牛蒡多酚超声波辅助低共熔溶剂提取工艺优化、生物活性评价及组分分析

Optimization of Ultrasonic-Assisted Deep Eutectic Solvent Extraction Process,Biological Activities and Components of Burdock Polyphenols

考察6种低共熔溶剂对牛蒡多酚的提取效果,运用响应面法优化超声波辅助低共熔溶剂提取牛蒡多酚的工艺条件,并通过分析其总还原力和清除DPPH自由基能力、对α-葡萄糖苷酶的抑制作用和对体外胆酸盐结合力,初步研究其生物活性,并分析其组成。结果显示,DES 5(氯化胆碱:乙二醇摩尔比为1:4)对牛蒡多酚的提取效果最优,料液比55:1 mg/mL,含水率为40%,提取温度49℃、时间41 min是其最佳提取工艺,在此条件下牛蒡多酚的得率为1.19%±0.11%。生物活性分析表明,牛蒡多酚的总还原力和清除DPPH自由基能力的IC_(50)分别为0.93 mg/mL和7.03μg/mL,表现出较好的抗氧化效果,但弱于VC;对α-葡萄糖苷酶抑制作用的IC_(50)为0.13 mg/mL,高于阿卡波糖,表明其降血糖能力较强;另外,样品质量浓度为1.5 mg/mL时,其胆酸盐结合率为33.23%,提示其具有一定的降血脂能力。HPLC分析表明,牛蒡多酚中含有绿原酸、咖啡酸和阿魏酸。试验结果为牛蒡多酚的绿色制备和作为抗氧化和降血糖、血脂的功能性成分开发利用提供了一定的理论依据。

The extraction effects of six deep eutectic solvents on burdock polyphenols(BPs)were investigated,and the response surface methodology was used to optimize the process conditions of ultrasonic-assisted deep eutectic solvent extraction of BPs,moreover,the total reducing power,the DPPH•scavenging capacity,the inhibition ofα-glucosidase and cholic acid binding capacity in vitro were studied,and its composition were analyzed by HPLC.The results showed that DES 5(the molar ratio of choline chloride to ethylene glycol was 1:4)was the best solvent system for the extraction of BPs.The optimum technological conditions were as follows,the water content of deep eutectic solvent was 40%,the ratio of material to liquid was 55:1 mg/mL,the extraction temperature was 49℃,and the extraction time was 41 min,under the above conditions,the yield of BPs was 1.19%±0.11%.The biological activity analysis showed that the IC_(50) of the total reducing power and DPPH•scavenging capacity of burdock polyphenol were 0.93 mg/mL and 7.03μg/mL,respectively,indicating that it had good antioxidant capacity,but weaker than VC.The IC_(50) ofα-glucosidase inhibition was 0.13 mg/mL,which was higher than acarbose,indicating that it possessed excellent hypoglycemic activity.In addition,its cholic acid binding rate was 33.23%when the mass concentration was 1.5 mg/mL,implied that it had a certain hypolipidemic activity.HPLC analysis showed that BPs contained chlorogenic acid,caffeic acid and ferulic acid.The results would provide a theoretical basis for the green preparation of burdock polyphenol and its development and utilization as a functional component of antioxidation,hypoglycemia and blood lipids.