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 miccrol plasma sample was extracted by ether and performed on Elite Hypersil C(18) column (200 mm x 4.6 mm, 5 microm) 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 C(max) of deoxyschizandrin were 15.8+/-3.1 and 34.3+/-16.8 ng/ml, T(max) were 0.51+/-0.13 and 3.83+/-1.83 h, T(1/2) were 5.3+/-2.2 and 6.5+/-3.4h.