Zhang Feng, Guo Zhimou, Zhang Feifang, Xue Xingya, Liang Xinmiao
Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, the Chinese Academy of Sciences, Dalian, China.
Se Pu. 2009 Jul;27(4):436-41.
A method for selective enrichment of iridoid glucosides in Hedyotis diffusa Willd. by tandem solid phase extraction (SPE) was developed. Oligo(ethylene glycol) (OEG) is a novel type of separation material made in this laboratory. The differences of the surface chemical structures between OEG material and ODS material resulted in their different retention capabilities for iridoid glucosides. Based on the differences, an OEG-ODS solid phase extraction method was designed for selective enrichment of iridoid glucosides. The water extract (150.28 mg) of Hedyotis diffusa Willd. was precipitated by ethanol, and an aliquot (27.03 mg) of the product from the supernatant solution was loaded onto an OEG cartridge and rinsed by 5 mL water. Then, the rinsing solution was loaded onto an ODS cartridge. After it was washed by 5 mL water and eluted by 5 mL methanol, 4.01 mg final product was obtained from the methanol eluent. All the products were characterized by ultra performance liquid chromatography (UPLC), and 14 representative peaks of iridoid glucosides were found. The enrichment results were proved effective by directly comparing the chromatograms each step. To further characterize the enrichment efficiency, the changes of the peak area of iridoid glucosides were investigated. The results showed that the content of 14 iridoid glucosides in the final product reached 6.10 times its original proportion in water extraction product and their recovery was 50.1% on average. Therefore, the iridoid glucosides can be enriched by the tandem solid phase extraction method from water extracting-ethanol precipitating solution of Hedyotis diffusa Willd. with a good selectivity and an acceptable recovery. The proposed method has the advantages of high enrichment efficiency and simple operation.
建立了一种通过串联固相萃取（SPE）选择性富集白花蛇舌草中环烯醚萜苷的方法。聚乙二醇（OEG）是本实验室制备的一种新型分离材料。OEG材料与ODS材料表面化学结构的差异导致它们对环烯醚萜苷具有不同的保留能力。基于这些差异，设计了一种OEG-ODS固相萃取方法用于选择性富集环烯醚萜苷。白花蛇舌草的水提取物（150.28mg）用乙醇沉淀，取上清液中的一份产物（27.03mg）上样至OEG柱，并用5mL水冲洗。然后，将冲洗液上样至ODS柱。用5mL水洗涤后，用5mL甲醇洗脱，从甲醇洗脱液中得到4.01mg最终产物。所有产物均通过超高效液相色谱（UPLC）进行表征，发现了14个环烯醚萜苷的代表性峰。通过直接比较每一步的色谱图，证明了富集结果是有效的。为了进一步表征富集效率，研究了环烯醚萜苷峰面积的变化。结果表明，最终产物中14种环烯醚萜苷的含量达到其在水提取产物中原始比例的6.10倍，平均回收率为50.1%。因此，采用串联固相萃取法可从白花蛇舌草水提醇沉液中富集环烯醚萜苷，具有良好的选择性和可接受的回收率。该方法具有富集效率高、操作简单的优点。
