尝试利用天然低共熔溶剂(NADES)提取甜叶菊(Stevia rebaudiana)中的甜菊糖, 探索一种高效、绿色和环保的甜菊糖提取新方法。以甜叶菊干叶为原料, 对照传统提取溶剂水, 以甜菊糖中甜菊苷和莱鲍迪苷A的提取浓度作为指标, 筛选出最优的NADES提取配方, 然后通过Box-Behnken响应面法对NADES提取甜叶菊中甜菊糖的工艺条件进行筛选优化。结果表明, 提取效率最高的NADES配方为1,2-丙二醇:甘油:水=8:1:1 (v/v/v), 提取的甜菊苷浓度为2.59 mg∙mL^-1, 比水提取高16.40%, 提取的莱鲍迪苷A浓度为1.06 mg∙mL^-1, 比水提取高12.62%; 通过响应面法得到最优提取条件: 提取时间90分钟, 提取温度60°C, 超声功率为80 J∙s^-1, 预测甜菊苷提取浓度为3.49 mg∙mL^-1, 莱鲍迪苷A提取浓度为1.43 mg∙mL^-1, 与实验验证值(甜菊苷浓度为3.48 mg∙mL^-1, 莱鲍迪苷A浓度为1.42 mg∙mL^-1)接近。在最优条件下, 甜菊苷提取浓度比初始条件提高了34.36%, 莱鲍迪甘A提取浓度比初始条件提高了33.96%。NADES绿色环保, 且提取效率高于传统溶剂, 可用于甜叶菊中甜菊糖的绿色提取; 同时, 该提取方法可为后续推广至其它大宗经济植物类天然产物的绿色工业生产提供参考。

Natural deep eutectic solvent (NADES) was used to extract steviosides from Stevia rebaudiana as an efficient, green and environmentally friendly new method. Compared with traditional solvent water, the optimal NADES formula was selected to extract S. rebaudiana dry leaves by measuring the concentration of stevioside and rebaudioside A, two main components in steviosides. The extraction conditions of NADES extracting steviosides were optimized by Box-Behnken design from response surface methodology. The best NADES formula for steviosides extraction was selected: 1,2-propanediol:glycerol:water=8:1:1 (v/v/v), the extraction concentration of stevioside was 2.59 mg∙mL^-1 (16.40% higher than water), and the extraction concentration of rebaudioside A was 1.06 mg∙mL^-1 (12.62% higher than water). The NADES extraction conditions were optimized by response surface methodology: extraction time was 90 min, extraction temperature was 60°C, ultrasonic power was 80 J∙s^-1, the predicted extraction concentration of stevioside was 3.49 mg∙mL^-1 and the concentration of rebaudioside A was 1.43 mg∙mL^-1, which was close to the experimental verification value (the concentration of stevioside is 3.48 mg∙mL^-1, the concentration of rebaudioside A is 1.42 mg∙mL^-1). Under the best condition, the extraction of stevioside was 34.36% higher than the initial condition, and the extraction of rebaudioside A was 33.96% higher than the initial condition. NADES is environmentally friendly and has higher extraction efficiency than traditional solvents. It can be used for the green extraction of steviosides from S. rebaudiana. At the same time, it provides a promising prospect for the green extraction of natural products from other bulk economic plants.