大孔树脂纯化黄精多酚及其抗氧化性与组成分析

考察4种树脂对黄精多酚粗提物的吸附-解吸特性,筛选出最佳的纯化树脂,并研究其纯化工艺,分析黄精多酚的体外抗氧化活性、红外光谱特性和单酚组成。结果表明,AB-8型大孔树脂最适合于对黄精多酚粗提液的纯化,静态吸附5 h达到饱和,静态解吸3 h达到平衡;在室温下,用质量浓度为0.80 mg/mL的黄精多酚粗提液以0.8 mL/min的流速上样;吸附平衡后以70%的乙醇为洗脱剂,在洗脱流速为1 mL/min时,大孔树脂纯化效果最好,经纯化后黄精多酚的纯度提高了3.37倍。黄精多酚具有较好的抗氧化能力,且具有良好的量效关系,纯化前后黄精多酚总还原能力的IC50值分别为(27.48±1.93)、(19.01±1.48)μg/mL,清除DPPH·的IC50值依次为(5.21±0.48)、(4.00±0.26)μg/mL,清除ABTS+·的IC50值依次为(4.89±0.82)、(4.21±0.53)μg/mL,经纯化后黄精多酚的抗氧化活性明显增强。红外光谱分析表明其具有多酚和黄酮的特征峰;HPLC-DAD分析表明,黄精多酚主要含绿源酸,阿魏酸,芦丁和熊果酸。

Antioxidantion and composition analysis of purified polygonatum sibiricum polyphenols using macroporous resin

Polygonatum sibiricum becomes generally used as a sort of traditional medicinal herbs for thousands of years in China. This herbs contains a large number of active ingredients, such as polysaccharides, flavonoids, polyphenols, to cure many physiological functions including antioxidant, anti-fatigue, hypoglycemic, hypolipidemic, anti-cancer etc. This present work focused on the purification processing of the raw Polygonatum polyphenols by using the specific macroporous resin. A sort of resin, named AB-8, was chosen as the ideal adsorbent due to the best adsorption and the desorption rate for Polygonatum polyphenols, after the comparison test for the adsorption-desorption characteristics of four different types of resins(AB-8, NKA-9, SP-825 and XAD-2) for crude Polygonatum polyphenols. In the static/dynamic adsorption and desorption experiments, the sample concentration, flow velocity of samples, ethanol concentration and flow velocity of desorption showed great influence on the macroporous resin in the process of separating and purifying the Polygonatum polyphenols. The ideal purification parameters for the resin of AB-8 were as follows, at room temperature, the concentration of crude polyphenol was 0.80 mg/mL with the flow velocity of 0.8 mL/min, and 70% ethanol was used as the eluent solvent with the elution flow rate of 1 mL/min. The Folin-phenol reagent method was adopted to determine the total phenol content during the purification. The results showed that the purity of Polygonatum polyphenols after purification by AB-8 resin increased by 3.37 times than the crude polyphenol extract indicating that AB-8 resin has great adsorption and enrichment effect for Polygonatum polyphenols. The total reduction capacity, scavenging capacity of DPPH· and ABTS+· were measured to investigate the antioxidant capacity of crude and purified Polygonatum polyphenols. The obtained results showed that Polygonatum polyphenols possessed good antioxidant capacity with the dose-effect relationship. IC50 values of total reduction capacity of Polygonatum polyphenols before and after purification were(27.48+1.93) mg/mL,(19.01+1.48) mg/mL, IC50 values of DPPH· scavenging activities were(5.21+0.48) mg/mL,(4.00+0.26) mg/mL, and IC50 values of ABTS+· scavenging activities were(4.89+0.82) mg/mL and(4.21±0.53) mg/mL, respectively. Obviously, the antioxidant activity of Polygonatum polyphenols was significantly enhanced after purification. The infrared spectrum and HPLC were also used to analyze the structure characteristics and compositions of the purified products. The characteristic peaks of some polyphenols and flavones can be detected, where Polygonatum polyphenols mainly contains green source acid, ferulic acid, rutin and ursolic acid. The present study can provide a scientific basis for the structure-activity analysis of Polygonatum polyphenols and their promising utilization in the functional food, medicine and cosmetics.