In this study, a deep eutectic solvent (DES) extraction combined with a magnetic bead ligand affinity analytical method was developed and used for α-glucosidase inhibitor identification from Pueraria lobata. Several critical parameters affecting the analysis performance, including the type of DES, molar ratio, water amount, pH, salt concentration, and volume of DES, were investigated. The selected analytical sample preparation conditions were as follows. The composition of DES is choline chloride-1,4-butanediol (1:3), the water content is 40%, pH is 7.0 and the volume of extraction solution is 2 mL. The obtained sample extraction solution was analyzed directly using α-glucosidase immobilized magnetic beads (GMBs). Three α-glucosidase inhibitors in Pueraria lobata, including puerarin, daidzin, and daidzein, were identified. Luteolin was used as a positive control to evaluate the method's selectivity. Results showed it could selectively bond to the GMBs in the DES. As the affinity analysis was performed directly in a DES, the solution-removing process could be avoided. The intra-day and inter-day precisions of the method are 5.21% and 6.38%, respectively. The solvent amount was 1/50–1/2000 of that used in traditional methods.

中文翻译：

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深共熔溶剂萃取结合磁珠配体捕获鉴定葛根中α-葡萄糖苷酶抑制剂

本研究开发了深共晶溶剂（DES）提取结合磁珠配体亲和分析方法，用于葛根中α-葡萄糖苷酶抑制剂的鉴定。研究了影响分析性能的几个关键参数，包括 DES 类型、摩尔比、水量、pH、盐浓度和 DES 体积。所选分析样品制备条件如下。DES的组成为氯化胆碱-1,4-丁二醇(1:3)，含水量为40%，pH为7.0，提取液体积为2 mL。使用α-葡萄糖苷酶固定化磁珠（GMB）直接分析获得的样品提取液。葛根中鉴定出三种 α-葡萄糖苷酶抑制剂，包括葛根素、大豆苷和大豆黄酮。使用木犀草素作为阳性对照来评估该方法的选择性。结果表明它可以选择性地与 DES 中的 GMB 结合。由于亲和力分析直接在 DES 中进行，因此可以避免去除溶液的过程。该方法的日内和日间精密度分别为5.21%和6.38%。溶剂用量为传统方法的1/50-1/2000。