金露梅黄酮提取工艺的响应面优化及其抗氧化和降血糖活性分析

【目的】优化金露梅中黄酮的超声提取工艺条件，检测黄酮化合物的种类及含量，并分析其抗氧化和降血糖活性，为金露梅的综合利用提供技术支持。【方法】以总黄酮提取率为指标，采用单因素和响应面分析法对超声提取金露梅黄酮的主要工艺参数进行优化分析，利用多重层析柱对黄酮化合物进行分离纯化，并比较各组分的抗氧化和降血糖活性。【结果】 4个因素对金露梅总黄酮提取率影响的显著性顺序为液料比>超声时间>乙醇体积分数>超声功率，建立的回归方程为Y=37.84+14.48A+14.93B+3.02C+9.38D-0.03AB-0.66AC-0.01AD-0.01BD-0.01CD-14.71A2-11.25B2-16.96C2-12.89D2（Y表示总黄酮提取率，A、B、C、D分别表示液料比、乙醇体积分数、超声功率和超声时间）；超声提取金露梅黄酮的最佳工艺条件为:液料比39.78:1 （mL/g）、乙醇体积分数65.47%、超声功率390.98 W、超声时间49.55 min，在此条件下金露梅总黄酮提取率为47.59 mg/g。金露梅黄酮化合物中发现含有8种化合物，其中含量最高的为槲皮素-7-O-β-D-葡萄糖醛酸（10.90 mg/g）。柚皮素对1，1-二苯基-2-三硝基苯肼（DPPH）自由基清除率最低，仅为5.0%，其余7种化合物对DPPH自由基的清除率均达50.0%以上，表现出良好的抗氧化活性。金露梅黄酮化合物对葡萄糖消耗率均高于二甲基亚砜（DMSO），其中（+）-儿茶素、槲皮素-3-O-β-D-葡萄糖醛酸和3-阿拉伯葡萄糖基槲皮素对葡萄糖的消耗率达19.5%以上，表现出良好的降血糖活性。【结论】经响应面优化的金露梅黄酮超声提取工艺切实可行，建立的回归方程具有较高的准确性；多重层析柱法可实现金露梅中黄酮化合物的分离纯化，各组分除柚皮素外，均具有明显的抗氧化活性，且各组分化合物均有一定的降血糖活性。金露梅可作为一种天然抗氧化剂和降血糖剂来源在食品、医药等方面进行开发利用。

Optimization for extraction process of flavonoids from Potentilla fruticosa L. by response surface method and the analysis of its antioxidant and hypoglycemic activities

【Objective】The ultrasonic extraction conditions of flavonoids from Potentilla fruticosa L. were optimized, the types and contents of flavonoids were detected, and their antioxidant and hypoglycemic capacities were analyzed, in order to provide technical support for comprehensive utilization of P. fruticosa L.【Method】The single factor method and the response surface methodology(RSM) were employed to optimize the main parameters of ultrasonic extraction of flavonoids from P. fruticosa L.,with extraction yield as the index. Multiple chromatographic columns were used for the separation and purification of the flavonoid compounds, and the antioxidant capacity and hypoglycemic capacity of these compounds were compared.【Result】The significant order of the four factors on the extraction yield of flavonoids was as follows:solvent/solid ratio>ultrasonic time>volume fraction of ethanol>ultrasonic power. The regression equation established was as follows:Y=37.84+14.48A+14.93B+3.02C+9.38D-0.03AB-0.66AC-0.01AD-0.01BD-0.01CD-14.71A2-11.25B2- 16.96C2-12.89D2(Y represented extraction rate of flavonoids; A, B, C and D represented liquid-solid ratio, ethanol volume fraction, ultrasonic power and ultrasonic time, respectively). The optimal extraction conditions were as follows:liquid-solid ratio of 39.78:1 (mL/g), ethanol volume fraction of 65.47%, ultrasonic power of 390.98 W and ultrasonic time of 49.55 min. Under these conditions, the extraction yield of flavonoids was 47.59 mg/g. Eight flavonoids were found in the extract of P. fruticosa L., among which the most abundant was quercetin-7-O-β-D-glucuronide(10.90 mg/g). Naringenin had the lowest scavenging yield of DPPH free radical,which was only 5.0%, while the scavenging yields of seven other compounds were greater than 50.0%, indicating good antioxidant activities. The glucose consumption yield of flavonoid compounds in P. fruticosa L. were higher than that of DMSO,and the glucose consumption yields of(+) -catechin, quercetin-3-O-β-D-glucuronide and quercetin-3-vicianoside reached more than 19.5%,suggesting their good hypoglycemic activities.【Conclusion】The optimized ultrasonic extraction process of flavonoids by RSM is feasible and the established regression equation has high accuracy. The multiple chromatographic columns can be used for the separation and purification of the flavonoids in P. fruticosa L. All components except naringenin have obvious antioxidant activity, and all components have a certain hypoglycemic activity. P. fruticosa L. can be developed as a natural source of antioxidants and hypoglycemic agents in food, medicine and other fields.