虎杖果实中白藜芦醇与大黄素提取工艺优化及其与3类根茎含量比较

Optimization of Simultaneous Extraction of Resveratrol and Emodin from Fruits of Polygonum cuspidatum and Comparison of Their Contents with Those of Rhizomes of Male and Female Plants

目的:研究虎杖果实中白藜芦醇与大黄素提取工艺,比较其果实与雄株、未结果雌株、结果雌株3类根茎中白藜芦醇与大黄素得率。方法:采用高效液相色谱法测定其果实与3类根茎中白藜芦醇与大黄素含量,确定果实中白藜芦醇与大黄素提取的溶剂与方法,采用正交试验法考察微波火力档、溶剂体积分数、料液比及提取时间对提取工艺的影响,确定微波辅助提取的最佳提取工艺,比较虎杖果实、3类根茎中二者得率。结果:正交试验与方差分析得出果实中白藜芦醇与大黄素的最佳提取条件为乙醇体积分数70%、料液比1:20(g/mL)、额定功率800 W微波炉先40火力处理3 min冷却后60火力处理3 min、提取时间6 min,高效液相色谱法测得虎杖雄株、未结果雌株根茎中的白藜芦醇与大黄素得率均高于结果雌株根茎及果实,果实及3类根茎中白藜芦醇与大黄素得率均超过《中国药典》(2010)规定值,提取工艺合理、稳定、可行,虎杖果实具备开发利用的价值。

Objective： To investigate the simultaneous extraction of resveratrol and emodin from the fruits of Polygonum cuspidatum and to compare their contents with those of the rhizomes of male, non-bearing and bearing female plants. Methods： High performance liquid chromatography（HPLC） was used to determine the contents of resveratrol and emodin. The microwave-assisted extraction of resveratrol and emodin was carried out using aqueous ethanol as extraction solvent. Microwave firepower, ethanol concentration, solid-to-solvent ratio and extraction time, all of which were found to influence extraction efficiency, were optimized by using orthogonal array experiments. Comparison of the contents of resveratrol and emodin in the fruits and rhizomes of Polygonum cuspidatum was performed. Results： The optimal extraction conditions were obtained as follows： ethanol concentration, 70%（V/V）; solid-to-solvent ratio, 1：20（g/mL）; microwave power, 800 W; microwave irradiation for 3 min at firepower 40 and for additional 3 min at firepower 60 after cooling; and extraction time, 6 min. The contents of resveratrol and emodin in the rhizomes of male and non-bearing female plants were significantly higher than those of the rhizomes of female plants and fruits of Polygonum cuspidatum, and all these values exceeded those specified in the Chinese Pharmacopoeia. The extraction process presented in this study was reasonable, stable and feasible. Differences in the contents of resveratrol and emodin existed among three types of rhizomes and fruits of P. cuspidatum. However, the fruit has the potential for development and utilization.