银杏叶总黄酮绿色提取工艺及抗氧化活性研究

Green Extraction Process and Antioxidant Activity of Total Flavonoids from Ginkgo biloba Leaves

采用单因素实验考察了低共熔溶剂种类、液料比、提取温度、n(氯化胆碱)∶n(尿素)、低共熔溶剂含水量、提取时间对银杏叶总黄酮提取率的影响,通过响应面法进一步优化了银杏叶总黄酮的提取工艺,并通过测定银杏叶总黄酮对DPPH自由基、ABTS自由基、·OH、·O_(2)^(-)的清除能力,金属离子螯合能力及总还原能力综合评价其抗氧化活性。结果表明,最优提取工艺为:液料比30∶1(mL∶g)、提取温度57℃、n(氯化胆碱)∶n(尿素)为1∶1.6、低共熔溶剂含水量40%、提取时间60 min,在此条件下,银杏叶总黄酮提取率为1.062%,且其抗氧化活性显著优于传统乙醇提取工艺。

We investigated the effects of deep eutectic solvents(DESs)type,liquid-solid ratio,extraction temperature,n(choline chloride)∶n(urea),water content of DESs,and extraction time on the extraction rate of total flavonoids from Ginkgo biloba leaves by single-factor experiments.Moreover,we further optimized the extraction process of total flavonoids from Ginkgo biloba leaves by response surface methodologies.Furthermore,we comprehensively evaluated the antioxidant activity of total flavonoids from Ginkgo biloba leaves by the determination of scavenging rates of DPPH free radicals,ABTS free radicals,hydroxyl free radicals,and superoxide anion free radicals,metal ion chelating ability,and total reduction ability.The results show that the optimal extraction process is as follows:the liquid-solid ratio of 30∶1(mL∶g),the extraction temperature of 57℃,the n(choline chloride)∶n(urea)of 1∶1.6,the water content of DESs of 40%,and the extraction time of 60 min.Under above conditions,the extraction rate of total flavonoids from Ginkgo biloba leaves can reach 1.062%,and its antioxidant activity is significantly better than that by traditional ethanol extraction.