甘薯叶中清除自由基活性物质的提取·保存与定性分析

Extraction Storage and Qualitative Analysis of Active Substance for Scavenging Free Radicals in Sweet Potato Leaves

[目的]为甘薯叶提取物应用于抗衰老化妆品提供理论依据。[方法]利用正交试验对甘薯叶中清除自由基的活性物质的提取及保存条件进行优化,并通过相关性分析对提取物中清除自由基能力的活性成分进行探讨。[结果]结果表明:甘薯叶中含有清除DPPH自由基和羟自由基的活性物质,提取剂种类是影响活性物质提取效率的最重要因素,其中最佳提取与保存条件为:以水为提取溶剂,提取液pH值为8,最佳保存温度为25℃。甘薯叶提取物总酚含量与其DPPH和羟自由基清除率呈正比关系且具有良好的线性关系;提取物总黄酮含量仅与羟自由基清除率有较好线性关系。[结论]提取物中的酚类物质能有效地清除DPPH自由基和羟自由基;提取物中的黄酮类物质仅能有效清除羟自由基。

[Objective] The research aimed to provide theoretical basis for applying extracts from sweet potato leaves in antiaging cosmetics. [Method] The extraction and storage conditions of active substances for scavenging free radicals in sweet potato leaves were optimized by orthogonal test and the active components for scavenging free radicals in the extracts were discussed by correlation analysis. [Result] Sweet potato leaves contained the active substances that scavenged DPPH free radicals and hydroxyl free radicals. The extractant species were fire most iroportant factors that affected the extraction rate of active substances. The optimum extraction and storage conditions were as follows： with water as extraction solvent, the pH value of the extraction liquid was 8 and the optimum storage temperature was 25 ℃. The total phenol content in the extracts froin sweet potato leaves showed direct proportional relations with the scavenging rates of DPPH free radicals and hydroxyl free radicals and they bad good linear relationships. The total flavone content only bad better linear relations with the scavenging rate of hydroxyl free radicals. [Conclusion] Phenols in the extracts can effectively scavenge DPPH free radicals and hydroxyl free radicals, while flavonoids in the extracts only can effectively scavenge hydroxyl free radicals.