HPLC测定白头翁皂苷D的油水分配系数及平衡溶解度

Determination of equilibrium solubility and n-octanol /water partition coefficient of pulchinenosiden D by HPLC

目的:测定白头翁皂苷D的油水分配系数及其在不同溶剂中的平衡溶解度。方法:采用摇瓶法与高效液相色谱法相结合测定白头翁皂苷D的油水分配系数,采用高效液相色谱法测定白头翁皂苷D在6种有机溶剂及不同pH缓冲液中的平衡溶解度。结果:白头翁皂苷D在不同pH条件下油水分配系数大于零,随着pH升高白头翁皂苷D的平衡溶解度逐渐增加,在不同溶剂中白头翁皂苷D的平衡溶解度以甲醇最大(达到255.89 g·L-1),乙腈中最小(0.20 g·L-1)。结论:在胃肠生理条件下,白头翁皂苷D以分子状态形式存在,由lgPapp可知其吸收性较好,但水溶性较差,提示增加白头翁皂苷D的溶解度可能有利于提高其生物利用度。

Objective： To determine the equilibrium solubility of pulchinenosiden D in different solvents and its n-octanol/wa- ter partition coefficients. Method： Combining shaking flask method and high performance liquid chromatography （HPLC） to detect the n-octanol/water partition coefficients of pulchinenosiden D, the equilibrium solubility of pulchinenosiden D in six organic solvents and different pH buffer solution were determined by HPLC analysis. Result： n-Octanol/water partition coefficients of pulchinenosiden D in different pH were greater than zero, the equilibrium solubility of pulchinenosiden D was increased with increase the pH of the buffer solution. The maximum equilibrium solubility of pulchinenosiden D was 255.89 g · L^-1 in methanol, and minimum equilibrium solubility of pulchinenosiden D was 0. 20 g · L^- 1 in acetonitrile. Conclusion： Under gastrointestinal physiological conditions, pulchinenosiden D exists in molecular state and it has good absorption but poor water-solubility, so increasing the dissolution rate of pulchinenosiden D may enhance its bioavailability.