超滤膜技术对黄芪水提物理化性质及其抗氧化活性的影响

目的 考察超滤膜技术对黄芪水提物理化性质及其抗氧化活性的影响。方法 采用截留相对分子质量分别为10、30、50 kDa的超滤膜对黄芪水提物进行分离纯化处理，考察超滤膜技术对黄芪水提物的溶液理化性质、皂苷类成分保留性及其吸湿性、油水分配系数等的影响。同时，采用体外抗氧化实验考察超滤膜技术对黄芪水提物抗氧化活性的影响。结果 超滤膜技术可降低黄芪水提物溶液的浊度，显著改善溶液的澄明度。经不同超滤膜分离纯化处理后，黄芪水提物中黄芪甲苷保留率>90%，总皂苷类成分保留率>85%，其总皂苷纯度提高了14%~19%。超滤膜技术可降低黄芪水提物的吸湿性，提高其抗氧化活性，并影响其皂苷类成分的油水分配系数。综合考虑杂质去除、有效成分保留及抗氧化活性，30 kDa超滤膜对黄芪水提物的分离纯化效果较好。结论 超滤膜技术提高了黄芪水提物中皂苷类成分含量，增强了其生物活性，为中药的分离纯化提供了一种途径。

Effect of Ultrafiltration Membrane Technology on Physicochemical Properties and Antioxidant Activity of Astragali Radix Water Extracts

Objective To investigate the effects of ultrafiltration membrane technology on the physicochemical properties and antioxidant activity of Astragali Radix water extracts.Methods The ultrafiltration membranes, with the cut-off relative molecular weights of 10, 30, 50 kDa, were used to separate and purify Astragali Radix water extracts. The effects of ultrafiltration membrane technology on the physicochemical properties, retention of saponin components, hygroscopicity, and oil-water partition coefficient of Astragali Radix water extracts were investigated. By using in vitro antioxidant experiments, the effect of ultrafiltration membrane technology on the antioxidant activity of Astragali Radix water extracts was also studied.Results Ultrafiltration membrane technology can reduce the turbidity of Astragali Radix water extract solutions and significantly improve solution clarity. After separation and purification by different ultrafiltration membranes, the retention rate of astragaloside Ⅳ in Astragali Radix water extracts is greater than 90%, and that of total saponin components is greater than 85%. The purity of total saponins is increased by 14%-19%. Ultrafiltration membrane technology can reduce the hygroscopicity of Astragali Radix water extracts, improve their antioxidant activity, and affect the oil-water partition coefficient of saponin components. By considering the removal of impurities, retention of active components, and antioxidant activity, it is found that the ultrafiltration membrane of 30 kDa has a good separation and purification effect on Astragali Radix water extracts.Conclusion Ultrafiltration membrane technology has increased the saponin content of Astragali Radix water extracts, enhanced their biological activity, and provided a method for the separation and purification of traditional Chinese medicine.