sinensis (Oliv.) Diels,a specific ultra-high performance liquid chromatography (UPLC) method was developed and validated for determining the concentration of ligustilide in serum of rats after ig administration of petroleum ether extract of A.sinensis (Oliv.) Diels. The chromatographic conditions were as follows: Waters UPLC was equipped with a reversed phase column (BEH C₁₈, 2.1 mm × 100 mm,1.7 μm).The mobile phase was a mixture of acetonitrile and 0.03% trifluoroacetic acid in water with the proportion of 45:55 (v/v).The flow rate was 0.5 mL/min.The column temperature was maintained at 40 ℃.The UV detection wavelength was set at 320 nm.The main pharmacokinetic parameters of ligustilide were obtained by DAS 3.0 software.The results of compartmental analysis indicated that the kinetic process of ligustilide in rats was best fitted to the two compartments model and the main pharmacokinetic parameters were as follows: C_max and t_1/2β being 0.38±0.04, 0.33±0.02 (μg/mL) and 4.08±0.25, 3.06±0.82（h） in high and middle dosage groups,respectively.The low dosage data was not detected because serum concentration of ligustilide in low dosage group was below limit of quantitation.The results indicated that the UPLCPDA method developed in this study was accurate,sensitive,and rapid for the determination of ligustilide in rats’ serum.The pharmacokinetic characteristic of ligustilide was non-dose-dependent by comparing the parameters of high and middle dosage group.

Key words: ligustilide, Angelica sinensis, pharmacokinetic, UPLC