金花茶花总黄酮双水相提取工艺优化及其抗氧化活性分析

研究了超声波辅助聚乙二醇(PEG)/(NH4)2SO4双水相提取金花茶花总黄酮工艺及其抗氧化活性.以黄酮萃取率为指标,在单因素实验的基础上,采用正交试验优化提取工艺.通过DPPH·和OH·清除率的测定,评价其抗氧化效果.采用HPLC分析对金花茶花中的芦丁、槲皮素和山奈酚等黄酮化合物进行了确认.实验结果表明,最佳提取条件...

Optimization of Aqueous Two-phase Extraction Technology of Total Flavonoids from the Flowers of Camellia chrysantha and Analysis of Its Antioxidant Activity

The ultrasonic assisted PEG/(NH₄)₂SO₄ aqueous two-phase extraction of total flavonoids from the flowers of Camellia chrysantha and its antioxidant activity were studied. Taking the extraction rate of flavonoids as the index, the extraction process was optimized by orthogonal design on the basis of single factor tests. The antioxidant effect was evaluated by the determination of DPPH· and OH· scavenging rates. Flavonoid compounds including rutin, quercetin and kaempferol in Camellia chrysantha were confirmed by HPLC analysis. The results showed that under the optimum extraction conditions (PEG molecular weight 600, PEG mass fraction 19%, ammonium sulfate mass fraction 20%, ethanol concentration 80%, ultrasonic time 30 min), the extraction rate of flavonoids could reach 98.50%, and the yield of flavonoids could reach 13.54%. The results of antioxidant experiments showed that the IC₅₀ of the flavonoid extract from the flowers of Camellia chrysantha to DPPH· and OH· were 0.070 and 0.679 mg/mL, respectively. The results suggest that the technology of ultrasonic assisted aqueous two-phase extraction of total flavonoids from the flowers of Camellia chrysantha is reasonable, the obtained flavonoids exhibiting good antioxidant capacity and can be further developed and utilized.