离子液体-微波辅助提取钩藤中生物碱的工艺研究

Study on ionic liquid-microwave assisted extraction for alkaloids in Uncaria rhynchophylla

目的优选钩藤中生物碱的提取工艺条件,制定出最佳提取工艺方案。方法采用离子液体-微波法提取,以4种代表生物碱(钩藤碱、异钩藤碱、去氢钩藤碱和异去氢钩藤碱)含量作为指标,通过单因素实验考察离子液体浓度、液料比、提取时间和pH值4个因素对提取率的影响,并通过均匀设计法优选最佳提取工艺参数。实验中用高效液相色谱法测定钩藤4种代表生物碱的含量。结果钩藤中生物碱的最佳提取条件为:选用0.54 mol.L-1离子液体[C4MIM]BF4的水溶液为提取溶剂,pH值调至1.42,液料比100∶1 mL.g-1,提取时间8 min。钩藤中4种代表生物碱的质量分数达2.52 mg.g-1。结论该提取工艺操作简便合理,重复性良好,具有可行性。

AIM To optimize the technology of extracting alkaloids from Uncaria Rhynchophylla and determine the best extraction process. METHODS Ionic liquid coupled with microwave-assisted extraction （IL- MAE） method was applied, and the effects of four process parameters （concentration of ILs, liquid-solid ratio, extraction time and pH value） on extraction efficiency were optimized by mono-factor test, using the content of representative alkaloids （rhynchophylline, isorhynchophylline, corynoxeine and isocorynoxeine） as index. The optimal extraction process parameters was determined by uniform design. HPLC was applied to determine the content of four representative alkaloids. RESULTS The optimal extraction conditions were as follows ： extraction solvent of 0.54 mol.L-1 [C4MIM] BF4 aqueous solution, pH adjusted tol.42, liquid/solid ratio of 100 ： 1 mL-μg, extraction time of 8 rain. The total content of representative alkaloids was 2.52 mg.g-1CONCLUSION The method is proved to be simple, reasonable, feasible and of good reproducibility.