云南栘依黄酮提取及其抗氧化、降血糖活性研究

以云南栘依果为研究对象，采用响应面分析法对超声波辅助酶法提取黄酮进行优化，并对其体外抗氧化和降血糖活性进行测定。结果表明，云南栘依黄酮提取最佳工艺参数为提取温度50℃、复合酶比例(纤维素酶和果胶酶)3:2、提取时间50 min、液料比30 mL/g、乙醇浓度55%、pH4.5，在此条件下云南栘依黄酮得率高达13.10%，与预测值(13.01%)接近。体外抗氧化实验发现云南栘依黄酮清除DPPH自由基、ABTS⁺自由基和羟基自由基的IC₅₀分别为0.04、0.29、0.70 mg/mL，当黄酮浓度分别为0.24、1.40、4.00 mg/mL时，对DPPH自由基、ABTS⁺自由基、羟基自由基清除率分别为93.98%、97.60%、84.26%，同时云南栘依黄酮还具有一定的铁离子还原能力，表明其具有较强的抗氧化能力；体外降血糖实验发现云南栘依黄酮抑制α-葡萄糖苷酶、α-淀粉酶的IC₅₀分别为0.86、0.37 mg/mL，当黄酮浓度为12.0、5.0 mg/mL时对α-葡萄糖苷酶、α-淀粉酶的抑制率分别为...

Extraction of Flavonoids from Docynia delavayi and Their Antioxidant and Hypoglycemic Activities

Taking Docynia delavayi as the raw material, the extraction of flavonoids by ultrasonic-assisted enzymatic method was optimized using response surface methodology, and the in vitro antioxidant and hypoglycemic activities were determined. The results showed that the optimal process parameters were extraction temperature of 50 ℃, complex enzyme (pectinase and cellulase) of 3:2, extraction time of 50 min, liquid-material ratio of 30 mL/g, ethanol concentration of 55%, and pH of 4.5. Under these conditions, the yield of flavonoids from D. delavayi was as high as 13.10%, which was close to the predicted value (13.01%). In vitro antioxidant assays showed that flavonoids from D. delavayi scavenged DPPH, ABTS+ and hydroxyl radicals with IC₅₀ values of 0.04, 0.29 and 0.70 mg/mL, and the scavenging rates of DPPH, ABTS+ and hydroxyl radicals were 93.98%, 97.60% and 84.26% when the flavonoid concentrations were 0.24, 1.40 and 4.00 mg/mL, respectively. At the same time, D. delavayi flavonoids also presented certain ability to reduce iron ions, which indicated that D. delavayi flavonoids possessed strong antioxidant activities. In vitro hypoglycemic assays found that flavonoids from D. delavayi inhibited α-glucosidase and α-amylase with IC₅₀ values of 0.86 and 0.37 mg/mL, and the α-glucosidase and α-amylase inhibition rates were 81.83% and 82.72% when the flavonoid concentrations were 12.0 and 5.0 mg/mL, respectively, which demonstrated that D. delavayi flavonoids possessed excellent inhibitory ability against α-glucosidase and α-amylase. This paper would provide an experimental basis for the comprehensive development and utilization of D. delavayi.