低共熔溶剂提取马尾松松针抗氧化成分的研究

  目的  马尾松松针富含多酚、黄酮类化合物，具有多种活性功能。通过对马尾松松针的低共熔溶剂（DES）提取物的制备及其抗氧化活性进行研究，深度开发林下资源，获得与传统提取方式相比更加绿色环保、活性优良并且高效的制备方法。  方法  采用超声波技术辅助低共熔溶剂提取马尾松松针中活性成分，首先通过对比提取效果对3种低共熔溶剂进行了筛选，进一步在选定的低共熔溶剂（氯化胆碱/葡萄糖）基础上，进行液料比、超声温度、超声时间、超声功率对提取效果影响的单因素试验。在单因素试验基础上，以多酚、黄酮得率为指标，响应面法优化主要工艺参数，对比提取物与传统醇提物对DPPH·、ABTS+·的清除能力以及还原能力的差异。  结果  马尾松松针提取物的最佳提取工艺为:液料比为10 mL/g，超声温度为48 ℃，超声时间为60 min，超声功率为300 W。在此条件下，多酚得率为7.387%，黄酮得率为10.377%，回归模型拟合良好，与醇提物相比，低共熔溶剂提取物的抗氧化活性整体优于醇提物。  结论  采用超声波技术辅助低共熔溶剂提取的马尾松松针提取物的得率显著高于普通醇提法，通过显著性分析比较得出DES提取物抗氧化活性显著优于醇提物。该方法绿色环保，可实现高效提取马尾松松针成分，并充分保持其生物活性，在提升马尾松的资源利用方面具有一定的意义。 

Antioxidant activities in extracts from Pinus massoniana needles by deep eutectic solvents

  Objective  The pine needles of Pinus massoniana are rich in polyphenols and flavonoids with multiple active functions. In this paper, the preparation and antioxidant activity of the deep eutectic solvents (DES) extract of pine needles of P. massoniana were studied to deepen the exploitation of the undergrowth resources under tree crowns and to provide a more environmentally-friendly extraction method of active ingredients with more activities and higher efficiencies compared with traditional ways.  Method  Active ingredients were extracted from P. massoniana needles by ultrasonic technology under the assistance of DES. Firstly, three kinds of DES were screened by comparing the extraction effect. Then, based on the selected DES-choline chloride/glucose, a single factor test was conducted on the effect of liquid-solid ratio, ultrasonic temperature, ultrasonic time and ultrasonic power on the extraction effect. Based on single factor experiments, different capacities between DES extract and conventional ethanol extract to scavenge and reduce DPPH·, ABTS+· was compared with the yield of polyphenols and flavonoids taken as indexes and response surface method as the optimization of main process parameter.  Result  The optimal process to produce P. massoniana needle extract was: ratio of liquid to solid 10 mL/g, ultrasonic temperature 48 ℃, ultrasonic time 60 min, ultrasonic power 300 W, yield of polyphenol in the above condition 7.387%, yield of flavonoids in the above condition 10.377%, regression model fits well. The antioxidant activity of DES extract was overall better than that of the conventional ethanol extract.  Conclusion  Ultrasonic technology under the assistance of DES has higher yield of the P. massoniana needles extract compared with conventional extraction methods, and it has significant effect on the antioxidant activity compared with ethanol extraction method. So this method can provide efficient extraction of P. massoniana needles ingredients while fully maintaining the biological activity. So this method can provide efficient extraction of P. massoniana needles ingredients while fully maintaining the biological activity. It will be significant in the resource utilization of the P. massoniana.