平衡透析法结合GC-MS测定银杏内酯B的血浆蛋白结合率

Determination of the plasma protein binding rate of ginkgolide B by equilibrium dialysis combined with GC-MS

为了测定银杏内酯B(ginkgolide B,GB)与不同种属血浆蛋白的结合率,采用平衡透析法平衡72 h,取透析袋内外两侧的液体加入内标物银杏内酯A,乙醚液液萃取后,用气相色谱-质谱联用仪测定GB浓度。GB在浓度为1、2、4μg/mL时与大鼠血浆蛋白的结合率分别为(16.4±5.3)%、(16.9±5.3)%和(21.3±2.8)%;与犬血浆蛋白的结合率分别为(14.8±8.3)%、(20.1±6.3)%和(22.4±5.0)%;与健康人血浆蛋白的结合率分别为(19.3±6.8)%、(19.9±2.9)%和(21.9±7.1)%。在1-4μg/mL浓度范围内,GB血浆蛋白结合率在14.8%-22.4%,各种属蛋白结合率无明显剂量依赖性,各种属间无显著差异性。GB蛋白结合率较低,约80%以游离药物形式存在。

To determine the binding rate of ginkgolide B（GB） to plasma proteins of different species,by equilibrium dialysis method for 72 h,the fluids of the internal and external dialysis bags were sampled and then the internal standard ginkgolide A was added into these samples. After these samples were extracted with ether,the concentration of GB was determined by gas chromatography-mass spectrometry（GC-MS）. The plasma protein binding rates of ginkgolide B with rat plasma in the dialysis bag at initial concentrations of 1,2,and 4 μg/mL were（16. 4 ± 5. 3） %,（16. 9 ± 5. 3） % and（21. 3 ± 2. 8） %,respectively. The binding rates with canine plasma proteins were（14. 8 ± 8. 3） %,（20. 1 ± 6. 3） % and（22. 4 ± 5. 0） %,respectively. The binding rates with healthy human plasma were（19. 3 ± 6. 8） %,（19. 9 ± 2. 9） % and（21. 9 ± 7. 1） %,respectively. In the GB concentration range of 1-4 μg/mL,the plasma protein binding rates to GB ranged from 14. 8% to 22. 4%,the protein binding rates of various genera were no notable dose-dependence and there were no significant differences amongthe various species. The binding rate was low,and about 80% GB was free.