In this study, the purification efficiency of paclitaxel was remarkably improved through ultrasonic acetone-pentane fractional precipitation. The time taken for precipitation was also shortened by a maximum of 192-fold (at 5°C, 180-250 W) with ultrasound as compared to that of the conventional method. The precipitation was completed within 30 min regardless of temperature (5-25°C), thereby improving the operating conditions (precipitation time and temperature) as compared to the conventional method. In addition, the rate constant in the fractional precipitation with ultrasound (80-250 W) was also increased by 8-to 13-fold (at 5°C) as compared to the conventional method. The standard enthalpy change and standard entropy change were negative, while the standard Gibbs free energy change was positive. These results indicate that the precipitation process was exothermic, irreversible, and non-spontaneous.

本研究通过超声丙酮-戊烷分级沉淀法显着提高了紫杉醇的纯化效率。与常规方法相比，超声波沉淀所需的时间也最多缩短了 192 倍（5°C，180-250 W）。无论温度（5-25°C）如何，都能在30分钟内完成沉淀，从而与常规方法相比改善了操作条件（沉淀时间和温度）。此外，与传统方法相比，超声分级沉淀 (80-250 W) 的速率常数也增加了 8 至 13 倍（在 5°C 下）。标准焓变和标准熵变为负，而标准吉布斯自由能变为正。