天然低共熔溶剂提取柑橘籽类柠檬苦素的工艺优化

Optimization of natural extraction process of limonins from citrus seeds in deep eutectic solvents

为建立柑橘籽中柠檬苦素类化合物的绿色环保提取方法,该研究制备了13种天然低共熔溶剂,并对其理化性质进行了测定。采用超声辅助提取法从柑橘籽中提取柠檬苦素类化合物,并应用超高效液相色谱检测3种主要的柠檬苦素类化合物(柠檬苦素、诺米林和黄柏酮)。与传统乙醇溶剂(体积分数80%)相比,由氯化胆碱和甲酸(物质的量之比1∶4)组成的天然低共熔溶剂具有较好的提取效率。在此基础上,采用响应面法对含水量、液固比、提取温度和提取时间进行优化。结果显示,含水量12%(体积分数)、液固比10∶1(mL∶g)、提取温度60℃、提取时间34 min为最佳提取工艺,类柠檬苦素得率为13.87 mg/g。该研究表明,制备的天然低共熔溶剂可以作为从柑橘籽中提取类柠檬苦素的替代溶剂,为进一步应用天然低共熔溶剂从天然产物中提取生物活性物质提供参考。

To establish an environment-friendly extraction method of limonoids from citrus seeds,13 natural deep eutectic solvents were prepared and their physical and chemical properties were tested.The ultrasonic-assisted extraction method was used to extract limonoids from citrus seeds,and three main limonoids(limonoid,nomilin,and phellodendron ketone)were determined by ultra-performance liquid chromatography.Compared with the traditional ethanol solvent(the volume fraction was 80%),the natural deep eutectic solvents composed of choline chloride and formic acid(the molar ratio was 1∶4)had better extraction efficiency.On this basis,the response surface method was used to optimize the water contents,solid-liquid ratio,extraction temperature,extraction time,and extraction temperature.As a consequence,the best extraction condition was the water content of 12%(v/v),the liquid-solid ratio of 10(mL∶g),the extraction temperature of 60℃,and the extraction time of 34 min.The yield of limonin was 13.87 mg/g.This study showed that the prepared natural eutectic solvent could be used as an alternative solvent for extracting limonoids from citrus seeds,which provided some references for further application of natural deep eutectic solvents to extract bioactive compounds from natural products.