Determination of deoxyschizandrin in rat plasma by LC–MS

A simple, rapid and sensitive LC–MS method was developed for quantification of deoxyschizandrin in rat plasma. A 50 μl plasma sample was extracted by ether and performed on Elite Hypersil C18 column (200 mm × 4.6 mm, 5 μm) with the mobile phase of methanol–water (84:16, v/v) in a run time of 6.5 min. The analyte was monitored with positive atmospheric pressure chemical ionization (APCI) by selected ion monitoring (SIM) mode. A good linear relationship was obtained over the range of 1.0–50.0 ng/ml and the validated method was successfully applied for the pharmacokinetic studies of deoxyschizandrin in rat. After oral administration of 4 mg/kg deoxyschizandrin and Schisandra extract which contained the same dose of deoxyschizandrin to male rats, the Cmax of deoxyschizandrin were 15.8 ± 3.1 and 34.3 ± 16.8 ng/ml, Tmax were 0.51 ± 0.13 and 3.83 ± 1.83 h, T1/2 were 5.3 ± 2.2 and 6.5 ± 3.4 h.