目的：考察鞣花酸在25℃和37℃下不同 pH 磷酸盐缓冲液中的平衡溶解度与表观油水分配系数（P app ）。方法采用紫外-可见分光光度法测定鞣花酸在不同 pH 缓冲液中的平衡溶解度；采用摇瓶法测定鞣花酸的 P app 值。结果25℃时鞣花酸在 pH 值为1．2、2．5、5．0、5．8、6．8、7．4、7．8～8．0的磷酸盐缓冲液中的平衡溶解度分别为2．77、4．97、8．14、6．16、1．22、1．33、1．01 g／mL，相应条件下 P app 值分别为－3．20、－2．36、－2．49、－2．50、－2．48、－2．37、－2．22；37℃时鞣花酸在上述 pH 缓冲液中的平衡溶解度为3．25、5．08、8．04、6．39、1．02、1．54、1．14 g／mL，相应条件下的 P app 值分别为－2．38、－2．32、－2．38、－2．41、－2．44、－2．38、－2．18。结论鞣花酸在酸性溶液中的平衡溶解度随 pH 值的升高而增大，在中性及弱碱性溶液中其溶解度较小。在 pH 值为1．2～8．0时，鞣花酸的 P app 值均＜－2，表明鞣花酸不易透过生物膜，推测其在胃肠道的吸收不好，且温度对鞣花酸的 P app 值几乎无影响。%Objective To determine the equilibrium solubility and the apperent oli/water partion coefficient (P app )of ellagic acid in different pH phosphate buffer solutions in 25℃ and 37℃.Methods Ultraviolet spectrophotometry was employed to determine the equilibrium solubility of ellagic acid in phosphate buffer solutions of different pH value,and the P app values of ellagic acid were determined by shaking flask. Results At 25℃ the equilibrium solubility of ellagic acid in different phosphate buffer solutions of pH 1.2, 2.5,5.0,5.8,6.8,7.4,7.8 - 8.0 were 2.77,4.97,8.14,6.16,1.22,1.33,1.01 g/mL,and the P app values of ellagic acid were - 3.20,- 2.36,- 2.49,- 2.50,- 2.48,- 2.37,- 2.22 respectively;At 37℃ the equilibrium solubility of ellagic acid in different phosphate buffer solutions of pH 1.2,2.5,5.0,5.8,6.8,7.4, 7.8-8.0 were 3.25,5.08,8.04,6.39,1.02,1.54,1.14 g/mL,and the P app values of ellagic acid were -2.38,-2.32,- 2.38,- 2.41,- 2.44,- 2.38,- 2.18 respectively.Conclusion The equilibrium solubility of ellagic acid is increasing with pH increases in acidic solution and its solubility is less in neutral and weak al-kaline solution.The P app values of ellagic acid were <-2 at the pH range from 1.2 to 8.0,which shows it is not easy to through the biological membrane and the absorption is poor in the gastrointestinal tract.The temperature has little influence on the P app values of ellagic acid.
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