目的 采用乙醇/NaH₂PO₄双水相气浮溶剂浮选技术, 结合响应曲面法对杜仲叶中京尼平苷酸进行分离富集研究。方法 考察了无机盐种类和用量、有机溶剂的种类和用量、粗提液加入量、空气体积流量和浮选时间对京尼平苷酸浮选效果的影响, 在单因素试验基础上, 选择NaH₂PO₄质量分数、乙醇体积分数和空气体积流量为实验因素, 采用Box-Behnken中心组合设计进行优化实验, 确定京尼平苷酸的最优浮选工艺, 并进行100倍放大研究。结果 在28% NaH₂PO₄、23%乙醇双水相体系中, 加入5 g粗提液, 当空气体积流量为40 mL/min, 浮选时间为20 min时, 京尼平苷酸浮选效率最佳, 达到97.88%, 富集倍数达到27.34。100倍放大后, 京尼平苷酸的浮选效率达到95.60%, RSD为0.77%。结论 乙醇/NaH₂PO₄双水相气浮溶剂浮选体系对京尼平苷酸的浮选效率高, 富集倍数大, 为杜仲叶中环烯醚萜类活性成分分离富集提供了一种有效的新方法。

Objective Ethanol/NaH₂PO₄ aqueous two-phase gas solvent sublation coupled with response surface methodology was developed for the separation/enrichment and analysis of geniposidic acid from the leaves of Eucommia ulmoides. Methods For the aqueous two-phase flotation project, the flotation effects of different solvent, salts, flotation rate, flotation time, amount of crude extract and so on were deeply investigated; Furthermore, a Box-Behnken central composite test design was studied to determine the best flotation process conditions of GPA, and three factors including the mass fraction of NaH₂PO₄, the mass fraction of ethanol, and the flotation rate were selected based on the single factor test in the design. A 100 times scale-up experiment also was tested. Results The optimal conditions of the flotation were as follows: the mass fraction of NaH₂PO₄ was 25%, the mass fraction of ethanol was 20%, the amount of crude extract was 5 g, the flotation rate was 30 mL/min, and the flotation time was 20 min. Under the optimal condition, the flotation efficiency was 97.88%, and the enrichment factor was 27.34; The 100 times scale-up results showed that the flotation efficiency of GPA was 95.60%, and the RSD value was 0.77%. Conclusion The method with ethanol/NaH₂PO₄ aqueous two-phase gas solvent sublation is suitable for the separation and enrichment of the active ingredients from E. ulmoides because of its high distribution coefficient and large enrichment factor.

湖南省自然科学基金资助项目(14JJ6037);吉首大学2013年人才引进专项项目资助(jsdxrcyjkyxm201301);林产化工工程湖南省重点实验室开放基金(13jdzb075);吉首大学2014年度校级科研项目(14JDY060)