目的 研究黄芪多糖APS-Ⅱ酶解寡糖结构信息，为明确黄芪多糖APS-Ⅱ构效关系的关键结构提供依据。方法 制备并使用内切α-1,4-葡聚糖糖苷水解酶降解了APS-Ⅱ，通过全甲基化衍生化方式对APS-Ⅱ酶解寡糖进行衍生化，结合MALDI-TOF-MS生物质谱以及高分辨质谱仪器ESI-Q Exactive-MS对全甲基化APS-Ⅱ酶解寡糖进行结构解析。结果 通过MALDI-TOF-MS生物质谱对全甲基化后的APS-Ⅱ酶解寡糖相对分子质量进行分析，得出全甲基化方法的可行性，并通过ESI-Q Exactive-MS高分辨质谱对酶解寡糖聚合度为2～11糖中20种糖链片段进行解析。结论 通过对全甲基化后的APS-Ⅱ酶解寡糖的结构解析，明确了糖链含有→4,6)-α-D-Glcp-(1→及→2,4)-α-D-Glcp-(1→等分支结构，推测含有该分支结构的糖链和1→4和1→6两种连接方式共存的支链结构为APS-Ⅱ发挥免疫活性的关键结构。

Objective To study the structural information of APS-II enzymatic oligosaccharides, so as to explore the relationship between the biological activity and structure of oligosaccharides in APS-II enzymatic oligosaccharides. Methods APS-II was prepared and degraded by endo-α-1,4-glucanase hydrolase, and APS-II enzymatic oligosaccharides were derivatized by permethylation derivatization, and the structure of permethylated APS-II enzymatic oligosaccharides was analyzed by MALDI-TOF-MS biomass spectrometry and high resolution mass spectrometry ESI-Q Exactive-MS. Results The molecular weight of APS-II enzymatic oligosaccharides after permethylation was analyzed by MALDI-TOF-MS biomass spectrometry, and the feasibility of the permethylation method was obtained. The ESI-Q Exactive-MS high resolution mass spectrometry was used to analyze the 20 sugar chain fragments in the enzymatic oligosaccharides with a degree of polymerization of 2—11. Conclusion Through the structural analysis of the permethylated APS-II enzymatic oligosaccharides, it was clarified that the sugar chain contained the branch structure of →4,6)-α-D-Glcp-(1→and→2,4)-α-D-Glcp-(1→. It is speculated that the sugar chain containing the above branch structure coexisting with the 1→4 and 1→6 connection modes are the key structures for APS-II to exert immune activity.

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国家自然科学基金资助项目（81872962）；国家博士后科学基金资助项目（2019M650851）；国家重点研发计划（2019YFC1710800）；山西省重点研发计划重点项目（201603D311101）；山西省优秀人才科技创新项目（201605D211030，201705D211020）；山西省科技创新人才团队专项基金