白桦脂酸血浆蛋白结合率的测定

目的建立白桦脂酸在大鼠血浆、人血浆和牛血清白蛋白中蛋白结合率的测定方法。方法采用平衡透析法测定白桦脂酸血浆蛋白结合率,利用HPLC测定血浆中白桦脂酸浓度,测定并比较不同血浆中白桦脂酸的血浆蛋白结合率。采用DiamonsilTMC18柱,柱温为30℃,流动相为乙腈-0.2%乙酸(75∶25),流速为1.0 mL/min,检测波长为203 nm。结果在50～100 mg/L,药物浓度对血浆蛋白结合率无显著影响,白桦脂酸与大鼠和人的血浆蛋白结合率存在显著性差异,白桦脂酸与人血浆蛋白结合率高于与大鼠血浆蛋白结合率。结论白桦脂酸与血浆蛋白具有较强的结合。HPLC法测定白桦脂酸与血浆蛋白结合率试验具有简便、快速、灵敏与选择性高的特点。

Determination of plasma protein binding rate of betulinic acid

Objective To develop a method for determining the plasma protein binding rate of betulinic acid in rat plasma,human plasma and bovine serum albumin(BSA).Methods The plasma protein binding rate of betulinic acid was determined by using equilibrium dialysis.The concentration of plasma betulinic acid was determined by using HPLC.The plasma protein binding rate of betulinic acid was determined and compared in different serum samples.The HPLC procedure was performed on DiamonsilTM C18 column at 30 ℃.The mobile phase was acetonitrile-0.2% acetic acid(75∶ 25) in gradient elution,flow velocity was 1.0 mL/min and detection wavelength was 203 nm.Results When the concentration was from 50 mg/L to 100 mg/L,the concentration of betulinic acid had no significant influence on plasma protein binding rate.There was a significant difference between the plasma protein binding rate of betulinic acid in rat plasma and that in human plasma.The plasma protein binding rate of betulinic acid in human plasma was higher than that in rat plasma.Conclusion Betulic acid has a higher binding intension with plasma protein.HPLC for determining the plasma protein binding rate of betulinic acid is simple,rapid and sensitive with a higher selectivity.